Rinsho Shinkeigaku (Clinical Neurology)

Symposium 1

Cerebellum and eye movement control
-Neuronal mechanisms of memory-based smooth-pursuit and their early clinical application-

Kikuro Fukushima1), Junko Fukushima2), Norie Ito3), Hidetoshi Takei4), Kunihiro Ikeno4), Peter M Olley1), Susumu Chiba3), Nobuyoshi Kobayashi3), Kiyoharu Inoue3) and Tateo Warabi1)3)

1)Clinical Brain Research Laboratory, Sapporo Yamanoue Hospital
2)Faculty of Health Sciences, Hokkaido University
3)Department of Neurology, Sapporo Yamanoue Hospital
4)Department of Radiology, Sapporo Yamanoue Hospital

Recent studies implicate the cerebellum in cognitive functions in addition to its well-established roles in motor control and learning. Using a memory-based smooth-pursuit task that separates visual working memory from motor preparation and execution, monkeys were trained to pursue (i.e., go) or not pursue (i.e., no-go), a cued direction, based on the working memory of visual motion-direction and a go/no-go instruction. Task-related neuronal activity was examined in cerebral and cerebellar major smooth-pursuit pathways. Different cerebral and cerebellar areas carried distinctly different signals during memory-based smooth-pursuit. In the cerebellum, prediction-related signals (visual working memory, pursuit selection and movement preparation) were represented in the vermal lobules VI-VII and caudal fastigial nucleus, whereas the floccular region (flocculus and ventral paraflocculus) contained predominantly execution-related signals. This task was applied to patients with cerebellar degeneration and idiopathic Parkinson's disease (PD). None of the PD patients tested exhibited impaired working memory of motion-direction and/or go/no-go selection, but they did show task-specific difficulty in generating an initial smooth-pursuit component, suggesting difficulty in smooth-pursuit preparation. In contrast, most cerebellar patients exhibited impaired visual working memory in addition to difficulty in preparing for and executing smoothpursuit. These results suggest different roles for the basal ganglia and cerebellum in smooth-pursuit planning.
Full Text of this Article in Japanese PDF (438K)

(CLINICA NEUROL, 52: 1001|1005, 2012)
key words: Cerebellum, eye movement, planning, working memory, Parkinson's disease

(Received: 23-May-12)