Kaplan + Sadock's Synopsis of Psychiatry, 11e

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31.3 Intellectual Disability

Figure 31.3-1 A. young child with Down syndrome. B. A young adult with fragile X syndrome. (Courtesy of L.S. Syzmanski, M.D., and A.C. Crocker, M.D.)

with intellectual disability than in the general population; how- ever, these findings do not elucidate specific diagnoses.

magnetic resonance imaging (MRI) have found high rates of abnormalities in those patients with microcephaly, significant delay, cerebral palsy, and profound disability. Among patients with intellectual disability, neuroimaging is indicated, accom- panying findings that suggest seizures, microcephaly or macro- cephaly, loss of previously acquired skills, or neurologic signs such as dystonia, spasticity, or altered reflexes. Although clinically not diagnostic, neuroimaging studies are currently also utilized to gather data that may eventually uncover biological mechanisms contributing to intellectual disability. Structural MRI, functional MRI (fMRI), and diffusion tensor imaging (DTI) are utilized in current research. For example, current data suggest that individuals with fragile X syndrome

Neuroimaging Neuroimaging studies with populations of intellectually dis- abled patients using either computerized tomography (CT) or

Figure 31.3-3 Two brothers, age 6 and 8 years, with Hunter’s syndrome, shown with their normal older sister. They have had significant devel- opmental delay, trouble with recurrent respiratory infection, and behavioral abnormalities. (Courtesy of L.S. Syzmanski, M.D., and A.C. Crocker, M.D.)

Figure 31.3-2 A 6-year-old girl with Hurler’s syndrome. Her care has involved a class for seriously multihandicapped children, attention to cardiac problems, and special counseling for patients. (Courtesy of L.S. Syzmanski, M.D., and A.C. Crocker, M.D.)