Retrocollis: classification, clinical phenotype, treatment outcomes and risk factors.

Retrocollis (RC) is a form of cervical dystonia (CD) that produces patterned, repetitive muscle contractions that result in neck extension. We performed a review of consecutive CD patients seen in our Division over a 15-year period. Out of 399 CD patients, 59 (14.8%) had features of RC. Pain was very frequently reported among patients ( approximately 80%). RC was frequently associated with neuroleptic exposure (20.3%) and a history of head/neck trauma (23.7%). Of patients injected with botulinum toxin type A, 24.5% reported excellent, 32.1% moderate, 16.9% mild and 24.5% no response to injections. Oral antidystonic medications had limited contribution to symptom relief.