Cerebellar volume in adults with Down syndrome
E. H. Aylward, R. Habbak, A. C. Warren, M. B. Pulsifer, P. E. Barta, M. Jerram and G. D. Pearlson
Division of Psychiatric Neuroimaging, Johns Hopkins University School of Medicine, Baltimore, Md, USA.
OBJECTIVES: To determine the effects of aging on cerebellar volume in
individuals with Down syndrome (DS). To determine whether volume of
cerebellum is associated with dementia or with age-related decline in
fine-motor control. DESIGN: Case-control study involving comparison of
cerebellar volumes in adults with DS and matched control subjects; survey
study involving correlations between cerebellar volume and subjects' age
and performance on a test of fine motor control; and longitudinal study
assessing change in cerebellar volume in adults with DS. SETTING: The Johns
Hopkins University School of Medicine, Baltimore, Md. PATIENTS AND OTHER
PARTICIPANTS: Subjects included 40 adults with DS. Thirty of them were
matched on age, sex, and race with cognitively normal subjects. A diagnosis
of probable dementia was made for 5 of the subjects with DS. Longitudinal
data were available for 23 of the 40 subjects with DS, with a mean
interscan interval of 2 years. MAIN OUTCOME MEASURES: Volumes of
cerebellum, total brain, and intracranial region were measured on magnetic
resonance imaging scans. The Purdue Pegboard, a test of fine-motor control,
was administered to 38 of the subjects with DS. RESULTS: Subjects with DS
had significantly smaller cerebellar volumes than matched controls, even
after adjusting for total brain volume or total intracranial volume. Volume
of cerebellum did not correlate significantly with age for either the
subjects with DS or controls. Longitudinal change in cerebellar volume in
subjects with DS was not significant. Volume of total brain, but not
cerebellum, correlated significantly with performance on the Purdue
Pegboard. CONCLUSIONS: Although cerebellar volumes are disproportionately
small in individuals with DS, they do not diminish significantly with age
and do not undergo age-related atrophy that is different from that of
normal controls. Volume reduction in the cerebellum does not appear to be
specifically responsible for the age-related decline in fine-motor control
that is observed in adults with DS.
