Since spontaneous oral dyskinesias are more prevalent in the elderly, and since these movements may be controlled by the balance of brain dopamine D1 and D2 dopamine receptors, we measured the densities of these receptors in 247 postmortem brain striata. In childhood, the densities of D1 and D2 dopamine receptors in the brain striatum rise and fall together. After age 20 years, D1 receptors disappear at 3.2% per decade while D2 receptors disappear at about 2.2% per decade. Overall, therefore, the D1/D2 ratio falls with age. Since perioral motion in rats is dominated by a high D1/D2 ratio, the observed decline in the human D1/D2 ratio with age suggests that the perioral control mechanisms for humans and rats may be different.

Malformations of the cerebral cortex are being recognized more frequently as a cause of epilepsy, developmental delay, neurological deficits, and mental retardation. Nonetheless, a standard nomenclature and classification system of these malformations, based upon state-of-the art knowledge derived from genetics, embryology, imaging, and pathology, has not been devised. In this manuscript, we propose such a classification system. Moreover, we have constructed the system such that both the framework and the classifications themselves are flexible and can be adapted as our knowledge of the embryology, genetics, imaging, and pathology of these disorders advances. We believe that the use of this classification system will help both clinicians and researchers to understand and think about these disorders and their causes better. In turn, we hope that this improved understanding will lead to further refinements in classification, to advances in our knowledge and, ultimately, to improvements in therapy.

The prognostic factors and survival data were analyzed for 35 children (aged under 16 years at diagnosis) with childhood infatentorial ependymomas treated surgically at The Hospital for Sick Children in Toronto during the years 1970 to 1987. Tumor histology was reviewed individually and grouped into three categories (Categories I to III) for survival analysis. An overall 5-year survival rate of 44.6% was obtained after the exclusion of perioperative mortality. Factors associated with an improved 5-year survival rate were: total tumor removal, noninvasive tumors, Category I histology, age greater than 6 years, and absent physical signs of parenchymal invasion or lower cranial nerve involvement. The 5-year survival rate was lower when associated with Category III histology, brain-stem or cranial nerve signs, age less than 2 years, tumor invasion and/or cranial nerve involvement, and subtotal tumor removal. Clinical evidence of spinal metastases was found to be uncommon (3.1%). Surgical excision followed by radiation therapy was the primary mode of treatment for these tumors. Different approaches regarding the volume of radiotherapy to be delivered and the use of adjuvant chemotherapy are discussed.