title: Cerebellar Contribution to Pattern Separation of Human Hippocampal Memory Circuits.
abstract: The cerebellum is a crucial structure for cognitive function as well as motor control. Benign brain tumors such as schwannomas, meningiomas, and epidermoids tend to occur in the cerebellopontine angle cisterns and may cause compression of the posterior lateral cerebellum near the superior posterior fissure, where the eloquent area for cognitive function was recently identified. The present study examined cognitive impairment in patients with benign cerebellar tumors before and after surgical intervention in order to clarify the functional implications of this region in humans. Patients with cerebellar tumors showed deficits in psychomotor speed and working memory compared with healthy controls. Moreover, these impairments were more pronounced in patients with right cerebellar tumors. Functional magnetic resonance imaging during performance of a lure task also demonstrated that cerebellar tumors affected pattern separation or the ability to distinguish similar experiences of episodic memory or events with discrete, non-overlapping representations, which is one of the important cognitive functions related to the hippocampus. The present findings indicate that compression of the human posterior lateral cerebellum affects hippocampal memory function.
authors.affiliation: Department of Neurosurgery, Graduate School of Medicine, University of the Ryukyus, 207 Uehara, Nishihara-machi, Nakagami-gun, Okinawa, 903-0215, Japan.
authors.forename: Ayano
authors.initials: A
authors.lastname: Shiroma
authors.affiliation: Department of Neurosurgery, Graduate School of Medicine, University of the Ryukyus, 207 Uehara, Nishihara-machi, Nakagami-gun, Okinawa, 903-0215, Japan.
authors.forename: Masahiko
authors.initials: M
authors.lastname: Nishimura
authors.affiliation: Department of Neurosurgery, Graduate School of Medicine, University of the Ryukyus, 207 Uehara, Nishihara-machi, Nakagami-gun, Okinawa, 903-0215, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Nagamine
authors.affiliation: Department of Neurosurgery, Graduate School of Medicine, University of the Ryukyus, 207 Uehara, Nishihara-machi, Nakagami-gun, Okinawa, 903-0215, Japan.
authors.forename: Tomohisa
authors.initials: T
authors.lastname: Miyagi
authors.affiliation: Department of Neurosurgery, Graduate School of Medicine, University of the Ryukyus, 207 Uehara, Nishihara-machi, Nakagami-gun, Okinawa, 903-0215, Japan.
authors.forename: Yohei
authors.initials: Y
authors.lastname: Hokama
authors.affiliation: Department of Neurosurgery, Graduate School of Medicine, University of the Ryukyus, 207 Uehara, Nishihara-machi, Nakagami-gun, Okinawa, 903-0215, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Watanabe
authors.affiliation: Department of Radiology, Graduate School of Medicine, University of the Ryukyus, 207 Uehara, Nishihara-machi, Nakagami-gun, Okinawa, 903-0215, Japan.
authors.forename: Sadayuki
authors.initials: S
authors.lastname: Murayama
authors.affiliation: Department of Pharmacology, Graduate School of Medicine, University of the Ryukyus, 207 Uehara, Nishihara-machi, Nakagami-gun, Okinawa, 903-0215, Japan.
authors.forename: Masato
authors.initials: M
authors.lastname: Tsutsui
authors.affiliation: Okinawa Study Center, The Open University of Japan, 1Senbru, Nishihara, Okinawa, 903-0219, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Tominaga
authors.affiliation: Department of Neurosurgery, Graduate School of Medicine, University of the Ryukyus, 207 Uehara, Nishihara-machi, Nakagami-gun, Okinawa, 903-0215, Japan. ishogo@med.u-ryukyu.ac.jp.
authors.forename: Shogo
authors.initials: S
authors.lastname: Ishiuchi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001931:Brain Mapping; D002528:Cerebellar Neoplasms / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000601:surgery; D002531:Cerebellum / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000601:surgery; D003072:Cognition Disorders / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology* / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D007839:Functional Laterality; D006624:Hippocampus / Q000000981:diagnostic imaging / Q000503:physiopathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009434:Neural Pathways / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery; D009483:Neuropsychological Tests; D010364:Pattern Recognition, Visual / Q000502:physiology; D011184:Postoperative Period; D057234:Preoperative Period; D011930:Reaction Time / Q000502:physiology; D012146:Rest; D055815:Young Adult
keywords: Brain tumor; Cognitive function; Hippocampus; Memory; Posterior lateral cerebellum; fMRI