Causes of peripheral neuropathy
Metabolic and endocrine- hyothyroidism, liver failure, renal failure, Posinfective po
Mechanism of peripheral nerve degeneration
Infarction – DM
Infiltration- leprosy and granulomas
Demyelination- Guillain-Barre Syndromes
Axonal degeneration- toxic neuropathies
Wallerian degemration
Compression- Carpal tunnel syndrome
Clinical fetures
Sensory : Paresthesia, burning pain, tingling sensation, numbness, loss proprioception, allodynia, loss of pain and temperature sensation
Motor: Wasting, hypotonia, hyporeflexia, fasciculation, deformity.
Autonomic: Postural hypotension, urinary retention, erectile dysfunction, diarrhea/constipation, diminished sweating, cardiac arrhythmias, gustatory sweating.
Diabetic neuropathy
Peripheral damage:
- Occlusion of th vasa nervorum
- Sorbitol and fructose accumulation in Schwann cells du
Common presentaios of diabetic neuropathy
- DIstal symmetrical polyneuropathy (stockings and gloves pattern)
- Acute painful neuropathyy
10 gram monofilament
for diabetic patiency
Carpal nerve
Median nerve entrapment
Clinical presentation:
Guillain-Barre syndrome
AIDP
Triggered by infections.
Investigation of peripheral neuropathy:
Urinalyis- glucose, protein
Haemotology- FBC, ESR, vitamin B12, folate
Biochemistry- HBA1c, fastingglucose, E/U/ Cr, LFT, TSH
CSF- protein high normal cell count. in GBS.
Nerve conduction studies
Electromyography (EMG)
Nerve biopsy: e.g. vasculities, sarcordoisis, CIDP, Leprosy,
Treatment
TREATMENT OF THE UNDERLYING CAUSE.
Treatment of neuropathic pain.
Nerve biopsy is useful in (5)
: most useful in inflammatory disorders such as vasculitis, sarcoidosis, CIDP, infectious diseases such as leprosy, or infiltrative disorders such as amyloidosis or tumour
Treatment of neuropathic pain
- Anticonvulsants- Gabapentin, pregabalin, sodium valproate
- Antidepressants- Amitriptyline, duloxetine, venlafaxine
- Opioids- tramadol, morphine, tapentadol
- Capsaicin cream
Anticonvulsants indicated for neuropathic pain.
Gabapentin, pregabalin, sodium valproate
