Varied electrophysiologic patterns in spinocerebellar ataxia type 2

Area of Science:

• Neuroscience
• Genetics
• Neurology

Background:

• Autosomal dominant ataxias are a diverse group of neurological disorders.
• Spinocerebellar ataxia type 2 (SCA2) is one such inherited condition.
• Previous studies indicated SCA2 primarily involves sensory nerves.

Purpose of the Study:

• To investigate potential motor nerve involvement in Spinocerebellar ataxia type 2 (SCA2).
• To determine if electrophysiologic testing reveals motor neuron or nerve involvement in SCA2.
• To characterize the spectrum of electrophysiologic findings in genetically confirmed SCA2 cases.

Main Methods:

• Retrospective review of historic and electrophysiologic data.
• Analysis of nerve conduction studies and needle electromyography in SCA2 patients.
• Inclusion of six genetically confirmed, unrelated SCA2 cases.

Main Results:

• Electrophysiologic findings in SCA2 were varied.
• Three patients showed motor neuronopathy or neuropathy without sensory involvement.
• One patient had pure sensory neuropathy, one had normal results, and one had mixed sensorimotor neuropathy.

Conclusions:

• Electrophysiologic findings in SCA2 are not exclusively sensory.
• Isolated motor neuron and/or axon involvement can occur in SCA2.
• SCA2 electrophysiologic results can mimic slowly progressive motor neuron diseases.