Evaluation of neuromuscular symptoms in UK Gulf War veterans: a controlled study.

OBJECTIVES: To determine whether Gulf War veterans with neuromuscular symptoms that included weakness and fatigue had either 1) objective correlates for muscle weakness or fatigue; or 2) any etiologic explanation for such symptoms; and if so, 3) whether such objective measures or etiologic mechanisms were specific to Gulf War service. METHODS: Forty-nine ill Gulf War veterans with more than four neuromuscular symptoms (Gulf-ill) were compared with 26 Gulf-well veterans, 13 symptomatic Bosnian veterans (Bosnia-ill), and 22 symptomatic troops who were not deployed to the Gulf (Era-ill). Quantitative myometry was used to objectively measure weakness and fatigue. Subjects had an ischemic forearm exercise test, a subanaerobic bicycle exercise test, and a muscle biopsy. RESULTS: Quantitative strength and fatigue measures did not correlate with self-perception of weakness or fatigue for any of our groups. No specific muscle biopsy abnormalities were found. There was no defect of adenylate deaminase or glycogenolysis found. Gulf-ill subjects did find the subanaerobic bicycle exercise more effortful and generated significantly higher plasma lactate concentrations compared with Gulf-well subjects. CONCLUSION: Because complaints of weakness and fatigue in unwell servicemen do not correlate with actual weakness or fatigue, explanations for these symptoms must lie outside of the neuromuscular system. Increased lactate production during subanaerobic bicycle exercise reflects mitochondrial inefficiency, but it is unclear whether this reflects mitochondrial damage sustained during Gulf War service or inactivity secondary to ill health.

Neurophysiologic analysis of neuromuscular symptoms in UK Gulf War veterans: a controlled study.

BACKGROUND: UK veterans who were deployed to the Gulf in 1990 to 1991 reported higher prevalence of neuromuscular symptoms. OBJECTIVE: To investigate whether these Gulf War-related symptoms were associated with objective evidence of neuromuscular dysfunction. METHODS: Forty-nine Gulf War veterans with more than four neuromuscular symptoms (Gulf-ill), 26 Gulf-well veterans, 13 symptomatic Bosnian veterans (Bosnia-ill), and 22 symptomatic veterans who were not deployed to the Gulf (Era-ill) underwent detailed neurophysiologic assessment: nerve conduction studies, quantitative sensory and autonomic testing, and concentric needle and single-fiber electromyography (EMG). RESULTS: Nerve conduction studies detected carpal tunnel syndrome in two Gulf-ill, two Gulf-well, one Bosnia-ill, and three Era-ill veterans. Ulnar neuropathy was detected in one Gulf-ill and two Era-ill veterans. However, results of detailed nerve conduction studies of the Gulf-ill veterans were comparable with results observed in the other three groups. Quantitative sensory and autonomic assessments also failed to show any specific abnormalities in the Gulf-ill group. Similarly, quantitative assessment of concentric needle and single-fiber EMG detected no chronic denervation or myopathic changes or any abnormalities of neuromuscular transmission in the Gulf-ill veterans. CONCLUSION: Gulf War-related neuromuscular symptoms are not associated with specific impairments of peripheral nerves, neuromuscular junctions, or skeletal muscles.