Assessing nerve abnormalities in HSP

A new method for assessing nerve abnormalities in HSPers found that there was no distinctive advantage over standard nerve conduction studies in us.

 

This study involved Dr. Carolyn Sue of Sydney’s Royal North Shore Hospital – known to many of the HSP community as a neurologist and through nasal biopsy sampling for the stem cell research project.

 

OBJECTIVE:

To identify peripheral nerve abnormalities in hereditary spastic paraplegia (HSP) due to mutations in the spastin gene (spastic paraplegia 4, SPG4) using standard nerve conduction (NCS) and novel tests of axonal excitability.

 

METHODS:

Eleven patients with known mutations in spastin were assessed with NCS for the upper and lower limbs, and axonal excitability testing on the median nerve.

 

RESULTS:

Standard nerve conduction studies revealed a sensorimotor neuropathy in two patients. Excitability studies on median motor axons showed an isolated abnormality (increased strength-duration time constant), but those on sensory axons were normal in nine patients with normal routine nerve conduction studies.

 

CONCLUSIONS:

Peripheral neuropathy occurs in HSP patients with SPG4 mutations, but axonal excitability studies provide limited additional evidence for subclinical peripheral nerve dysfunction, and add little further to standard nerve conduction studies.

 

SIGNIFICANCE:

The features of HSP due to SPG4 mutations include sensorimotor polyneuropathy. The value of excitability studies is limited in individual patients.

 

SOURCE:  Clin Neurophysiol. 2011 Dec 21. [Epub ahead of print] Copyright © 2011 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.  PMID: 22192498 [PubMed – as supplied by publisher]

 

Peripheral neuropathy in hereditary spastic paraplegia due to spastin (SPG4) mutation – A neurophysiological study using excitability techniques.

 

Kumar KR, Sue CM, Burke D, Ng K.

 

Department of Neurology and Clinical Neurophysiology, Royal North Shore Hospital, Australia.