TY - JOUR
T1 - Oculomotor abnormalities in myoclonic tremor
T2 - A comparison with spinocerebellar ataxia type 6
AU - Bour, L.J.
AU - van Rootselaar, A.F.
AU - Koelman, J.H.T.M.
AU - Tijssen, M.A.J.
PY - 2008/9
Y1 - 2008/9
N2 - In the present study, eye movements are recorded in two patient groups with an autosomal dominantly inherited cerebellar disorder, i.e. spinocerebellar ataxia type 6 (SCA6) and familial cortical myoclonic tremor with epilepsy (FCMTE). In SCA6 and FCMTE patients striking similarities with the extensive Purkinje cell changes in the cerebellar cortex were described, but the two disorders have a distinctive clinical picture. SCA6 is a late-onset cerebellar syndrome, with relatively minimal brain stem and cerebral cortex symptoms. In contrast, FCMTE is clinically characterized by cortical symptomatology with a distal cortical myoclonic tremor and infrequent epileptic attacks without cerebellar dysarthria and limb ataxia. Comparison of oculomotor function of six FCMTE patients, five SCA6 patients and 18 healthy controls demonstrated both in SCA6 patients and FCMTE patients square wave jerks, downbeat nystagmus (DBN) and a stronger reduced downward smooth pursuit gain than an upward smooth pursuit gain. Only in SCA6 patients horizontal smooth pursuit gain was reduced. Except for the downward direction mean saccadic gain in both patient groups was reduced. This is consistent with cerebellar cortical pathology in both disorders. Subsequently, both patient groups showed increase of DBN with hyperventilation. As a novel finding, only the FCMTE patients showed a significantly increased amount of express saccades in the pro-saccade paradigm.
AB - In the present study, eye movements are recorded in two patient groups with an autosomal dominantly inherited cerebellar disorder, i.e. spinocerebellar ataxia type 6 (SCA6) and familial cortical myoclonic tremor with epilepsy (FCMTE). In SCA6 and FCMTE patients striking similarities with the extensive Purkinje cell changes in the cerebellar cortex were described, but the two disorders have a distinctive clinical picture. SCA6 is a late-onset cerebellar syndrome, with relatively minimal brain stem and cerebral cortex symptoms. In contrast, FCMTE is clinically characterized by cortical symptomatology with a distal cortical myoclonic tremor and infrequent epileptic attacks without cerebellar dysarthria and limb ataxia. Comparison of oculomotor function of six FCMTE patients, five SCA6 patients and 18 healthy controls demonstrated both in SCA6 patients and FCMTE patients square wave jerks, downbeat nystagmus (DBN) and a stronger reduced downward smooth pursuit gain than an upward smooth pursuit gain. Only in SCA6 patients horizontal smooth pursuit gain was reduced. Except for the downward direction mean saccadic gain in both patient groups was reduced. This is consistent with cerebellar cortical pathology in both disorders. Subsequently, both patient groups showed increase of DBN with hyperventilation. As a novel finding, only the FCMTE patients showed a significantly increased amount of express saccades in the pro-saccade paradigm.
KW - Downbeat nystagmus
KW - Express saccades
KW - Myoclonic tremor
KW - SPEM
KW - Spinocerebellar ataxia
UR - http://www.scopus.com/inward/record.url?scp=50849117509&partnerID=8YFLogxK
U2 - 10.1093/brain/awn177
DO - 10.1093/brain/awn177
M3 - Article
C2 - 18687731
AN - SCOPUS:50849117509
SN - 0006-8950
VL - 131
SP - 2295
EP - 2303
JO - Brain
JF - Brain
IS - 9
ER -