title: Downbeating nystagmus and muscle spasms in a patient with glutamic-acid decarboxylase antibodies.
abstract: OBJECTIVE
  To report the ophthalmic findings and response to treatment in a patient with glutamic-acid decarboxylase antibodies.
  
  
  METHODS
  Case report.
  
  
  METHODS
  A 55-year-old woman developed progressive, painful, low back muscle spasms, vertical diplopia, downbeating nystagmus, and asymmetric appendicular ataxia.
  
  
  RESULTS
  Downbeating nystagmus was present in primary gaze with an alternating skew deviation in lateral gaze. Serum and cerebrospinal fluid GAD antibodies were detected. Treatment with diazepam led to resolution of spasticity, whereas repeated courses of intravenous immunoglobulin improved cerebellar function, including appendicular ataxia and downbeating nystagmus.
  
  
  CONCLUSIONS
  Patients with GAD antibodies may have elements of both Stiff-person syndrome (muscle rigidity and spasms) and prominent cerebellar dysfunction. Treatment with diazepam rapidly improved Stiff-person symptoms, whereas IVIg was partially effective at the early stage of cerebellar dysfunction.
authors.affiliation: Department of Neurology, Hospital of the University of Pennsylvania, Philadelphia, PA 19104, USA. beau.ances@uphs.upenn.edu
authors.forename: Beau M
authors.initials: BM
authors.lastname: Ances
authors.forename: Josep O
authors.initials: JO
authors.lastname: Dalmau
authors.forename: Jean
authors.initials: J
authors.lastname: Tsai
authors.forename: M Josh
authors.initials: MJ
authors.lastname: Hasbani
authors.forename: Steven L
authors.initials: SL
authors.lastname: Galetta
mesh_terms: D001323:Autoantibodies / Q000097:blood* / Q000134:cerebrospinal fluid; D003975:Diazepam / Q000627:therapeutic use; D004172:Diplopia / Q000150:complications / Q000175:diagnosis / Q000188:drug therapy; D004359:Drug Therapy, Combination; D005260:Female; D005968:Glutamate Decarboxylase / Q000276:immunology*; D006801:Humans; D016756:Immunoglobulins, Intravenous / Q000627:therapeutic use; D008775:Methylprednisolone / Q000627:therapeutic use; D008875:Middle Aged; D009125:Muscle Relaxants, Central / Q000627:therapeutic use; D009127:Muscle Rigidity / Q000150:complications / Q000175:diagnosis / Q000188:drug therapy; D018482:Muscle, Skeletal / Q000473:pathology*; D009759:Nystagmus, Pathologic / Q000150:complications* / Q000175:diagnosis / Q000188:drug therapy; D013035:Spasm / Q000150:complications* / Q000175:diagnosis / Q000188:drug therapy; D016750:Stiff-Person Syndrome / Q000150:complications* / Q000175:diagnosis / Q000188:drug therapy
chemical_list: D001323:Autoantibodies; D016756:Immunoglobulins, Intravenous; D009125:Muscle Relaxants, Central; D005968:Glutamate Decarboxylase; D003975:Diazepam; D008775:Methylprednisolone