Impaired upper limb coordination in alcoholic cerebellar degeneration

BACKGROUND

Alcoholic cerebellar degeneration (ACD) is a disorder resulting from severe chronic alcoholism and malnutrition and is characterized by cognitive disturbances, ataxia of gait, and truncal instability, with generally preserved coordination of the upper extremities.

OBJECTIVES

To determine whether cognitive deficits in patients with ACD are the same as those seen in patients with severe chronic alcoholism without ACD and to determine whether upper limb motor coordination is different in the 2 groups.

DESIGN

We examined cognitive function and upper limb coordination in 56 patients with severe chronic alcoholism, 13 with ACD and 43 without ACD, who had comparable levels of total alcohol intake. Neuropsychological and motor function was measured using an expanded Halstead-Reitan Neuropsychological Test Battery, including the Tactual Performance Test and Grooved Pegboard Test.

RESULTS

Neither group had impaired coordination of upper limb function on clinical neurological examination. Both groups had impaired performance on neuropsychological tests involving executive function, but the patients with ACD had greater impairment of upper limb coordination than the patients without ACD as measured by the Tactual Performance Test and Grooved Pegboard Test.

CONCLUSIONS

The findings suggest that these 2 groups have similar cognitive deficits but that upper extremity motor functions are more significantly impaired in the ACD group and that quantitative tasks of motor function reveal these impairments.

Unilateral striatal lesions in the cat disrupt well-learned motor plans in a GO/NO-GO reaching task

We examined the changes in learned and spontaneous motor behavior after a unilateral excitotoxin lesion of the neostriatum. Cats were trained to perform a sensory-cued GO/NO-GO reaching task. Success rate, reaction time, movement speed and kinematic patterns were used to characterize motor system properties. In addition, motor properties before and after the lesion were compared by clinical neurological examinations and video tape observations of free-range behavior. We found that in normal animals motor performance in the task was fluent, highly automatic and skillful with consistent patterns from trial to trial and day to day. The striatal lesion resulted in a marked impairment in the animals' ability to perform the automatic response to the sensory cues in the motor task. In contrast, sensorimotor behavior in contexts apart from the task was altered minimally, with changes that were often difficult to detect. The animals recovered their ability to perform the task gradually, although they never reached prelesion performance levels in up to 24 weeks of evaluation. The animals had difficulty making reaching movements in GO trials and, in NO-GO trials failures to withhold movements were more frequent. Failures were due to a specific inability to execute previously well-learned movements in response to cues and not to an inability to recognize and interpret the cues. The lesion effects were restricted to the automatic motor response to the learned cues, as the animals could make reaching movements to the target without obvious impairment in response to novel stimuli. They also made similar spontaneous movements apart from the motor task that appeared to be unimpaired. The unique motor style and strategies that characterized the behavior of individual animals prior to the lesion were still evident after the lesion, even though they were superimposed on lower success rates and slower movement speeds. Our findings suggest that the basal ganglia facilitate the fluent and rapid execution of sequences of well-learned sensorimotor behavior, but the representations of motor plans are not stored in the basal ganglia.

Utilization of the Denny-Brown collection: differential recovery of forelimb and hind limb stepping after extensive unilateral cerebral lesions

The Denny-Brown collection of primate lesion material was used to test the hypothesis that there is a difference in the rate of forelimb and hind limb recovery of locomotor movements after major unilateral cerebral ablation (pre/postcentral gyrus, decortication or hemispherectomy). The results indicate that, following major cerebral injury, hind limb recovery precedes that of the forelimb in adolescent and adult primates, but not in infants. This suggests that there is an underlying physiological basis to the widely-held belief that, in humans, lower limb recovery after stroke is generally more complete than that of the upper limb.

Decreased striatal monoaminergic terminals in olivopontocerebellar atrophy and multiple system atrophy demonstrated with positron emission tomography

We used [11C]dihydrotetrabenazine, a new ligand for the type 2 vesicular monoamine transporter (VMAT2), with positron emission tomography to study striatal monoaminergic presynaptic terminals in 4 patients with multiple system atrophy, 8 with sporadic olivopontocerebellar atrophy, and 9 normal control subjects. Specific binding in the striatum was significantly reduced in the multiple system atrophy patients as compared with the normal control group, with average reductions of 61% in the caudate nucleus (p = 0.002) and 58% in the putamen (p = 0.009). Smaller reductions were found in the sporadic olivopontocerebellar atrophy group, averaging 26% in the caudate nucleus (p = 0.05) and 24% in the putamen (p = 0.11). Mean blood-to-brain [11C]dihydrotetrabenazine transport (K1) was significantly different between groups only in the cerebellum, with values for the sporadic olivopontocerebellar atrophy group diminished compared with the normal control group. Cerebellar K1 was not significantly decreased in the multiple system atrophy group. The finding of reduced striatal VMAT2 in sporadic olivopontocerebellar atrophy patients suggests nigrostriatal pathology, indicating that some may later develop symptomatic extrapyramidal disease.

Presynaptic monoaminergic vesicles in Parkinson's disease and normal aging

We present development and human application of a method for determining the regional cerebral density of the type 2 vesicular monoamine transporter (VMAT2) using positron emission tomography (PET) and [11C]dihydrotetrabenazine (DTBZ). Previous animal studies indicate striatal VMAT2 density is linearly related to the integrity of substantia nigra dopamine neurons and is not subject to drug- or lesion-compensatory regulation. In the present studies, kinetic compartmental modeling was employed to estimate blood-brain [11C]DTBZ transport (K1) and VMAT2 binding site density (tissue-to-plasma DTBZ distribution volume, DV) from the cerebral and plasma DTBZ time courses after intravenous tracer injection. In controls, we found reductions of putamen DTBZ DVwith advancing age, corresponding to losses of 0.77% per year in specific VMAT2 binding. Parkinson's disease (PD) patients had reduction in specific DTBZ DV in the putamen (-61%) and in the caudate nucleus (-43%). There was no overlap of lowest specific putamen DTBZ DV between individual elderly controls and PD patients. The present results indicate the suitability of [11C]DTBZ PET for objective quantification of nigrostriatal integrity, including evaluation of PD progression and its possible therapeutic modification.

Effects of disulfiram on positron emission tomography and neuropsychological studies in severe chronic alcoholism

Disulfiram is an aldehyde dehydrogenase inhibitor that is widely used as an adjunctive agent in the treatment of patients with severe chronic alcoholism. Recent positron emission tomography (PET) studies of local cerebral metabolic rates for glucose (ICMRglc) and benzodiazepine receptor binding in alcoholic patients have shown regional cerebral abnormalities; however, some of the patients were studied while receiving disulfiram, which could influence the biochemical processes under investigation. In a retrospective investigation, we examined the influence of disulfiram administration on the results of PET studies of ICMRglc and benzodiazepine receptor binding and neuropsychological tests of cognition and executive function in patients with severe chronic alcoholism. [18F]Fluorodeoxyglucose was used to measure ICMRglc in 48 male patients, including 11 receiving and 37 not receiving disulfiram in therapeutic doses. [11C]Flumazenil was used to measure benzodiazepine receptor binding in 17 male patients, including 3 receiving and 14 not receiving disulfiram. All patients studied with FMZ were also examined with fluorodeoxyglucose. PET studies of ICMRglc revealed significantly decreased global values in the patients receiving disulfiram compared with those not receiving disulfiram. PET studies of benzodiazepine receptor binding revealed decreased flumazenil influx and distribution volume in patients receiving disulfiram. The neuropsychological tests demonstrated no differences between the two groups of subjects. The findings suggest that disulfiram may influence the results of PET studies of glucose metabolism and benzodiazepine receptor binding.

Positron emission tomographic studies of cerebral benzodiazepine-receptor binding in chronic alcoholics

Positron emission tomography was used with [11C]flumazenil (FMZ) and [18F]fluorodeoxyglucose to study GABA type A/benzodiazepine (GA-BA-A/BDZ) receptors and cerebral metabolic rates for glucose (1CMRg1c) in 17 male patients with severe chronic alcoholism (ALC), 8 with (ACD) and 9 without alcoholic cerebellar degeneration (non-ACD). In comparison with male normal controls of similar ages, the ALC group had significantly reduced FMZ ligand influx (K1), FMZ distribution volume (DV), and 1CMRg1c bilaterally in the medial frontal lobes, including superior frontal gyrus and rostral cingulate gyrus; the ACD group had significant reductions of K1, DV, and 1CMRg1c bilaterally in the same distribution, and also in the superior cerebellar vermis; and the non-ACD group had significant reductions of K1, DV, and 1CMRg1c bilaterally in the same regions of the frontal lobes but not in the superior cerebellar vermis. When compared with the non-ACD group, the ACD group had significant reductions of K1, and DV bilaterally in the superior cerebellar vermis. The results suggest that severe chronic alcoholism damages neurons containing GA-BA-A/BDZ receptors in the superior medial aspects of the frontal lobes, and in patients with clinical signs of ACD, neurons containing GABA-A/BDZ receptors in the superior cerebellar vermis.

Characteristics of the dysarthria of multiple system atrophy

OBJECTIVE

To characterize the dysarthria in patients with multiple system atrophy (MSA).

DESIGN

Motor speech examinations, consisting of oral motor, oral agility, and perceptual speech analysis, were performed on 46 patients with MSA.

SETTING

University department of neurology referral center.

RESULTS

All patients had dysarthria with combinations of hypokinesia, ataxia, or spasticity. Thirty-two patients had all 3 components, 13 had 2 components, and 1 had only 1 component. In most patients the hypokinetic components were the most severe. Hypokinetic components predominated in 22 patients (48%), whereas ataxic components predominated in 16 (35%), and spastic components in 5 (11%). In 1 patient (2%) the hypokinetic and spastic components were equal and greater than the ataxic components, and in 1 patient (2%) the hypokinetic and ataxic components were equal and greater than the spastic components. One patient (2%) had only ataxic dysarthria. The predominant type of dysarthria corresponded well to the subtype of MSA.

CONCLUSIONS

The finding of a mixed dysarthria with combinations of hypokinetic, ataxic, and spastic components is consistent with both the overall clinical and the neuropathologic changes in MSA. Motor speech examination can provide helpful information in evaluating patients who might have MSA.

Total quality management in hospitals: the contributions of commitment, quality councils, teams, budgets, and training to perceived improvement at Veterans Health Administration hospitals

Studies of total quality management as a means of improving health care quality to date have relied on case studies of individual teams or hospitals. The Total Quality Improvement Registry Project surveyed quality coordinators (n = 36) and quality improvement team leaders (n = 228) to collect both site-level and team-level data on quality improvement in Veterans Health Administration hospitals. Usable responses were received from 100% of quality coordinators and 73.7% (168) of team leaders. Site-level data include hospital structural characteristics and measures of training and commitment, as well as features and activities of the hospital quality councils. Team-level data include size, membership, task, age, activities, and a proxy measure of quality improvement. The authors report on the relations between levels of commitment to total quality management principles, training levels, activities of quality councils, and team formation and success. These data provide support for a model of commitment to quality improvement that involves four realms of influence within the medical centers: (1) management, (2) physician leadership, (3) physician staff and middle management, and (4) nurses and employees. The authors also report on the activities of quality councils and the relation of their activities to commitment and perceived improvement. Using bivariate correlation and multiple regression, the authors found that the age of the quality council, overall facility commitment to total quality management philosophy, and physician commitment are the most critical variables in explaining numbers of teams, training intensity, and total perceived improvement at this sample of medical centers. Specifically, we find that commitment to total quality management philosophy and the number of active teams explains 41% of the observed variation in quality improvement. In future articles, the authors will report details of team activities and the development of teams over time.

DC60: an example of one of the 450 cases that compose the Denny-Brown collection of primate lesion material

The Denny-Brown collection consists of films depicting the behavioral responses of approximately 450 monkeys after central nervous system lesions; operative, behavioral, and neuropathologic descriptions; and histologic slides. This collection is available for use by interested investigators. This report describes one case, DC60, to provide an example of the types of material that are available and how these materials might be used better to understand the nervous system. To demonstrate how precisely the actual lesions can be defined and compared with the planned ablations, this report also includes a detailed evaluation of the extent of the lesions made in this case, based on the histologic slides and on photographs of the brain taken before histologic processing.

Utilization of available films and records of primates with central nervous system lesions

For many decades, ablation experiments were used to evaluate the function of central nervous system structures in primates. The use of this technique has greatly diminished with the development of neuronal unit recording. Nevertheless, the available films and written descriptions from prior ablation studies can still be used to further our understanding of: (1) the functional organization of the primate brain; (2) the differences in function between similar cerebral structures in primates and other mammals, and (3) ontogenetic changes in the functional characteristics of cerebral structures. We are in the process of making some of the films and records from these prior studies available to interested scientists.

Spinocerebellar ataxia type 1 with multiple system degeneration and glial cytoplasmic inclusions

Spinocerebellar ataxia type 1 (SCA1) is a dominantly inherited progressive neurological disorder characterized by neuronal degeneration and reactive gliosis in the cerebellum, brainstem, spinocerebellar tracts, and dorsal columns. Multiple system atrophy is a sporadic progressive neurological disorder with degeneration and gliosis in the basal ganglia, cerebellum, brainstem, and spinal autonomic nuclei, and with argyrophilic glial cytoplasmic inclusions. We describe 4 members of a family with the SCA1 mutation and a dominantly inherited progressive ataxia in which autopsy examination of 1 member showed neuropathological changes typical of multiple system atrophy, including glial cytoplasmic inclusions. In this patient, magnetic resonance imaging revealed marked brainstem and cerebellar volume loss and mild supratentorial generalized volume loss. Positron emission tomography with [18F]fluorodeoxyglucose revealed widespread hypometabolism in a pattern found in sporadic multiple system atrophy and not in dominantly inherited olivopontocerebellar atrophy. Positron emission tomography with [11C]flumazenil revealed normal benzodiazepine receptor distribution volumes, similar to those seen in sporadic multiple system atrophy. Two other family members still living had similar changes in the imaging studies. The findings in this family suggest that the SCA1 gene mutation can result in a disorder similar to multiple system atrophy, both clinically and neuropathologically.

Neuronal activity in the striatum and pallidum of primates related to the execution of externally cued reaching movements

We studied changes in basal ganglia neuronal activity associated with reaching movements of the arm in two monkeys. Data were obtained from 427 single neuronal units in putamen, 199 in caudate nucleus, and 216 in globus pallidus with multiwire electrodes allowing simultaneous recordings from multiple neurons. In all structures, changes in activity related to movement occurred most often after the onset of EMG: 43% of tested neurons in the putamen, 32% in the caudate nucleus, and 38% in the globus pallidus. Less frequently, changes began before EMG activation: 20% of neurons in the putamen, 19% in caudate nucleus, and 17% in globus pallidus. In general, these changes in neuronal activity lasted longer than EMG activity associated with reaching. The proportions of neurons activated were significantly larger in the putamen than the caudate nucleus. In the pallidum, the proportions were not statistically different from either the putamen or caudate nucleus, and no significant difference was found between the internal and external pallidal segments. Significant selectivity for movements to different targets was observed in 36% of neurons in the putamen, 28% in the caudate nucleus and 9% in the globus pallidus. The lower proportion in the globus pallidus compared to the striatum was significant (P < 0.002). Clusters of activated neurons were found in the striatum, however, the timing of changes was often different for individual neurons in these clusters. A cross-correlation analysis of the activity of neurons in the clusters revealed no evidence of common inputs, suggesting that striatal neurons in close proximity with neurons showing similar changes in activity are driven by different populations of neurons. In the putamen, the anatomical locations of neurons with changes in activity related to movement execution were on average significantly more posterior and lateral than neurons with changes related to the preparation of movement described earlier. These findings support the view that the putamen and the caudate nucleus contain distinct functional areas. The present studies show that most anatomical regions in both the striatum and pallidum participate in the control of executing reaching movements.

Cavernous malformation of the mammillary bodies: neuropsychological implications. Case report

The authors present the first documented case of a cavernous malformation of the mammillary bodies. A 34-year-old woman presented with a 2-month history of headaches and acute memory changes. Magnetic resonance imaging studies demonstrated a retrochiasmatic interpeduncular lesion that was initially thought to be a craniopharyngioma. Operative resection confirmed the diagnosis of a cavernous malformation. This particular case is unique in its destruction of the mammillary bodies and presents further evidence of the relationship of these regions to memory. This report is also the first to document results of pre- and postoperative neuropsychological evaluations that specifically address the memory deficits created by destruction of the mammillary bodies.

Benzodiazepine receptor binding in cerebellar degenerations studied with positron emission tomography

We used positron emission tomography with [11C]flumazenil to study gamma-aminobutyric acid type A/benzodiazepine receptor binding quantitatively in the cerebral hemispheres, basal ganglia, thalamus, cerebellum, and brainstem of 72 subjects, including 14 with multiple system atrophy of the ataxic (olivopontocerebellar atrophy) type, 5 with multiple system atrophy of the extrapyramidal/autonomic (Shy-Drager syndrome) type, 18 with sporadic olivopontocerebellar atrophy, 15 with dominantly inherited olivopontocerebellar atrophy, and 20 normal control subjects with similar age and sex distributions. In comparison with data obtained from the normal control subjects, we found significantly decreased ligand influx in the cerebellum and brainstem of multiple system atrophy patients of the olivopontocerebellar atrophy type and in patients with sporadic olivopontocerebellar atrophy, but not in patients with multiple system atrophy of the Shy-Drager syndrome type. Despite these differences in ligand influx, benzodiazepine binding was largely preserved in the cerebral hemispheres, basal ganglia, thalamus, cerebellum, and brainstem in patients with multiple system atrophy of both types as well as those with sporadic or dominantly inherited olivopontocerebellar atrophy as compared with normal control subjects. The finding of relative preservation of benzodiazepine receptors indicates that these sites are available for pharmacological therapy in these disorders.

A comparison of cerebral blood flow and glucose metabolism in olivopontocerebellar atrophy using PET

OBJECTIVE

In sporadic cases of olivopontocerebellar atrophy (OPCA), to determine whether local cerebral blood flow (lCBF) is reduced, whether lCBF is coupled to local cerebral metabolic rate for glucose (lCMRglc), and whether lCBF measurements are potentially useful in diagnosing OPCA.

DESIGN

Positron emission tomography was used with [15O]H2O to measure lCBF and with [18F]fluorodeoxyglucose to measure lCMRglc in 17 patients with OPCA and 21 normal control subjects.

RESULTS

In OPCA patients, lCBF was significantly decreased in the cerebellum, but not in the cerebral cortex, basal ganglia, thalamus, or brainstem. In the same patients, lCMRglc was significantly decreased in the cerebellum and brainstem, where the largest changes were observed, and also in the cerebral cortex, basal ganglia, and thalamus. The ratio of lCBF to lCMRglc, an indicator of the coupling of blood flow to metabolism, was similar in OPCA patients and normal subjects for all regions except the brainstem, where the ratio was marginally decreased in OPCA patients. Using logistic discriminant analysis to assess the ability of lCBF and lCMRglc to differentiate OPCA patients from normal subjects, we found the cross-validated sensitivity of absolute lCMRglc as a predictor of OPCA was 82% with a corresponding specificity of 71%; the sensitivity of absolute lCBF was 71% and the specificity 76%.

CONCLUSIONS

In sporadic cases of OPCA, lCBF is reduced in the cerebellum, CBF remains coupled to lCMRglc, and the lCBF pattern is a useful predictor of the diagnosis.

Increasing coordination of the dementia service delivery network: planning for the Community Outreach Education Program

Dementia is an emerging public health concern because of its prevalence and the cost and extent of care typically needed for people with cognitive disorders. When family members seek assistance in providing care, they frequently encounter a fragmented service delivery network. To increase the coordination of services for people with dementia, the Community Outreach Education Program (COEP) has been designed to provide educational interventions to disseminate information about the diagnosis, assessment, management, and treatment of dementia to health care professionals, service providers, staff of volunteer and community organizations, and family members. This article describes plans for the COEP within the context of a community development perspective.

The Denny-Brown collection: a research and teaching resource

A large collection of potentially valuable materials compiled by the late Dr Derek Denny-Brown is described. This consists of 2,200 films of monkeys with central nervous system lesions, associated behavior and neuropathological descriptions, and histological slides. There are also 500 films of patients with a wide assortment of diseases, including some not currently seen, like postencephalitic parkinsonism. This description will enable contemporary researchers to utilize this collection in their research and teaching programs.