Cauda Equina Syndrome

VERSION: 1.0 CREATED: January 27, 2026 STATUS: Approved

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DIAGNOSIS: Cauda Equina Syndrome (CES)

ICD-10: G83.4 (Cauda equina syndrome), M48.06 (Spinal stenosis, lumbar region), M51.16 (Intervertebral disc disorders with radiculopathy, lumbar region), M51.17 (Intervertebral disc disorders with radiculopathy, lumbosacral region), G95.89 (Other specified diseases of spinal cord)

CPT CODES: 85025 (CBC with differential), 80053 (CMP (BMP + LFTs)), 87040 (Blood cultures (x2 sets)), 82947 (Blood glucose), 86900 (Type and screen), 81003 (Urinalysis), 84703 (Pregnancy test (β-hCG)), 84145 (Procalcitonin), 83036 (HbA1c), 86334 (SPEP / free light chains), 87389 (HIV), 72148 (MRI lumbar spine without contrast (emergent)), 72158 (MRI lumbar spine WITH contrast (gadolinium)), 72131 (CT lumbar spine without contrast), 72132 (CT myelogram), 78816 (PET/CT)

SYNONYMS: Cauda equina syndrome, CES, cauda equina compression, saddle anesthesia, saddle anesthesia syndrome, urinary retention with back pain, bowel/bladder dysfunction, lower spine emergency, cauda equina

SCOPE: Emergency evaluation and management of cauda equina syndrome in adults. Covers urgent recognition of incomplete vs. complete CES, emergent MRI, surgical decompression timing, etiologic workup (disc herniation, tumor, abscess, hematoma), bladder management, and functional prognostication. Excludes conus medullaris syndrome (partially overlaps — key distinguishing features addressed), malignant epidural spinal cord compression above the conus (separate template), and chronic lumbar stenosis without CES features.

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PRIORITY KEY: STAT = Immediate | URGENT = Within hours | ROUTINE = Standard | EXT = Extended/atypical cases | - = Not applicable to this setting

═══════════════════════════════════════════════════════════════ SECTION A: ACTION ITEMS ═══════════════════════════════════════════════════════════════

1. LABORATORY WORKUP

1A. Essential/Core Labs

Test	ED	HOSP	OPD	ICU	Rationale	Target Finding
CBC with differential (CPT 85025)	STAT	STAT	-	STAT	Infection (epidural abscess); baseline for surgery; leukocytosis; anemia assessment	Normal; leukocytosis → consider abscess; thrombocytopenia affects surgical candidacy
CMP (BMP + LFTs) (CPT 80053)	STAT	STAT	-	STAT	Electrolytes; renal function (contrast, NSAIDs); glucose; hepatic function (anesthetic risk)	Normal
PT/INR, aPTT (CPT 85610, 85730)	STAT	STAT	-	STAT	Coagulopathy; anticoagulation status; surgical clearance; epidural hematoma etiology	Normal; INR <1.5 for surgery; prolonged → consider epidural hematoma
ESR / CRP (CPT 85652, 86140)	STAT	STAT	-	STAT	Epidural abscess differential (ESR >20 mm/hr: 94% sensitivity for spinal abscess); discitis; malignancy	Normal; markedly elevated (ESR >30-50, CRP >10) → strongly consider abscess or infection
Blood cultures (x2 sets) (CPT 87040)	STAT	STAT	-	STAT	Epidural abscess; bacteremia; source identification if infectious etiology suspected	Negative; positive → epidural abscess or hematogenous source
Blood glucose (CPT 82947)	STAT	STAT	-	STAT	Baseline; anesthetic risk; diabetic patients at increased disc herniation and infection risk	<180 mg/dL
Type and screen (CPT 86900)	STAT	STAT	-	STAT	Surgical candidacy; blood product availability for emergency decompression	On file
Urinalysis (CPT 81003)	STAT	STAT	-	STAT	UTI (common comorbidity and mimicker of urinary symptoms); neurogenic bladder assessment; baseline	Normal; UTI may coexist — treat but do NOT attribute bladder dysfunction solely to UTI if CES features present
Pregnancy test (β-hCG) (CPT 84703)	STAT	STAT	-	STAT	MRI and anesthetic planning; pregnancy may exacerbate disc herniation (increased lordosis/weight)	Negative; if positive → MRI still indicated (no gadolinium needed for CES diagnosis)
Procalcitonin (CPT 84145)	STAT	STAT	-	STAT	Bacterial infection differential (more specific than CRP); if abscess suspected	<0.25 (low bacterial probability); >0.5 → consider abscess

1B. Extended Workup (Second-line)

Test	ED	HOSP	OPD	ICU	Rationale	Target Finding
HbA1c (CPT 83036)	-	ROUTINE	ROUTINE	-	Diabetes assessment (risk factor for disc herniation, infection, neuropathy); post-operative wound healing	<7.0%
Tumor markers (PSA, CEA, etc.)	-	ROUTINE	ROUTINE	-	If imaging suggests neoplastic etiology rather than disc herniation	Normal; elevated → guides oncologic workup
SPEP / free light chains (CPT 86334)	-	ROUTINE	ROUTINE	-	Multiple myeloma presenting as cauda equina compression	No M-protein; normal kappa/lambda ratio
LDH	-	ROUTINE	ROUTINE	-	Lymphoma; tumor burden	Normal; elevated → lymphoma, aggressive malignancy
HIV (CPT 87389)	-	ROUTINE	ROUTINE	-	Immunocompromised → infection risk; primary CNS lymphoma differential	Negative
Urine culture	STAT	STAT	-	STAT	Pre-existing UTI; post-catheterization planning; differentiate neurogenic bladder from UTI	Negative; if positive → treat but continue CES workup
Post-void residual (PVR) — bladder scan	STAT	STAT	ROUTINE	STAT	KEY DIAGNOSTIC TEST: bladder retention is hallmark of CES; PVR >200 mL is highly concerning; >500 mL strongly suggestive of neurogenic retention	PVR <100 mL (normal); PVR >200 mL → significant retention; >500 mL → almost certainly neurogenic

1C. Rare/Specialized (Refractory or Atypical)

Test	ED	HOSP	OPD	ICU	Rationale	Target Finding
CSF analysis (only at surgery or LP if needed)	-	EXT	EXT	-	If inflammatory/infectious etiology suspected (GBS affecting cauda equina = rare); leptomeningeal carcinomatosis	Normal; elevated protein → GBS, tumor; malignant cells → leptomeningeal disease
Paraneoplastic antibody panel	-	EXT	EXT	-	Atypical CES without structural cause; paraneoplastic cauda equina neuritis (anti-CRMP5/CV2, anti-amphiphysin)	Negative; positive → paraneoplastic syndrome
Anti-ganglioside antibodies (GM1, GD1b, GQ1b)	-	EXT	EXT	-	GBS variant affecting cauda equina roots (rare); if imaging shows nerve root enhancement without structural compression	Negative; positive → GBS/CIDP affecting cauda equina
AQP4-IgG / MOG-IgG	-	EXT	EXT	-	If conus medullaris lesion rather than cauda equina compression; NMOSD can affect conus	Negative; positive → NMOSD/MOGAD
Sarcoidosis workup (ACE, chest CT, lysozyme)	-	EXT	EXT	-	Neurosarcoidosis affecting cauda equina (nerve root inflammation/enhancement without structural lesion); elevated ACE	Normal ACE; chest CT: no hilar lymphadenopathy; if positive → neurosarcoidosis
EMG/NCS	-	EXT	EXT	-	Chronic or atypical CES; differentiate from peripheral neuropathy, plexopathy; establish nerve root involvement pattern; prognostic (denervation = poor recovery)	Abnormal: acute denervation (fibrillations, positive sharp waves) in L4-S4 myotomes bilaterally; absent H-reflex bilaterally; abnormal pudendal nerve conduction

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2. DIAGNOSTIC IMAGING & STUDIES

2A. Essential/First-line

Study	ED	HOSP	OPD	ICU	Timing	Target Finding	Contraindications
MRI lumbar spine without contrast (emergent) (CPT 72148)	STAT	STAT	-	STAT	Within 4 hours of ED arrival — SURGICAL EMERGENCY; ideally within 1 hour; extends to thoracolumbar junction (T10-sacrum) to include conus medullaris	Large disc herniation (most common — 45% of CES cases) compressing cauda equina; canal compromise; level of compression; number of roots compressed; disc fragment migration; tumor, abscess, or hematoma as alternative cause; conus medullaris location and signal	MRI-incompatible implants; severe claustrophobia (sedate — do NOT delay MRI for anxiety); GFR <30 for contrast (but contrast NOT required for disc herniation diagnosis — obtain non-contrast first)
MRI lumbar spine WITH contrast (gadolinium) (CPT 72158)	STAT	STAT	-	STAT	Add contrast if: suspected abscess, tumor, or inflammatory etiology; ring-enhancing epidural collection = abscess; homogeneous enhancement = tumor; nerve root enhancement = inflammatory/neoplastic	Epidural abscess (ring enhancement, restricted diffusion); tumor (enhancing mass); nerve root enhancement (inflammatory, leptomeningeal disease); distinguish from disc herniation (which does NOT enhance)	GFR <30 (gadolinium risk — benefit outweighs risk in emergency); gadolinium allergy (premedicate)
Bladder scan (post-void residual)	STAT	STAT	-	STAT	Before MRI if possible — critical triage tool; have patient attempt to void → immediate bladder ultrasound for PVR	PVR >200 mL = significant retention → HIGH probability of CES; PVR >500 mL = almost certain neurogenic retention; normal PVR does NOT exclude early/incomplete CES	None (bedside ultrasound)
Plain radiographs (lumbar spine AP/lateral)	STAT	STAT	-	STAT	While awaiting MRI; identifies vertebral collapse, spondylolisthesis, fracture, alignment; limited value but rapid triage tool	Disc space narrowing; spondylolisthesis; fracture; alignment abnormality; NOTE: X-rays CANNOT diagnose disc herniation — MRI is required	Pregnancy (shield abdomen)

2B. Extended

Study	ED	HOSP	OPD	ICU	Timing	Target Finding	Contraindications
CT lumbar spine without contrast (CPT 72131)	STAT	STAT	-	STAT	If MRI not available or contraindicated; inferior to MRI for soft tissue but shows bone and canal narrowing; CT myelogram if MRI impossible	Disc herniation (seen as soft tissue density in canal); bone fragments; canal diameter; fracture; spondylolisthesis	CT alone has limited sensitivity for disc herniation vs. MRI; myelogram adds invasive risk
CT myelogram (CPT 72132)	STAT	STAT	-	STAT	If MRI absolutely contraindicated (implant); intrathecal contrast via LP → CT; demonstrates level of block and root compression	Complete or partial block; compressed cauda equina roots; level and extent of compression; may miss small free fragments	LP contraindicated if abscess suspected at LP site; coagulopathy; rare but important if MRI impossible
MRI whole spine	-	URGENT	-	URGENT	If etiology unclear; evaluate for additional levels of disease; concurrent cord compression; tumor staging; multilevel disc disease	Additional sites of compression; intramedullary lesion (conus); multifocal disease	Same as lumbar MRI
Urodynamic studies	-	-	ROUTINE	-	Post-acute phase; quantify bladder dysfunction; detrusor areflexia (CES pattern); plan long-term bladder management	Detrusor areflexia (areflexic bladder) = cauda equina denervation; decreased bladder sensation; increased capacity; poor emptying	Acute UTI; recent surgery (timing per surgeon)
Anal manometry / pudendal nerve testing	-	-	EXT	-	Quantify sphincter dysfunction; prognostic for recovery; pudendal nerve conduction	Reduced anal sphincter pressures; denervated pudendal nerve	Patient tolerance; acute phase may not be appropriate
EMG/NCS (lower extremities + paraspinal) (CPT 95886, 95907-95913)	-	-	ROUTINE	-	2-3 weeks post-onset (acute denervation takes 2-3 weeks to appear on EMG); prognosis; differentiate from peripheral neuropathy or plexopathy	Bilateral L4-S4 denervation; reduced CMAP amplitudes in bilateral L5/S1 distribution; absent H-reflexes bilaterally; bilateral pudendal neuropathy	Too early in acute phase (<2 weeks = may be false negative for denervation); patient tolerance

2C. Rare/Advanced

Study	ED	HOSP	OPD	ICU	Timing	Target Finding	Contraindications
CT angiography (lumbar)	-	EXT	-	EXT	If vascular malformation suspected (spinal dural AV fistula causing venous hypertension → CES symptoms); progressive myelopathy/CES with dilated serpiginous vessels on MRI	Spinal AV fistula; AVM; arteriovenous malformation feeding vessels	Contrast allergy; renal impairment
Spinal angiography	-	EXT	EXT	-	Definitive diagnosis and treatment of spinal dural AV fistula; also pre-operative embolization for vascular tumors	Fistula location; endovascular treatment candidate	Invasive; contrast risk; radiation exposure
PET/CT (CPT 78816)	-	-	EXT	-	If malignancy causing CES — staging; unknown primary identification	Primary tumor; metastatic burden	Uncontrolled diabetes; pregnancy
Cystometrogram	-	-	EXT	-	Formal bladder function assessment; post-decompression recovery monitoring; long-term bladder management planning	Bladder compliance; detrusor function; capacity; sensation thresholds	Active UTI

Lumbar Puncture

Study	ED	HOSP	OPD	ICU	Timing	Target Finding	Contraindications
LP — Generally NOT indicated acutely	-	EXT	EXT	-	LP is NOT required for diagnosis of typical CES (disc herniation, tumor, abscess seen on MRI); ONLY if inflammatory/infectious etiology without clear structural cause; OR CT myelogram if MRI impossible	CSF protein elevation (GBS, tumor); pleocytosis (infection, inflammation); malignant cells (leptomeningeal disease); albuminocytologic dissociation (GBS)	Do NOT perform LP if large disc herniation compressing cauda equina (could theoretically worsen by altering pressure dynamics — proceed to surgery instead); coagulopathy; abscess at LP site

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3. TREATMENT PROTOCOLS

3A. Acute/Emergent Treatment

Treatment	Route	Indication	Dosing	Contraindications	Monitoring	ED	HOSP	OPD	ICU
Emergent surgical decompression	-	-	N/A :: - :: once :: THIS IS A SURGICAL EMERGENCY — TIME IS NERVE; Emergent neurosurgery/spine surgery consultation; posterior lumbar laminectomy with discectomy (most common procedure); Timing: Within 24h of symptom onset — ideally within 24h but outcome improves the sooner surgery is performed; <24h clearly better than >48h; some evidence supports <12h for best outcomes; Complete CES (CES-R with retention): Truly emergent — surgery as soon as possible (within hours); Incomplete CES (CES-I): Urgent — surgery within 24h; risk of progressing to complete	-	Ahn et al. (2000): Decompression <48h = significantly better outcomes for bladder recovery (70% vs. 30%); Todd (2005) meta-analysis: Earlier surgery = better outcomes, but exact time threshold debated; DeBois et al. (2019): <24h optimal, <48h acceptable; Srikandarajah et al. (2020): Urgent surgery (<24h) associated with better functional outcomes	STAT	STAT	-	-
Bladder management	-	-	200 mL :: - :: - :: Bladder scan (PVR) STAT on arrival — do NOT wait for MRI; if PVR >200 mL → Foley catheter placement; if PVR >500 mL → Foley + strict I&O monitoring; avoid overdistension (>600 mL causes detrusor damage — may become irreversible); document voiding pattern; post-operative: trial of void at 24-48h with PVR checks; CIC (clean intermittent catheterization) teaching if retention persists	-	Bladder overdistension causes detrusor muscle damage → irreversible areflexic bladder; early catheterization prevents secondary damage; bladder recovery is the MOST SENSITIVE indicator of CES recovery and the MOST COMMON persistent deficit	STAT	STAT	-	STAT
Pain management	IV	-	650-1000 mg :: IV :: q6h :: Back pain and radicular pain often severe; acetaminophen 650-1000 mg q6h (scheduled) + opioids (morphine 2-4 mg IV q3h PRN or hydromorphone 0.5-1 mg IV q3h PRN); NSAIDs: ketorolac 15-30 mg IV q6h (short-term, if no surgical contraindication and normal renal function — pre-op use is surgeon-dependent); neuropathic: gabapentin 300 mg TID (start if radicular pain prominent); avoid excessive sedation that obscures neurologic exam	-	Adequate analgesia essential for patient assessment and MRI tolerance; balance with need for neurologic monitoring	STAT	STAT	-	STAT
Dexamethasone (if tumor or abscess)	IV	-	10 mg :: IV :: q6h :: Disc herniation CES: Steroids NOT routinely indicated (no evidence of benefit; some centers use short course); Tumor-related CES: Dexamethasone 10 mg IV bolus → 4 mg q6h (same as MSCC protocol); Abscess-related CES: Dexamethasone controversial (may impair immune response) — use only if severe edema with rapid neurologic decline	-	No RCT evidence supporting steroids for disc-related CES; tumor CES: Sorensen et al. (1994) supports steroids; abscess: prioritize antibiotics + surgical drainage	STAT	STAT	-	STAT
Antibiotics (if abscess suspected)	IV	-	25-30 mg/kg :: IV :: q12h :: Epidural abscess causing CES: Empiric: Vancomycin 25-30 mg/kg IV load + ceftriaxone 2g IV q12h (or cefepime 2g IV q8h); adjust to culture/sensitivity; MRSA coverage essential; Duration: Typically 6-8 weeks IV antibiotics for epidural abscess; Timing: Start AFTER blood cultures drawn but do NOT delay if patient is deteriorating	-	S. aureus (including MRSA) is most common organism in epidural abscess (60-70%); gram-negative coverage for UTI/abdominal source; streptococci, anaerobes less common	STAT	STAT	-	STAT
DVT prophylaxis	SC	-	40 mg :: SC :: daily :: SCDs immediately; pharmacologic prophylaxis: enoxaparin 40 mg SQ daily starting post-operatively (typically 12-24h after surgery per surgeon protocol); immobile CES patients at high VTE risk	-	Immobility + lower extremity weakness = high DVT risk; mechanical prophylaxis pre-operatively; early pharmacologic prophylaxis post-operatively	STAT	STAT	-	STAT
Bowel management	PR	-	100 mg :: PR :: BID :: Assess rectal tone (digital rectal exam — absent/reduced in CES); bowel regimen: docusate 100 mg BID + senna 2 tabs HS; bisacodyl suppository daily if no BM in 48h; monitor for fecal incontinence vs. constipation (both occur in CES); opioid-related constipation compounds the issue	-	Bowel dysfunction common in CES; S2-S4 denervation affects external anal sphincter and rectal sensation; proactive management prevents complications	STAT	STAT	-	STAT

3B. Definitive/Targeted Treatment

Treatment	Route	Indication	Dosing	Contraindications	Monitoring	ED	HOSP	OPD	ICU
Lumbar laminectomy + discectomy (disc herniation CES)	-	-	N/A :: - :: once :: Most common surgery: Posterior approach; laminectomy at affected level(s); remove herniated disc fragment; decompress cauda equina; Approach: Midline; may require bilateral laminotomy or hemi-laminectomy for lateralized discs; large central herniations often require bilateral approach; Key: Ensure COMPLETE decompression — incomplete decompression leads to persistent deficit; intraoperative confirmation with direct visualization of free cauda equina nerve roots	-	Gold standard for disc-related CES; no RCT comparing surgery vs. non-operative (would be unethical to randomize given natural history); observational data uniformly supports early surgical decompression	-	STAT	-	-
Microdiscectomy (if technically appropriate)	-	-	N/A :: - :: once :: Minimally invasive approach; appropriate for contained disc herniations without significant canal stenosis; faster recovery; less tissue disruption; may not provide adequate decompression for massive central disc herniation	-	Smaller incision, less muscle disruption; but surgeon must ensure adequate decompression — do NOT compromise canal visualization for a smaller incision in CES	-	STAT	-	-
Surgical drainage + decompression (epidural abscess)	IV	-	N/A :: IV :: once :: Posterior approach; laminectomy; drain abscess; culture material; irrigate; leave wound open or with drain; may require multi-level decompression; Combined with: IV antibiotics 6-8 weeks; follow with serial MRI and inflammatory markers	-	Epidural abscess with CES = surgical emergency; medical management alone (antibiotics without surgery) only if: no neurologic deficit AND very high surgical risk; most CES presentations require surgery	-	STAT	-	-
Tumor resection + decompression	-	-	N/A :: - :: once :: If tumor-related CES (e.g., schwannoma, ependymoma, metastasis); posterior decompression ± en bloc or piecemeal tumor resection; send pathology; may need subsequent radiation/chemotherapy	-	Intradural-extramedullary tumors (schwannoma, meningioma, myxopapillary ependymoma) are potentially curable with complete resection; metastatic CES → decompression + radiation	-	STAT	-	-
Hematoma evacuation	-	-	N/A :: - :: once :: Epidural hematoma causing CES (spontaneous on anticoagulation, post-procedural, or post-traumatic); emergent laminectomy with hematoma evacuation; reverse anticoagulation STAT	-	Spontaneous spinal epidural hematoma: Groen & Ponssen (1990): better outcomes with surgery <12h of onset; anticoagulation reversal essential (4F-PCC for warfarin, idarucizumab for dabigatran, andexanet for Xa inhibitors)	-	STAT	-	-
Non-operative management (rare, selected cases)	-	-	N/A :: - :: q2-4h :: ONLY appropriate if: (1) Imaging does NOT show significant structural compression, (2) Symptoms are improving spontaneously, (3) Patient refuses surgery (document informed refusal thoroughly), (4) Medically inoperable (extremely high surgical risk); Requires: Close monitoring with serial neuro exams q2-4h; repeat MRI if worsening; immediate surgery if any progression	-	Non-operative management is NOT standard of care for CES with structural compression; delayed surgery has worse outcomes; informed consent must document risks of non-operative management (permanent bladder/bowel/sexual dysfunction, progressive weakness)	-	-	ROUTINE	-

3C. Adjunctive Treatment

Treatment	Route	Indication	Dosing	Contraindications	Monitoring	ED	HOSP	OPD	ICU
Clean intermittent catheterization (CIC) training	-	-	100 mL :: - :: - :: If bladder function does not recover by 48-72h post-surgery; teach patient CIC q4-6h; target PVR <100 mL before discontinuing CIC; may take weeks to months to recover	-	CIC is preferred over indwelling Foley for long-term bladder management (lower UTI risk); most patients can learn self-catheterization; bladder recovery may take 6-12 months	-	ROUTINE	ROUTINE	-
Neuropathic pain management	PO	-	300 mg :: PO :: TID :: Gabapentin 300 mg PO TID → titrate to 600-900 mg TID over 1-2 weeks; OR pregabalin 75 mg BID → 150-300 mg BID; duloxetine 30 mg daily → 60 mg daily; amitriptyline 10-25 mg HS (caution: urinary retention may worsen); topical lidocaine 5% patches for localized radicular pain	-	Neuropathic pain (burning, tingling, electric shocks in perineum, legs) is common and debilitating after CES; may persist chronically; multimodal approach needed	-	STAT	ROUTINE	STAT
Physical therapy / rehabilitation	-	-	N/A :: - :: daily :: PT evaluation within 24h post-operatively; early mobilization; lower extremity strengthening; gait training; core stabilization; progressive activity as tolerated; pelvic floor PT for bladder/bowel recovery	-	Early rehabilitation improves functional outcomes; pelvic floor rehabilitation is evidence-based for bladder/bowel recovery after CES	-	URGENT	ROUTINE	-
Occupational therapy	-	-	N/A :: - :: daily :: ADL assessment; adaptive equipment; if lower extremity weakness impairs function; bathroom modifications; return-to-work planning	-	Functional independence optimization	-	ROUTINE	ROUTINE	-
Pelvic floor rehabilitation	-	-	N/A :: - :: daily :: Specialized pelvic floor PT; biofeedback for bladder and bowel retraining; Kegel exercises (if able); electrical stimulation of pelvic floor; sacral neuromodulation evaluation if persistent dysfunction >12 months	-	Evidence supports pelvic floor PT for bladder and bowel recovery after CES; biofeedback improves outcomes	-	-	ROUTINE	-
Psychological support	-	-	N/A :: - :: once :: CES has devastating psychosocial impact (sexual dysfunction, incontinence, chronic pain, disability in often-young patients); depression screening (PHQ-9); anxiety screening; sexual health counseling; support groups; consider psychiatry referral	-	Depression affects 30-60% of CES patients long-term; sexual dysfunction is profoundly distressing; early psychological intervention improves coping and recovery	-	ROUTINE	ROUTINE	-
Stool softener / bowel program	-	-	100 mg :: - :: BID :: Docusate 100 mg BID + senna 2 tabs HS; bisacodyl suppository PRN; digital stimulation for areflexic bowel; timed bowel program; fiber supplementation; adequate hydration	-	Neurogenic bowel management reduces complications (impaction, incontinence); establish routine bowel program early	STAT	STAT	ROUTINE	STAT

3D. Medications to AVOID or Use with Caution

Treatment	Route	Indication	Dosing	Pre-Treatment Requirements	Contraindications	Monitoring	ED	HOSP	OPD	ICU
Anticholinergics (oxybutynin, tolterodine — for urgency)	-	-	-	-	-	-	-	-	-	-
Tricyclic antidepressants (amitriptyline, nortriptyline)	-	-	-	-	-	-	-	-	-	-
Alpha-blockers (tamsulosin, silodosin) — without urologic guidance	-	-	-	-	-	-	-	-	-	-
NSAIDs (prolonged, peri-operative)	-	-	-	-	-	-	-	-	-	-
Epidural steroid injection (as treatment for CES)	-	-	-	-	-	-	-	-	-	-
Chiropractic manipulation (lumbar)	-	-	-	-	-	-	-	-	-	-
Excessive IV fluids (post-operatively)	IV	-	-	-	-	-	-	-	-	-

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4. OTHER RECOMMENDATIONS

4A. Essential

Recommendation	ED	HOSP	OPD	ICU	Details
Neurosurgery / Spine surgery consultation — EMERGENCY	STAT	STAT	-	STAT	IMMEDIATE consultation upon clinical suspicion of CES — do NOT wait for MRI to consult; communicate urgency; CES is a recognized surgical emergency; the spine surgeon should be contacted concurrently with MRI ordering; if no spine surgeon available → emergent transfer to facility with 24/7 spine surgery capability
Post-void residual (bladder scan)	STAT	STAT	-	STAT	Perform BEFORE MRI — PVR is a rapid, non-invasive triage tool; PVR >200 mL in the setting of bilateral radiculopathy/perineal symptoms = HIGH suspicion for CES; informs urgency of MRI and surgical consultation
Digital rectal examination	STAT	STAT	-	STAT	Assess perianal sensation (S2-S4); anal sphincter tone (reduced or absent in CES); voluntary contraction; anocutaneous reflex (absent in CES — tests S2-S4 arc); this is an essential component of the neurologic exam and MUST be documented
Comprehensive neurologic exam documentation	STAT	STAT	-	STAT	Document: bilateral lower extremity strength (L2-S2 myotomes); sensation (light touch, pinprick) — especially perianal/perineal (S2-S5 dermatomes); deep tendon reflexes (ankle jerks); plantar responses; bulbocavernosus reflex; anal wink; rectal tone; bladder function; sexual function (ask about erectile function/genital sensation)
Classify CES subtype	STAT	STAT	-	STAT	CES-Incomplete (CES-I): Altered urinary sensation, difficulty initiating voiding, reduced perineal sensation BUT still has some bladder function (partial retention); CES-Retention (CES-R): Painless urinary retention, overflow incontinence, absent perineal sensation, absent anal tone; CES-R is a more advanced stage with worse prognosis
Informed consent for surgery	STAT	STAT	-	-	Document discussion of: surgical risks, CES natural history without surgery (progressive permanent paralysis, incontinence, sexual dysfunction), realistic outcome expectations (bladder recovery is slowest and most uncertain), risk of persistent deficits even with surgery
Transfer to surgical center (if no spine surgeon)	STAT	-	-	-	If presenting ED does not have spine surgery capability → EMERGENT transfer; obtain MRI at presenting facility first if possible (saves time at receiving facility); Foley catheter before transfer; dexamethasone if tumor-related

4B. Extended

Recommendation	ED	HOSP	OPD	ICU	Details
Urology consultation	-	ROUTINE	ROUTINE	-	Neurogenic bladder management; urodynamic testing at 6-12 weeks post-surgery; long-term bladder plan (CIC vs. indwelling vs. suprapubic catheter); sexual health assessment
PM&R / Rehabilitation consultation	-	URGENT	ROUTINE	-	Inpatient rehab candidacy if significant motor deficits; PT/OT coordination; assistive devices; functional goals; return-to-work timeline
Pain management consultation	-	ROUTINE	ROUTINE	-	If pain refractory to standard analgesics + neuropathic agents; chronic pain planning; may need interventional pain procedures (nerve blocks, neuromodulation) in chronic phase
Sexual health counseling	-	ROUTINE	ROUTINE	-	Sexual dysfunction affects 40-70% of CES patients long-term; erectile dysfunction in males (S2-S4); female sexual dysfunction (decreased genital sensation, lubrication difficulties); refer to sexual health specialist; PDE5 inhibitors (sildenafil) for ED; vacuum devices; referral to urology/gynecology
Colorectal surgery / GI consultation	-	-	ROUTINE	-	Persistent fecal incontinence; sacral nerve stimulation evaluation; biofeedback-refractory bowel dysfunction; anal sphincter repair assessment
Social work / case management	-	ROUTINE	ROUTINE	-	Disability assessment; workplace accommodations; home modifications (bathroom accessibility); caregiver support; insurance navigation; support groups (Cauda Equina Syndrome Association)
Medicolegal documentation	STAT	STAT	ROUTINE	STAT	CES is one of the most litigated conditions in spine surgery; document: time of symptom onset, time of presentation, time of MRI, time of surgical consultation, time of surgery, neurologic exam at each time point, bladder function assessment, rationale for any delays; CES diagnosis is a recognized emergency standard of care

4C. Atypical/Refractory

Recommendation	ED	HOSP	OPD	ICU	Details
Revision surgery	-	URGENT	ROUTINE	-	If post-operative MRI shows residual compression (retained disc fragment); persistent or worsening deficits after initial surgery; recurrent disc herniation
Sacral neuromodulation	-	-	EXT	-	For refractory neurogenic bladder or fecal incontinence >12 months post-decompression; InterStim device implantation; requires trial stimulation first; evidence growing for neurogenic populations
Intrathecal baclofen pump	-	-	EXT	-	If spasticity develops (rare in pure cauda equina lesion — suggests conus involvement); more relevant for conus medullaris syndrome
Chronic pain management program	-	-	ROUTINE	-	Multidisciplinary chronic pain program; cognitive behavioral therapy for pain; mindfulness-based stress reduction; graded activity program; may need long-term opioid management with monitoring
Psychiatric referral	-	ROUTINE	ROUTINE	-	PTSD, depression, anxiety common post-CES; body image disturbance; sexual dysfunction grief; chronic pain coping; may need medication management
Legal documentation review	-	-	ROUTINE	-	If delayed diagnosis is a concern; risk management consultation; ensure complete medical record documentation

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═══════════════════════════════════════════════════════════════ SECTION B: SUPPORTING INFORMATION ═══════════════════════════════════════════════════════════════

5. DIFFERENTIAL DIAGNOSIS

Primary Differential Diagnoses

Diagnosis	Key Differentiating Features	Distinguishing Studies
Conus medullaris syndrome	Upper motor neuron AND lower motor neuron signs; bilateral and symmetric; early bladder/bowel dysfunction; back pain less prominent than radicular pain; reflexes may be hyperactive (UMN) or absent (LMN); typically at T12-L2 level; more symmetric than CES	MRI: lesion at T12-L2 level (conus); cord signal change (T2 hyperintensity); CES lesion is below L1-L2 (cauda equina roots only); conus lesion → Babinski may be present (CES → absent or flexor)
Lumbar spinal stenosis (without CES)	Neurogenic claudication (walking-induced symptoms relieved by sitting/flexion); chronic progressive course; bilateral leg pain/weakness with walking; no bladder/bowel dysfunction (unless severe CES from stenosis); intermittent symptoms	MRI: multilevel stenosis; trefoil canal shape; ligamentum flavum hypertrophy; NO acute disc herniation; symptoms are exercise-induced, not constant; PVR normal
Acute disc herniation (without CES)	Unilateral radiculopathy; no bilateral symptoms; no saddle anesthesia; no bladder/bowel dysfunction; straight leg raise positive; single dermatomal pattern	MRI: lateral or posterolateral disc herniation compressing single root; NO cauda equina compression; normal PVR; normal rectal tone
Epidural abscess	Fever (50-66%); IVDU, immunocompromised, recent procedure; rapidly progressive; ESR >20 (94% sensitivity); severe spinal tenderness; leukocytosis; can cause CES if lumbar location	MRI: ring-enhancing epidural collection with restricted diffusion; blood cultures positive (60%); ESR/CRP markedly elevated; clinical triad: back pain → radiculopathy → weakness (classic but only 10-15% present with full triad)
Epidural hematoma	Acute onset; anticoagulation or post-procedural (epidural injection, spinal surgery, LP); severe back pain → rapid progressive weakness; coagulopathy history	MRI: epidural collection with blood signal (T1 bright in subacute); coagulation studies abnormal; anticoagulation history; post-procedural temporal relationship
Guillain-Barré syndrome (GBS)	Ascending symmetric weakness; areflexia; post-infectious (Campylobacter, CMV, EBV); sensory symptoms but often mild; facial weakness may be present; no saddle anesthesia typically; CSF: albuminocytologic dissociation	MRI spine: may show nerve root enhancement BUT no structural compression; CSF: elevated protein, normal cells; NCS: demyelinating pattern or AMAN pattern; anti-ganglioside antibodies
Peripheral neuropathy (bilateral)	Chronic course; distal > proximal; length-dependent pattern; diabetes, alcohol; stocking-glove distribution; gradual onset; reflexes may be reduced distally; NO saddle anesthesia; NO acute bladder retention	EMG/NCS: diffuse length-dependent neuropathy; MRI: no structural compression; HbA1c; B12; SPEP; gradual course distinguishes from acute CES
Lumbosacral plexopathy	Unilateral (usually); painful; diabetic amyotrophy; radiation-induced; tumor infiltration; asymmetric weakness/sensory loss in lumbosacral plexus distribution; typically NO bladder dysfunction (unless bilateral)	MRI pelvis: plexus enhancement or mass; EMG: plexus distribution denervation; CT abdomen/pelvis: retroperitoneal mass; HbA1c; typically unilateral
Functional neurological disorder (FND)	Inconsistent exam findings; Hoover's sign positive; non-anatomical sensory pattern; normal imaging; normal PVR; no objective sphincter dysfunction; give-way weakness; history of psychological stressors	MRI: normal; PVR: normal; rectal tone: normal; neurophysiology: normal; psychiatric history; clinical inconsistency (e.g., inability to lift leg on command but normal gait observed); NOTE: FND is a diagnosis of exclusion in CES — always obtain MRI first

CES-I vs. CES-R Classification

Feature	CES-Incomplete (CES-I)	CES-Retention (CES-R)
Bladder function	Altered sensation; difficulty initiating stream; incomplete emptying; urgency	Painless retention; overflow incontinence; no desire to void
PVR	200-500 mL (partial retention)	>500 mL (complete retention)
Perineal sensation	Reduced but present	Absent or markedly reduced
Anal tone	Reduced	Absent
Prognosis with surgery	Better outcomes; most regain bladder function	Worse outcomes; 30-50% persistent bladder dysfunction
Urgency	Urgent (within 24h)	Emergent (within hours — ASAP)

Red Flags Requiring Urgent Reassessment

Red Flag	Concern	Action
Progressive bilateral leg weakness	Evolving CES; worsening compression; expanding hematoma	STAT MRI; emergent surgery; escalate surgical urgency
Loss of bladder function (CES-I → CES-R)	Progression from incomplete to complete CES; bladder recovery significantly worse after retention onset	IMMEDIATE surgery; do NOT wait for elective OR time; OR should be arranged within hours
Complete saddle anesthesia	Complete S2-S5 denervation; poor prognostic sign	STAT surgery; this represents advanced CES-R
Bilateral foot drop (new)	L4-L5 root denervation bilaterally; severe compression	Emergent decompression
Fever + back pain + neurologic deficit	Epidural abscess potentially causing/mimicking CES	Blood cultures; MRI with contrast; empiric antibiotics; surgical drainage if abscess confirmed
Fecal incontinence (new)	S2-S4 denervation progressing; significant cauda equina compromise	Emergent surgery if not already performed; if post-operative → urgent MRI for residual compression
Urinary retention increasing despite Foley (inability to trial void)	Worsening or persistent denervation; incomplete decompression; re-herniation	Post-op MRI; urodynamics; consider revision surgery if compression persists

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6. MONITORING PARAMETERS

Acute Phase Monitoring (Pre-operative and First 72h Post-operative)

Parameter	Frequency	Target	Action if Abnormal
Neurologic examination (lower extremity strength, sensation, reflexes)	q2-4h pre-operatively; q4h post-operatively x 48h	Stable pre-op; improving post-op	Pre-op worsening: escalate surgical urgency; post-op worsening: STAT MRI (hematoma, residual compression, re-herniation)
Perianal/perineal sensation and rectal tone	q4h (at minimum with each neuro check)	Improving or stable	Worsening: STAT MRI
Bladder function / PVR	Continuous monitoring via Foley with hourly I&O pre/post-op; Trial of void at 24-48h post-op with PVR check	PVR <100 mL to discontinue catheter; voiding spontaneously	PVR >200 mL after trial of void → replace Foley; begin CIC teaching; urology consult
Pain assessment (NRS)	q4h	NRS <4/10	Escalate analgesics; add neuropathic agents; new/worsening pain post-op → concern for hematoma/complication
Wound assessment (post-operative)	q8h	No drainage, swelling, erythema, dehiscence	Wound complication → surgical team notification; drain output monitoring
Bowel function	Daily	BM within 48-72h post-op	Bowel regimen intensification; abdominal X-ray if distended; rectal exam
Temperature	q4h	Afebrile	Fever: wound infection, UTI (Foley-associated), DVT, abscess; cultures and imaging as indicated
DVT screening	Daily calf circumference; symptoms	No DVT signs	Bilateral lower extremity duplex US if symptoms; therapeutic anticoagulation if confirmed

Subacute/Outpatient Monitoring

Parameter	Frequency	Target	Action if Abnormal
Neurologic examination	2 weeks post-op, 6 weeks, 3 months, 6 months, 12 months	Progressive improvement; stable at plateau	Worsening: MRI for re-herniation or residual disease; EMG at 3 months
Bladder function (PVR)	Each visit until resolved; formal urodynamics at 6-12 weeks if persistent dysfunction	PVR <100 mL; spontaneous voiding; continent	PVR >200 mL → continue CIC; urology follow-up; sacral neuromodulation evaluation at 12 months if persistent
Bowel function	Each visit	Regular BMs; continent	Persistent incontinence → colorectal referral; biofeedback; sacral neuromodulation
Sexual function assessment	6 weeks, 3 months, 6 months, 12 months	Recovering sensation; erectile function (males); genital sensation (all)	PDE5 inhibitors for ED; sexual health counseling; pelvic floor PT
Pain assessment	Each visit	Controlled with oral medications; decreasing over time	Chronic neuropathic pain management; multidisciplinary pain program if persistent >6 months
MRI lumbar spine	6 weeks post-op (baseline), then PRN if symptoms recur	No residual compression; no recurrent herniation	Recurrent herniation: revision surgery if symptomatic
EMG/NCS	3 months post-onset (if persistent deficits)	Reinnervation signs; improving motor unit potentials	No reinnervation at 3-6 months → guarded prognosis; continued rehabilitation; adaptive strategies
Depression/psychological screening (PHQ-9)	Each visit	PHQ-9 <5	SSRI; psychological referral; support group (CES Association)
Functional assessment (Oswestry Disability Index, SF-36)	3 months, 6 months, 12 months	Improving scores	Intensify rehabilitation; address barriers; vocational rehabilitation

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7. DISPOSITION CRITERIA

Admission Criteria

Level of Care	Criteria
ICU admission	Post-operative monitoring (surgeon-dependent — many post-laminectomies go to floor); bilateral lower extremity paralysis with hemodynamic concerns; epidural abscess with sepsis; significant comorbidities affecting anesthetic recovery; autonomic dysfunction
General neurosurgery/spine floor	ALL CES patients require admission; pre-operative CES awaiting surgical decompression; post-operative monitoring; pain management; bladder/bowel monitoring; PT/OT initiation; epidural abscess requiring IV antibiotics
Observation (NOT appropriate)	CES is NEVER an observation diagnosis — all suspected CES patients require emergent MRI and admission for surgical evaluation; even if MRI is negative for structural compression, admission for monitoring is prudent if clinical suspicion is high

Discharge Criteria

Criterion	Details
Neurologic stability	Stable or improving neurologic exam for ≥24-48h post-surgery; no progressive deficits
Pain controlled	Adequate pain control on oral medications; able to participate in PT
Bladder management plan	Voiding spontaneously with PVR <100 mL OR CIC teaching completed and patient/caregiver competent; urology follow-up arranged
Bowel function	BM occurred; bowel regimen established; patient educated on bowel program
Wound healing	Surgical wound clean, dry, intact; no signs of infection; wound care instructions provided
Mobility assessment	PT clearance; safe ambulation (with or without assistive device); home safety assessment; OR inpatient rehab transfer
DVT prophylaxis plan	Pharmacologic prophylaxis continuing (enoxaparin for 2-4 weeks post-op per surgeon protocol); or transitioned to mobilization-based prevention
Follow-up arranged	Spine surgery (2 weeks), urology (4-6 weeks), PM&R (2-4 weeks if deficits), PCP (1 week), pelvic floor PT (after surgical clearance)
Patient/family education	Activity restrictions (lifting, bending, twisting restrictions per surgeon — typically 6 weeks); when to return to ED (new weakness, loss of bladder/bowel function, fever, wound drainage); CIC technique if applicable; bowel program; realistic expectations for recovery timeline

Discharge Prescriptions Checklist

Medication	Details
Analgesics	Acetaminophen scheduled; limited opioid PRN with taper plan (2-4 weeks); avoid prolonged opioids
Neuropathic pain agent	Gabapentin or pregabalin if radicular/neuropathic pain
Bowel regimen	Docusate + senna (especially if on opioids); PRN bisacodyl
DVT prophylaxis	Enoxaparin 40 mg SQ daily x 2-4 weeks (per surgeon protocol)
Antibiotics (if abscess)	Completion of IV antibiotics (arrange PICC and home IV antibiotics); typically 6-8 weeks total course
CIC supplies (if applicable)	Catheters, lubricant, collection bags; home health nursing for CIC training reinforcement
Stool softeners	Ongoing bowel program medications

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8. EVIDENCE & REFERENCES

Key Guidelines

Guideline	Source	Year	Key Recommendation
Cauda Equina Syndrome Standards of Care	British Association of Spine Surgeons (BASS) / Society of British Neurological Surgeons (SBNS)	2020	CES is a surgical emergency; MRI within 4h; surgical decompression within 24h (ideally ASAP); classify CES-I vs. CES-R; bladder scan is essential triage tool
CES Emergency Pathway	NICE / NHS England	2018 (updated 2023)	Suspected CES → emergent MRI → same-day surgical review; do NOT delay MRI; 24/7 access to MRI required; document timeline meticulously
AANS/CNS Guidelines on Lumbar Disc Herniation	AANS/CNS Joint Section on Disorders of the Spine and Peripheral Nerves	2014	CES from disc herniation is a surgical emergency; emergent decompression recommended

Landmark Studies

Study	Finding	Impact
Ahn et al. (2000)	Systematic review: Decompression <48h of CES onset → 70% bladder recovery vs. 30% if >48h; motor outcomes also significantly better with early surgery	Established 48h as important threshold; but sooner is always better
Todd (2005) — Meta-analysis	42 studies: Earlier decompression consistently associated with better outcomes across motor, bladder, and bowel domains; no clear cutoff but <24h is optimal	Confirmed urgency of CES surgical decompression; surgical timing is KEY modifiable factor
Srikandarajah et al. (2020)	UK Cohort: Urgent surgery (<24h) vs. delayed (>24h): better bladder outcomes (OR 2.1) and motor outcomes (OR 1.6) with urgent surgery	Modern evidence supporting <24h surgical timing; NHS pathway development
DeBois et al. (2019)	Timing analysis: <12h, 12-24h, 24-48h, >48h: progressive decline in outcomes with each delay interval; <12h had best bladder recovery	Supports as-soon-as-possible approach; <12h may be ideal
Gleave & Macfarlane (2002)	CES-I vs. CES-R outcomes: CES-I (incomplete) with early surgery → 95% good bladder outcome; CES-R (retention) with early surgery → 53% good bladder outcome; CES-R with delayed surgery → 27% good outcome	Established CES-I vs. CES-R classification; demonstrated that retention onset is critical prognostic marker
Groen & Ponssen (1990)	Spinal epidural hematoma: better outcomes with surgery <12h of onset; anticoagulation most common cause	Established surgical urgency for hematoma-related CES
Kostuik et al. (1986)	Classic paper on CES natural history: untreated CES from disc herniation → permanent bladder dysfunction in >90%, persistent weakness in >70%, chronic pain in >80%	Established that CES without surgical treatment leads to devastating permanent deficits
McCarthy et al. (2014)	Medicolegal analysis: CES is the most litigated condition in spinal surgery; delayed diagnosis is the most common reason for successful claims; failure to perform timely MRI and delayed surgery are key factors	Documentation of timeline is CRITICAL; standardized CES pathways reduce medicolegal risk

Clinical Classification

CES Subtypes (Gleave & Macfarlane Classification)

Subtype	Definition	Key Features	Prognosis
CES-Suspected (CES-S)	Bilateral radiculopathy/symptoms WITHOUT bladder dysfunction	Bilateral leg pain/weakness; bilateral sensory changes; NO urinary symptoms; normal PVR	Best prognosis; may not progress to CES if decompressed promptly; but ~70% will progress to CES-I or CES-R without surgery
CES-Incomplete (CES-I)	Altered urinary function WITHOUT retention	Difficulty initiating stream; reduced sensation of voiding; urgency; partial retention (PVR 200-500 mL); reduced but present perineal sensation; reduced anal tone	Good prognosis with early surgery: 95% good bladder outcome (Gleave & Macfarlane, 2002)
CES-Retention (CES-R)	Painless urinary retention WITH overflow incontinence	Painless retention (PVR >500 mL); overflow incontinence; absent perineal sensation; absent anal tone; often absent bulbocavernosus reflex	Poorer prognosis: 53% good outcome with early surgery; 27% with delayed surgery

Examination Checklist for CES

Component	Bilateral L4	Bilateral L5	Bilateral S1	S2-S4 (Sacral roots)
Motor	Knee extension (quad)	Ankle dorsiflexion (TA), great toe extension (EHL), hip abduction	Ankle plantarflexion (gastroc); hip extension (gluteus max)	Anal sphincter tone (DRE); bulbocavernosus reflex
Sensory	Medial leg/shin	Lateral leg, dorsum of foot, first web space	Lateral foot, sole, posterior calf	Perianal (S2-S5); perineum; posterior thigh; "saddle area"
Reflex	Patellar (L3-L4)	Tibialis posterior (L5 — inconsistent)	Achilles ankle jerk (S1-S2)	Anocutaneous reflex ("anal wink"); bulbocavernosus reflex (S2-S4)
Function	Walking, stairs	Heel walking	Toe walking	Bladder: voiding, PVR; Bowel: rectal sensation, tone; Sexual: erectile function, genital sensation

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APPENDICES

Appendix A: CES Etiologies and Frequency

Etiology	Frequency	Key Features	Treatment
Lumbar disc herniation (massive central)	45-50%	Most common cause; L4-L5 or L5-S1 most frequent; large central or central-lateral fragment; may follow heavy lifting, trauma, or spontaneous	Emergent laminectomy + discectomy
Lumbar spinal stenosis (severe)	15-20%	Chronic stenosis with acute-on-chronic decompensation; multilevel; often older patients; spondylolisthesis may contribute	Decompressive laminectomy ± fusion for instability
Tumor (primary or metastatic)	10-15%	Intradural-extramedullary (schwannoma, meningioma, ependymoma); extradural (metastasis, myeloma); progressive course; may be insidious or acute	Surgical resection ± radiation; dexamethasone if edema
Epidural abscess	5-10%	Fever; IVDU; recent procedure; immunocompromised; ESR/CRP elevated; subacute course (days to weeks); S. aureus most common	Surgical drainage + IV antibiotics (6-8 weeks)
Epidural hematoma	3-5%	Anticoagulation; post-procedural; coagulopathy; acute onset with rapid progression	Emergent hematoma evacuation; reverse anticoagulation
Trauma / fracture	3-5%	Burst fracture with retropulsed fragments; sacral fracture; seatbelt injury; high-energy mechanism	Surgical stabilization and decompression
Post-operative (complication)	2-3%	After lumbar surgery (hematoma, retained fragment, excessive retraction); onset hours to days after initial surgery	Revision surgery; evacuate hematoma; remove retained fragment
Inflammatory (sarcoidosis, arachnoiditis)	1-2%	Nerve root clumping (arachnoiditis); enhancing roots (sarcoidosis); chronic progressive; often diagnosis of exclusion	Immunosuppression (sarcoidosis); limited options for arachnoiditis (intrathecal steroids controversial)
Vascular (AVM, dural AV fistula)	<1%	Progressive myelopathy/CES; dilated vessels on MRI; may have episodic worsening; can cause venous congestion of conus/cauda equina	Endovascular embolization; surgical ligation
Chiropractic manipulation (iatrogenic)	Rare but reported	Disc herniation during manipulation; acute onset during or immediately after treatment	Emergent surgical decompression

Appendix B: CES Emergency Pathway

SUSPECTED CAUDA EQUINA SYNDROME
(Bilateral radiculopathy + ANY of: bladder dysfunction, saddle anesthesia, bowel dysfunction, bilateral weakness)
                    │
                    ├── TRIAGE (within 15 minutes of arrival)
                    │     • Bladder scan (PVR) — STAT
                    │     • Digital rectal exam — perianal sensation + anal tone
                    │     • Document bilateral LE strength + sensation
                    │     • Document time of symptom onset
                    │
                    ├── PVR Result?
                    │     PVR >500 mL → CES-Retention → EMERGENT MRI + Surgery ASAP
                    │     PVR 200-500 mL → CES-Incomplete → URGENT MRI + Surgery within 24h
                    │     PVR <200 mL → CES less likely BUT:
                    │           If saddle anesthesia + bilateral symptoms → URGENT MRI anyway
                    │           If no CES features → standard radiculopathy workup
                    │
                    ├── Order MRI STAT (lumbar spine, without contrast initially)
                    │     Target: MRI within 1-4 hours of presentation
                    │     If MRI unavailable → CT myelogram OR transfer to MRI-capable facility
                    │
                    ├── Contact Spine Surgery IMMEDIATELY (concurrent with MRI)
                    │     Do NOT wait for MRI results to call
                    │
                    ├── MRI Results:
                    │     Structural compression confirmed → Emergent surgical decompression
                    │     │     • Disc herniation → Laminectomy + discectomy
                    │     │     • Abscess → Drainage + antibiotics
                    │     │     • Tumor → Decompression ± dexamethasone
                    │     │     • Hematoma → Evacuation + reverse anticoagulation
                    │     │
                    │     No structural compression → Consider:
                    │           • GBS (CSF, NCS)
                    │           • Inflammatory (sarcoidosis, arachnoiditis)
                    │           • Vascular (AV fistula)
                    │           • Reconsider diagnosis (conus, FND)
                    │
                    └── Post-Operative:
                          • Neurologic checks q4h x 48h
                          • Trial of void at 24-48h → PVR check
                          • PT/OT within 24h
                          • Document all timelines meticulously

Appendix C: CES vs. Conus Medullaris Syndrome — Comparison

Feature	Cauda Equina Syndrome	Conus Medullaris Syndrome
Anatomic level	Below L1-L2 (nerve roots only)	T12-L2 (spinal cord terminus)
Motor	Asymmetric (root distribution); LMN pattern; atrophy; fasciculations	Symmetric; may have UMN signs (Babinski, spasticity) AND LMN signs
Sensory	"Saddle" anesthesia (perianal S2-S5); asymmetric; radicular pattern; dermatomal	Symmetric saddle anesthesia; bilateral; may have dissociated sensory loss
Pain	Severe radicular pain; unilateral or bilateral; often prominent	Less prominent pain; may have visceral-type pain
Reflexes	Absent ankle jerks; reduced patellar reflexes	Ankle jerks absent; Babinski may be present (UMN component); bulbocavernosus reflex absent
Bladder	Late onset (may be subtle initially → progression to retention)	Early and prominent (often presenting feature); areflexic bladder
Bowel	Late; often preserved initially	Early; constipation and incontinence
Sexual function	Late; asymmetric erectile dysfunction	Early; bilateral
Onset	Often acute (disc herniation); can be subacute	May be more gradual; depends on etiology
MRI finding	Compressive lesion below L1-L2; compressed nerve roots	Lesion at T12-L2; intramedullary conus signal change; may have cord expansion

Appendix D: Recovery Timeline and Expectations

Function	Expected Recovery Timeline	Prognostic Factors	Long-term Outcome
Motor (leg strength)	Begins within days-weeks; majority of recovery in first 6 months; continues up to 12-18 months	Pre-operative motor grade; duration of deficit before surgery; CES-I vs. CES-R	80-90% recover functional ambulation if decompressed within 24-48h; foot drop may be slow/incomplete
Bladder	Slowest to recover; may take 6-12 months; initial period of retention → may evolve to urgency/frequency → hopefully normalizes	MOST IMPORTANT: PVR at presentation (retention = worse); surgical timing (<24h = better); bilateral vs. unilateral root involvement	70% recover useful bladder function if <48h surgery (Ahn et al.); 30-50% persistent dysfunction in CES-R; CIC may be lifelong
Bowel	Moderate recovery; weeks to months; fecal urgency common before continence improves	Degree of S2-S4 denervation; surgical timing	60-70% recover satisfactory continence; 10-20% have persistent fecal incontinence
Sexual function	Variable; months to years; often incomplete	S2-S4 root recovery; psychological factors; pre-existing function	40-70% report persistent sexual dysfunction; male erectile dysfunction common; female genital sensation changes; psychological impact significant
Pain	Radicular pain often improves rapidly post-decompression; neuropathic pain may persist or develop over weeks; chronic pain syndrome in 20-40%	Nerve root damage severity; psychological comorbidity; chronicity before surgery	20-40% develop chronic neuropathic pain syndrome; multimodal management needed
Overall	Most recovery occurs in first 6-12 months; slower improvement may continue up to 2 years; deficits persisting beyond 2 years are likely permanent	Surgical timing; pre-operative deficit severity; CES-I vs. CES-R; age; comorbidities	Quality of life significantly impacted in 30-50% long-term; multidisciplinary rehabilitation and psychological support essential

Appendix E: Medicolegal Considerations

Issue	Documentation Required	Risk Mitigation
Time of symptom onset	Exact time; patient and family statement; ambulance records	Standardized CES screening tool in ED triage
Time of ED arrival	Triage time stamp; registration time	Electronic health record timestamps
Time of clinical assessment	Time of exam documented; neurologic exam details; bladder assessment	Dedicated CES assessment proforma
Time of MRI request	Order time stamp; radiology communication log	Standardized CES pathway with MRI within 4h target
Time of MRI completion	MRI completion time; radiology read time	Prioritized MRI slot for suspected CES
Time of surgical consultation	Time called; time responded; time seen by surgeon	Documented communication; spine surgery contact log
Time of surgical decompression	Anesthesia start time; knife-to-skin time; case end time	OR availability for emergency CES cases
Neurologic exam pre/post-surgery	Detailed exam with motor grading, sensory mapping, rectal tone, PVR	Standardized CES neurologic assessment form
Delays and reasons	If any delay: documented reason (MRI availability, OR availability, patient consent, medical optimization)	Contemporaneous notes; clear communication to patient/family about delays
Informed consent	Surgical risks discussed; prognosis discussed; realistic expectations documented; patient questions addressed	Standardized consent form for CES decompression

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This template represents the initial build phase (Skill 1) and requires validation through the checker pipeline (Skills 2-6) before clinical deployment.