title: Clinical subtypes of anterocollis in parkinsonian syndromes.
abstract: BACKGROUND
  Disproportionate anterocollis is a debilitating condition which occurs in the later stages of parkinsonian syndromes and for which there is no effective therapy. Multiple hypotheses have been proposed to explain its underlying etiology, including myopathy of the cervical extensors, and dystonia of the cervical flexors.
  
  
  METHODS
  We examined the records of 39 patients (8 prospectively) with anterocollis and parkinsonian syndromes to explore demographics, historical and clinical data, findings from electromyography and response to therapies. We classified our patients based on whether or not they were weak on neck extension and also based on primary diagnosis (PD vs atypical parkinsonian syndrome). Demographic, clinical, historical and EMG features are reported for each group.
  
  
  RESULTS
  There were no significant demographic differences between clinical subtypes, or primary diagnosis. Electromyographic (EMG) findings demonstrated myopathic changes in both groups, although they were more prominent in the group which was weak in extension. Historical features were similar between groups except for dopamine agonist use, which was more common in the myopathic subgroup (p=0.02). There were no other significant clinical differences between clinical subtypes or primary diagnosis with the exception that patients with atypical parkinsonian syndromes had more advanced motor symptoms.
  
  
  CONCLUSIONS
  We conclude that anterocollis is a heterogeneous condition in which at least two distinct subtypes exist. Recognizing these subtypes may help guide therapy and future research.
authors: Department of Neurosciences, Division of Neurology, Movement Disorder Program, Medical University of South Carolina, Charleston, SC 29425, USA. revuelta@musc.edu
authors: Gonzalo J
authors: GJ
authors: Revuelta
authors: Michael
authors: M
authors: Benatar
authors: Alan
authors: A
authors: Freeman
authors: Thomas
authors: T
authors: Wichmann
authors: H A
authors: HA
authors: Jinnah
authors: Mahlon R
authors: MR
authors: DeLong
authors: Stewart A
authors: SA
authors: Factor
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D004576:Electromyography / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D020734:Parkinsonian Disorders / Q000150:complications* / Q000175:diagnosis* / Q000503:physiopathology; D011446:Prospective Studies; D012189:Retrospective Studies; D014103:Torticollis / Q000150:complications* / Q000175:diagnosis* / Q000503:physiopathology