Cervical dystonia mimicking dropped-head syndrome after radiotherapy for laryngeal carcinoma.

We report a case of cervical dystonia mimicking dropped-head syndrome (DHS) in a 57-year-old man treated for laryngeal carcinoma by radiotherapy (74.4 Gy) 3 months before. Cervical computerized tomographic scan and magnetic resonance imaging (MRI) did not find any muscle fat changes but found a high-intensity signal on T2 weighted images in the cervical spinal cord. Clinical and electromyographic findings were consistent with cervical dystonia. A trapezius biopsy was normal. Spontaneous remission of the dystonia was observed for 1 month whereas the laryngeal carcinoma progressed. The link between cervical dystonia and radiotherapy might be acute radiation-induced damage to the cervical spinal cord.