Laboratory evaluation of suspected motor neuron disease: A survey of physicians.

INTRODUCTION

The clinical diagnosis of amyotrophic lateral sclerosis (ALS) relies on exclusion of mimic syndromes, but there are no specific guidelines regarding the extent of laboratory testing required.

METHODS

A survey was sent to 274 physicians listed in the Neuromuscular Section of the American Academy of Neurology. The survey asked how often they order 21 different laboratory tests in patients suspected of having ALS.

RESULTS

Ninety-nine responses were received (36% response rate). Greater than 75% ordered serum creatine kinase, chemistry panel, and thyroid functions often or always. Fewer than 25% tested for serum complement, hexosaminidase A, spinal muscular atrophy, Kennedy disease, heavy metals, or human T-cell lymphotrophic virus often or always. Twelve other tests had intermediate responses.

CONCLUSIONS

There is a lack of consensus among respondents regarding the laboratory evaluation of suspected ALS. Prospective studies are needed to define the diagnostic yield and cost-effectiveness of laboratory testing in this population.