Unique Distribution of Benzodiazepine Receptors in the Brain during the First Two Years of Life.

BACKGROUND: 123I-iomazenil (IMZ) single-photon emission computed tomography (SPECT) is a tool for evaluating epileptic foci and brain damage. To apply the method to children, information regarding the age-specific expression of benzodiazepine receptors (BDZ-Rs) is required. Unfortunately, there is no information currently available for children <2 years of age. METHODS: We used IMZ SPECT once in infants aged 3-8 months and again at 2 years of age in order to describe the maturational changes in BDZ-R distribution. RESULTS: No neurological deficits were found in any of the infants at the first examination. The BDZ-Rs were more dominantly distributed in the occipital lobe than in the frontal lobe before the age of 2 years. The frontal-occipital gradients of the distribution were obvious in children <8 months of age. Magnetic resonance imaging showed a spreading of myelination toward the frontal lobes simultaneously with BDZ-R expression. CONCLUSION: Information regarding the alteration in the BDZ-R distribution pattern is useful when assessing infantile epilepsy and brain injury. The age-related pattern of BDZ-R distribution could correspond with myelination, cerebral blood flow, metabolism and behavioral development.

Improvement in cognitive function after radical excision of an anterior skull base meningioma--a report of 2 cases.

It has been well documented that memory difficulties in patients with anterior skull base meningioma may improve after tumour resection. However, there have been few reports on studies where precise testing of cognitive function has been conducted before and after surgery. Here we report 2 cases of anterior skull base meningioma where 2 tests of cognitive function, the Wechsler adult intelligence scale-revised (WAIS-R) and the Wechsler memory scale-revised (WMS-R), were performed by the patient before and after surgical treatment. After the operation there was a dramatic increase in the performance IQ as measured by the WAIS-R. In addition, the scores for both the "Attention/Concentration" and the "Delayed Recall" subsets of the WMS-R scale improved. There were differences between the 2 patients in the length of time required for functional recovery and this was thought to be due to the tumour size and the age of the patient. The use of these scales would enable physicians who are treating patients with anterior skull base meningioma to assess the recovery time that is likely to be needed before full return of cognitive function after surgery.