Parkinsonism and neck extensor myopathy: a new syndrome or coincidental findings?

BACKGROUND Dropped head in parkinsonism has been attributed to dystonia or unbalanced muscle rigidity. To our knowledge, isolated neck extensor myopathy with parkinsonism has been described in only one patient. OBJECTIVES To assess the occurrence of neck extension weakness resulting in dropped head in patients with parkinsonism and to explore whether the head drop might be the consequence of neck extensor myopathy. PATIENTS AND METHODS All patients who were evaluated because of parkinsonism in the Department of Neurology in our hospital between January 1, 1997, and December 31, 1999, and were found to have both parkinsonism and neck extension weakness resulting in head drop were studied. The patients underwent clinical examination, blood tests including the levels of creatine kinase and myoglobin and neurophysiological evaluation with needle electromyography and autonomic tests. Open biopsy on a neck muscle was performed in the patients who could cooperate. RESULTS Of 459 patients evaluated because of parkinsonism, 7 were found to have neck extensor weakness resulting in head drop. Needle electromyography revealed myopathic changes in all 7 patients. Muscle biopsy, which was performed in 5 patients, disclosed myopathic changes in all 5 patients. Electron microscopy revealed mitochondrial abnormalities in 2 of these 7 patients. Three of the patients had concomitant neck rigidity that could contribute to the neck position. All 7 patients had autonomic dysfunction and 6 responded poorly to levodopa therapy, making a diagnosis of multiple system atrophy probable. CONCLUSION Parkinsonism may be associated with isolated neck extensor myopathy resulting in dropped head, and this condition should be suggestive of multiple system atrophy.