Thalamocortical Radiations - Absence Seizures

Absence Seizures

Thalamocortical radiations have been researched extensively in the past due to their relationship with attention, wakefulness, and arousal. Past research has shown how an increase in spike-and-wave activity within the TC network can disrupt normal rhythms involved with the sleep-wakefulness cycle, ultimately causing absence seizures and other forms of epileptic behavior. Burst firing within a part of the TC network stimulates GABA receptors within the thalamus causing moments of increased inhibition, leading to frequency spikes, which offset oscillation patterns . Another study done on rats suggests during spike-and-wave seizures, thalamic rhythms are mediated by local thalamic connections, while the cortex controls the synchronization of these rhythms over extended periods of time. Thalamocortical dysrhythmia is a term associated with spontaneously reoccurring low frequency spike-and-wave activity in the thalamus, which causes symptoms normally associated with impulse control disorders such as obsessive compulsive disorder, Parkinson's disease, attention deficit hyperactivity disorder, and other forms of chronic psychosis . Other evidence has shown how reductions in the distribution of connections of nonspecific thalamocortical systems is heavily associated with loss of consciousness, as can be seen with individuals in a vegetative state, or coma.