Neurotransmitters cognitive impairment

Antiepileptics Na+, Ca2+ channels GABA receptors l Na+currents l Ca2+ currents GABA receptor activity l Excitability of peripheral and central neurons l Release of excitatory neurotransmitters Sedation, dizziness, cognitive impairment, ataxia, hepatotoxicity, thrombocytopenia... 

In DLB, fluctuations in both the level of consciousness and in the content of consciousness (hallucinations and delusions) develop. These alterations, together with much of the ensuing cognitive impairment, fluctuate to such an extent that patients can transiently return to being symptom-free in the course of the disease. This temporal pattern implicates functional as opposed to structural neuropathological abnormalities in symptom aetiology. Several neurotransmitter correlates have been identified in autopsy tissue from retrospectively, and more recently, prospectively assessed patients. 

Tourette s syndrome is a well-studied condition, characterized by motor and phonic tics and by behavioral and psychological problems. While many neurotransmitters were implicated in the etiology of this disorder, it is now believed that the dopaminergic system and noradrenergic systems are involved. Two major clinical trials (Shapiro et ah, 1989 Sallee et al, 1997) indicated that haloperidol and pimozide reduced the severity of tics by 65%. However, these medications are associated with side effects (including possible cognitive impairment, sedation, dysphoria, and tardive dyskinesia) that may limit their effectiveness in children with MR. 

This chapter is concerned with the neurochemical basis of developmental disability which is considered here in two forms the globally delayed or halted development seen in mental retardation, and the more circumscribed pattern of disordered development of autism. A range of deficits of important key aspects of consciousness are apparent in both conditions. Of particular relevance to consciousness are the cognitive and behavioural impairments in attention, concentration, memory, information processing and social behaviour which are commonly present. Consideration of aberrant neurotransmitter activities in these developmental deficits may provide insights into the role of neurotransmitters in consciousness. 

---