Neuropeptides are endogenous substances present in nerve cells and involved in nervous system functions. Neuropeptides are synthetized in large precursor proteins and several are formed in the same precursor. Neuropeptides affect learning and memory processes, social, sexual and maternal behavior, pain and addiction, body temperature, food and water intake e.a. In addition, neuropeptides possess trophic influences on the nervous system, neuroleptic-like andpsychostimulant-like activities. Disturbances in classical neurotransmitter activity as found in Parkinson's disease, psychoses, and dementia, may also be caused by disturbances in neuropeptide activity. In fact, alterations in the concentration of a number of neuropeptides in schizophrenia, depression, and dementia have been found.

Much work has been done during the last decade on the influence of neuropeptides in schizophrenia, autism, depression, and in various disorders associated with memory disturbances. These studies concern neuropeptides related to adrenocorticotropic hormone (ACTH) and melanocyte stimulating hormone (MSH), vasopressin- and endorphin-type neuropeptides, thyrotropic releasing hormone (TRH), and the C-terminal part of oxytocin Pro-Leu-Gly-NH2 (PLG). Several of these exert positive effects but in not more than 25% the response is clinically relevant. This may have to do with the severity of the disease and its chronicity. The modest effects may also be caused by the poor bioavailability of peptides and insufficient pharmacotherapeutic experience regarding dose, and duration of treatment.

A review is given of the neuropsychological conceptualizations of aphasia and apraxia in SDAT. In the beginning of this century localisationism was prevailing. Later, developmental and cognitive psychology gave an important impetus to reconsider these symptoms in an holistic framework. More recently, since the application of new brain imaging techniques, there is a revival of localizing conceptualizations.

Dystonie reactions and hallucinations: a rare adverse-effect? One of the intriguing side-effects of neuroleptics is the acute dystonie reaction like oculogyric crises. It is seldom mentioned that the dystonie reaction may be combined with hallucinations. This combination of acute dystonia with hallucinations may be explained by overstimulation of dopamine-receptors in the striatal neurons. Awareness of these hallucinations as a complication of neuroleptics is essential to prevent that neuroleptic dose will be increased; instead it must be lowered. Prevention of the dystonia is critical. These side effects may be suppressed with anti-parkinsonian drugs. Information to the patient in due time may prevent anxiety about the side effects.

Dementia and Amyotrophic Lateral Sclerosis

The case-histories of two patients are presented with Amyo-trofic Lateral Sclerosis and dementia (ALS-D), followed by a discussion of recent literature on this topic. This condition can be considered as the interface between non-Alzheimer frontal lobe dementia and amyotrophic lateral sclerosis. The nosological classification of the ALS-D complex has not been established yet.

In deze rubriek zal worden ingegaan op recente observaties betreffende de psychofarmakologie in de breedst mogelijke zin. Vaak zullen zaken uit de literatuur worden behandeld. De gekozen onderwerpen dienen altijd klinische relevantie te hebben. Ook zal deze rubriek gaan over gewoontes die in psychofarmakologische behandeling of in onderzoek zijn geslopen die volgens de auteur lang niet altijd logisch zijn. Soms zal deze rubriek een oproep bevatten om te reageren op een bijdrage gepubliceerd in dit of in een ander tijdschrift. Ook zal de lezer worden aangemoedigd hier zijn eigen ervaringen mee te delen. Het is niet de bedoeling in deze rubriek onderzoeken uitvoerig te rapporteren. Daarvoor staan andere pagina's van de Acta Neuropsychiatrica voor u open.