At the top of any UK/US list of causes must be diabetes and alcohol, worldwide think leprosy
Different forms | Comments |
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Wallerian Degeneration | The nerve for one reason or other is transected. There is both a myelin and axonal type neuropathy. The nerve distal to the injury dies off and must regrow proximal to distal usually with variable success
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Axonal degeneration | Usually toxic, metabolic, nutritional. The largest and longest nerves are the most vulnerable. Tends to the affected distal nerve first and the nerve dies back. Consider diabetes as the commonest cause or toxins.
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Demyelination | Loss of myelin with preservation of the axon. Can be patchy with the early loss of reflexes. Can be due to Schwann cell damage or an attack on the myelin sheath. Examples include GBS and CIDP.
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Neuronal cell body disease | Anterior horn cell e.g. Polio Motor weakness or motor neuron disease or some paraneoplastic syndromes |
Dorsal root ganglion | sensory loss affected in paraneoplastic disease and Sjogren's syndrome
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Different patterns | Comments |
Polyneuropathy | often synonymous with peripheral neuropathy with a distal glove and stocking sensory and/or distal motor loss. These can be axonal like Diabetes where the neuronal cell body is intact. Alternatively, there are diseases where the primary pathology is demyelination. In some, the cell body is affected e.g. Polio and MND. The commonest causes are diabetes and pre-diabetes, B12/folate deficiency, alcohol, Lyme disease. Comprehensive list. |
Mononeuropathy | single nerve affected. Diphtheria and Diabetes and nerve compression |
Mononeuritis multiplex | several different nerves affected simultaneously or sequentially. Vasculitis |
Autonomic neuropathy | affects the non-voluntary, non-sensory nerves. Diabetes, Amyloidosis, Porphyria, Paraneoplastic neuropathy, Lymphoma, Heavy metals, Thiamine deficiency
Vincristine toxicity, GBS, Alcoholic neuropathy
Acute Pan dysautonomia |
Abrupt onset | Ischaemic neuropathies, PAN, RA, Diabetes (Cranial and amyotrophy), Nerve compression, HIV/AIDS |
Cranial nerves | Often bilateral LMN VII : Diabetes mellitus
GBS, HIV/AIDS, Lyme disease, Sarcoidosis, Neoplastic invasion of skull base or meninges, Diphtheria
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Causes of Peripheral neuropathy | Comments |
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Diabetes Mellitus (axonal) | Symmetrical distal sensory loss, Autonomic |
Alcohol | Distal, symmetric axonal sensorimotor neuropathy. May be painful. |
Rheumatoid arthritis | Distal motor and sensory symmetrical neuropathy |
Systemic Lupus erythematosus | Distal motor and sensory symmetrical neuropathy |
Paraneoplastic (axonal) | Lymphoma, Pure sensory neuropathies, autonomic, Motor neuropathy |
B12 deficiency (axonal) | Mainly proprioceptive loss and loss of ankle jerks, Symmetrical distal sensory loss |
Vasculitis (axonal) | Distal motor and sensory symmetrical neuropathy |
Uraemia | Often in those on renal replacement therapy |
Cisplatinum | Symmetrical distal loss |
Guillain-Barré Syndrome | Distal motor and sensory symmetrical neuropathy, autonomic, Bilateral LMN VIIth. Elevated CSF protein |
CIDP (demyelinating) | Distal motor and sensory symmetrical neuropathy, Bilateral LMN VIIth. Elevated CSF protein |
HMSN 1 (demyelinating) and HMSN 2 (axonal) | |
Amyloid | Autonomic, Distal sensorimotor |
Paraprotein related | Screen for myeloma, MGUS or other haematological malignancies |
B1 deficiency | Pure sensory neuropathies |
Folate deficiency | Pure sensory neuropathies |
B6 deficiency and excess | |
Porphyria | Autonomic |
Lead | |
Isoniazid | |
Vincristine | Pure sensory neuropathies |
Toxins (axonal) | |
Diphtheria | |
Sarcoid | |
CMT | Distal symmetrical sensory and motor |
Lyme disease | Bilateral LMN VIIth |
Leprosy (axonal) | Nerve thickening |
HIV (demyelinating/axonal) | Symmetrical distal. Medications used to treat HIV infection also cause a distal symmetric axonal sensorimotor neuropathy. |
MMN | |
Motor neurone disease | Asymmetrical LMN motor weakness |