Widespread alterations of alpha-synuclein in multiple system atrophy

Glial cytoplasmic inclusions (GCI) are the hallmark of multiple system atrophy (MSA), a rare movement disorder frequently associated with autonomic dysfunction. In this study of 21 cases of MSA, GCI were consistently immunoreactive for alpha-synuclein and double-immunostained for ubiquitin and oligodendroglial markers, but not glial fibrillary acidic protein. No statistically significant difference was found in the density of GCI in various brain regions in the two forms of MSA, striatonigral degeneration (SND) and olivopontocerebellar atrophy (OPCA). Postmortem brain samples from 9 cases of MSA were fractionated according to solubility in buffer, Triton-X 100, sodium dodecyl sulfate (SDS), and formic acid, and alpha-synuclein immunoreactivity was measured in Western blots. Total alpha-synuclein immunoreactivity was increased in MSA compared to controls, with no statistically significant difference between SND and OPCA. Most of the increase was due to alpha-synuclein in SDS fractions. In controls this fraction had little or no immunoreactivity. In 7 cases and 4 controls correlations were investigated between quantitative neuropathology and biochemical properties of alpha-synuclein. Surprisingly, the amount of SDS-soluble alpha-synuclein correlated poorly with the number of GCI in adjacent sections. Furthermore, areas with few or no GCI unexpectedly had abundant SDS-soluble alpha-synuclein. These findings provide evidence that modifications of alpha-synuclein in MSA may be more widespread than obvious histopathology. Moreover, these alterations may constitute a biochemical signature for the synucleinopathies.

Denny-Brown's views on the pathophysiology of dystonia

We review Denny-Brown's hypotheses on the mechanisms underlying motor behavior and his views on how dysfunction in these mechanisms can result in dystonia. His formulations were based upon clinical observations of patients with diseases of the central nervous system and on monkeys with surgically-induced lesions of structures affected by diseases in his patients. Denny-Brown viewed dystonia as resulting from an imbalance of reflex responses to natural stimulation, both tonically and phasically. The evidence for this view came from demonstration of alterations of dystonic postures by natural vestibular, cutaneous, proprioceptive and visual stimuli. His formulations remain highly useful to clinicians faced with a bewildering variety of postural and movement disorders.

Racial variation in the use of laparoscopic cholecystectomy in the Department of Veterans Affairs medical system

BACKGROUND

While studies have found racial differences in the rates of use of established invasive cardiac and cerebrovascular procedures, no study has evaluated racial variation in the rates of adoption of new surgical procedures. For patients undergoing laparoscopic cholecystectomy, the procedure represents a new and safe option that shortens the duration of postoperative hospitalization by almost one week. In this study, we evaluated whether, in the equal access Veterans Affairs (VA) medical system, the rate of adoption of this procedure and improvements in the duration of postoperative hospitalization differed between African-American and Caucasian patients.

STUDY DESIGN

Data were obtained from two sources-administrative claims files and prospectively compiled dinical data from medical records and patient interviews. In both data sets, frequency of use, length of stay, and outcomes for African-American and Caucasian patients undergoing minimally invasive and open gallbladder surgery were analyzed for the first four years of use of the procedure in the VA system (1992 to 1995).

RESULTS

Analyses based on claims files indicated that, after adjustment for potentially confounding variables, African-American patients who underwent cholecystectomy in VA medical centers were 25% less likely to undergo a minimally invasive cholecystectomy during the first 4 years of use of the new procedure (adjusted odds ratio, 0.74; 95% confidence interval, 0.66-0.83). Shortening of the average postoperative length of stay from 9 days or more in the prelaparoscopic era to less than 4.5 days for patients undergoing the laparoscopic procedure occurred in the first year for Caucasian patients, but did not occur until the fourth year for African-American patients (p<0.001). The overall difference in postoperative length of stay between African-American and Caucasian patients more than doubled from 1.7 days before introduction of laparoscopic cholecystectomy to 3.8 days in the fourth year. In comparison, analyses based on nurse-compiled clinical data indicated that, after adjustment for relevant clinical factors, racial variations in the rate of laparoscopic surgery were even larger (adjusted odds ratio for laparoscopic versus open cholecystectomy for African-American versus Caucasian veterans, 0.68; 95% confidence interval, 0.55-0.84).

CONCLUSIONS

Compared to Caucasian patients, African-American patients who underwent cholecystectomy in VA medical centers had an approximately 25% to 32% lower likelihood of undergoing minimally invasive cholecystectomy procedures. The differences in rates of adoption of laparoscopic surgery did not appear to be from more comorbid illnesses among African-American patients. African-American and Caucasian veterans may differ in their preference for new surgical procedures like laparoscopic cholecystectomy. Conversely, VA physicians may have been less likely to recommend laparoscopic cholecystectomies to African-American patients.

Decreased striatal monoaminergic terminals in multiple system atrophy detected with positron emission tomography

We examined the density of striatal presynaptic monoaminergic terminals, using a ligand for the type 2 vesicular monoamine transporter, (+)-[11C]dihydrotetrabenazine, with positron emission tomography in 7 normal control subjects, 8 multiple system atrophy (MSA) patients with predominantly parkinsonian features (MSA-P), 8 MSA patients with principally cerebellar dysfunction (MSA-C), and 6 sporadic olivopontocerebellar atrophy (sOPCA) patients. The findings were correlated with the results of neurological evaluations and magnetic resonance imaging studies. Specific binding was significantly reduced in the putamen of all patient groups in the order MSA-P < MSA-C < sOPCA, compared with controls. Mean blood-to-brain ligand transport (K1) was significantly decreased in the putamen of all patient groups and in the cerebellar hemispheres of MSA-C and sOPCA but not MSA-P groups, compared with controls. Significant negative correlations were found between striatal binding and the intensity of parkinsonian features and between cerebellar K1 and the intensity of cerebellar dysfunction. The results suggest fundamental differences between MSA-P and MSA-C groups reflecting differential severity of degeneration of nigrostriatal and cerebellar systems in these two forms of MSA. The findings also show that some sOPCA patients have subclinical nigrostriatal dysfunction and are at risk of developing MSA with disease progression.

Disorders of proprioceptive responses in monkeys after cerebellar lesions: an analysis using the Denny-Brown Collection

We used the Denny-Brown Research Collection to study in detail the reflex responses of monkeys after ablation of the anterior lobe, posterior lobe or the entire cerebellum. The Collection includes written, film and histological records, and photographs of the brain at autopsy. Large cerebellar ablations severely suppress proprioceptive responses, thereby significantly impairing the capacity to stand, walk, and hop. Cutaneous reflexes are also impaired, although more selectively, permitting expression of normally suppressed responses such as magnet reactions and tactile avoiding responses. Enhancement (release) of responses to truncal cutaneous stimulation, along with suppression of opposing proprioceptive responses, leads to postures of persistent flexion. Large cerebellar lesions also interfere with reflex responses mediated by visual and vestibular systems. More limited cerebellar ablations have similar, but less severe effects.

Consensus statement on the diagnosis of multiple system atrophy

We report the results of a consensus conference on the diagnosis of multiple system atrophy (MSA). We describe the clinical features of the disease, which include four domains: autonomic failure/urinary dysfunction, parkinsonism and cerebellar ataxia, and corticospinal dysfunction. We set criteria to define the relative importance of these features. The diagnosis of possible MSA requires one criterion plus two features from separate other domains. The diagnosis of probable MSA requires the criterion for autonomic failure/urinary dysfunction plus poorly levodopa responsive parkinsonism or cerebellar ataxia. The diagnosis of definite MSA requires pathological confirmation.

Diagnostic criteria for Parkinson disease

The clinical diagnosis of Parkinson disease (PD) is based on the identification of some combination of the cardinal motor signs of bradykinesia, rigidity, tremor, and postural instability, but few attempts have been made to develop explicit diagnostic criteria. We propose a clinical diagnostic classification based on a comprehensive review of the literature regarding the sensitivity and specificity of the characteristic clinical features of PD. Three levels of diagnostic confidence are differentiated: Definite, Probable, and Possible. The diagnoses of Possible and Probable PD are based on clinical criteria alone. Neuropathologic confirmation is required for the diagnosis of Definite PD in patients with the clinical diagnosis of Possible or Probable PD. Criteria for histopathologic confirmation of PD are also presented.

Consensus statement on the diagnosis of multiple system atrophy

We report the results of a consensus conference on the diagnosis of multiple system atrophy (MSA). We describe the clinical features of the disease, which include four domains: autonomic failure/urinary dysfunction, parkinsonism and cerebellar ataxia, and corticospinal dysfunction. We set criteria to define the relative importance of these features. The diagnosis of possible MSA requires one criterion plus two features from separate other domains. The diagnosis of probable MSA requires the criterion for autonomic failure/urinary dysfunction plus poorly levodopa responsive parkinsonism or cerebellar ataxia. The diagnosis of definite MSA requires pathological confirmation.

Consensus statement on the diagnosis of multiple system atrophy. American Autonomic Society and American Academy of Neurology

We report the results of a consensus conference on the diagnosis of multiple system atrophy (MSA). We describe the clinical features of the disease, which include four domains: autonomic failure/urinary dysfunction, parkinsonism and cerebellar ataxia, and corticospinal dysfunction. We set criteria to define the relative importance of these features. The diagnosis of possible MSA requires one criterion plus two features from separate domains. The diagnosis of probable MSA requires the criterion for autonomic failure/urinary dysfunction plus poor levodopa responsive parkinsonism or cerebellar ataxia. The diagnosis of definite MSA requires pathological confirmation.

Decreased striatal monoaminergic terminals in severe chronic alcoholism demonstrated with (+)[11C]dihydrotetrabenazine and positron emission tomography

We used (+)[11C]dihydrotetrabenazine, a new ligand for the type 2 vesicular monoamine transporter, with positron emission tomography to study striatal monoaminergic presynaptic terminals in 7 male severe chronic alcoholic subjects without Wernicke-Korsakoff disease compared with 7 male normal controls of similar ages. We found reduced specific binding in the caudate nucleus and putamen in the alcoholic group, and the difference reached significance in the putamen. Specific binding was not decreased in the thalamus, which was examined as a reference structure. We also detected deficits in blood-to-brain transfer rate, K1, in the same regions of the alcoholic group, with a significant difference in the putamen. K1 was unchanged in the thalamus. The finding of reduced striatal VMAT2 in severe chronic alcoholic patients suggests that nigrostriatal monoaminergic terminals are reduced, with or without loss of neurons from the substantia nigra. The findings suggest that the damaging effects of severe chronic alcoholism on the central nervous system are more extensive than previously considered.

'Mouth-feeding' in monkeys after sensorimotor system lesions: an analysis based upon the Denny-Brown collection

Utilizing the Denny-Brown collection, we investigated an unusual feeding behavior exhibited by monkeys after sequential pre- and post-central gyrus lesions. The behavior involves ingestion of food by placing the lips directly over the food object, i.e., 'mouth-feeding.' Interestingly, this behavior persists long after recovery of the ability to hand-feed. In all of the cases within the collection and in descriptions of mouth-feeding found in the literature, mouth-feeding occurs only after bilateral lesions. We suggest that the co-existence of mouth- and hand-feeding behavior in animals with pre- and post-central gyrus lesions results partly from the sparing of corticospinal projections arising outside these gyri, e.g., the cingulate region, thereby preserving to a certain extent discrete use of the forelimbs.

The significance of family history status in relation to neuropsychological test performance and cerebral glucose metabolism studied with positron emission tomography in older alcoholic patients

Patients with severe chronic alcoholism have decreased rates of glucose metabolism in the medial frontal lobe and correlated abnormalities of neuropsychological functioning. The potential influence of family history of alcoholism has not been examined in these patients. In a retrospective study, we used neuropsychological tests and neuroimaging employing [18F]fluorodeoxyglucose with positron emission tomography to study 48 older subjects who had histories of severe, chronic alcohol dependence. These patients were divided into two groups: 27 with a first-degree relative with chronic alcoholism and 21 patients without first-degree relative with chronic alcoholism. No differences were found between groups on either neuropsychological or neuroimaging tests. These results suggest that a family history of alcoholism does not moderate the damaging effects of severe chronic alcoholism on the functioning of the medial frontal lobe.

Positive and negative factors in movement control: a current review of Denny-Brown's hypothesis

In his extensive writings, Denny-Brown hypothesized that two competitive 'tropisms,' one positive (exploratory) and one negative (withdrawal) act to coordinate normal movements at all levels of the neuraxis. Lesions in particular areas of the central nervous system result in disequilibrium between these tropisms, leading to disorders of posture and movement, including involuntary movements. The tactile manifestations of unbalanced exploratory tropisms are grasping responses, whereas the complementary withdrawal tropisms are avoiding responses. In Denny-Brown's view, at the level of the cerebral cortex, grasping responses result from frontal lobe injury whereas avoiding responses result from parietal lobe lesions. In this report we review Denny-Brown's conceptions of positive and negative tropisms, their anatomical loci, and whether his hypothesis has merit in a contemporary approach to brain function. We find that Denny-Brown's view on the anatomical loci associated with these behaviors is incomplete, but that the idea of conflicting behavioral tendencies is valuable for understanding and managing some neurological and perhaps also psychiatric disorders. For example, his hypothesis offers an important perspective in understanding the paradoxical success of stereotaxic surgery to alleviate the symptoms of Parkinson's disease.

Diagnostic criteria for dementia in clinical trials. Position paper from the International Working Group on Harmonization of Dementia Drug Guidelines

Some of the issues associated with standardizing the diagnosis of dementia in clinical trials are outlined. Deliberations of the Working Group on Diagnostic Criteria and their recommendations for future actions needed to develop a consensus are described.

An Internet Multicast Symposium Concerning the Microcirculation of the Islets of Langerhans

The Internet Globally-linked Computer System was used to conduct an international scientific symposium. The symposium was held at the VAMC-Long Beach and consisted of prepared lectures that were multicast over the Internet. The basic unit of hardware used for the Internet Multicast was the Silicon Graphics Indy Unix Workstation, which was equipped with a color video camera. The multicast required four additional pieces of software from the file transfer protocol. The multicast backbone protocol allowed for simultaneous audio and video signals (the presenter, the slides, and the videotape images of islet microcirculation studies) to be transmitted over the computer network. The faculty included 12 experts in microcirculation, who gave 15-min lectures that included a question and answer period. All lectures were received at 14 computer stations in six countries. Eleven of the faculty gave their lectures at the VAMC-Long Beach, and one gave her lecture at the Massachusetts Institute of Technology in Boston, MA. The presenter from Boston was able to receive and answer questions from the faculty at the VAMC-Long Beach. An estimated $12,000 was saved in travel, hotel, and food costs and an estimated 180 travel hours were saved by viewers who did not have to travel to the symposium. We have demonstrated that a scientific symposium can be conducted using the Internet. We propose that many of our future meetings will be organized over the computer network. This format of multiimage projections allows us to effectively communicate in a personal way with a reduction in expensive and time-consuming travel.

Frontotemporal dementia and parkinsonism linked to chromosome 17: a consensus conference. Conference Participants

We held an international consensus conference on frontotemporal dementia, behavioral disturbances, and parkinsonism linked to chromosome 17 to determine whether these are homogeneous or heterogeneous disorders, to agree on terminology, and to develop strategies for further research. The group identified 13 kindreds with sufficient evidence for linkage, finding in common to all a critical 2 cM between markers D17S791 and D17S800. There was agreement that (1) despite previous descriptions that have emphasized one or another clinical or neuropathological feature, the kindreds share clinical and neuropathological features; (2) until more specific information about the genetic defects becomes available, this disorder is best termed frontotemporal dementia and parkinsonism linked to chromosome 17; and (3) further research will be enhanced by identifying the gene or genes responsible for this disorder, detecting additional cases within known families and, in new families, correlating mutations with phenotypes and more fully delineating the clinical, neuropsychological, and neuropathological characteristics of this disorder.

Effects of abstinence and relapse upon neuropsychological function and cerebral glucose metabolism in severe chronic alcoholism

Prolonged excessive consumption of alcohol has been associated with a variety of cognitive disorders accompanied by neuropathological and neurochemical abnormalities of the brain, particularly in the frontal lobes. Studies with positron emission tomography (PET) have shown decreased local cerebral metabolic rates for glucose (lCMRglc) in frontal regions, with correlated abnormalities on neuropsychological tests sensitive to executive functioning. This investigation was designed as a pilot study to examine the effects of abstinence and relapse in patients with severe chronic alcoholism studied longitudinally with PET and with neuropsychological evaluation to assess both general and executive functioning. Six patients, including 4 who remained relatively abstinent and 2 who relapsed following their initial evaluation, were studied twice, with inter-evaluation intervals ranging from 10 to 32 months. The patients who remained abstinent or who had minimal alcohol use showed partial recovery of lCMRglc in two of three divisions of the frontal lobes and improvement on neuropsychological tests of general cognitive and executive functioning, whereas the patients who relapsed had further declines in these areas. These results, although based upon a relatively small number of subjects, provide preliminary support for at least partial recovery of metabolic and cognitive functioning in individual patients who abstain from alcohol.