Case definition for polyneuropathy developed to standardize research

A new case definition for distal symmetrical polyneuropathy has been developed by the American Academy of Neurology, the American Association of Electrodiagnostic Medicine, and the American Academy of Physical Medicine and Rehabilitation. The definition is published in the January 25 issue of Neurology, the scientific journal of the American Academy of Neurology. This represents a new effort to standardize and facilitate clinical research.

The three organizations initially intended to develop a practice guideline about treatment for polyneuropathy, a noninflammatory nerve disease. The definition of polyneuropathy was inconsistent in available studies, making it impossible to compare the studies and make recommendations for practice. This led to the decision to write a case definition. “Where case definitions have been developed, they have improved clinical research,” said co-author John D. England, MD, of Deaconess Billings Clinic in Billings, Mont.

The author panel evaluated the diagnostic accuracy of the predictors of polyneuropathy and used an extensive literature review and a formal consensus process to develop an approach ranked by the likelihood of disease.

According to the definition, the combination of neuropathic symptoms, signs, and abnormal electrodiagnostic studies provides the most accurate diagnosis of distal symmetrical polyneuropathy. Electrodiagnostic studies are recommended, since they are objective and validate tests of peripheral nerve function. Electrodiagnostic studies should not be used alone to make the diagnosis because their sensitivity and specificity are not perfect.

The case definition will be available for downloading on January 25 at www.aan.com/professionals/practice/guideline/index.cfm.