Learning in Parkinson's disease: eyeblink conditioning, declarative learning, and procedural learning.
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OBJECTIVE: To assess the degree of learning ability in Parkinson's disease. METHODS: Three different learning tasks: eyeblink classical conditioning with delay and trace paradigms, the California verbal learning test (CVLT), and a serial reaction time task (SRTT) were studied in patients with Parkinson's disease and normal (control) subjects. RESULTS: In the eyeblink conditioning tasks, both patients and normal subjects showed significant learning effects without between group differences. In the CVLT, patients remembered significantly fewer words than normal subjects in both short term and long term cued recall tasks. In the SRTT, normal subjects had significantly reduced response time and error rates across blocks of repeated sequence trials, whereas patients had significantly reduced error, but not response time rates. CONCLUSION: Impairment of nigrostriatal pathways selectively affects performance in complex learning tasks that are competitive and require alertness such as the SRTT, but not in simple learning procedures such as eyeblink conditioning. (+info)
Right frontal lobe slow frequency repetitive transcranial magnetic stimulation (SF r-TMS) is an effective treatment for depression: a case-control pilot study of safety and efficacy.
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Major depression may result from decreased left frontal lobe function with respect to the right. Fast frequency repetitive transcranial magnetic stimulation (FF r-TMS) excites the underlying cortex whereas slow frequency repetitive transcranial magnetic stimulation (SF r-TMS) causes cortical inhibition. Left frontal FF r-TMS attenuates major depression whereas the inhibitory effects of right frontal SF r-TMS are unknown. This study tested the hypothesis that right frontal SF r-TMS would treat depressed patients with minimal effect on controls. A psychiatrist administered the Beck depression inventory and Hamilton D depression rating scales to eight depressed patients and six controls before and after the treatment protocol. Eight sessions of 100 right frontal lobe SF r-TMS were given at motor threshold and 0.5 Hz over a 6 week period. No adverse outcomes were noted in either group. A significant antidepressant effect was noted in depressed patients on the Beck and Hamilton D depression rating scales (p<0.05). No change on either scale was noted in the controls. In conclusion right frontal lobe SF r-TMS is a safe, non-invasive treatment for major depression that deserves further investigation. (+info)
Neuroendocrine and psychophysiologic responses in PTSD: a symptom provocation study.
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Biological research on post-traumatic stress disorder (PTSD) has focused on autonomic, sympatho-adrenal, and hypothalamo-pituitary-adrenal (HPA) axis systems. Interactions among these response modalities have not been well studied and may be illuminating. We examined subjective, autonomic, adrenergic, and HPA axis responses in a trauma-cue paradigm and explored the hypothesis that the ability of linked stress-response systems to mount integrated responses to environmental threat would produce strong correlations across systems. Seventeen veterans with PTSD, 11 veteran controls without PTSD, and 14 nonveteran controls were exposed to white noise and combat sounds on separate days. Subjective distress, heart rate, skin conductance, plasma catecholamines, ACTH, and cortisol, at baseline and in response to the auditory stimuli, were analyzed for group differences and for patterns of interrelationships. PTSD patients exhibited higher skin conductance, heart rate, plasma cortisol, and catecholamines at baseline, and exaggerated responses to combat sounds in skin conductance, heart rate, plasma epinephrine, and norepinephrine, but not ACTH. The control groups did not differ on any measure. In canonical correlation analyses, no significant correlations were found between response systems. Thus, PTSD patients showed heightened responsivity to trauma-related cues in some, but not all, response modalities. The data did not support the integrated, multisystem stress response in PTSD that had been hypothesized. Individual response differences or differing pathophysiological processes may determine which neurobiological system is affected in any given patient. (+info)
Neurovascular deficits in cocaine abusers.
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The nature of the neurological and cerebrovascular deficits in cocaine abusers and whether they persist in abstinence is unclear. Blood flow velocity of the anterior and middle cerebral arteries was measured by transcranial Doppler sonography in cocaine abusers (n = 50) and control subjects (n = 25). Blood flow velocity was measured within 3 days and again after about 28 days after being admitted to an inpatient research ward to determine whether blood flow velocity improved during monitored abstinence conditions. The mean, systolic, and diastolic velocities as well as the pulsatility index in middle and anterior cerebral arteries significantly differed between controls and cocaine abusers (p < .05). Cerebrovascular resistance is increased in cocaine abusers and the increase persists for over a month of abstinence. Further research is needed to determine whether cerebrovascular resistance can be improved by pharmacological manipulations and whether improved blood flow relates to improved treatment outcome. (+info)
Alcohol-related problems among adolescent suicides in Finland.
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We studied 106 adolescent suicides out of a total nationwide population of 1397 suicides. Forty-four (42%) of these 13-22-year-old victims were classified as having suffered either a DSM-III-R alcohol use disorder or diagnostically subthreshold alcohol misuse according to retrospective evaluation using the Michigan Alcoholism Screening Test (MAST). These victims were found to differ from the other adolescent suicides in several characteristics: they were more likely to have comorbid categorical DSM-III-R disorders, antisocial behaviour, disturbed family backgrounds, precipitating life-events as stressors and severe psychosocial impairment. In addition, they also had a greater tendency to be alcohol-intoxicated at the time of the suicidal act, which tended to occur during weekends, suggesting that drinking in itself, and its weekly pattern, each contributed to the completion of their suicides. (+info)
Drinking pattern and alcohol-related medical disorders.
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Although heavy alcohol intake is known to be one of the most common causative factors of liver disease, pancreatitis, upper gastrointestinal and neurological disorders, the influence of the drinking pattern is largely unknown. The study investigated the relationship of alcohol-related medical disorders in alcoholics and their drinking pattern. Two hundred and forty-one chronic alcoholics were referred consecutively for detoxification and their drinking pattern was sufficient for them to be included in this study. History of alcohol abuse as well as drinking behaviour in the last 6 months were assessed by a semi-structured interview. Findings included intensive clinical examination with abdominal ultrasound in most subjects. Heavy drinking with frequent inebriation was most often found in our sample (44.4%), whereas continuous heavy alcohol consumption without intoxication (33.6%), and an episodic drinking style (22.0%) were less frequent. The heavy drinkers suffered more often from pancreatitis, oesophageal varices, polyneuropathy or erectile dysfunction than episodic drinkers. They also showed more upper gastrointestinal disorders, although the estimated life-time alcohol intake was comparable to continuous drinkers. No difference relating to withdrawal delirium or seizures could be found between the groups of alcoholics. Frequent heavy drinkers showed a trend to more alcohol-related medical disorders than alcoholics with a different drinking pattern, although they were younger and their estimated life-time alcohol intake was comparable to that of continuous drinkers. Thus, the drinking pattern, particularly frequent inebriation, has an influence on the occurrence of alcohol-related disorders. (+info)
Patients with chronic alcohol abuse in Dutch family practices.
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Routine data from the Dutch Transition project on 236 027 episodes of care collected by 54 family physicians (FPs) for 93 297 patient years in their listed practices and classified with the International Classification of Primary Care, were used to analyse chronic alcohol abuse episodes of care in Dutch family practices. Data on 332 episodes are presented. In a subsample with a 4-year registration period, 70 patients were identified. Important reasons for an encounter are the patient's explicit presentation of the problem and the FPs' initiatives. FPs show considerable sensitivity to psychosocial problems, including alcohol abuse. It is concluded that over the years registered FPs actively deal with chronic alcohol abuse in approximately 2% of all visiting men aged 25-64 years. In an average Dutch family practice with 2200 listed patients, approximately 20 patients are known by the FP to have chronic alcohol abuse. Real life studies in registered family practice populations are necessary to better establish how patients with abundant alcohol consumption as a risk factor develop the chronic alcohol abuse episode of care, and what FPs can do to prevent this effectively. (+info)
Risperidone versus haloperidol on secondary memory: can newer medications aid learning?
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The introduction of the new generation of antipsychotic medications for the treatment of schizophrenia has been accompanied by a growing interest in the neurocognitive effects of these drugs. The present study compared the effects of risperidone and haloperidol on secondary memory in a group of treatment-resistant schizophrenia patients. The study design included a baseline phase and two double-blind phases in which patients were randomly assigned to medication under two different dose conditions (fixed dose and flexible dose). Secondary memory was assessed at baseline, fixed-dose, and flexible-dose phases, using the California Verbal Learning Test (CVLT). Six measures were selected, which formed three factors (general verbal learning ability, retention, and learning strategy). Risperidone-treated patients showed greater improvement than haloperidol-treated patients in general verbal learning ability, a finding characterized by significant treatment effects on CVLT measures of learning acquisition, recall consistency, and recognition memory. After controlling for benztropine status, differences on the measures of learning acquisition and recall consistency remained significant, and differences in recognition memory weakened slightly (p = 0.07). No significant treatment effects were noted on retention or learning strategy. These findings suggest that risperidone may exert a facilitating effect on the acquisition of new verbal information, an effect that does not appear to be due to the activation of semantic encoding strategies. (+info)