Oculomotor function in multiple system atrophy: clinical and laboratory features in 30 patients.
We reviewed the clinical and laboratory oculomotor features in 30 patients with probable multiple system atrophy (MSA), 22 with MSA-P and 8 with MSA-C. Six patients were also examined post mortem, MSA being confirmed in four and excluded in two (Parkinson's disease and progressive supranuclear palsy). Clinical examination showed the following abnormalities; excessive square wave jerks--21 of 30 patients; mild vertical supranuclear gaze palsy--8 of 30; gaze-evoked nystagmus--12 of 30 patients, three of whom had no extraocular evidence of cerebellar dysfunction; positioning downbeat nystagmus--10 of 25; mild or moderate saccadic hypometria--22 of 30; impaired ("broken up") smooth pursuit--28 of 30; reduced VOR suppression--16 of 24. Electro-oculography and caloric testing did not add significant extra information. In patients presenting with an akinetic-rigid syndrome it can be difficult to differentiate idiopathic Parkinson's disease from MSA-P and other causes of atypical parkinsonism. Our findings suggest that the presence of excessive square wave jerks, mild-moderate hypometria of saccades, impaired VOR suppression, spontaneous nystagmus or positioning downbeat nystagmus may be oculomotor "red flags" or clues to the presence of MSA. Further, the presence of clinically slow saccades, or moderate-to-severe gaze restriction, suggests a diagnosis other than MSA.
Anderson
Tim
T
Van Der Veer Institute for Parkinson's and Brain Research, Christchurch, New Zealand.
Luxon
Linda
L
Department of Neuro-otology, The National Hospital for Neurology and Neurosurgery, Queen Square, London, United Kingdom.
Quinn
Niall
N
Sobell Department of Motor Neuroscience and Movement Disorders, Institute of Neurology, Queen Square, London, United Kingdom.
Daniel
Susan
S
Queen Square Brain Bank for Neurological Disorders, Institute of Neurology, Queen Square, London, United Kingdom.
David Marsden
C
C
Van Der Veer Institute for Parkinson's and Brain Research, Christchurch, New Zealand.
Bronstein
Adolfo
A
Department of Neuro-otology, The National Hospital for Neurology and Neurosurgery, Queen Square, London, United Kingdom.|Division of Neurosciences and Mental Health, Medicine, Imperial College, London, United Kingdom.
D001072:Apraxias / Q000175:diagnosis / Q000453:epidemiology; D002150:Caloric Tests; D003937:Diagnosis, Differential; D004585:Electrooculography; D005260:Female; D005403:Fixation, Ocular / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D019578:Multiple System Atrophy / Q000175:diagnosis / Q000453:epidemiology / Q000473:pathology*; D009760:Nystagmus, Physiologic / Q000502:physiology; D015840:Oculomotor Nerve Diseases / Q000453:epidemiology / Q000503:physiopathology*; D010300:Parkinson Disease / Q000175:diagnosis; D012027:Reflex, Vestibulo-Ocular / Q000502:physiology; D012438:Saccades / Q000502:physiology; D012720:Severity of Illness Index; D015837:Vestibular Diseases / Q000453:epidemiology / Q000503:physiopathology