Electromyography (EMG) and Nerve Conduction Study (NCS) Case Bank

The patient is a 31 year old female with a history of Charcot Marie Tooth (CMT).

This is an abnormal study, with electrodiagnostic evidence of a sensorimotor demyelinating polyneuropathy.  Active axon loss is not found, but chronic denervation is recorded in distal muscles of the leg. These findings are most consistent with a CMT1A gene mutation. 

Patient is a 48 year old male with a history of lower extremity weakness:

This is an abnormal study with electrodiagnostic evidence of moderate length-dependent sensorimotor dysmyelinating polyneuropathy. These types of findings are most commonly seen in patients with CMT1A phenotypes. 

61-year-old female referred for evaluation of CMT:

This is an abnormal study with electrodiagnostic evidence of sensorimotor mixed polyneuropathy with uniform slowing. This pattern of neuropathy can be seen with hereditary neuropathies like CMT1X, CMT1B and 1A.

The patient is a 71 year old male with a history of mild ankle weakness and balance issues for the last 6 years. A few of his siblings and father had the same symptoms. On exam he has high arches and hammertoes.

This EMG showed evidence of a severe sensorimotor axonal polyneuropathy. EMG showed evidence of acute and chronic denervation. Given his exam and family history, this is most likely an inherited neuropathy, likely CMT type 2.

The patient is a 56 year old female with painful paresthesias for the last several years. She endorses a family history of similar symptoms in many family members.

This is an abnormal study with electrodiagnostic evidence of severe, axonal, length dependent sensorimotor polyneuropathy.  Given the prominence of family history, these findings are suggestive of genetic polyneuropathy, such as CMT type 2.