NEUROPATHY-APPROACH

SUMMARY

1. Motor, sensory, autonomic or combination
- Motor: GBS, CIDP, multifocal motor neuropathy (MMN), toxic (lead, amiodarone, vincristine, botulism), porphyria, heriditary neuropathies
- Sensory: DM, Vit B₁₂ def, uraemia, B₆ intoxication, HIV, leprosy, amyloid, Sjogren's syndrome, sarcoidosis, paraneoplastic syndromes
- Predominantly autonomic: DM, autoimmune, paraneoplastic, amyloid, GBS, botulism, prophyria, toxic

2. Large (touch, pressure, vibration sense) or small fibre neuropathies (pain & temperature sense)
- Small fibre neuropathy: DM, amyloidosis

3. Single nerve (mononeuropathy), multiple single nerves (mononeuritis multiplex; individual nerve involvement in a stepwise progression over time) or polyneuropathy (length-dependent or independent)
- Mononeuropathy: carpal tunnel syndrome, ulnar neuropathy, peroneal entrapment, meralgia paraesthetica (entrapment of the lateral cutaneous n.), tarsal tunnel syndrome
- Length dependent polyneuropathy (starts distally and progress proximally): metabolic, toxic, idiopathic, inherited
- Length independent polyneuropathy (can involve any portion): CIDP, multifocal motor neuropathy, demyelinating (autoimmune, infectious), cancer (lymphoma), amyloid,
- Length independent sensory ganglionopathy (can involve face, trunk, asymmetric): heavy metals, cisplatin, B₆ intoxication, paraneoplastic (anti-Hu), Sjogren syndrome, HIV

4. Primary axonal process or demyelination
- Axonal: Miller-Fisher syndrome
- Demyelination: CMT 1, HNPP, GBS, CIDP, systemic illnesses (IBD, infection, CTD), MMN, paraproteinaemia

5. Temporal profile: acute (< 4 weeks) or chronic; sudden or insidious in onset; relapsing or slowly progressive
- Acute: infectious, vasculitic, GBS, porphyria, toxic
- Subacute: toxic, nutritional, malignancy/paraneoplastic syndromes, metabolic
- Relapsing: CIDP, porphyria, repeated toxic exposure, vasculitis

6. Background history: endocrinopathies, hepatic/renal disease, CT diseases, vasculitis, skin conditions, cancer, medications
- Hereditary: no positive sensory symptoms, symmetric, chronic course, few symptoms relative to signs, assoc. skeletal abnormalities

7. Facial diplegia vs. sensory loss
- Facial diplegia: acute GBS, CIDP, amyloidosis, Lyme disease, sarcoidosis
- Facial sensory loss: coeliac neuropathy, Sjogren syndrome

8. "Double-hit" hypothesis: mononeuropathy superimposed on polyneuropathy

Reference(s)

Wilkinson, I., Furmedge, D. and Sinharay, R. (2017). Oxford handbook of clinical medicine. Oxford: Oxford University Press. Get it on Amazon.
Feather, A., Randall, D. and Waterhouse, M. (2020). Kumar And Clark’s Clinical Medicine. 10th ed. S.L.: Elsevier Health Sciences. Get it on Amazon.
Hannaman, R. A., Bullock, L., Hatchell, C. A., & Yoffe, M. (2016). Internal medicine review core curriculum, 2017-2018. CO Springs, CO: MedStudy.
Therapeutic Guidelines. Melbourne: Therapeutic Guidelines Limited. https://www.tg.org.au [Accessed 2021].