Some Causes of Peripheral Nervous System Disorders

Motor neuron*

Hereditary

Spinal muscular atrophy types 0–4

Acquired, acute

Polio, infections due to coxsackievirus and other enteroviruses (rare), West Nile virus infection

Acquired, chronic

Amyotrophic lateral sclerosis, paraneoplastic syndrome, postpolio syndrome, progressive bulbar palsy

Nerve root

Hereditary

Neurofibromatosis

Acquired

Herniated disk, infections, metastatic cancer, spinal foraminal stenosis, trauma

Plexus

Acquired

Acute brachial neuritis, autoimmune disorders, diabetes mellitus, hematoma, local tumors (eg, schwannoma), metastatic cancer, neurofibromatosis (rare), traction during birth, severe trauma, radiation therapy

Peripheral nerve

Entrapment

Carpal tunnel syndrome, cubital tunnel syndrome, radial nerve palsy, peroneal nerve palsy, tarsal tunnel syndrome

Hereditary

Hereditary adult-onset neuropathies, hereditary sensory and motor neuropathies (eg, Charcot-Marie-Tooth disease), hereditary sensory and autonomic neuropathies

Infectious

Hepatitis C, herpes zoster, HIV infection, Lyme disease, syphilis, SARS-CoV-2

In developing nations: Diphtheria, leprosy, parasite infections

Inflammatory

Chronic inflammatory demyelinating polyradiculoneuropathy, Guillain-Barré syndrome and variants

Ischemic

Femoral nerve infarction (diabetic amyotrophy), vasculitis causing multiple mononeuropathy (mononeuritis multiplex)

Toxic-metabolic

Amyloidosis, diabetes mellitus, dysproteinemic neuropathy, chronic excessive alcohol consumption with undernutrition (particularly deficiency of B vitamins), ICU neuropathy, leukodystrophies (rare), renal insufficiency, toxins (eg, arsenic, lead

Neuromuscular junction

Various

Botulism in infants, congenital myasthenia (very rare), Eaton-Lambert syndrome, myasthenia gravis, toxic or drug-induced neuromuscular junction dysfunction (eg, due to exposure to insecticides or nerve gas, abnormally high magnesium levels, or use of neuromuscular blockers)

Muscle fiber

Dystrophies

Distal muscular dystrophy (late distal hereditary myopathy; rare), Duchenne muscular dystrophy and related dystrophies, fascioscapulohumeral muscular dystrophy, limb-girdle muscular dystrophy, oculopharyngeal dystrophy (rare)

Channelopathies (myotonic)

Familial periodic paralysis, myotonia congenita (Thomsen disease), myotonic dystrophy (Steinert disease)

Congenital

Central core disease, centronuclear myopathy, nemaline myopathy (very rare)

Endocrine

Acromegaly, Cushing syndrome, diabetes mellitus, hypothyroidism, thyrotoxic myopathy

Inflammatory

Infection (viral more than bacterial), polymyositis and dermatomyositis

Metabolic

Acid maltase deficiency, alcoholism, carnitine deficiency, glycogen storage and lipid storage diseases (rare), hypokalemia