Treatable dropped head syndrome in hypothyroidism.

Abstract

Neck extensor weakness resulting in dropped head is more often a part of a generalized neuromuscular disorder such as MG, ALS, or polymyositis. The term “dropped head syndrome” (isolated neck extension myopathy) usually refers to a condition characterized by severe weakness of the neck extensors in the absence of a generalized neuromuscular disorder and may be due to a restricted noninflammatory myopathy.1,2⇓ In such a case, there may, in fact, be additional weakness affecting periscapular, shoulder, and thoracic muscles or even more extensive distribution of weakness—“dropped head plus syndrome.”3 Hypothyroidism is often accompanied by a myopathy with proximal distribution.4 In 1880, William M. Ord described a woman with myxedema who had, among many other symptoms, head drop.5 There are, to our knowledge, no reports in the literature on isolated neck extensor weakness caused by hypothyroidism. We report a case of hypothyroidism presenting as an isolated dropped head syndrome, which subsided almost completely during treatment with levothyroxine. A 53-year-old man presented with a 4-year history of slowly progressive neck weakness and pain in the neck. He had “head drop” while sitting and standing and had noticed that his posterior neck muscles had increased in volume. For 6 months, he had also experienced a slight weakness in the arms and legs. His local neurologist had assessed the …