PubMed Health⌕ Search

Biomedical subjects

H Bergman

Publications and source records attributed to H Bergman.

At least 37 records · Page 2Linked to original sources
PubMed1999

The recognition, assessment and management of dementing disorders: conclusions from the Canadian Consensus Conference on Dementia.

OBJECTIVE: To develop evidence based consensus statements on which to build clinical practice guidelines for primary care physicians toward the recognition, assessment and management of dementing disorders and to disseminate and evaluate the impact of these statements and guidelines built on these statements. OPTIONS: Structured approach to assessment, including recommended laboratory tests, choices for neuroimaging and referral, management of complications (especially behavioural problems and depression) and use of cognitive enhancing agents. POTENTIAL OUTCOMES: Consistent and improved clinical care of persons with dementia; cost containment by more selective use of laboratory investigations; neuroimaging and referrals; and appropriate use of cognitive enhancing agents. EVIDENCE: Authors of each background paper were entrusted to perform a literature search, discover additional relevant material, including references cited in retrieved articles, consult with other experts in the field and then synthesize information. Standard rules of evidence were applied. Based on this evidence, consensus statements were developed by a group of experts, guided by a steering committee of 8 individuals, from the areas of Neurology, Geriatric Medicine, Psychiatry, Family Medicine, Preventive Health Care and Health Care Systems. VALUES: Recommendations have been developed with particular attention to the context of primary care, and are intended to support family physicians in their ongoing assessment and care of patients with dementia. BENEFITS HARM AND COSTS: Potential for improved clinical care of people with dementia. A dissemination and evaluation strategy will attempt to measure the impact of the recommendations. RECOMMENDATIONS: Forty-eight recommendations are offered that address the following aspects of dementia care: early recognition; importance of careful history and examination in making a positive diagnosis; essential laboratory tests; rules for neuroimaging and referral; disclosure of diagnosis; importance of monitoring and providing support to caregivers; cultural aspects; detection and treatment of depression; observation and management of behavioural disturbances; detection and reporting of unsafe motor vehicle driving; genetic factors and opportunities for preventing dementia; pharmacological treatment with particular emphasis on cognitive enhancing agents. VALIDATION: Four other sets of consensus statement or guidelines have been published recently. These recommendations are generally congruent with our own consensus statements. The consensus statements have been endorsed by relevant bodies in Canada.

Automobile Driving↗
PubMed1999

Comparison of MPTP-induced changes in spontaneous neuronal discharge in the internal pallidal segment and in the substantia nigra pars reticulata in primates.

The basal ganglia are currently viewed as components of segregated corticosubcortical reentrant circuits. One of these circuits, the "motor" circuit, is critically involved in the development of parkinsonian motor signs. Current pathophysiologic models postulate that parkinsonism is associated with increased activity in the basal ganglia output nuclei. The neuronal activity in the motor portion of one of these output nuclei, the internal segment of the globus pallidus (GPi), has been characterized in detail in intact and parkinsonian animals, but the neuronal activity in the second major basal ganglia output nucleus, the substantia nigra pars reticulata (SNr), has received far less attention. This study in primates represents a comparison of the effects of parkinsonism, induced by injections of the dopaminergic neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), on the neuronal discharge in the GPi and SNr. These electrophysiologic recording experiments were carried out in three African green and two rhesus monkeys. One hundred and twenty-four neurons were recorded in the GPi before treatment with MPTP, and 93 neurons thereafter. In the SNr, 55 cells were recorded before treatment with MPTP, and 41 cells thereafter. MPTP induced a non-significant increase in the average discharge rate and a significant decrease in the median interspike interval length (ISI) in the GPi (by 13%), whereas no changes were detected in either parameter in the SNr. The average ISI distributions were markedly asymmetric in both structures, and could be modeled by a logarithmic normal distribution. With the MPTP treatment, the mode of the ISI distribution fell by 24% in the GPi (P< or =0.01), whereas it did not change significantly in the SNr. An algorithm that detects burst discharges in the raw ISI data (based on the method by Legendy and Salcman) detected a significant increase in the proportion of action potentials that participated in bursts of discharge in both structures (increase by 257% in the GPi, and by 67% in the SNr). Power spectral and autocorrelation analysis revealed that treatment with MPTP increased the proportion of cells with oscillatory burst patterns at 3-8 Hz in both structures (from 0.8% to 27% of all neurons in the GPi, and from none to 10% in the SNr). The results show that neuronal discharge in the SNr is affected in parkinsonism, but that the changes in the SNr are less pronounced then those seen in the GPi.

Animals↗
PubMed1999

Randomized controlled trial of nurse case management of frail older people.

OBJECTIVES: To compare the effects of nurse case management with usual care provided to community-dwelling frail older people in regard to quality of life, satisfaction with care, functional status, admission to hospital, length of hospital stay, and readmission to emergency department. DESIGN: Randomized controlled trial. SETTING: University hospital and two proximal community health centers. PARTICIPANTS: 427 frail older people (> or = 70 years of age and at risk for repeated hospital admissions) discharged home from the emergency department. INTERVENTIONS EXPERIMENTAL: Nurse case management, which consisted of coordination and provision of healthcare services by nurses, both in and out of hospital, for a 10-month period. CONTROL: Usual care, which varied by healthcare provider and community health center. MEASUREMENTS: Outcomes were assessed 10 months post-randomization by telephone and/or home interview and by medical record review. Questionnaires included the SF-36, CSQ-8, and OARS. RESULTS: No significant differences were found in quality of life, satisfaction with care, functional status, admission to hospital, or length of hospital stay. Nurse-case-managed older adults were readmitted to the emergency department significantly more often than their usual care counterparts. CONCLUSIONS: Frail older people receiving nurse case management are more likely to use emergency health services without a concomitant increase in health benefits.

Activities of Daily Living↗
PubMed1999

Frontal cognitive impairments and saccadic deficits in low-dose MPTP-treated monkeys.

There is considerable overlap between the cognitive deficits observed in humans with frontal lobe damage and those described in patients with Parkinson's disease. Similar frontal impairments have been found in the 1-methyl-4-phenyl-1,2,3, 6-tetrahydropyridine (MPTP) primate model of Parkinsonism. Here we provide quantitative documentation of the cognitive, oculomotor, and skeletomotor dysfunctions of monkeys trained on a frontal task and treated with low-doses (LD) of MPTP. Two rhesus monkeys were trained to perform a spatial delayed-response task with frequent alternations between two behavioral modes (GO and NO-GO). After control recordings, the monkeys were treated with one placebo and successive LD MPTP courses. Monkey C developed motor Parkinsonian signs after a fourth course of medium-dose (MD) MPTP and later was treated with combined dopaminergic therapy (CDoT). There were no gross motor changes after the LD MPTP courses, and the average movement time (MT) did not increase. However, reaction time (RT) increased significantly. Both RT and MT were further increased in the symptomatic state, under CDoT. Self-initiated saccades became hypometric after LD MPTP treatments and their frequency decreased. Visually triggered saccades were affected to a lesser extent by the LD MPTP treatments. All saccadic parameters declined further in the symptomatic state and improved partially during CDoT. The number of GO mode (no-response, location, and early release) errors increased after MPTP treatment. The monkeys made more perseverative errors while switching from the GO to the NO-GO mode. Saccadic eye movement patterns suggest that frontal deficits were involved in most observed errors. CDoT had a differential effect on the behavioral errors. It decreased omission errors but did not improve location errors or perseverative errors. Tyrosine hydroxylase immunohistochemistry showed moderate ( approximately 70-80%) reduction in the number of dopaminergic neurons in the substantia nigra pars compacta after MPTP treatment. These results show that cognitive and motor disorders can be dissociated in the LD MPTP model and that cognitive and oculomotor impairments develop before the onset of skeletal motor symptoms. The behavioral and saccadic deficits probably result from the marked reduction of dopaminergic neurons in the midbrain. We suggest that these behavioral changes result from modified neuronal activity in the frontal cortex.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗
PubMed1999

Sensory-motor transformation and motor planning in the primate frontal cortex.

To examine the role of the frontal cortex in sensory-motor processing, we trained a Rhesus monkey to perform a behavioral task with alternations between localization (LOC) and non-localization (NL) paradigms. In the LOC block, the monkey had to remember the modality and location of two sequential cues. Two different GO signals instructed the monkey to touch the memorized location of either auditory or visual spatial cues (GO-AUD or GO-VIS, respectively). In the NL paradigm the monkey received the same stimuli, but was instructed to touch a fixed target, disregarding the location and modality of the spatial and GO signals. Reaction time was significantly longer after GO-AUD signals in the LOC mode compared to the reaction time following GO-VIS signals, or in the NL mode. We examined 961 neurons in the frontal cortex and 427 parietal neurons. A group of frontal task-related neurons (72/430; 16.7%) showed evoked activity both after the visual and the GO-AUD stimuli in the LOC mode. The units did not respond to the GO-VIS signal that instructed the monkey to move to the same location, or to the identical stimuli in the NL mode. No such neurons were found in the sampled areas of the parietal cortex. Our findings suggest that the monkey initially planned a default response towards the location of the visual stimulus and immediately updated his motor plans when instructed to touch the memorized location of the auditory stimulus. We suggest that frontal activity may also be related to such modifications of sensory-motor associations.

Animals↗
PubMed1999

Lack of prognostic significance of SPECT abnormalities in non-demented elderly subjects with memory loss.

OBJECTIVE: To determine if hypoperfusion abnormalities on single photon emission computed tomography (SPECT) are associated with poorer cognitive function at baseline or increased risk of decline in cognitive function and progression to dementia in memory-impaired but non-demented elderly subjects meeting the criteria for aging associated cognitive decline (AACD). DESIGN: Cross sectional study of 36 AACD subjects comparing hexamethyl propylene-amine oxime (HMPAO) SPECT results rated by visual inspection with base line cognitive functioning. Prospective study of these AACD subjects with clinical and neuropsychological follow-up over 35 months. SETTING: The memory clinic and nuclear medicine unit of a university teaching hospital. SUBJECTS: Thirty-six subjects meeting the criteria for AACD recruited from patients seen on a physician referral basis. MAIN OUTCOME MEASURES: 1) Baseline cognitive function as measured by the Mini Mental State Examination (MMSE), Boston naming, Logical Memory I subtest of the WAIS-R, and verbal fluency, correlated with SPECT status. 2) Decline in cognitive function as measured by clinical exam and the MMSE, with progression to dementia on follow-up being correlated with SPECT status at baseline. RESULTS: 18 of the 36 subjects progressed to dementia (probable Alzheimer's Disease) over follow-up. No correlation was found between the presence or absence of SPECT abnormality and MMSE or other cognitive measures. There was no correlation between the presence or absence of SPECT abnormality at initial examination, and cognitive decline according to the MMSE, or with the occurrence of clinical dementia on follow-up. CONCLUSIONS: We conclude that SPECT abnormalities assessed by visual inspection do not correlate with severity of impairment in AACD individuals, and are not useful in predicting progression to dementia in AACD subjects.

Aged↗
PubMed1998

[Ten questions about alcohol as identifier of addiction problems. Psychometric tests at an emergency psychiatric department].

It is important to develop and evaluate methods of identifying alcohol dependent patients and patients at risk of alcohol problems. The World Health Organisation recommends a 10-item questionnaire, AUDIT (Alcohol Use Disorders Identification Test), which assesses hazardous alcohol use, dependence symptoms, and harmful alcohol use. The article describes a Swedish version of AUDIT that has been psychometrically tested on a sample of patients admitted to a psychiatric emergency ward. Both internal consistency, reliability and validity were found to be satisfactory in terms of sensitivity and specificity in predicting DSM alcoholism diagnoses.

Adult↗
PubMed1998

[Alcohol-induced cognitive impairment is reversible. Neuropsychological tests but not MRT show improvement after abstinence].

Of alcoholic patients who underwent MRI (magnetic resonance imaging) of the brain and neuropsychological tests shortly after discontinuation of heavy drinking, a subgroup underwent repeat MRI scans and neuropsychological assessment one year later. The reduction in drinking habits was associated with cognitive improvement but no significant difference in MRI variables including T1-relaxation time.

Adult↗
PubMed1998

Prevalence of potentially reversible dementias and actual reversibility in a memory clinic cohort.

BACKGROUND: Although clinics for the evaluation of cognitive dysfunction have typically emphasized the detection and treatment of the reversible causes of dementia, it remains unclear whether the treatment of such causes results in reversal of the dementia. Therefore, the appropriate work-up for dementia is in dispute. METHODS: A chart review was performed with records from an urban tertiary care referral-based memory clinic. The records for 196 patients with dementia or suspected dementia, seen between October 1991 and December 1993, were examined to determine the prevalence of potentially reversible dementias and whether the cognitive dysfunction improved or resolved after treatment. Data abstracted from the medical charts included demographic information, medication use, presence of depression, and results of neuropsychological tests, blood work and neuroimaging. The clinical diagnosis, the response to treatment, if applicable, and the outcome (mean follow-up period 16 months) were analysed. The recommendations of the 1989 Canadian Consensus Conference on the Assessment of Dementia (CCCAD) on the use of CT were retrospectively applied in each case. RESULTS: Of the 196 patients, 45 (23.0%) had a potentially reversible condition identified by history, physical examination, blood testing or CT; in only 7 (3.6% of the total) did treatment result in improvement or resolution of the dementia. These 7 patients had higher results for the Mini-Mental State examination (mean result 26) and exhibited only mild cognitive deficits. Potentially reversible lesions were found in the CT scans of 6 (3.1%) patients: 4 had normal-pressure hydrocephalus and 2 had a brain tumour. If the CCCAD recommendations had been followed, CT would have been performed in 76 (38.8%) of the patients, and 1 of the 6 patients with a lesion would have been missed. INTERPRETATION: Both potential and actual reversibility of dementia was low in these memory clinic patients. The patients whose condition improved with intervention had early and milder cognitive deficits, which suggests that thorough evaluation of early memory loss is warranted.

Aged↗
PubMed1998

Primary motor cortex is involved in bimanual coordination.

Many voluntary movements involve coordination between the limbs. However, there have been very few attempts to study the neuronal mechanisms that mediate this coordination. Here we have studied the activity of cortical neurons while monkeys performed tasks that required coordination between the two arms. We found that most neurons in the primary motor cortex (MI) show activity specific to bimanual movements (bimanual-related activity), which is strikingly different from the activity of the same neurons during unimanual movements. Moreover, units in the supplementary motor area (SMA; the area of cortex most often associated with bimanual coordination) showed no more bimanual-related activity than units in MI. Our results challenge the classic view that MI controls the contralateral (opposite) side of the body and that SMA is responsible for the coordination of the arms. Rather, our data suggest that both cortical areas share the control of bilateral coordination.

Animals↗
PubMed1998

Physiology of MPTP tremor.

Rhesus and vervet monkeys respond differently to treatment with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine hydrochloride neurotoxin (MPTP). Both species develop akinesia, rigidity, and severe postural instability. However, rhesus monkeys only develop infrequent, short episodes of high-frequency tremor, whereas vervet monkeys have many prolonged episodes of low-frequency tremor. After MPTP treatment, the spiking activity of many pallidal neurons became oscillatory and highly correlated. Oscillatory autocorrelation functions were dominated by lower frequencies, cross-correlograms by higher frequencies. The phase shift distribution of the oscillatory cross-correlograms of pallidal cells in MPTP-treated vervet monkey were clustered around 0 phase shift, unlike the oscillatory correlograms in the MPTP-treated rhesus monkey, which were widely distributed between 0 degrees and 180 degrees. Analysis of the instantaneous phase differences between tremors of two limbs in the MPTP monkeys and human parkinsonian patients showed short periods of tremor synchronization. We thus concluded that the rhesus and the vervet models of MPTP-induced parkinsonism may represent the tremulous and nontremulous variants of human parkinsonism. We suggest that the tremor phenomena of Parkinson's disease (PD) are related to the emergence of synchronous neuronal oscillations in the basal ganglia. Finally, the oscillating neuronal assemblies in the pallidum of tremulous parkinsonian primates are more stable (in time and in space) than those of parkinsonian primates without overt tremor.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗
PubMed1998

Physiological aspects of information processing in the basal ganglia of normal and parkinsonian primates.

There are two views as to the character of basal-ganglia processing - processing by segregated parallel circuits or by information sharing. To distinguish between these views, we studied the simultaneous activity of neurons in the output stage of the basal ganglia with cross-correlation techniques. The firing of neurons in the globus pallidus of normal monkeys is almost always uncorrelated. However, after dopamine depletion and induction of parkinsonism by treatment with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), oscillatory activity appeared and the firing of many neurons became correlated. We conclude that the normal dopaminergic system supports segregation of the functional subcircuits of the basal ganglia, and that a breakdown of this independent processing is a hallmark of Parkinson's disease.

Animals↗
PubMed1998

Compliance of frail elderly with health services prescribed at discharge from an acute-care geriatric ward.

OBJECTIVES: A model of compliance by frail elderly with prescribed healthcare services was developed and tested. The discrepancy between primary care, geriatric and community health center (CLSC) services prescribed at discharge after comprehensive geriatric evaluation and treatment was measured, as were those services actually used during a 6-week interval (compliance). In this model, compliance was directly related to elders' intention to adhere to prescribed services, but this relationship was modified by organizational factors, reinforcing factors, and changes in health status during the observation period. Intention to adhere resulted from individual and reinforcing factors existing before discharge. METHODS: This model was tested on 211 patients discharged to community settings from an acute-care hospital geriatrics ward. Information was obtained through interviews with the patients or care givers and from hospital, outpatient, and local community health center charts. RESULTS: On average, patients used 56.9% of services prescribed; 13% of patients did not use any of the services prescribed for them, whereas 22% used all the services prescribed. Intention to adhere was influenced by patients' perception of the benefits of prescribed services and by their perception of the ease of access to transportation. Intention itself was not found to be an important determinant of overall compliance. Among organizational factors, having the ward staff make a follow-up appointment with the patients' family doctor and with the geriatric clinic before discharge and communication with the local community health center increased overall compliance. Moreover, patients who perceived they had access to transportation and to an accompanying person were more likely to comply. CONCLUSIONS: The results suggest that when discharging patients to the community, steps taken for them by the discharging healthcare providers will improve compliance.

Aged↗
PubMed1998

Personality characteristics of women with alcohol addiction: a Rorschach study of women in an early treatment programme.

This study identifies personality characteristics in a group of Swedish women (N = 60) attending their first treatment for alcohol problems. The treatment programme specifically addressed women in an early phase of their drinking career, and was called "Early Treatment of Women with Alcohol Addiction" (EWA). Rorschach personality profiles of the 60 women differed significantly in almost all investigated aspects in a psychopathological direction from norms reported by Exner for a reference group of female non-patients. The findings are consistent with the assumption that, although the EWA women were socially well-functioning and fairly early in their drinking career, they nevertheless reveal serious underlying psychopathology. Clinical implications of the findings are discussed.

Adult↗
PubMed1998

A two-year follow-up of geriatric consults in the emergency department.

OBJECTIVE: To characterize the population and provide a 2-year follow-up for those patients for whom a geriatric consult was requested in the emergency department (ED) of an acute care hospital. BACKGROUND: Older people tend to use health services, including the ED, disproportionately. This phenomenon has implications for medical services as the number of older people continues to increase. To our knowledge, long-term follow-up of patients for whom ED geriatric consultation was requested has not been described. SETTING: The emergency department of a 628-bed tertiary care university hospital in Montreal, Canada. SUBJECTS: 326 older patients examined in the ED by a geriatric consult team (GCT). METHODS: The records kept by the GCT during a 12-month period were reviewed retrospectively, and the patient cohort was followed for 2 years by telephone or review of hospital charts. Mortality, rate of revisit to ED, readmission to hospital, and final disposition were examined. RESULTS: The study revealed a particularly high hospital admission rate (63.5%) among those older people consulted by the GCT. The high prevalence rates for the classic geriatric syndromes of falls, incontinence, iatrogenic events, and confusional states suggest a need to address these problems early in their presentation, preferably beginning in the ED. A 2-year follow-up exhibited high mortality rates (33.7%) as well as a long-term institutionalization rate of 52%. CONCLUSION: The older patients seen in the ED of the acute care hospital for whom multidisciplinary geriatric consult is requested constitute a high-risk population. Within 2 years after initial consultation, many are dead and more than half have been institutionalized. The results of our follow-up imply the need for multidisciplinary intervention early on in the course of an older patient's ED visit as well as close follow-up after hospital discharge.

Aged↗
PubMed1998

Aging-related clinical and health services research in Canada.

Research by Canadian geriatricians has grown significantly since the Canadian Society of Geriatric Medicine was founded in 1981. Most research has been clinical or related to health service use. More recently, the Canadian Study of Health and Aging (CSHA) has proved an important focus for population-based research, and research on dementia. An increasing number of Canadian geriatricians have undertaken formal research training, and the CSHA study team and other groups are providing opportunities for multicentre, multidisciplinary, collaborative studies. These developments point to continued growth in research by Canadian geriatricians, most likely research with a clinical and population focus and employing multicenter designs.

Aged↗