Charcot-Marie-Tooth and Other Hereditary Motor and Sensory Neuropathies Differential Diagnoses

Updated: May 22, 2018
  • Author: Timothy C Parsons, MD; Chief Editor: Nicholas Lorenzo, MD, MHA, CPE  more...
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DDx

Diagnostic Considerations

The differential diagnosis of neuropathy is wide. A positive family history makes CMT likely, and a pedigree can help elucidate the inheritance pattern, which can narrow the differential diagnosis between CMT subtypes. Nerve conduction velocities, in most cases, can separate CMT1 (very slow) from CMT2 (mildly slow to normal).

It is essential to separate the demyelinating forms of CMT from acquired, potentially treatable demyelinating neuropathies. Uniform conduction slowing is seen in CMT1, whereas in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and other immune-mediated neuropathies, conduction velocity varies between segments in the same nerve and different nerves. The Guillain-Barre syndrome has similar electrodiagnostic findings to CIDP but the rapidity of onset that defines the disease should prevent confusion.

Other inherited neuropathic syndromes, such as Friedreich Ataxia and Spinal Muscular Atrophy, can be confused with CMT or have overlapping features.

Other causes of acquired neuropathy should not be overlooked. Neuropathy may be due to diabetes mellitus or other metabolic/nutritional causes, drugs of abuse such as alcohol, neurotoxic medications, infections (including leprosy, which may cause thickened, palpable nerves), compression, or vasculitis, among others.

Myopathies and muscular dystrophies can be clinically confused with CMT in some cases.