Writing tremor after discrete cortical infarction

BACKGROUND: Hand tremor is a rare manifestation of stroke, and writing tremor has not been reported to be produced by stroke. We describe a patient who developed a unilateral hand tremor mimicking primary writing tremor after discrete cerebral cortical infarction. CASE DESCRIPTION: A 67-year-old man developed mild right hemiparesis. Brain magnetic resonance imaging showed a discrete cortical infarct in the left frontal area. After recovery of motor power, the patient showed significant right hand tremor exclusively during writing or similar motor activities including tooth brushing or shaving. The tremor was temporarily alleviated by clonazepam but persisted until 7 months of follow-up. Medical history suggested that the patient had mild essential tremor, but he did not experience tremor on writing before the onset of stroke. CONCLUSIONS: This observation suggests that unilateral hand tremor mimicking primary writing tremor may be produced by cortical infarction. It remains unclear whether the patient's previous essential tremor played an additional role in the development of this symptom.     

Impairment of memory for spatial context in schizophrenia.

A group of 33 patients with schizophrenia were compared with control participants using a spatial memory task in which words were presented on locations of a grid. In the first part of the experiment, recognition of target information (words) was tested. In the second, 2 tasks of spatial location (contextual information) were given involving different sets of words placed in different locations: A location memory task (determining which word was in a particular spatial location) explored an associative form of spatial memory, and a relocation task (determining where a particular word was located) explored an associative and a nonassociative form of spatial memory. Patients were more impaired with regard to the location memory task than to the target recognition and relocation tasks. The impairment was negatively correlated with Stroop task performance. The results suggest that schizophrenia is associated with a spatial context memory deficit, which could be due to defective associations between target and spatial information. This deficit seemed to be related to frontal dysfunction. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Time-based prospective memory impairment in patients with thalamic stroke.

The role of the thalamus in memory is potentially very complex. However, most studies on the memory impairments of thalamic lesions have focused on retrospective memory, rarely on prospective memory. To explore the effect of thalamic lesions on event-based prospective memory (EBPM) and time-based prospective memory (TBPM), respectively, and to verify the hypothesis that the thalamus is involved in the prospective memory, EBPM and TBPM tasks were administered to 18 thalamic stroke patients and 18 age- and education-matched healthy controls. In the EBPM task, subjects were asked to perform an action whenever particular words were presented. In the TBPM task, subjects were asked to perform an action at certain times. Compared with the performance of healthy controls on EBPM and TBPM tasks (EBPM, 4.3 ± 1.5; TBPM, 5.4 ± 1.0), there was a significant difference in the performance of thalamic stroke patients in the TBPM tasks (2.4 ± 1.6), but no difference was found in EBPM tasks (3.7 ± 1.1). These results may indicate that the thalamus is involved in PM and particularly in TBPM. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Impairment of consciously controlled use of memory in schizophrenia.

Recent studies of memory in schizophrenia have shown that explicit but not implicit memory performance is impaired. The hypothesis that schizophrenia is associated with a failure of consciously but not unconsciously (automatic) controlled influence of memory on performance was tested using a procedure providing uncontaminated estimates of consciously controlled and automatic memory processes (i.e., the process-dissociation procedure in a stem completion task). Performance of 35 patients with schizophrenia was compared with that of 35 normal participants. Consciously controlled use but not automatic influences of memory was significantly lower in patients with schizophrenia than in controls. Consciously controlled use of memory was negatively and significantly correlated with positive symptoms of schizophrenia. Schizophrenia differentially affects 2 types of memory processes: It impairs consciously controlled use of memory but spares automatic influences. Positive symptoms could reflect the lack of control from higher level conscious processes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Bilateral paramedian thalamic infarction: Neuropsychological and perfusional followup study.

Conducted a 2-yr follow-up of a woman (aged 35 yrs) who had a bilateral paramedian thalamic infarction and suffered from a sudden impairment of consciousness followed by a global deficit of cognitive functions. Two years after clinical onset, verbal and visuospatial memory, verbal fluency, constructional praxia, and categorization were mainly affected. In the acute phase, a single-photon emission-computed tomography study showed a severe and diffuse cerebral blood flow (CBF) impairment, more marked on the right side. Radioisotope uptake in frontal and temporal cortices was still reduced 2 yrs later. The CBF depression in these regions suggests that the decline of cognitive functions could be due to an interruption of thalamocortical projections. A degenerative process rather than a "diaschisis" could be responsible for the long-lasting deficit of cognitive functions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Impairment of semantic and figural memory by acute ethanol: age-dependent effects

Alcohol drinking is prevalent among young adults in the U.S. Moreover, heavy drinking is acknowledged by a substantial percentage of young adults in both college and military subpopulations, despite the known cognitive demands associated with these endeavors and the cognitive impairments associated with alcohol usage. We assessed the acute effects of ethanol (0.6 g/kg) on the acquisition of both semantic and figural memory in a sample of young adults from 21 to 29 years of age using a repeated-measures, placebo-controlled experimental design. Ethanol significantly impaired memory acquisition in both domains. In addition, the effect of ethanol on three of the four memory measures assessed was dependent on the age of the subjects. Subjects in a young subgroup (21 to 24 years of age) were significantly more impaired in memory measures than those in the subgroup that was 25 to 29 years of age. These results indicate a divergence of the potency of ethanol against memory acquisition across a narrow age range in early adulthood. Whereas these data are preliminary, and should be generalized cautiously, they are also consistent with a growing literature using animal models that indicates that acute ethanol is a more potent antagonist of memory and memory-related hippocampal activity in adolescent animals compared with adults.     

Impairment of spontaneous alternation behavior in sequential test procedures following mammillary body lesions in mice: Evidence for time-dependent interference-related memory deficits.

The experiments reported here examined the effects of either radio frequency or kainic acid lesions of the median mammillary nucleus (MM) on spatial spontaneous alternation (SA) in mice. Animals were tested in a T-maze with sessions of six to nine successive trials given at varying intertrial intervals (ITIs). In the first experiment, conducted with an ITI of 30 s, damaged animals exhibited normal rates of SA on the second trial of the session but were progressively impaired on subsequent trials compared with controls. This finding was interpreted as an increased vulnerability to proactive interference. The second experiment was designed to investigate the effect of the ITI, and the results indicated that the previously observed impairment was completely suppressed by reducing the ITI from 30 s to 5 s. In order to further test our interference hypothesis, a third experiment was designed to investigate whether providing the animals with an extrinsic cue on one trial (5th) would increase the rate of SA on the subsequent (6th) trial (release from interference). Unexpectedly, results from this experiment showed that performance dramatically improved as soon as the cue was provided (i.e., on the 5th trial). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Myocardial infarction following electric shock

A 17 year old man presented with a five-month history of swelling of the distal phalanx and a small ulcer on the pulp of the right fifth finger. Despite biopsy the diagnosis was missed until more than six months after onset, when the lesion was excised and histological examination showed a dermal leiomyosarcoma.     

Effect of nimodipine on memory after cerebral infarction

OBJECTIVES: Epidemiological studies indicate widespread memory impairment in patients with stroke in the early post-ictal stage. Nimodipine may have psychopharmacological properties and may improve memory. We conducted a single-blind randomized controlled trial to determine whether nimodipine given 7-14 days after cerebral infarction improved memory. MATERIAL AND METHODS: One hundred patients with acute cerebral infarction were consecutively enrolled between D7 to D14. After stratification, patients were randomized to receive oral nimodipine 90 mg daily for 12 weeks, or no drug. Independent assessors administered Mini-Mental State Examination (MMSE) and Fuld Object-Memory Evaluation (FOME) at baseline, 6 weeks, and 12 weeks. RESULTS: Patients receiving nimodipine showed greater improvement in FOME mean scores at 12 weeks (P=0.0334), and also in FOME score change across time (P=0.0283). Patients with severe disability who received nimodipine also showed greater MMSE score change across time (P=0.0495). CONCLUSION: Nimodipine given 7-14 days after cerebral infarction for 3 months results in memory improvement.     

Impaired allocentric spatial working memory and intact retrograde memory after thalamic damage caused by thiamine deficiency in rats.

Rats were tested on an allocentric-spatial working-memory task—delayed matching-to-place (DMTP) in a water maze—before and after either pyrithiamine-induced thiamine deficiency (PTD) or electrolytic lesions of the lateral internal medullary laminae (IML), an area damaged by PTD. DMTP trials consisted of paired swims, with the escape platform in a new location on each trial. PTD rats were impaired at retention delays of 300 s, but not at delays of 4 or 60 s. Rats with IML lesions performed normally at all delays. Both groups displayed normal retention of object-discrimination problems that they had learned at different intervals before treatment (5 weeks, 3 weeks, and 1 week). The results suggest that PTD causes delay-dependent deficits of allocentric spatial working memory and that damage outside the IML is probably responsible. Neither PTD-induced diencephalic damage nor restricted IML lesions appear to produce a global retrograde amnesia. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dissociation of declarative and nondeclarative memory after bilateral thalamic lesions: a case report

The case of a 63-year-old woman who suffered bilateral ischemic damage in the region of blood supply of the paramedian thalamic arteries is reported. She displayed severe deficits on immediate and delayed recall of both verbal and visuospatial material in the presence of intact IQ and attentional abilities. Performance on tests of all major components of nondeclarative memory (skill acquisition, perceptual priming, classical conditioning) was also preserved. The present report, thus, provides a further example for dissociations of declarative and nondeclarative memory functions following bilateral thalamic damage.     

Alterations in intralaminar and motor thalamic physiology following nigrostriatal dopamine depletion

Methoxyacetaldehyde (MALD), a metabolite of 2-methoxyethanol, has been shown to be clastogenic and mutagenic in CHO-AS52 cells. PCR-based-deletion screening of MALD induced CHO-AS52 mutants indicates that MALD induces large deletion mutation. Since MALD has an aldehyde as its reactive functional group, it can react with aldehyde oxidase to produce superoxide. The generation of these reactive oxygen species (superoxide, hydrogen peroxide and hydroxyl radical) may be the mechanism for genotoxicity of MALD. In the present study, TEMPOL and catalase which are ROS modulators were used to study the effects on MALD-induced chromosome damage in CHO-AS52 cells. The results showed that neither TEMPOL nor catalase can protect cells from MALD-induced chromosome aberrations. Therefore, the generation of reactive oxygen species may not be the primary mechanism of action of MALD.     

Impairment of plasma fibrinolysis in young survivors of myocardial infarction with silent ischaemia

OBJECTIVE: To determine the effect of mild dehydration (5%) on expired breath H2 concentrations in dogs. ANIMALS: 10 healthy, colony-source dogs. PROCEDURE: Expired breath samples were collected at baseline, and every 90 minutes for 18 hours after ingestion of a test meal (commercial dog food and kibbled wheat) in fully hydrated dogs and in the same dogs when they had lost 5% of their body weight after food and water deprivation. The areas under the breath H2 concentration versus time curves (AUC) for the dehydrated and nondehydrated states were compared, using a two-stage, balanced, crossover, repeated measures technique. The number of breath samples considered to be contaminated by flatus were compared by use of a one-sided sign test. RESULTS: Expired breath H2 concentration of dogs during the dehydration test period was significantly (P < 0.02) greater than that during the nondehydration test period. In addition, flatulence was significantly (P < 0.033) more frequent in dogs during the dehydration period. CONCLUSIONS: Dehydrated dogs have greater expired breath H2 concentration and produce more flatus after ingestion of a carbohydrate-containing meal. Considered together, these findings suggest that dehydration results in an increase in the net amount of H2 produced in the gastrointestinal tract. CLINICAL RELEVANCE: Care should be taken to assess the hydration status, and to correct hydration deficits of dogs prior to breath H2 testing.     

Aortic infarction following dissecting aortic aneurysm

Aortic infarction was observed in 21 of 34 cases of dissecting aortic aneurysm. This lesion occurred as a central zone of necrosis with preserved elastic laminae, sparing media adjacent to the true and false lumens. In cases where the false lumen was occluded, the central infarction extended to this lumen. The infarction followed rather than preceded dissection, took approximately 48 hours to develop, and did not organize with time. The lesion occurred exclusively in the thoracic aorta, and bore no relationship to medial cystic necrosis. Present surgical therapy does not extirpate these areas, and the implication of these lesions in terms of management remains to be determined.     

Successful revascularization of mesenteric infarction following aortography

Two cases of bowel infarction following abdominal aortography are presented. In both patients, two of the three major arteries supplying the bowel were occluded before the study. The superior mesenteric artery in one and the inferior mesenteric artery in the other were the only arteries supplying the bowel and their lumens were reduced. After the aortogram, the residual lumen clotted, leading to bowel necrosis. Survival was made possible in these two cases by revascularizing the superior mesenteric artery and resecting the necrotic bowel.     

Sexual counseling following acute myocardial infarction

Sexual counseling needs of myocardial infarction (MI) patients are frequently overlooked by nurses. This study sought to determine to what extent sexual counseling of MI patients was addressed in the acute care setting. The survey of 96 patients showed that sexual counseling was largely not addressed for this group of patients and that specific information on resuming sexual activity was not provided for most patients. Seventy-one percent of patients believed that staff should address sexuality in the hospital setting. It was found that receipt of sexual counseling significantly differed by marital status of the patient. Nurses need to take a more active role in sexual assessment and education in order to improve the quality of life of patients post-MI.     

Rehabilitation of patients following myocardial infarction.

Cardiac rehabilitation (CR) provides formal treatment for the physical and psychosocial sequelae of myocardial infarction (MI). In this review, three behavioral strategies are critically examined, including exercise therapy, Type A modification, and nonspecific psychological therapies. Data generally support the value of CR as a method for improving the quality of life among post-MI patients. However, data do not conclusively demonstrate that CR prolongs life or significantly reduces morbidity rates in post-MI patients when it is compared with routine medical care. Nevertheless, CR is generally accepted by the medical community, and psychological expertise in behavioral assessment and treatment is a valuable aspect of the multidisciplinary CR program. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Impairment of long-term associative memory in aging snails (Lymnaea stagnalis).

Age-dependent impairment in learning and memory functions occurs in many animal species, including humans. Although cell death contributes to age-related cognitive impairment in pathological forms of aging, learning and memory deficiencies develop with age even without substantial cell death. The molecular and cellular basis of this biological aging process is not well understood but seems to involve a decline in the aging brain's capacity for experience-dependent plasticity. To aid in resolving this issue, we used a simple snail appetitive classical conditioning paradigm in which the underlying molecular, cellular, and neural network functions can be directly linked to age-associated learning and memory performance (i.e., the Lymnaea stagnalis feeding system). Our results indicate that age does not affect the acquisition of appetitive memory but that retention and/or consolidation of long-term memory become progressively impaired with advancing age. The latter phenomenon correlates with declining electrophysiological excitability in key neurons controlling the feeding behavior. Together, these results present the Lymnaea feeding system as a powerful paradigm for investigations of cellular and molecular foundations of biological aging in the brain. (PsycINFO Database Record (c) 2010 APA, all rights reserved)