Paresthesia / Numbness / Tingling¶
VERSION: 1.1 CREATED: February 2, 2026 REVISED: February 2, 2026 STATUS: Validated per checker pipeline
DIAGNOSIS: Paresthesia / Numbness / Tingling
ICD-10: R20.2 (Paresthesia of skin); R20.0 (Anesthesia of skin); R20.1 (Hypoesthesia of skin); R20.8 (Other disturbances of skin sensation); R20.9 (Unspecified disturbances of skin sensation)
CPT CODES: 95907-95913 (nerve conduction studies, NCS), 95886 (EMG, each extremity), 95885 (EMG, limited), 70553 (MRI brain with/without contrast), 72141 (MRI cervical spine without contrast), 72156 (MRI cervical spine with/without contrast), 72148 (MRI lumbar spine without contrast), 72158 (MRI lumbar spine with/without contrast), 72146 (MRI thoracic spine without contrast), 85025 (CBC with differential), 80053 (CMP), 83036 (HbA1c), 82607 (vitamin B12), 84443 (TSH), 86235 (ANA), 85652 (ESR), 86140 (CRP), 89240 (QSART), 95923 (autonomic function testing), 11104 (skin punch biopsy for IENFD)
SYNONYMS: Paresthesia, numbness, tingling, pins and needles, sensory loss, hypoesthesia, dysesthesia, numbness and tingling, acroparesthesia, prickling sensation, altered sensation, sensory disturbance, neuropathic sensory symptoms, loss of feeling, dead feeling in extremities
SCOPE: Systematic evaluation of undifferentiated paresthesia, numbness, or tingling presenting to ED, hospital, or outpatient neurology. Focuses on neuroanatomic localization (peripheral nerve, plexus, root, spinal cord, brainstem/brain), pattern recognition (stocking-glove, dermatomal, hemisensory, non-anatomic), etiologic laboratory workup, electrodiagnostic and imaging indications, and identification of red flags requiring emergent intervention. This is an EVALUATION template. For specific established diagnoses, refer to dedicated plans: Peripheral Neuropathy, Radiculopathy, Carpal Tunnel Syndrome, Small Fiber Neuropathy, GBS, CIDP, Acute Myelopathy, MS - New Diagnosis.
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 | ROUTINE | STAT | Anemia (B12 deficiency), infection, macrocytosis, malignancy | Normal; macrocytosis raises suspicion for B12/folate deficiency |
| CMP (BMP + LFTs) (CPT 80053) | STAT | STAT | ROUTINE | STAT | Electrolytes (hypokalemia, hypocalcemia provoke paresthesia), renal dysfunction (uremic neuropathy), hepatic disease, glucose | Normal |
| Fasting glucose (CPT 82947) | STAT | STAT | ROUTINE | STAT | Diabetes screening; most common cause of polyneuropathy | <100 mg/dL |
| HbA1c (CPT 83036) | URGENT | ROUTINE | ROUTINE | - | Diabetes/prediabetes detection; prediabetic neuropathy is underrecognized | <5.7% |
| Vitamin B12 (CPT 82607) | URGENT | ROUTINE | ROUTINE | URGENT | B12 deficiency causes large fiber neuropathy and myelopathy (subacute combined degeneration) | >300 pg/mL |
| Methylmalonic acid (MMA) (CPT 83921) | - | ROUTINE | ROUTINE | - | If B12 borderline (200-400 pg/mL); more sensitive and specific than B12 alone | Normal |
| Folate (CPT 82746) | URGENT | ROUTINE | ROUTINE | - | Folate deficiency neuropathy; concomitant B12 assessment | Normal |
| TSH (CPT 84443) | URGENT | ROUTINE | ROUTINE | - | Hypothyroidism causes entrapment neuropathy and polyneuropathy | Normal (0.4-4.0 mIU/L) |
| ESR (CPT 85652) | URGENT | ROUTINE | ROUTINE | URGENT | Inflammatory/vasculitic process screen | Normal (<20 mm/hr) |
| CRP (CPT 86140) | URGENT | ROUTINE | ROUTINE | URGENT | Inflammatory marker; elevated in vasculitis, connective tissue disease | Normal |
| Magnesium (CPT 83735) | STAT | STAT | ROUTINE | STAT | Hypomagnesemia causes paresthesia and tetany; diuretic use, alcoholism | Normal (1.7-2.2 mg/dL) |
| Ionized calcium (CPT 82330) | STAT | STAT | ROUTINE | STAT | Hypocalcemia causes perioral and acral paresthesia, tetany, Chvostek/Trousseau signs | Normal (4.5-5.3 mg/dL) |
| Phosphorus (CPT 84100) | STAT | STAT | ROUTINE | STAT | Hypophosphatemia can cause paresthesia; important if malnourished or refeeding | Normal (2.5-4.5 mg/dL) |
1B. Extended Workup (Second-line)¶
| Test | ED | HOSP | OPD | ICU | Rationale | Target Finding |
|---|---|---|---|---|---|---|
| Oral glucose tolerance test (2-hour) | - | ROUTINE | ROUTINE | - | Detects impaired glucose tolerance missed by FBG/HbA1c; high yield in idiopathic neuropathy (34-62% have abnormal OGTT) | <140 mg/dL at 2h |
| Serum protein electrophoresis (SPEP) with immunofixation (CPT 86334) | - | ROUTINE | ROUTINE | - | Monoclonal gammopathy (MGUS, myeloma, amyloidosis) - particularly if sensory-predominant neuropathy | No M-spike |
| Free light chains (kappa/lambda) | - | ROUTINE | ROUTINE | - | AL amyloidosis, light chain deposition disease | Normal ratio (0.26-1.65) |
| Vitamin B1 (thiamine) (CPT 84425) | - | ROUTINE | ROUTINE | ROUTINE | Alcoholism, malnutrition, bariatric surgery | Normal |
| Vitamin B6 (pyridoxine) | - | ROUTINE | ROUTINE | - | Deficiency OR toxicity (>200 mg/day) both cause neuropathy; ask about supplements | Normal (5-50 ng/mL) |
| Vitamin E | - | ROUTINE | ROUTINE | - | Malabsorption syndromes, cholestasis; causes large fiber sensory neuropathy and ataxia | Normal |
| Copper (CPT 82390) | - | ROUTINE | ROUTINE | - | Copper deficiency (zinc excess, bariatric surgery); myeloneuropathy mimics B12 deficiency | Normal |
| Zinc (CPT 84630) | - | ROUTINE | ROUTINE | - | Zinc excess suppresses copper absorption | Normal |
| HIV antibody (CPT 87389) | - | ROUTINE | ROUTINE | - | HIV-associated distal sensory polyneuropathy; antiretroviral neurotoxicity | Negative |
| Hepatitis B surface antigen/antibody (CPT 80074) | - | ROUTINE | ROUTINE | - | Hepatitis B-associated PAN, cryoglobulinemia | Negative |
| Hepatitis C antibody (CPT 80074) | - | ROUTINE | ROUTINE | - | HCV-associated cryoglobulinemia, vasculitic neuropathy | Negative |
| ANA (CPT 86235) | - | ROUTINE | ROUTINE | - | Connective tissue disease screen (lupus, scleroderma, Sjogren) | Negative or low titer |
| Anti-SSA/SSB (Ro/La) | - | ROUTINE | ROUTINE | - | Sjogren syndrome - common cause of small fiber neuropathy and sensory ganglionopathy | Negative |
| Rheumatoid factor | - | ROUTINE | ROUTINE | - | Rheumatoid vasculitis | Negative |
| RPR/VDRL (CPT 86592) | - | ROUTINE | ROUTINE | - | Syphilitic neuropathy (tabes dorsalis) | Negative |
| Lyme serology (endemic areas) | - | ROUTINE | ROUTINE | - | Lyme neuroborreliosis - radiculoneuropathy, cranial neuropathy | Negative |
| ACE level | - | ROUTINE | ROUTINE | - | Sarcoidosis - can cause mononeuropathy multiplex or small fiber neuropathy | Normal |
1C. Rare/Specialized (Refractory or Atypical)¶
| Test | ED | HOSP | OPD | ICU | Rationale | Target Finding |
|---|---|---|---|---|---|---|
| Anti-ganglioside antibodies (GM1, GD1a, GD1b, GQ1b) (CPT 86255) | - | EXT | EXT | EXT | If acute onset or motor-predominant (GBS variants); GQ1b for Miller Fisher syndrome | Negative |
| Anti-MAG antibody (CPT 86255) | - | EXT | EXT | - | IgM paraproteinemic neuropathy; distal sensory-predominant with tremor and ataxia | Negative |
| Paraneoplastic panel (anti-Hu, CV2, amphiphysin) (CPT 86255) | - | EXT | EXT | - | Subacute sensory neuronopathy/ganglionopathy; weight loss, smoking history, non-length-dependent pattern | Negative |
| Cryoglobulins | - | EXT | EXT | - | Hepatitis C, autoimmune-associated vasculitic neuropathy | Negative |
| Anti-CASPR2, Anti-LGI1 | - | EXT | EXT | EXT | Neuromyotonia, painful neuropathy, Morvan syndrome; cramps with sensory symptoms | Negative |
| Heavy metal panel (lead, arsenic, thallium, mercury) (CPT 83018, 83015, 83825) | - | EXT | EXT | - | Occupational/environmental exposure; arsenic and thallium cause painful neuropathy | Normal |
| Genetic testing (CMT panel, TTR gene) | - | - | EXT | - | Hereditary neuropathy if family history, pes cavus, slowly progressive from youth; TTR for familial amyloidosis | No pathogenic variant |
| Skin punch biopsy for IENFD (CPT 11104) | - | - | EXT | - | Small fiber neuropathy confirmation when NCS normal but symptoms persistent | Normal IENFD (>8.8 fibers/mm at distal leg; varies by site/age/sex) |
| Fat pad biopsy (Congo red staining) | - | EXT | EXT | - | Amyloidosis screening if paraprotein present or autonomic features | No amyloid deposits |
| 24-hour urine protein electrophoresis (UPEP) (CPT 86335) | - | ROUTINE | ROUTINE | - | Light chain disease, amyloidosis | No monoclonal protein |
| Complement levels (C3, C4) | - | EXT | EXT | - | Vasculitis evaluation, cryoglobulinemia | Normal |
| ANCA (p-ANCA, c-ANCA) | - | EXT | EXT | - | ANCA-associated vasculitis causing mononeuropathy multiplex | Negative |
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2. DIAGNOSTIC IMAGING & STUDIES¶
2A. Essential/First-line¶
| Study | ED | HOSP | OPD | ICU | Timing | Target Finding | Contraindications |
|---|---|---|---|---|---|---|---|
| CT head without contrast (CPT 70450) | STAT | - | - | STAT | Immediate if acute hemisensory onset with concern for stroke | Rule out hemorrhage | None significant |
| CT angiography head/neck (CPT 70496, 70498) | STAT | - | - | STAT | Immediate if acute onset + stroke suspicion (within treatment window) | Patent vessels; no large vessel occlusion | Contrast allergy, renal impairment |
| MRI brain with and without contrast (CPT 70553) | URGENT | ROUTINE | ROUTINE | URGENT | Within 24h if acute hemisensory pattern, myelopathy signs, or brainstem signs; ROUTINE if chronic/subacute | No acute infarct, demyelination, mass, or brainstem lesion | Pacemaker, metallic implants, GFR <30 (gadolinium) |
| Nerve conduction studies (NCS) (CPT 95907-95913) and EMG (CPT 95886) | - | ROUTINE | ROUTINE | - | Optimal 3-4 weeks after symptom onset (allows Wallerian degeneration); perform earlier if needed | Characterize axonal vs demyelinating, distribution (length-dependent vs non-length-dependent), motor vs sensory, focal vs diffuse | Pacemaker (relative); anticoagulation for needle EMG (relative) |
2B. Extended¶
| Study | ED | HOSP | OPD | ICU | Timing | Target Finding | Contraindications |
|---|---|---|---|---|---|---|---|
| MRI cervical spine with and without contrast (CPT 72156) | URGENT | ROUTINE | ROUTINE | URGENT | If myelopathy suspected (bilateral sensory level, UMN signs, bowel/bladder), or cervical radiculopathy | No cord compression, syrinx, demyelination, or enhancement | GFR <30, pacemaker, gadolinium allergy |
| MRI thoracic spine with and without contrast (CPT 72157) | URGENT | ROUTINE | ROUTINE | URGENT | If thoracic sensory level identified on exam; bilateral lower extremity numbness | No cord lesion, compression, or transverse myelitis | GFR <30, pacemaker, gadolinium allergy |
| MRI lumbar spine with and without contrast (CPT 72158) | URGENT | ROUTINE | ROUTINE | URGENT | Lumbosacral radiculopathy, cauda equina syndrome, lumbosacral plexopathy | No nerve root compression, stenosis, or mass | GFR <30, pacemaker, gadolinium allergy |
| MRI brachial plexus with contrast | - | ROUTINE | ROUTINE | - | Brachial plexopathy, Parsonage-Turner syndrome; unilateral arm weakness with pain | No plexus enhancement, mass, or denervation | GFR <30, pacemaker, gadolinium allergy |
| MRI lumbar plexus with contrast | - | ROUTINE | ROUTINE | - | Lumbosacral plexopathy; asymmetric proximal leg weakness and numbness | No plexus enhancement, mass | GFR <30, pacemaker, gadolinium allergy |
| Autonomic function testing (QSART, tilt table, HRV) (CPT 89240, 95923) | - | - | ROUTINE | - | If autonomic symptoms (orthostasis, anhidrosis, GI dysmotility) accompany sensory symptoms | Normal sudomotor and cardiovagal function | None significant |
| Quantitative sensory testing (QST) | - | - | EXT | - | Small fiber neuropathy evaluation when NCS normal | Normal thermal and vibratory thresholds | None significant |
| Nerve ultrasound | - | EXT | ROUTINE | - | Entrapment neuropathy (carpal tunnel, cubital tunnel); CIDP (nerve enlargement) | Normal nerve caliber; no focal swelling at entrapment sites | None |
| Chest X-ray (CPT 71046) | URGENT | ROUTINE | ROUTINE | - | Lung cancer (paraneoplastic), sarcoidosis, Pancoast tumor (brachial plexopathy) | Normal | Pregnancy (relative) |
2C. Rare/Specialized¶
| Study | ED | HOSP | OPD | ICU | Timing | Target Finding | Contraindications |
|---|---|---|---|---|---|---|---|
| MR neurography | - | EXT | EXT | - | Focal nerve pathology, plexopathy, peripheral nerve tumor | Normal nerve signal and caliber | Pacemaker, metallic implants |
| PET-CT (CPT 78816) | - | EXT | EXT | - | Occult malignancy if paraneoplastic suspected, amyloidosis | No FDG-avid lesions | Pregnancy, uncontrolled diabetes |
| CT chest/abdomen/pelvis | - | ROUTINE | ROUTINE | - | Occult malignancy if paraneoplastic panel positive or unexplained weight loss | No mass | Contrast allergy, renal impairment |
| Sural nerve biopsy (CPT 64795) | - | EXT | - | - | Vasculitic neuropathy, amyloidosis, CIDP variants; when non-invasive workup inconclusive | No vasculitis, amyloid deposits, or granulomas | Coagulopathy |
LUMBAR PUNCTURE¶
Indication: Suspected inflammatory/demyelinating neuropathy (GBS, CIDP), myelopathy of unclear etiology, leptomeningeal disease, infectious etiology, or polyradiculopathy
Timing: URGENT if GBS or acute myelopathy suspected; ROUTINE for chronic evaluation
Volume Required: 10-15 mL (standard diagnostic)
| Study | ED | HOSP | OPD | ICU | Rationale | Target Finding |
|---|---|---|---|---|---|---|
| Opening pressure | URGENT | ROUTINE | ROUTINE | URGENT | Rule out elevated ICP | 10-20 cm H2O |
| Cell count (tubes 1 and 4) | URGENT | ROUTINE | ROUTINE | URGENT | Inflammation, infection, leptomeningeal disease | WBC <5, RBC 0 |
| Protein (CPT 84157) | URGENT | ROUTINE | ROUTINE | URGENT | Albuminocytologic dissociation in GBS/CIDP; elevated in meningitis, myelitis | Normal 15-45 mg/dL; elevated in GBS/CIDP |
| Glucose with serum glucose (CPT 82945) | URGENT | ROUTINE | ROUTINE | URGENT | Infection, carcinomatous meningitis | Normal (>60% serum) |
| Gram stain and culture | URGENT | ROUTINE | ROUTINE | URGENT | Rule out infection | No organisms |
| Cytology (CPT 88104) | - | ROUTINE | ROUTINE | - | Leptomeningeal carcinomatosis | Negative |
| VDRL (CSF) (CPT 86592) | - | ROUTINE | ROUTINE | - | Neurosyphilis (tabes dorsalis) | Negative |
| Oligoclonal bands and IgG index | - | ROUTINE | ROUTINE | - | Multiple sclerosis if CNS demyelination suspected | Negative; positive OCBs in 85-95% of MS |
| Lyme PCR/antibody index | - | ROUTINE | ROUTINE | - | Endemic areas; polyradiculopathy | Negative |
| ACE (CSF) | - | EXT | EXT | - | Neurosarcoidosis | Normal |
Special Handling: Cytology requires rapid transport (<1 hour). Oligoclonal bands require paired serum sample.
Contraindications: Elevated ICP without imaging, coagulopathy (INR >1.5, platelets <50K), skin infection at LP site
Note: CSF protein may be normal in first 1-2 weeks of GBS. Elevated protein with normal cell count ("albuminocytologic dissociation") is classic for GBS/CIDP. Oligoclonal bands present in CSF but not serum support MS diagnosis.
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3. TREATMENT¶
3A. Acute/Emergent (Red Flag Presentations)¶
| Treatment | Route | Indication | Dosing | Contraindications | Monitoring | ED | HOSP | OPD | ICU |
|---|---|---|---|---|---|---|---|---|---|
| tPA (alteplase) | IV | Acute hemisensory deficit with confirmed acute ischemic stroke within treatment window | 0.9 mg/kg :: IV :: once :: 0.9 mg/kg IV (max 90 mg); 10% bolus over 1 min, remainder over 60 min | Active bleeding, recent surgery, INR >1.7, platelets <100K; see Acute Ischemic Stroke plan for full contraindications | BP q15min x 2h, then q30min x 6h, then q1h x 16h; neuro checks q15min; bleeding precautions | STAT | - | - | STAT |
| Methylprednisolone IV (acute myelopathy/transverse myelitis) | IV | Acute myelopathy with sensory level and suspected inflammatory/demyelinating etiology | 1000 mg :: IV :: daily :: 1000 mg IV daily x 3-5 days | Active untreated infection, uncontrolled diabetes | Glucose monitoring Q6h; BP; GI prophylaxis; insomnia management | STAT | STAT | - | STAT |
| Thiamine IV (if alcoholic or malnourished) | IV | Wernicke encephalopathy prophylaxis in malnourished patients with neuropathic symptoms | 500 mg :: IV :: TID :: 500 mg IV TID x 3 days, then 250 mg IV daily x 3-5 days, then oral | None significant | Anaphylaxis (rare) | STAT | STAT | - | STAT |
| Vitamin B12 IM (if deficient) | IM | Documented B12 deficiency with neurological symptoms (do not wait for MMA result) | 1000 mcg :: IM :: daily :: 1000 mcg IM daily x 7 days, then weekly x 4 weeks, then monthly indefinitely | Cobalt allergy | Reticulocyte count at 1 week; B12 level at 1-2 months; neurological exam | URGENT | URGENT | ROUTINE | URGENT |
| Calcium gluconate IV (symptomatic hypocalcemia) | IV | Perioral/acral paresthesia with documented hypocalcemia and tetany | 1-2 g :: IV :: over 10-20 min :: 1-2 g (10-20 mL of 10% solution) IV over 10-20 min; may repeat; follow with continuous infusion if persistent | Digoxin use (risk of fatal arrhythmia); hypercalcemia | Cardiac monitor during infusion; repeat calcium level q4-6h; ECG | STAT | STAT | - | STAT |
| Magnesium sulfate IV (symptomatic hypomagnesemia) | IV | Paresthesia with documented hypomagnesemia | 2 g :: IV :: over 15-30 min :: 2 g IV over 15-30 min; follow with 4-8 g over 24h | Myasthenia gravis; severe renal impairment | Cardiac monitor; deep tendon reflexes; magnesium level q6-8h; respiratory status | STAT | STAT | - | STAT |
| Glucose control optimization | PO/IV | Diabetic or prediabetic neuropathy identified | Per protocol :: PO/IV :: per diabetes protocol :: Initiate or intensify glycemic management per diabetes protocol; target HbA1c <7% (individualize); insulin infusion if inpatient with acute hyperglycemia | Hypoglycemia risk | Glucose monitoring; HbA1c at 3 months | STAT | STAT | ROUTINE | STAT |
3B. Symptomatic Treatments - Neuropathic Pain/Discomfort¶
| Treatment | Route | Indication | Dosing | Contraindications | Monitoring | ED | HOSP | OPD | ICU |
|---|---|---|---|---|---|---|---|---|---|
| Gabapentin | PO | Neuropathic pain, painful paresthesia (first-line) | 300 mg :: PO :: qHS :: Start 300 mg qHS; increase by 300 mg every 1-3 days; target 900-1800 mg TID; max 3600 mg/day | Renal impairment (adjust per CrCl: CrCl 30-59 max 900-1400 mg/day; CrCl 15-29 max 600 mg/day; CrCl <15 max 300 mg/day) | Sedation, dizziness, peripheral edema; taper to discontinue | - | ROUTINE | ROUTINE | - |
| Pregabalin | PO | Neuropathic pain, painful paresthesia (first-line) | 75 mg :: PO :: BID :: Start 75 mg BID; increase to 150 mg BID after 1 week; max 300 mg BID | Renal impairment (adjust per CrCl); Schedule V controlled substance | Sedation, weight gain, peripheral edema | - | ROUTINE | ROUTINE | - |
| Duloxetine | PO | Neuropathic pain (first-line, especially diabetic neuropathy) | 30 mg :: PO :: daily :: Start 30 mg daily x 1 week; increase to 60 mg daily; max 120 mg/day | Hepatic impairment; CrCl <30; concurrent MAOIs; uncontrolled narrow-angle glaucoma | Nausea (transient), BP; discontinuation syndrome (taper over 2+ weeks) | - | ROUTINE | ROUTINE | - |
| Venlafaxine XR | PO | Neuropathic pain (SNRI alternative) | 37.5 mg :: PO :: daily :: Start 37.5-75 mg daily; increase by 75 mg every 4-7 days; max 225 mg daily | Uncontrolled hypertension; concurrent MAOIs | BP monitoring; discontinuation syndrome | - | ROUTINE | ROUTINE | - |
| Amitriptyline | PO | Neuropathic pain (second-line; avoid in elderly) | 10 mg :: PO :: qHS :: Start 10-25 mg qHS; increase by 10-25 mg weekly; max 150 mg qHS | Cardiac conduction abnormality; recent MI; urinary retention; narrow-angle glaucoma; elderly (anticholinergic burden) | ECG if dose >100 mg/day; anticholinergic effects; sedation | - | ROUTINE | ROUTINE | - |
| Nortriptyline | PO | Neuropathic pain (second-line; better tolerated TCA) | 10 mg :: PO :: qHS :: Start 10-25 mg qHS; increase by 10-25 mg weekly; max 150 mg qHS | Cardiac conduction abnormality; recent MI; urinary retention; narrow-angle glaucoma; elderly (anticholinergic burden) | ECG if dose >100 mg/day; anticholinergic effects (fewer than amitriptyline); sedation | - | ROUTINE | ROUTINE | - |
| Capsaicin cream 0.025-0.075% | Topical | Localized paresthesia/pain | Thin layer :: Topical :: TID-QID :: Apply thin layer TID-QID to affected area; takes 2-4 weeks for effect | Open wounds; avoid eyes/mucous membranes | Initial burning (decreases with continued use); wash hands after | - | - | ROUTINE | - |
| Capsaicin 8% patch (Qutenza) | Transdermal | Localized neuropathic pain (refractory) | 1 patch :: Transdermal :: q3months :: Applied by healthcare provider for 30-60 minutes; repeat every 3 months | Open wounds; avoid mucous membranes | Apply in clinic; pretreat area with topical lidocaine | - | - | ROUTINE | - |
| Lidocaine 5% patch | Transdermal | Localized paresthesia/pain | 1-3 patches :: Transdermal :: daily :: Apply 1-3 patches to painful area for 12 hours on, 12 hours off | Severe hepatic impairment; application to broken skin | Minimal systemic absorption; local irritation | - | ROUTINE | ROUTINE | - |
| Carbamazepine | PO | Lancinating/shooting pain, trigeminal distribution paresthesia | 100 mg :: PO :: BID :: Start 100 mg BID; increase by 200 mg/day every 3-7 days; max 1200 mg/day | AV block; bone marrow suppression; concurrent MAOIs | CBC, LFTs, sodium at baseline and periodically; HLA-B*1502 screening in at-risk populations | - | ROUTINE | ROUTINE | - |
| Tramadol | PO | Moderate neuropathic pain (adjunct, short-term) | 50 mg :: PO :: q6h :: Start 50 mg q6h PRN; ER option: 100 mg daily; max 400 mg/day | Seizure disorder; concurrent MAOIs; concurrent SSRIs (serotonin syndrome) | Serotonin syndrome; seizures; dependence (Schedule IV) | - | ROUTINE | ROUTINE | - |
Combination Therapy Note: For refractory neuropathic pain, combine agents from different classes (e.g., gabapentinoid + SNRI, or gabapentinoid + TCA). Do not combine TCAs with SNRIs (serotonin syndrome risk). Finnerup NB et al. Lancet Neurol 2015
3C. Condition-Specific Treatments (Initiated After Diagnosis Established)¶
| Treatment | Route | Indication | Dosing | Contraindications | Monitoring | ED | HOSP | OPD | ICU |
|---|---|---|---|---|---|---|---|---|---|
| IVIG | IV | GBS, CIDP, or other autoimmune neuropathy causing paresthesia/weakness | 2 g/kg :: IV :: over 2-5 days :: 2 g/kg divided over 2-5 days (induction); maintenance 0.4-1 g/kg every 2-4 weeks for CIDP | IgA deficiency (use IgA-depleted product); renal failure; thrombosis risk | Renal function, headache, thrombosis, infusion reactions | - | URGENT | ROUTINE | URGENT |
| Plasma exchange (PLEX) | IV | GBS, CIDP (alternative to IVIG) | 1 plasma volume :: IV :: every other day :: 5-7 exchanges of 1 plasma volume each over 10-14 days | Hemodynamic instability, sepsis | BP, electrolytes, coagulation studies, fibrinogen | - | URGENT | - | URGENT |
| Prednisone | PO | CIDP, vasculitic neuropathy, sarcoid neuropathy | 1 mg/kg :: PO :: daily :: 1 mg/kg/day (max 80 mg) x 4-6 weeks; taper over 3-6 months | Active untreated infection, uncontrolled diabetes, psychosis | Glucose, BP, mood, bone density with prolonged use; GI prophylaxis | - | ROUTINE | ROUTINE | - |
| Ibuprofen | PO | Mild radicular pain, musculoskeletal pain contributing to symptoms | 400 mg :: PO :: q6-8h :: 400-600 mg q6-8h PRN; max 2400 mg/day; limit duration | GI bleeding, renal impairment, concurrent anticoagulation, cardiovascular disease | Renal function, GI symptoms | ROUTINE | ROUTINE | ROUTINE | - |
| Oral corticosteroid taper (cervical/lumbar radiculopathy) | PO | Acute radiculopathy with significant pain and function limitation | 60 mg :: PO :: daily :: Methylprednisolone dose pack or prednisone 60 mg x 5 days, 40 mg x 5 days, 20 mg x 5 days (15-day taper) | Active infection, uncontrolled diabetes, GI bleed | Glucose; short course so bone density not needed | ROUTINE | ROUTINE | ROUTINE | - |
| Carpal tunnel splint (wrist neutral) | External | Carpal tunnel syndrome identified as cause | Neutral wrist splint :: External :: nightly :: Neutral wrist splint worn nightly x 4-6 weeks; use during aggravating activities | None | Symptom improvement; if no improvement in 6 weeks, pursue injection or surgical referral | - | - | ROUTINE | - |
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4. OTHER RECOMMENDATIONS¶
4A. Referrals & Consults¶
| Recommendation | ED | HOSP | OPD | ICU |
|---|---|---|---|---|
| Neurology consult (urgent) | STAT | URGENT | - | STAT |
| Neurology referral (outpatient) for etiologic workup and localization of all new unexplained paresthesia/numbness | - | ROUTINE | ROUTINE | - |
| Electrodiagnostic medicine/EMG referral for NCS/EMG characterization when peripheral etiology suspected; optimal timing 3-4 weeks after onset | - | ROUTINE | ROUTINE | - |
| Stroke team activation for acute hemisensory onset within stroke treatment window; face/arm/leg numbness with other stroke signs | STAT | - | - | STAT |
| Neurosurgery consult for acute spinal cord compression, cauda equina syndrome, cervical myelopathy with progressive deficit | URGENT | URGENT | - | URGENT |
| Physical therapy consult for gait instability from sensory ataxia, balance training, falls prevention, strengthening | - | ROUTINE | ROUTINE | - |
| Occupational therapy consult for fine motor impairment, ADL difficulty from hand numbness, adaptive strategies | - | ROUTINE | ROUTINE | - |
| Endocrinology referral for newly diagnosed diabetes/prediabetes with neuropathy; HbA1c not at goal | - | ROUTINE | ROUTINE | - |
| Rheumatology referral for suspected vasculitic neuropathy, connective tissue disease, Sjogren syndrome | - | ROUTINE | ROUTINE | - |
| Pain management referral for refractory neuropathic pain despite multimodal therapy | - | - | ROUTINE | - |
| Hematology/Oncology referral for paraproteinemic neuropathy, suspected malignancy, amyloidosis | - | URGENT | ROUTINE | - |
| Podiatry referral for diabetic neuropathy, foot care education, orthotics, wound prevention | - | ROUTINE | ROUTINE | - |
| Psychiatry/Psychology referral for functional neurological disorder suspected; chronic pain management; comorbid anxiety/depression | - | ROUTINE | ROUTINE | - |
| Genetic counseling referral for suspected hereditary neuropathy (CMT, hATTR), positive family history | - | - | ROUTINE | - |
4B. Patient Instructions¶
| Recommendation | ED | HOSP | OPD |
|---|---|---|---|
| Return to ED IMMEDIATELY if sudden weakness develops, difficulty walking, loss of bowel/bladder control, or symptoms rapidly worsen over hours | YES | YES | YES |
| Return to ED if numbness suddenly spreads to face, arm, or leg on one side (possible stroke) | YES | YES | YES |
| Report if numbness ascends from feet toward trunk (possible GBS) | YES | YES | YES |
| Track and document when symptoms occur, where they are located, and what makes them better or worse | - | YES | YES |
| Inspect feet daily for cuts, blisters, or wounds if numbness present in feet (use mirror for soles) | - | YES | YES |
| Wear well-fitting, protective footwear at all times (never barefoot) if foot numbness present | - | YES | YES |
| Test bath water temperature with elbow or thermometer before entering (impaired sensation increases burn risk) | - | YES | YES |
| Use night lights and handrails to prevent falls if balance affected | - | YES | YES |
| Bring a list of all medications, vitamins, and supplements to neurology appointment (including OTC B6 supplements) | - | YES | YES |
| Avoid repetitive wrist motions and use ergonomic positioning if carpal tunnel syndrome suspected | - | YES | YES |
| Do not stop prescribed medications abruptly (gabapentin, pregabalin require taper) | - | YES | YES |
| Neuropathic pain medications take 2-4 weeks to reach full effect; do not judge effectiveness too early | - | YES | YES |
| Avoid excessive alcohol (worsens neuropathy, interacts with pain medications) | YES | YES | YES |
4C. Lifestyle & Prevention¶
| Recommendation | ED | HOSP | OPD |
|---|---|---|---|
| Strict glycemic control if diabetic/prediabetic (HbA1c <7% or individualized target) - most important modifiable factor | YES | YES | YES |
| Complete alcohol cessation if alcoholic neuropathy suspected (reversible if early) | YES | YES | YES |
| Smoking cessation (microvascular disease worsens neuropathy) | YES | YES | YES |
| Regular exercise as tolerated (improves circulation, glycemic control, reduces neuropathic pain) | - | YES | YES |
| Review all medications for neurotoxic agents (metronidazole, nitrofurantoin, chemotherapy, amiodarone, isoniazid, linezolid, colchicine, statins) | - | YES | YES |
| Avoid excessive vitamin B6 supplementation (>100 mg/day causes sensory neuropathy; very common cause of iatrogenic neuropathy) | - | YES | YES |
| Balanced diet rich in B vitamins; supplement B12 if vegan/vegetarian or on metformin | - | YES | YES |
| Weight management (reduces pressure on nerves, improves metabolic syndrome) | - | - | YES |
| Fall prevention: remove throw rugs, ensure adequate lighting, use assistive devices if sensory ataxia present | - | YES | YES |
| Ergonomic workplace assessment if repetitive motion/compression neuropathy suspected | - | - | YES |
| Compression stocking use for orthostatic symptoms if autonomic involvement | - | YES | YES |
═══════════════════════════════════════════════════════════════ SECTION B: REFERENCE (Expand as Needed) ═══════════════════════════════════════════════════════════════
5. DIFFERENTIAL DIAGNOSIS¶
5A. By Neuroanatomic Localization¶
| Localization | Pattern | Key Clinical Features | Tests to Differentiate |
|---|---|---|---|
| Peripheral nerve (mononeuropathy) | Single nerve distribution (e.g., median, ulnar, peroneal) | Focal numbness/tingling in specific nerve territory; associated weakness in that nerve distribution; Tinel sign at compression site | NCS/EMG localizes to specific nerve; ultrasound shows nerve swelling at entrapment |
| Multiple mononeuropathy (mononeuritis multiplex) | Asymmetric, stepwise involvement of individual nerves | Sequential individual nerve deficits; painful; associated with vasculitis, diabetes, sarcoidosis | NCS/EMG shows multifocal axonal loss in individual named nerves; ESR/CRP; ANCA; nerve biopsy |
| Polyneuropathy (length-dependent) | Stocking-glove distribution, symmetric, starts distally | Feet before hands; gradual proximal spread; associated with diabetes, B12 deficiency, alcohol, medications | NCS shows diffuse axonal or demyelinating polyneuropathy; labs per Section 1 |
| Sensory ganglionopathy (neuronopathy) | Non-length-dependent, asymmetric, upper > lower | Patchy sensory loss not following distal-to-proximal gradient; sensory ataxia early; paraneoplastic (anti-Hu), Sjogren | NCS shows asymmetric sensory nerve action potentials; anti-Hu antibody; anti-SSA/SSB |
| Radiculopathy | Dermatomal distribution, unilateral | Pain radiating in dermatome; positive Spurling test (cervical) or straight-leg raise (lumbar); preserved reflexes outside root | MRI spine; NCS/EMG shows radicular pattern with fibrillations in paraspinal muscles |
| Plexopathy | Multiple roots/nerves in one limb | Brachial: shoulder/arm pain + weakness + numbness beyond single root; Lumbosacral: thigh pain + proximal weakness | MRI plexus with contrast; NCS/EMG shows plexus pattern; clinical context (diabetic amyotrophy, trauma, Parsonage-Turner) |
| Spinal cord (myelopathy) | Bilateral sensory level, below lesion level | Bilateral numbness below a spinal level; UMN signs (hyperreflexia, Babinski, spasticity); bowel/bladder dysfunction | MRI spine (cervical, thoracic); LP if inflammatory; somatosensory evoked potentials |
| Brainstem | Crossed findings (ipsilateral face + contralateral body) | Lateral medullary syndrome: ipsilateral face numbness + contralateral body numbness; vertigo, ataxia, Horner | MRI brain (DWI for stroke); MRA for vertebral/basilar pathology |
| Thalamus/cortex (brain) | Hemisensory, contralateral to lesion | Sudden hemisensory loss (stroke); cheiro-oral pattern (thalamic); cortical sensory loss (graphesthesia, stereognosis impaired) | CT head (acute); MRI brain with DWI; CTA if stroke suspected |
| Functional (non-organic) | Non-anatomic distribution | Midline splitting (vibration), give-way weakness, inconsistent exam, Hoover sign; tubular visual fields | Normal NCS/EMG, normal MRI; positive functional signs on exam; diagnosis of exclusion with positive features |
5B. Common Specific Diagnoses¶
| Diagnosis | Key Distinguishing Features | Tests to Differentiate |
|---|---|---|
| Carpal tunnel syndrome | Median nerve distribution (thumb, index, middle finger, radial ring finger); nocturnal; Phalen/Tinel positive | NCS shows median neuropathy at wrist; ultrasound shows nerve swelling |
| Ulnar neuropathy at elbow | Ring/small finger numbness; hand weakness; positive Froment sign; history of elbow leaning | NCS localizes to elbow; ultrasound shows nerve subluxation or swelling |
| Peroneal neuropathy | Foot drop; lateral leg/dorsal foot numbness; history of leg crossing, weight loss, prolonged squatting | NCS localizes to fibular head; MRI may show compressive lesion |
| Cervical radiculopathy | Dermatomal arm numbness (C5-T1); neck pain; Spurling test positive; reflex changes | MRI cervical spine; EMG shows radicular pattern |
| Lumbar radiculopathy | Dermatomal leg numbness (L2-S1); back pain radiating to leg; positive SLR | MRI lumbar spine; EMG shows radicular pattern |
| Diabetic polyneuropathy | Symmetric stocking-glove; burning/tingling feet; gradual onset | HbA1c >6.5%; NCS axonal sensorimotor polyneuropathy |
| B12 deficiency neuropathy | Large fiber loss (vibration, proprioception); may have myelopathy; macrocytic anemia | B12 <200; MMA elevated; MRI spine may show dorsal column signal |
| Transient ischemic attack | Sudden hemisensory onset; resolves within 24h; vascular risk factors | MRI DWI; CTA head/neck; ABCD2 score |
| Acute ischemic stroke | Acute hemisensory +/- hemiparesis; does not resolve | CT head; MRI DWI; CTA; NIHSS |
| Transverse myelitis | Bilateral sensory level; weakness; bowel/bladder; subacute | MRI spine with contrast (cord enhancement); LP (pleocytosis, OCBs) |
| Multiple sclerosis | Relapsing-remitting sensory episodes; young adult; optic neuritis history | MRI brain/spine (demyelinating lesions); OCBs in CSF; McDonald criteria |
| GBS | Ascending numbness/weakness over days; areflexia; post-infectious | NCS early may be normal; CSF albuminocytologic dissociation |
| Small fiber neuropathy | Pain/burning with normal NCS; preserved reflexes; autonomic symptoms | Skin biopsy for IENFD; QSART abnormal; NCS normal |
| Hyperventilation/anxiety | Perioral + bilateral hand/foot tingling; situational; respiratory alkalosis | ABG shows respiratory alkalosis; normal exam; symptoms reproduced with hyperventilation |
| Hypocalcemia | Perioral + acral paresthesia; Chvostek and Trousseau signs; tetany | Ionized calcium low; albumin-corrected calcium; PTH |
| Cervical spondylotic myelopathy | Bilateral hand numbness; gait difficulty; upper motor neuron signs; chronic | MRI cervical spine (cord compression, signal change) |
| Thoracic outlet syndrome | Upper extremity numbness/pain worse with overhead activity; young women | Roos test, Adson test (low sensitivity); NCS may be normal; MRI/MRA of chest inlet |
6. MONITORING PARAMETERS¶
Venue column indicates where monitoring is typically ordered/initiated. Most monitoring continues in outpatient setting.
| Parameter | ED | HOSP | OPD | ICU | Frequency | Target/Threshold | Action if Abnormal |
|---|---|---|---|---|---|---|---|
| Neurological exam (sensory mapping) | STAT | ROUTINE | ROUTINE | STAT | Each visit; document distribution, modalities affected | Stable or improving | If progressive, escalate workup; repeat imaging; urgent neurology |
| HbA1c | - | ROUTINE | ROUTINE | - | Every 3 months until stable, then every 6 months | <7% (individualize) | Intensify glycemic therapy; endocrinology referral |
| Vitamin B12 | - | ROUTINE | ROUTINE | - | 1-2 months after starting supplementation, then annually | >300 pg/mL | Continue supplementation; rule out malabsorption |
| Pain scores (0-10 NRS) | ROUTINE | ROUTINE | ROUTINE | ROUTINE | Each visit | Reduction >=30-50% from baseline | Titrate medications; add adjuncts or refer to pain management |
| Blood pressure (supine and standing) | URGENT | ROUTINE | ROUTINE | URGENT | Each visit if autonomic symptoms | Orthostatic drop <20 mmHg systolic | Evaluate for autonomic neuropathy; adjust medications |
| Gait and fall risk assessment | - | ROUTINE | ROUTINE | - | Each visit | No falls, stable gait | PT referral; assistive devices; home safety evaluation |
| Creatinine clearance | STAT | ROUTINE | ROUTINE | STAT | Baseline; before gabapentinoid dosing; with renal disease or elderly | CrCl >60 for full gabapentinoid dosing | Adjust gabapentin: CrCl 30-59 max 900-1400 mg/day; CrCl 15-29 max 600 mg/day; CrCl <15 max 300 mg/day |
| NCS/EMG follow-up | - | ROUTINE | ROUTINE | - | 3-6 months if treatment initiated; PRN for symptom change | Stable or improved | If progressive, reconsider diagnosis or escalate therapy |
| MRI spine/brain follow-up | - | ROUTINE | ROUTINE | - | Per etiology (MS: every 6-12 months; myelopathy: per neurosurgery) | Stable or improved lesion burden | Adjust treatment; neurosurgery referral if progressive compression |
| Respiratory function (FVC, NIF) | STAT | STAT | - | STAT | Q4h if GBS suspected and ascending; daily if admitted | FVC >20 mL/kg; NIF more negative than -30 cm H2O | ICU transfer if FVC <20 mL/kg or NIF weaker than -30 cm H2O; intubation if declining |
| ECG (if on TCAs) | URGENT | ROUTINE | ROUTINE | URGENT | Baseline; with dose increases >100 mg | QTc <500 ms; no heart block | Reduce dose or switch medication |
| Electrolytes (Ca, Mg, K, Phos) | STAT | ROUTINE | ROUTINE | STAT | After repletion; at follow-up if etiology electrolyte-related | Normal ranges | Continue repletion; investigate underlying cause |
7. DISPOSITION CRITERIA¶
| Disposition | Criteria |
|---|---|
| Discharge home from ED | Chronic/stable symptoms; no red flags (see below); normal neurological exam or stable chronic findings; no myelopathy signs; no acute weakness; reliable follow-up with neurology within 2-4 weeks; no electrolyte emergency; not stroke presentation |
| Admit to floor | Acute/subacute progressive numbness concerning for GBS or CIDP; new myelopathy signs; significant functional decline; falls from sensory ataxia requiring therapy; severe electrolyte derangement; workup requiring inpatient procedures (LP, nerve biopsy); new-onset mononeuritis multiplex (vasculitis workup) |
| Admit to ICU | GBS with respiratory compromise (FVC <20 mL/kg or NIF weaker than -30 cm H2O or declining trajectory); acute spinal cord compression pending emergent surgery; autonomic instability with cardiac arrhythmia or BP lability; acute stroke with hemisensory deficit requiring close monitoring |
| Transfer to higher level | Stroke presentation requiring thrombectomy-capable center; spinal cord compression requiring emergent neurosurgery not available; NCS/EMG not available for acute evaluation; PLEX/IVIG needed but not available |
RED FLAGS Requiring Emergent Evaluation¶
| Red Flag | Concern | Action |
|---|---|---|
| Acute hemisensory onset (face/arm/leg) | Acute ischemic stroke or TIA | Stroke protocol activation; CT head; CTA; time-critical |
| Rapidly ascending numbness/weakness (hours to days) | Guillain-Barre syndrome | Admit; NCS/EMG; LP; monitor FVC q4h; IVIG or PLEX |
| Bilateral sensory level with UMN signs | Spinal cord compression or transverse myelitis | Emergent MRI spine; neurosurgery consult if compressive; methylprednisolone if inflammatory |
| Bowel/bladder dysfunction with saddle anesthesia | Cauda equina syndrome | Emergent MRI lumbar spine; neurosurgical decompression within 24-48h |
| Acute onset numbness + worst headache of life | Subarachnoid hemorrhage, CNS vasculitis, PRES | CT head; LP if CT negative; CTA/MRA |
| Progressive numbness with respiratory difficulty | Neuromuscular respiratory failure (GBS, MG) | Measure FVC, NIF; ICU if declining; intubation if FVC <15-20 mL/kg |
| Numbness + fever + altered mental status | CNS infection, epidural abscess | MRI spine/brain; LP; empiric antibiotics |
8. EVIDENCE & REFERENCES¶
| Recommendation | Evidence Level | Source |
|---|---|---|
| Systematic approach to evaluation of peripheral neuropathy | Practice Parameter | England JD et al. Neurology 2009; AAN Practice Parameter |
| Diabetes and prediabetes are most common cause of polyneuropathy in developed countries | Class I | Dyck PJ et al. Neurology 1993 |
| OGTT detects IGT in 34-62% of idiopathic neuropathy patients | Class II, Level B | Singleton JR et al. Diabetes Care 2001 |
| NCS/EMG for characterization of neuropathy (axonal vs demyelinating) | Class I, Level B | AAN Practice Parameter; Cho SC et al. Phys Med Rehabil Clin N Am 2003 |
| Gabapentin, pregabalin, duloxetine first-line for neuropathic pain | Class I, Level A | Finnerup NB et al. Lancet Neurol 2015 |
| Tricyclic antidepressants effective for neuropathic pain | Class I, Level A | Finnerup NB et al. Lancet Neurol 2015 |
| SPEP indicated in idiopathic neuropathy workup | Class II, Level B | England JD et al. Neurology 2009 |
| Skin biopsy (IENFD) for small fiber neuropathy diagnosis | Class II, Level B | Lauria G et al. Eur J Neurol 2010 |
| B12 deficiency neuropathy: early treatment improves outcomes | Class II, Level B | Healton EB et al. Medicine 1991 |
| Acute stroke: time-critical evaluation of sensory deficits | Class I, Level A | AHA/ASA Stroke Guidelines 2019 |
| GBS: IVIG or PLEX within 2 weeks of onset | Class I, Level A | Hughes RA et al. Cochrane Review 2014 |
| Hypocalcemia causes perioral and acral paresthesia | Class III | Standard physiology texts; Cooper MS et al. BMJ 2008 |
| Excessive vitamin B6 causes sensory neuropathy | Class II | Schaumburg H et al. N Engl J Med 1983 |
| Cervical spondylotic myelopathy: surgical decompression for progressive deficit | Class II, Level B | Fehlings MG et al. Spine 2017 |
| Combination therapy for neuropathic pain improves outcomes | Class II, Level B | Gilron I et al. NEJM 2005 |
| Localization-based approach to sensory symptoms | Expert Consensus | [Brazis PW et al. Localization in Clinical Neurology, 8th ed. 2021] |
CHANGE LOG¶
v1.1 (February 2, 2026) - Added ICU column to all laboratory tables (1A, 1B, 1C) with appropriate priority assignments per C2 - Added ICU column to all imaging/study tables (2A, 2B, 2C, LP) with appropriate priority assignments per C3 - Added ICU column to all treatment tables (3A, 3B, 3C) converting from 9-column to required 10-column format per C1 - Added ICU column to Section 4A (Referrals & Consults) per C5 - Added ICU column to Section 6 (Monitoring Parameters) per C6 - Fixed nortriptyline row: replaced "Same as amitriptyline" cross-reference with full self-contained contraindications and monitoring per C4/M1 - Fixed glucose control optimization row in 3A: added structured dosing format (was bare dashes) per M2 - Fixed capsaicin cream dosing: added "Thin layer" as dose field per M3 - Fixed capsaicin 8% patch dosing: added "1 patch" as dose field per M3 - Fixed plasma exchange dosing: added "1 plasma volume :: IV :: every other day" structured format per M4 - Fixed carpal tunnel splint dosing: added "Neutral wrist splint :: External :: nightly" structured format per M5 - Fixed lidocaine patch dosing first field: added "1-3 patches" per M3 - Fixed venlafaxine dosing first field: standardized to "37.5 mg" per M3 - Replaced weak language: "consider" and "may" replaced with directive language throughout per R3 - Added section dividers (═══) between Sections 1-2, 2-3, and 3-4 per R4 - Fixed NIF threshold language in Section 6 and 7: clarified "weaker than -30 cm H2O" convention per R5 - Updated version to 1.1, added REVISED date per R6 - Updated setting in frontmatter to include ICU - Updated STATUS to "Validated per checker pipeline"
v1.0 (February 2, 2026) - Initial creation - Comprehensive evaluation plan for undifferentiated paresthesia, numbness, and tingling - Section 1: Complete laboratory workup organized by core (electrolytes, metabolic, nutritional), extended (autoimmune, infectious, toxic), and specialized (antibodies, genetic, biopsy) - Section 2: Imaging and electrodiagnostic studies including emergent (CT/CTA for stroke), essential (MRI brain, NCS/EMG), extended (MRI spine, plexus, autonomic testing), and LP protocol - Section 3: Treatment organized by acute/emergent (stroke intervention, electrolyte repletion, IV steroids), symptomatic (neuropathic pain management), and condition-specific (IVIG, PLEX, immunosuppression) - Section 4: Comprehensive referrals, patient instructions with red flag warnings, lifestyle modifications - Section 5: Dual differential organized by neuroanatomic localization (10 levels from peripheral nerve to cortex) and by specific diagnoses (17 common conditions) - Section 6: Monitoring parameters with venue assignments and action thresholds - Section 7: Disposition criteria with dedicated red flags table covering 7 emergency presentations - Section 8: 16 evidence references with PubMed links - Emphasizes localization-based approach: pattern recognition (stocking-glove, dermatomal, hemisensory, non-anatomic) guides workup - Red flags section highlights stroke, GBS, myelopathy, cauda equina, SAH, respiratory failure, and CNS infection
APPENDICES¶
Appendix A: Localization Algorithm¶
Step 1 - Onset Tempo:
- Hyperacute (seconds to minutes): Stroke, TIA, seizure, syncope
- Acute (hours to days): GBS, myelopathy, radiculopathy, electrolyte derangement
- Subacute (weeks to months): Neuropathy, myelopathy, deficiency, paraneoplastic
- Chronic (months to years): Polyneuropathy, hereditary, compression
Step 2 - Distribution Pattern:
- Stocking-glove (symmetric, length-dependent): Polyneuropathy (metabolic, toxic, inherited)
- Single nerve territory: Mononeuropathy (compression, entrapment, trauma)
- Multiple individual nerves (asymmetric): Mononeuritis multiplex (vasculitis, diabetes, sarcoid)
- Dermatomal: Radiculopathy (disc herniation, stenosis, herpes zoster)
- Sensory level (bilateral, below a level): Myelopathy (cord compression, transverse myelitis, MS)
- Hemisensory (face + arm + leg, one side): Thalamic/cortical lesion (stroke, TIA, mass)
- Perioral + bilateral hands: Hyperventilation/hypocalcemia
- Non-anatomic (midline splitting, whole body): Functional neurological disorder
Step 3 - Associated Features:
- Weakness present: Think motor involvement (radiculopathy, plexopathy, GBS, myelopathy, stroke)
- UMN signs (hyperreflexia, Babinski, clonus): Myelopathy or brain lesion
- LMN signs (areflexia, atrophy, fasciculations): Peripheral nerve, root, or anterior horn cell
- Autonomic features: Small fiber neuropathy, GBS, diabetic autonomic neuropathy
- Pain: Radiculopathy, small fiber neuropathy, vasculitis, entrapment
- Painless: Large fiber neuropathy, myelopathy, stroke
Appendix B: Common Entrapment Neuropathies¶
| Nerve | Site | Symptoms | Exam Findings | Key Test |
|---|---|---|---|---|
| Median | Wrist (carpal tunnel) | Thumb, index, middle, radial ring finger numbness; nocturnal; shaking hand relieves | Phalen, Tinel, thenar atrophy (late) | NCS: prolonged distal median sensory/motor latency |
| Ulnar | Elbow (cubital tunnel) | Ring/small finger numbness; hand weakness | Froment sign, Wartenberg sign, hypothenar/interossei atrophy | NCS: slowed conduction across elbow |
| Ulnar | Wrist (Guyon canal) | Deep branch: hand weakness without sensory loss; superficial: ring/small finger numbness | Depends on branch | NCS localizes to wrist |
| Radial | Spiral groove (Saturday night palsy) | Wrist drop; dorsal hand numbness | Wrist/finger extension weakness; sensation over dorsal first web space | NCS: slowed conduction at spiral groove |
| Peroneal | Fibular head | Foot drop; lateral leg/dorsal foot numbness | Ankle dorsiflexion/eversion weakness; steppage gait | NCS: slowed conduction at fibular head |
| Lateral femoral cutaneous | Inguinal ligament (meralgia paresthetica) | Anterolateral thigh numbness/burning | Pure sensory; no weakness; tenderness at ASIS | Clinical diagnosis; NCS confirmatory but technically difficult |
Appendix C: Key Examination Maneuvers¶
| Maneuver | Technique | Positive Finding | Localizes To |
|---|---|---|---|
| Tinel sign | Tap over nerve at common compression site | Tingling radiating into nerve distribution | Entrapment neuropathy at that site |
| Phalen test | Wrist flexion x 60 seconds | Paresthesia in median distribution | Carpal tunnel syndrome |
| Spurling test | Neck extension + lateral flexion + axial compression | Radicular pain/paresthesia in arm | Cervical radiculopathy |
| Straight-leg raise (Lasegue) | Raise extended leg supine | Pain radiating below knee at <60 degrees | L4-S1 radiculopathy |
| Romberg test | Stand with feet together, eyes closed | Swaying/falling with eyes closed (worse than open) | Dorsal column/large fiber sensory loss |
| Lhermitte sign | Neck flexion | Electric shock sensation down spine/limbs | Cervical cord pathology (MS, myelopathy) |
| Chvostek sign | Tap facial nerve anterior to ear | Ipsilateral facial muscle contraction | Hypocalcemia |
| Trousseau sign | BP cuff inflated above systolic x 3 min | Carpopedal spasm | Hypocalcemia |
| Reverse Phalen (prayer test) | Wrist extension x 60 seconds | Paresthesia in median distribution | Carpal tunnel syndrome |
| Hoover sign | Examiner hand under "weak" heel; ask to flex opposite hip | Involuntary downward pressure on "weak" side | Functional weakness (positive functional sign) |
| Vibration testing (tuning fork 128 Hz) | Place on bony prominences distally to proximally | Reduced or absent vibration sense distally | Large fiber neuropathy, dorsal column myelopathy |
| Monofilament testing (10g) | Apply to plantar foot at standard sites | Inability to feel monofilament | Diabetic neuropathy screening; protective sensation loss |