Verbal fluency tasks are frequently used in clinical
neuropsychology. Clustering (the production of words within
semantic subcategories) and switching (the ability to shift
between clusters) have been described as 2 components underlying
fluency performance. We compared the use of clustering
and switching in schizophrenic patients and healthy subjects.
Seventy-eight schizophrenic subjects (DSM–IV criteria)
and 64 control participants matched for age and educational
level were recruited. Negative, disorganized, and productive
clinical dimensions were evaluated using the SANS and SAPS
scales. The number of words generated per semantic–phonemic
cluster and the number of switches were evaluated during
2 verbal fluency tasks (phonemic and semantic). In the
healthy controls switching and clustering were closely
related to the total number of words generated in the verbal
fluency tests. The role of the 2 components was partly
dependent on the specific task. Switching was prevalent
in formal fluency, while both switching and clustering
contributed to semantic fluency. In comparison to the healthy
controls, the overall group of schizophrenic patients showed
a significant impairment of switching in the formal fluency
task and of both switching and clustering in the semantic
fluency task, and both the negative and disorganized dimensions
correlated with verbal fluency performance, the number
of switches during the phonemic fluency task, and the clustering
during semantic fluency task. (JINS, 1998, 4,
539–546.)
Zolpidem belongs to a new class of hypnotic agents, chemically distinct from the pre-existing ones, and has a unique neuropharmacological profile. It induces sedative/hypnotic effects in rodents at doses much lower than those for anticonvulsant and myorelaxant activities. Clinically, zolpidem is indicated for the short term treatment of insomnia. It has a short half-life (2.4h), with no active metabolite, and does not accumulate during repeated administration. The pharmacokinetic profile associated with the absence of active metabolites is consistent with the short duration of action and absence of residual effects that have been observed. Polysomnographic experience indicates that zolpidem induces a sleep pattern which is similar to that of physiological sleep, and which produces either no or only minimal effects on sleep architecture after abrupt discontinuation. Aspects of the general safety of zolpidem have been studied in data obtained from healthy volunteers and patients, both adult and elderly, during its clinical development and in post-marketing experience. Zolpidem appears to be well-tolerated in adults and in the elderly, when administered in accordance with prescribing instructions. The available data indicate that, in these circumstances, the risk of abuse or dependence is minimal.
Apathy is defined as a lack of motivation. The aim of this study was to investigate the relation between two major dimensions of apathy (lack of initiative and lack of interest) and brain perfusion. in patients with Alzheimer's disease (AD). Brain perfusion was measured by single photon emission tomography (SPECT). Thirty-one AD patients were included. Lack of initiative and interest were assessed with the Apathy Inventory. Nineteen AD subjects presented a lack of initiative and interest pathological score whereas 12 AD subjects did not. The lack of initiative and interest score correlated significantly with the right frontal and the right inferior temporal lobes. The AD patients with lack of initiative and interest showed a significantly lower perfusion in the right anterior cingulate than the AD patients without lack of initiative and interest. These results derive from rather small subgroups of patients but have the interest to dismantle the complementary aspects of emotion and motivation in apathy and suggest that the latter one is more related to cingulate area.
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