BACKGROUND Pilocytic astrocytoma (PA) is the most prevalent central nervous system (CNS) tumor in pediatric population and accounts for an approximate of 5-6% of all gliomas. This neoplasm can occur at all levels of the neuraxis, with majority (67%) arising in the cerebellum and optic pathway. PAs are World Health Organization Grade I tumors and are the most benign of all astrocytomas character...

We studied the effect of cerebellar lesions on the 3-D control of the rotational vestibuloocular reflex (RVOR) to abrupt yaw-axis head rotation. Using search coils, three-dimensional (3-D) eye movements were recorded from nine patients with cerebellar disease and seven normal subjects during brief chair rotations (200 degrees /s(2) to 40 degrees /s) and manual head impulses. We determined the a...

In the past years, claims of cognitive and attentional function of the cerebellum have first been raised but were later refuted. One reason for this controversy might be that attentional deficits only occur when specific cerebellar structures are affected. To further elucidate this matter and to determine which cerebellar regions might be involved in deficits of covert visual attention, we used...

BACKGROUND Cerebellar involvement in spatial data management has been suggested on experimental and clinical grounds. OBJECTIVE To attempt a specific analysis of visuospatial abilities in a group of subjects with focal or atrophic cerebellar damage. METHODS Visuospatial performance was tested using the spatial subtests of the WAIS, the Benton line orientation test, and two tests of mental r...

It is widely accepted that the cerebellum acquires and maintain internal models for motor control. An internal model simulates mapping between a set of causes and effects. There are two candidates of cerebellar internal models, forward models and inverse models. A forward model transforms a motor command into a prediction of the sensory consequences of a movement. In contrast, an inverse model ...

The relationship between cerebellar function and reading abilities is unclear. One theory of developmental dyslexia implicates the cerebellum in this reading disorder. Neuroimaging studies in normal readers consistently show cerebellar activation in tasks that involve reading. However, neuropsychological evidence for a relationship between cerebellar function and skilled reading is sparse. To f...

We use the generalized singular value decomposition (GSVD), formulated as a comparative spectral decomposition, to model patient-matched grades III and II, i.e., lower-grade astrocytoma (LGA) brain tumor and normal DNA copy-number profiles. A genome-wide tumor-exclusive pattern of DNA copy-number alterations (CNAs) is revealed, encompassed in that previously uncovered in glioblastoma (GBM), i.e...

OBJECTIVE Although gemistocytic astrocytomas are graded as World Health Organization II astrocytomas, they behave more aggressively than other astrocytomas. Their proliferative potential is low, and it remains an intriguing question why these tumors are so biologically "successful." They show a high mutation rate of the P53 gene, cytological abnormalities, and frequent perivascular mononuclear ...