Lateral ventriculomegaly was greater in bipolar disorder patients who had had repeated manic episodes, but it does not appear to be secondary to small critical periventricular structures. A larger than normal striatum, which has been reported in previous studies, was observed in first-episode patients. These results support the importance of prospectively studying neuroanatomic changes in bipolar disorder.

The age-related changes observed in this study provide evidence of increased neuroplasticity of language in this age group and may have implications for further investigations of normal and aberrant language development.

To investigate functional magnetic resonance imaging (fMRI) in pediatric cochlear implantation candidates with residual hearing who are under sedation for evaluation of auditory function. Design: During fMRI, subjects heard a random sequence of tones (250-4000 Hz) presented 10 dB above hearing thresholds. Tones were interleaved with silence in a block-periodic fMRI design with 30-second on-off intervals. Twenty-four axial sections (5 mm thick) covering most of the brain were obtained every 3 seconds for a total acquisition time of 5.5 minutes.

Previous studies have shown evidence of cortical reorganization following unilateral sensorineural hearing loss (USNHL). In addition, subjects with right USNHL have shown greater deficits in academic and language performance compared to subjects with left USNHL. A preliminary functional MRI investigation was performed on a small cohort of subjects, 4 with left USNHL and 4 with right USNHL, using the paradigm of listening to random tones. While the subjects with left USNHL displayed greater activation in the right superior temporal gyrus, the subjects with right USNHL displayed greater activation in the left inferior frontal area immediately anterior to the superior temporal gyrus. The results provide preliminary evidence of disparate neural circuitry supporting auditory processing in subjects with left and right USNHL.