Peripheral Neuropathy Dr. Mohammad Tanvir Islam

Nervous System • CNS• PNS

Loss of function“- symptoms”

Disturbed function“+ symptoms”

Motor nerves WastingHypotoniaWeaknessHyporeflexiaOrthopedic deformity

FasiculationsCramps

The clinical response to motor nerve injury

www.neuro.wustl.edu/neuromuscular/pics/people/patients/Hands/handatrophymnd3.jpg

Loss of function“- symptoms”

Disordered function“+ symptoms”

Sensory “Large Fiber”

↓ Vibration↓ ProprioceptionHyporeflexiaSensory ataxia

Paresthesias

Sensory “Small Fiber”

↓ Pain↓ Temperature

DysesthesiasAllodynia

The clinical response to sensory nerve injury

Loss of function“- symptoms”

Disturbed function“+ symptoms”

Autonomic nerves ↓ SweatingHypotensionUrinary retentionImpotenceVascular color changes

↑ Sweating Hypertension

The clinical response to autonomic nerve injury

http://www.neuro.wustl.edu/neuromuscular/nother/skel.html#nosteo

The two types of peripheral neuropathies:axonopathies and myelinopathies

Causes Conditions causing mononeuropathy

• Acute (trauma-related)• Chronic (nerve entrapment)

Disorders causing mononeuropathy multiplexAcute

• Diabetes mellitus• Multifocal motor neuropathy• Vasculitic syndromes

Chronic• Acquired immunodeficiency syndrome• Leprosy• Sarcoidosis

Causes Conditions causing neuropathy with autonomic features• Alcoholism• Amyloidosis• Chemotherapy-related neuropathy• Diabetes• Heavy metal toxicity• Porphyria• Vitamin B12 deficiency

Causes Conditions causing painful neuropathy• Diabetes• Alcoholism• Amyloidosis• Chemotherapy (heavy metal toxicity)• Idiopathic polyneuropathy• Porphyria• Paraneoplastic syndrome

Axonal & Demyelinating causes • Axonal• Diabetes mellitus• Alcohol• Uraemia• Cirrhosis• Amyloid• Myxoedema• Acromegaly• Paraneoplastic• Drugs and toxins• Deficiency states

• Hereditary• Infection • Idiopathic• Demyelinating• Chronic inflammatory demyelinating

polyradiculoneuropathy• Multifocal motor neuropathy• Paraprotein-associated demyelinating

neuropathy• Charcot–Marie–Tooth disease type I and

type X

In short

Inherited: e.g. Charcot-Marie-Tooth disease (HMSN)Infectious: e.g. LeprosyInflammatory: e.g. Guillain Barre syndrome (AIDP)Neoplastic: e.g. Monoclonal gammopathyMetabolic: e.g. DiabetesDrug: e.g. VincristineToxic: e.g. Ethanol

History• The temporal course of a neuropathy varies, based on the etiology.

• Trauma or ischemic infarction-acute, with the most severe symptoms at onset• Inflammatory and some metabolic neuropathies have a subacute course

extending over days to weeks. • A chronic course over weeks to months is the hallmark of most toxic and

metabolic neuropathies

History• A chronic, slowly progressive neuropathy over many years

• Hereditary neuropathies • Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP)

• Neuropathies with a relapsing and remitting course include • CIDP• acute porphyria• Refsum's disease• hereditary neuropathy with liability to pressure palsies (HNPP)• familial brachial plexus neuropathy• repeated episodes of toxin exposure

• Ischemic neuropathies often have pain as a prominent feature

• Small-fiber neuropathies often present with burning pain, lightning-like or lancinating pain, aching, or uncomfortable paresthesias (dysesthesias).

History

• The clinical assessment should include:• Careful past medical history • looking for systemic diseases, eg. CTD

History

• All patients should be questioned regarding • HIV risk factors• diet (nutrition)• vitamin use (especially B6) • possibility of a tick bite (Lyme disease) • Constitutional symtoms (malignancy)

History

Investigations: