Symmetric sensory polyneuropathy: (‘glove & stocking’ numbness, tingling, and pain, eg worse at night).
℞: paracetamol → tricyclic (amitriptyline 10–25mg nocte; gradually ↑ to 150mg) → duloxetine, gabapentin, or pregabalin → opiates. Avoiding weight-bearing helps.
Mononeuritis multiplex: (eg iii & vi cranial nerves). Treatment: hard! If sudden or severe, immunosuppression may help (corticosteroids, iv immunoglobulin, ciclosporin).
Amyotrophy: Painful wasting of quadriceps and other pelvifemoral muscles. Use electrophysiology to show, eg lumbosacral radiculopathy, plexopathy, or proximal crural neuropathy. Natural course: variable with gradual but often incomplete improvement. iv immunoglobulins have been used.
Autonomic neuropathy: (p[link]) Postural bp drop; ↓cerebrovascular autoregulation; loss of respiratory sinus arrhythmia (vagal neuropathy); gastroparesis; urine retention; erectile dysfunction; gustatory sweating; diarrhoea (may respond to codeine phosphate).
Gastroparesis (early satiety, post-prandial bloating, nausea/vomiting) is diagnosed by gastric scintigraphy with a 99technetium-labelled meal; anti-emetics, erythromycin, or gastric pacing.
Postural hypotension may respond to fludrocortisone (se: oedema, ↑bp)/midodrine (α-agonist; se: ↑bp).