Some Causes of Peripheral Nerve Disorders
Type |
Examples |
Motor neuron diseases |
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Hereditary |
Spinal muscular atrophy types I–IV |
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Acquired diseases that begin suddenly |
Polio, infections due to coxsackievirus or other enteroviruses (rare), and West Nile virus infection |
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Acquired diseases that are chronic |
Amyotrophic lateral sclerosis (Lou Gehrig disease), paraneoplastic syndromes, postpolio syndrome, and progressive bulbar palsy |
Nerve root disorders |
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Hereditary |
Neurofibromas (soft, fleshy growths of nerve tissue) |
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Acquired |
A herniated disk, infections, injuries, and metastatic cancer |
Plexus disorders |
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Acquired |
Acute brachial neuritis, autoimmune disorders, damage during delivery in newborns, diabetes mellitus, a hematoma (a pocket of blood), severe injuries (such as those due to high-speed motor vehicle accidents), metastatic cancer, neurofibromatosis (rare), and nerve tumors |
Peripheral nerve disorders |
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Hereditary |
Hereditary neuropathies (such as Charcot-Marie-Tooth disease) |
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Infectious |
In developing countries, diphtheria, leprosy, and parasite infections |
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Inflammatory |
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Ischemic (due to blockage of the blood supply) |
Vasculitis (inflammation of blood vessels) |
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Metabolic |
Amyloidosis, diabetes mellitus, vitamin B deficiencies, undernutrition due to chronic excess consumption of alcohol, and kidney failure |
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Pressure-related (called nerve entrapment syndromes) |
Carpal tunnel syndrome, cubital tunnel syndrome (a type of ulnar nerve palsy), radial nerve palsy, peroneal nerve palsy, and tarsal tunnel syndrome |
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Toxins |
Arsenic, lead, and mercury |
Neuromuscular junction disorders |
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Various |
Botulism in infants, Eaton-Lambert syndrome, myasthenia gravis, and dysfunction caused by exposure to insecticides or nerve gas (such as sarin) or by use of certain drugs |
Muscle disorders* |
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Hereditary |
Duchenne muscular dystrophy, Becker muscular dystrophy, familial periodic paralysis, limb-girdle muscular dystrophy, myotonia congenita (Thomsen disease), and myotonic dystrophy (Steinert disease) |
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Endocrine |
Acromegaly (excessive growth due to overproduction of growth hormone), Cushing syndrome, diabetes mellitus, hyperthyroidism (an overactive thyroid gland), and hypothyroidism (an underactive thyroid gland) |
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Inflammatory |
Infections (usually viral) and polymyositis and dermatomyositis |
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Metabolic |
Lipid and glycogen storage diseases, alcoholism, and hypokalemia (low potassium levels) |
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*Disorders that affect muscle rather than nerves cause muscle weakness, as can peripheral nerve disorders. Doctors do tests to determine whether the cause of weakness is a muscle or a nerve disorder. |
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