Focal myopathy as a cause of anterocollis in Parkinsonism.

We present a patient with levodopa-responsive Parkinsonism who developed disproportionate anterocollis over a period of 4 to 5 weeks. A neurological evaluation, including EMG and muscle biopsy, demonstrated the presence of a focal myopathy typical of the so-called "dropped head syndrome" or "isolated neck extensor myopathy." Parkinsonian patients presenting with disproportionate anterocollis should be evaluated for focal myopathy, as this may represent one possible cause.