Rapid eye movement sleep and neuronal development.

PURPOSE OF REVIEW: To understand the importance of rapid eye movement (REM) sleep in the cognitive and sensorimotor development via neural plasticity during embryonic development and infants. RECENT FINDINGS: REM sleep has remained a mystery as many of the underlying mechanisms of REM sleep remain unclear. Recent findings have demonstrated that REM sleep selectively prunes newly formed dendritic spines in the developing brain as well as strengthening new synapses in the developing brain. This process is critical for normal neuronal circuit development and behavioral improvement after learning. SUMMARY: Although many mechanisms of REM sleep remain unclear, recent findings strongly suggest that REM sleep is vitally important in pruning synapses as well as maintaining new synapses for the development of a healthy brain. Developmental neuroplasticity refers to the continuous change of the developing brain during fetal development. Lack of plasticity may result in reduced intellectual ability, reduced learning and memory consolidation, and mental illness.

Restrictive cerebral cortical venopathy: A new clinicopathological entity.

We present a case of a novel restrictive cerebral venopathy in a child, consisting of a bilateral network of small to medium cortical veins without evidence of arteriovenous shunting, absence of the deep venous system, venous ischemia, elevated intracranial pressure, and intracranial calcifications. The condition is unlike other diseases characterized by networks of small veins, including cerebral proliferative angiopathy, Sturge-Weber syndrome, or developmental venous anomaly. While this case may be the result of an anatomic variation leading to the congenital absence of or early occlusion of the deep venous system, the insidious nature over many years argues against this. The absence of large cortical veins suggests a congenital abnormality of the venous structure. The child's presentation with a seizure-like event followed by protracted hemiparesis is consistent with venous ischemia. We propose that this is likely to represent a new clinicopathological entity.