Functional MRI Measures of the Cerebellar Vermis in Childhood ADHD
Vermis: a midline region of the cerebellum.
The Vermis and ADHD?
Clinical Signs in ADHD
Objective Measures of Hyperactivity
PPT Slide
Functional MRI of methylphenidate effects
BOLD (Blood Oxygen Level Dependence) fMRI
T2 Relaxometry
ROIs (regions of interest)
RESULTS: A significant dose-dependent resting blood flow decrease was observed only in the vermis [F 3,21 = 5.123, p< .01]. Trend analysis supported a dose-dependent linear decline of blood flow (reflected in elevated T2 values) in the vermis [F 1,27 = 13.676, p< .001].
Dose-Dependent Changes in T2
RESULTS: Objective measures of attention and activity collected within 1 - 3 hours of methylphenidate adminstration exhibited significant dose-dependent effects that paralled vermal blood flow alterations.
RESULTS: -Movements or "micro events" during the CPT were dose-dependently inhibited. -The complexity of temporal patterns of movement were dose-dependently increased during the CPT, indicative of lower activity.
Behavior vs. Vermial T2
RESULTS: -The SD of CPT performance was significantly lowered in a dose-dependent fashion, indicating an association between attention and vermal blood flow.
Other ROIs (regions of interest)
The Vermis and Behavior (un-medicated)
The Vermis and Behavior (medicated)
CONCLUSIONS AND SPECULATIONS: Lower blood flow in the cerebellar vermis is associated with reductions in inattention, hyperactivity and impulsivity in objectively hyperactive children. Psychopharmacological theories of stimulant action in ADHD may need to be reevaluated in light of the emerging role of the cerebellum in the developmental pathophysiology of this disorder.
CONCLUSIONS AND SPECULATIONS: Abnormal vermal blood flow or metabolism is associated with psychiatric symptoms in ADHD, Early Child Abuse, Bipolar Disorder, PTSD, and schizophrenia. The vermis may function in motor and emotional coordination through bihemispheric influences on dopamine release in the basal ganglia, amygdala and accumbens (Snider and Maiti 1976; Supple and Kapp 1994) via fastigial nucleus projections (Heath and Harper 1974) to pontine and mesencephalic and hypothalamic nuclear groups .
Developmental Biopsychiatry Program at McLean Hospital Steve B. Lowen Ann Polcari Cindy E. McGreenery Luis C. Maas Perry F. Renshaw Martin H. Teicher
Cortical projections to the cerebellum
The Vermis and Behavior
Email: carl_anderson@hms.harvard.edu
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