Biomedical subjects

I Litvan

Publications and source records attributed to I Litvan.

At least 73 records · Page 4Linked to original sources

PubMed1998

Dysfunction of Ib (autogenic) spinal inhibition in patients with progressive supranuclear palsy.

We compared the activity of Ib spinal interneurons in five patients with progressive supranuclear palsy (PSP) with six age-matched control subjects. Stimulation of the medial gastrocnemius nerve at motor threshold intensity activated Ib afferents that in turn inhibit H reflexes from the soleus muscle. Maximum inhibition occurred at interstimulus intervals of 6 and 8 ms for both control subjects and PSP patients and was significantly greater in the PSP patients. Increased Ib activity of PSP patients may be caused by loss of inhibition of Ib interneurons through degeneration of the medullary reticulospinal pathway. The corticospinal pathways, unopposed by the medullary reticulospinal tract, may excessively activate Ib interneurons.

Afferent Pathways↗

PubMed1998

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.

Antiparkinson Agents↗

PubMed1998

Retrospective application of a set of clinical diagnostic criteria for the diagnosis of multiple system atrophy.

We estimated the accuracy of a modified commonly used set of clinical diagnostic criteria for the diagnosis of multiple system atrophy (MSA) by retrospectively applying the criteria to the features recorded by six neurologists who had evaluated 105 autopsy-confirmed cases (16 MSA and 89 non-MSA disorders). Cases were abstracted from the records of the patients' first visit to an academic center, and were presented as clinical vignettes to six neurologists, each of whom recorded the main clinical features of the presented clinical vignette on a standardized form. Sensitivity and positive predictive values were chosen as validity outcome measures and were calculated by comparing the applied diagnostic criteria to the neuropathologic information. Of note, most MSA patients in this study (mainly those with Shy-Drager type) had not received levodopa therapy since the primary neurologists often had not perceived a need to administer this treatment. The validity of the retrospectively applied criteria for the diagnosis of possible MSA (sensitivity: median, 53%, range, 50-69%; positive predictive value: 30%, 28-39%) and probable MSA (sensitivity: 44%, 31-60%; positive predictive value: 68%, 54-80%) at the first visit was suboptimal. The best, still not perfect, accuracy for this set of diagnostic criteria was obtained when six out of eight features (sporadic adult onset, dysautonomia, parkinsonism, pyramidal signs, cerebellar signs, no levodopa response, no cognitive dysfunction, or no downward gaze supranuclear palsy) were present (median sensitivity, 59%; range, 50-75%; positive predictive value: 67%, 53-83%). This is the first study to validate criteria for the clinical diagnosis of MSA. Our data suggest that it is difficult to achieve an early and accurate clinical diagnosis of this disorder. The probability of correctly diagnosing MSA increases when at least six features of this modified set of criteria are present or when requiring the set for probable MSA.

Adult↗

PubMed1998

Accuracy of the clinical diagnosis of postencephalitic parkinsonism: a clinicopathologic study.

The accuracy of the clinical diagnosis of postencephalitic parkinsonism (PEP) is unknown. We determined the validity of the clinical diagnosis of PEP by presenting 105 records with neuropathologic diagnoses of PEP (n = 7), progressive supranuclear palsy (n = 24), Parkinson's disease (n = 15), dementia with Lewy bodies (n = 14), multiple system atrophy (n = 16), corticobasal degeneration (n = 10), Creutzfeldt-Jakob disease (n = 4), and other dementia disorders (n = 15), as clinical vignettes to six neurologists unaware of the autopsy findings. The neurologists' own clinical diagnoses were compared with neuropathologic diagnoses for measures of diagnostic accuracy, including reliability (kappa statistics), sensitivity and positive predictive values for the first and last visits. The group reliability for the diagnosis of PEP was almost perfect (kappa = 0.91, 0.9). The mean sensitivity at the first visit was 86% (range, 71-100%) with minimal change at the last visit (83%; range, 71-100%). Positive predictive values remained unchanged (100%). The high reliability, sensitivity and positive predictive values of the clinical diagnosis of PEP indicate that neurologists identify this disorder even when they report that they have never evaluated a case. In our data set, the best predictors for the diagnosis of PEP included onset below middle age; symptom duration lasting more than 10 years, and the presence of oculogyric crisis. History of encephalitis lethargica, present in most PEP cases, was an important individual diagnostic predictor. Copyright 1998 Lippincott Williams & Wilkins

Journal Article↗

PubMed1998

Natural history and survival of 14 patients with corticobasal degeneration confirmed at postmortem examination.

OBJECTIVE: To analyse the natural history and survival of corticobasal degeneration by investigating the clinical features of 14 cases confirmed by postmortem examination. METHODS: Patients with definite corticobasal degeneration were selected from the research and clinical files of seven tertiary medical centres in Austria, the United Kingdom, and the United States. Clinical features were analysed in detail. RESULTS: The sample consisted of eight female and six male patients; mean age at symptom onset was 63 (SD 7.7) years, and mean disease duration was 7.9 (SD 2.6) years. The most commonly reported symptom at onset included asymmetric limb clumsiness with or without rigidity (50%) or tremor (21%). At the first neurological visit, on average 3.0 (SD 1.9) years after symptom onset, the most often encountered extrapyramidal features included unilateral limb rigidity (79%) or bradykinesia (71%), postural imbalance (45%), and unilateral limb dystonia (43%). Ideomotor apraxia (64%), and to a lesser extent cortical dementia (36%), were the most common cortical signs present at the first visit. During the course of the disease, virtually all patients developed asymmetric or unilateral akinetic rigid parkinsonism and a gait disorder. No patient had a dramatic response to levodopa therapy. Median survival time after onset of symptoms was 7.9 (SD 0.7) (range, 2.5-12.5) years, and, after the first clinic visit, 4.9 (SD 0.7) (range, 0.8-10) years. Early bilateral bradykinesia, frontal syndrome, or two out of tremor, rigidity, and bradykinesia, predicted a shorter survival. CONCLUSION: The results confirm that unilateral parkinsonism unresponsive to levodopa and limb ideomotor apraxia are the clinical hallmarks of corticobasal degeneration, and only a minority of patients with corticobasal degeneration present with dementia. The study also suggests that a focal cognitive and extrapyramidal motor syndrome is indicative of corticobasal degeneration. Survival in corticobasal degeneration was shortened by the early presence of (more) widespread parkinsonian features or frontal lobe syndrome.

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PubMed1998

Neuropsychiatric features of corticobasal degeneration.

OBJECTIVE: To characterise the neuropsychiatric symptoms of patients with corticobasal degeneration (CBD). METHODS: The neuropsychiatric inventory (NPI), a tool with established validity and reliability, was administered to 15 patients with CBD (mean (SEM), age 67.9 (2) years); 34 patients with progressive supranuclear palsy (PSP) (66.6 (1.2) years); and 25 controls (70 (0.8) years), matched for age and education. Both patient groups had similar duration of symptoms and mini mental state examination scores. Semantic fluency and motor impairment were also assessed. RESULTS: Patients with CBD exhibited depression (73%), apathy (40%), irritability (20%), and agitation (20%) but less often had anxiety, disinhibition, delusions, or aberrant motor behaviour (for example, pacing). The depression and irritability of patients with CBD were more frequent and severe than those of patients with PSP. Conversely, patients with PSP exhibited significantly more apathy than patients with CBD. The presence of high depression and irritability and low apathy scale scores correctly differentiated the patients with CBD 88% of the time. The irritability of patients with CBD was significantly associated with disinhibition (r=0.85) and apathy (r=0.72). In CBD, apathy was associated with disinhibition (r=0.67); disinhibition was associated with aberrant motor behaviour (r=0.68) and apathy (r=0.67); and aberrant motor behaviour with delusions (r=1.0). On the other hand, depression was not associated with any other behaviour, suggesting that it has a different pathophysiological mechanism. Symptom duration was associated with total motor scores (r=0.69). However, total motor score was not associated with any behaviour or cognitive scores. CONCLUSIONS: The findings indicate that frontosubcortical pathways mediating cognition, emotion, and motor function in CBD are not affected in parallel. Patients with CBD and PSP have overlapping neuropsychiatric manifestations, but they express distinctive symptom profiles. Evaluating the behavioural abnormalities of parkinsonian patients may help clarify the role of the basal ganglia in behaviour.

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PubMed1998

Apathy is not depression.

If depression is associated with apathy, then they should be expressed together in different dementia syndromes and should co-occur at varying levels of disease severity. The authors performed a cross-sectional comparison of neuropsychiatric symptoms in 30 Alzheimer's disease, 28 frontotemporal dementia, 40 Parkinson's disease, 34 Huntington's disease, and 22 progressive supranuclear palsy patients, using a standardized rating scale (the Neuropsychiatric Inventory). Apathy did not correlate with depression in the combined sample; apathy (r = -0.40, P < 0.0001), but not depression, correlated with lower cognitive function as measured by the Mini-Mental State Examination. The relationship of apathy to depression also varied across diagnostic groups. Apathy is a specific neuropsychiatric syndrome that is distinct from depression. Distinguishing these two syndromes has therapeutic implications.

Adult↗

PubMed1998

Clinical and genetic aspects of progressive supranuclear palsy.

Progressive supranuclear palsy (PSP) is, after Parkinson's disease, the most common form of degenerative parkinsonism. Several clinical features are used in the recognition of this disorder as well as in the differentiation from related disorders. Clinical criteria that could increase diagnostic accuracy in research studies are also emphasized. Due to a better understanding of the genetic aspects of PSP, recent studies have suggested that it is a recessive disorder in linkage disequilibrium with the tau (tau) gene, rather than a sporadic disorder. In addition, the recent identification of mutations in the tau gene associated with a similar neurodegenerative condition (frontotemporal dementia and parkinsonism linked to chromosome 17) has further strengthened the argument that tau dysfunction is somehow involved in the pathogenesis of PSP. Nongenetic factors that could trigger or perpetuate the cascade of events leading to neuronal degeneration in PSP are also reviewed.

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PubMed1998

Progressive supranuclear gaze palsy is in linkage disequilibrium with the tau and not the alpha-synuclein gene.

We studied two candidate genes, tau (tau) and alpha-synuclein (SNCA), for evidence of linkage disequilibrium on a group of unrelated individuals with progressive supranuclear palsy (PSP) and a group of age-matched control subjects. The tau alpha1 allele and the tau alpha1alpha1 genotype were overrepresented in individuals with PSP and the tau polymorphism was in linkage disequilibrium with the PSP disease locus when a recessive inheritance model was employed. We also report a lack of evidence to support linkage disequilibrium between PSP and the SNCA candidate Parkinson's disease gene on chromosome 4q21-q23.

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PubMed1998

Progressive supranuclear palsy: a survey of the disease course.

BACKGROUND: The most accurate knowledge about progressive supranuclear palsy (PSP) comes from small sample studies that preclude precise estimation of the proportion of PSP patients affected with various symptoms and the examination of factors predicting survival time. OBJECTIVE: To describe the course of PSP in a large clinically diagnosed sample of PSP patients and to identify factors predicting survival time. METHODS: We surveyed the caregivers of 318 living and 119 deceased patients with progressive supranuclear palsy. The main outcome measures were a principal symptom severity questionnaire and a signs and symptoms questionnaire. RESULTS: The estimated age of PSP symptom onset depends critically on how symptom onset is defined, with estimates differing by as much as 1.5 years. Men and women were represented equally (51.6% versus 48.4%) in the living sample, but men formed 61.8% of the deceased sample. Men were diagnosed later than women following symptom onset (33.4 versus 24.1 months) and died earlier following the diagnosis (37.0 versus 47.6 months). Motor and visual symptoms appeared first, followed by emotional and personality problems, cognitive impairment, and sleep changes. Whereas motor symptoms eventually affected almost every patient, emotional/personality and cognitive symptoms did not. The early onset, presence of falls, slowness, and inability to move eyes downward early in the development of the disease predicted survival time. CONCLUSION: PSP is a rapidly progressive disease dominated by motor symptoms, and it affects men more frequently than women.

Affective Symptoms↗

PubMed1998

Caregiving in progressive supranuclear palsy.

BACKGROUND: Basic issues regarding factors influencing progressive supranuclear palsy (PSP) patient caregiver burden remain unresolved, including whether and how disease severity and duration influence caregiver burden. OBJECTIVE: To examine the relation between PSP patient caregiver burden and disease severity, describe the time course of caregiver burden in relation to disease progression, and identify the contribution of other factors (e.g., patient memory and behavioral problems, caregiver gender) to caregiver burden. METHODS: Mail survey of 180 caregivers of PSP patients (living at home and cared for by nonprofessionals) who were members of the Society for Progressive Supranuclear Palsy. The survey included the Burden Interview, an instrument measuring caregiver burden by inquiring how they feel about different aspects and demands of caregiving. RESULTS: Caregiver burden was related to both PSP disease severity (r = 0.40) and disability/need for assistance (r = 0.43). The relation between burden and disease duration was nonlinear, following the same time course as disease severity; the burden increased during the first 18 months postdiagnosis and leveled off thereafter. Women reported more burden than men (caregiver sex delta r2 = 0.05), even after controlling for disease severity and duration (delta r2 = 0.22) and patient gender (delta r2 < 0.01; NS), patient depression (delta r2 = 0.09), and aggressiveness (delta r2 = 0.02). CONCLUSION: Burden in PSP is related to disease severity, disease duration, and caregiver gender (even after controlling for patient's memory, patient depression, and aggression).

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PubMed1998

Progressive supranuclear palsy revisited.

Current understanding on the historic, epidemiologic, genetic, clinical, neuropathologic, neurochemical, diagnostic and therapeutic aspects of progressive supranuclear palsy (PSP) are revisited. In addition, new research directions are described.

Diagnosis, Differential↗

PubMed1998

[Parkinsonian syndromes and Parkinson's disease: differential clinical diagnosis].

Explore the source record for details and available documents.

Diagnosis, Differential↗

PubMed1998

Progressive supranuclear palsy revisited.

Diagnosis, Differential↗

PubMed1997

What is the accuracy of the clinical diagnosis of multiple system atrophy? A clinicopathologic study.

BACKGROUND: The presentation of symptoms for multiple system atrophy (MSA) varies. Because there are no specific markers for its clinical diagnosis, the diagnosis rests on the results of the neuropathologic examination. Despite several clinicopathologic studies, the diagnostic accuracy for MSA is unknown. OBJECTIVES: To determine the accuracy for the clinical diagnosis of MSA and to identify, as early as possible, those features that would best predict MSA. DESIGN: One hundred five autopsy-confirmed cases of MSA and related disorders (MSA [n=16], non-MSA [n=89]) were presented as clinical vignettes to 6 neurologists (raters) who were unaware of the study design. Raters identified the main clinical features and provided a diagnosis based on descriptions of the patients' first and last clinic visits. METHODS: Interrater reliability was evaluated with the use of kappa statistics. Raters' diagnoses and those of the primary neurologists (who followed up the patients) were compared with the autopsy-confirmed diagnoses to estimate the sensitivity and positive predictive values at the patients' first and last visits. Logistic regression analysis was used to determine the best predictors to diagnose MSA. RESULTS: For the first visit (median, 42 months after the onset of symptoms), the raters' sensitivity (median, 56%; range, 50%-69%) and positive predictive values (median, 76%; range, 61%-91%) for the clinical diagnosis of MSA were not optimal. For the last visit (74 months after the onset of symptoms), the raters' sensitivity (median, 69%; range, 56%-94%) and positive predictive values (median, 80%; range, 77%-92%) improved. Primary neurologists correctly identified 25% and 50% of the patients with MSA at the first and last visits, respectively. False-negative and -positive misdiagnoses frequently occurred in patients with Parkinson disease and progressive supranuclear palsy. Early severe autonomic failure, absence of cognitive impairment, early cerebellar symptoms, and early gait disturbances were identified as the best predictive features to diagnose MSA. CONCLUSIONS: The low sensitivity for the clinical diagnosis of MSA, particularly among neurologists who followed up these patients in the tertiary centers, suggests that this disorder is underdiagnosed. The misdiagnosis of MSA is usually due to its confusion with Parkinson disease or progressive supranuclear palsy, thus compromising the research on all 3 disorders.

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PubMed1997

Supranuclear gaze palsy and eyelid apraxia in postencephalitic parkinsonism.

We describe six patients with clinicopathologically confirmed post-encephalitic parkinsonism (PEP) in whom oculomotor abnormalities developed several years after suffering the initial episode of encephalitis lethargica. Four of the cases had vertical supranuclear gaze palsy and two eyelid apraxia, features typically associated with progressive supranuclear palsy (PSP). Our findings indicate that the presence of gaze palsy alone may not be a reliable clinical discriminator between PEP and PSP. Involvement of the dorsal central gray nucleus, nucleus centralis pontis oralis, nucleus dorsal raphe interpositus, rostral interstitial nucleus of the medial longitudinal fasciculus (riMLF), nucleus interstitialis of Cajal, nucleus of the posterior commissure, pedunculopontine nuclei and frontal cortex was observed in several of our PEP cases and may contribute to the oculomotor abnormalities in this disorder. Whether the dorsal tegmental nucleus, caudal to the supratrochlear nucleus, severely affected in all our PEP cases, has a role in vertical gaze needs to be further studied.

Adult↗

PubMed1997

Which clinical features differentiate progressive supranuclear palsy (Steele-Richardson-Olszewski syndrome) from related disorders? A clinicopathological study.

The difficulty in differentiating progressive supranuclear palsy (PSP, also called Steele-Richardson-Olszewski syndrome) from other related disorders was the incentive for a study to determine the clinical features that best distinguish PSP. Logistic regression and classification and regression tree analysis (CART) were used to analyse data obtained at the first visit from a sample of 83 patients with a clinical history of parkinsonism or dementia confirmed neuropathologically, including PSP (n = 24), corticobasal degeneration (n = 11), Parkinson's disease (PD, n = 11), diffuse Lewy body disease (n = 14). Pick's disease (n = 8) and multiple system atrophy (MSA, n = 15). Supranuclear vertical gaze palsy, moderate or severe postural instability and falls during the first year after onset of symptoms classified the sample with 9% error using logistic regression analysis. The CART identified similar features and was also helpful in identifying particular attributes that separate PSP from each of the other disorders. Unstable gait, absence of tremor-dominant disease and absence of a response to levodopa differentiated PSP from PD. Supranuclear vertical gaze palsy, gait instability and the absence of delusions distinguished PSP from diffuse Lewy body disease. Supranuclear vertical gaze palsy and increased age at symptom-onset distinguished PSP from MSA. Gait abnormality, severe upward gaze palsy, bilateral bradykinesia and absence of alien limb syndorme separated PSP from corticobasal degeneration. Postural instability successfully classified PSP from Pick's disease. The present study may help to minimize the difficulties neurologists experience when attempting to classify these disorders at early stages.

Fixation, Ocular↗

PubMed1997

Proton magnetic resonance spectroscopic imaging in progressive supranuclear palsy, Parkinson's disease and corticobasal degeneration.

We used proton magnetic resonance spectroscopic imaging (1H-MRSI) to assess the in vivo cortical and subcortical neuronal involvement in progressive supranuclear palsy, Parkinson's disease and corticobasal degeneration. This technique permitted the simultaneous measurement of compounds containing N-acetylaspartate (NA), choline (Cho), creatine-phosphocreatine (Cre) and lactate, from four 15-mm slices divided into 0.84-ml single-volume elements. The study included 12 patients with progressive supranuclear palsy, 10 with Parkinson's disease, nine with corticobasal degeneration and 11 age-matched normal control subjects. Regions of interest were selected from the brainstem, caudate, thalamus, lentiform nucleus, centrum semiovale, and from frontal, parietal, precentral, temporal and occipital cortices. Progressive supranuclear palsy patients, compared with control subjects, had significantly reduced NA/Cre in the brainstem, centrum semiovale, frontal and precentral cortex, and significantly reduced NA/Cho in the lentiform nucleus. Corticobasal degeneration patients, compared with control subjects, had significantly reduced NA/Cre in the centrum semiovale, and significantly reduced NA/Cho in the lentiform nucleus and parietal cortex. There were no significant differences between Parkinson's disease patients and control subjects, or between patients groups in any individual region of interest. In the parietal cortex of corticobasal degeneration patients, NA/Cho was significantly reduced contralateral to the most affected side. There were statistically significant group differences in the regional pattern of NA/Cre and NA/Cho reduction, comparing normal control subjects with all patient groups, Parkinson's disease with corticobasal degeneration, and Parkinson's disease with progressive supranuclear palsy. Although the occurrence of significant groups differences does not imply that it is possible to differentiate between individual patients using 1H-MRSI in progressive supranuclear palsy and corticobasal degeneration, detection of specific cortical and subcortical patterns of neuronal involvement is possible with this technique. We suggest that this regional pattern of neuronal involvement found in progressive supranuclear palsy and corticobasal degeneration may help in the diagnostic evaluation of affected individuals.

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