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Elan D Louis

Publications and source records attributed to Elan D Louis.

At least 37 records · Page 2Linked to original sources
PubMed2006

Neurologic manifestations of Whipple's disease.

Whipple's disease is a rare, multisystem, infectious disorder caused by the bacterium Tropheryma whippelii. Patients with central nervous system (CNS) involvement may present in a variety of ways, including cognitive impairment, psychiatric manifestations, gaze palsies, upper motor neuron signs, and hypothalamic dysfunction. A tissue-based diagnosis of Whipple's disease is made based on the presence of periodic acid-Schiff-stained material or by the identification of bacterial RNA using polymerase chain reaction. To avoid relapse, patients should be treated with antimicrobial agents that penetrate the CNS, and therapy should be continued for at least 1 year.

Journal Article↗
PubMed2006

Essential tremor.

Essential tremor (ET) is among the most common neurologic disorders. The traditional view of this disorder as a benign, monosymptomatic, familial condition is being replaced by a more complex view of ET as perhaps a family of diseases with etiologic, clinical, and pathologic heterogeneity. This article discusses the major clinical features of ET and approaches to its diagnosis and treatment.

Central Nervous System Agents↗
PubMed2006

Essential tremor: emerging views of a common disorder.

Essential tremor (ET) is the most prevalent tremor disorder. ET has traditionally been viewed as a monosymptomatic disorder characterized by a kinetic arm tremor, but this definition is gradually being replaced. The clinical spectrum has come to include several motor features, including tremor and ataxia, and several non-motor features, including possible cognitive impairment and personality disturbances. Postmortem studies are revealing several different patterns of pathology. The emerging view is that ET might be a family of diseases, unified by the presence of kinetic tremor, but further characterized by etiological, clinical and pathological heterogeneity. Effective pharmacological treatments for the disorder remain limited, although new insights into disease mechanisms might result in more-effective therapies. In addition, recent investigations of environmental toxicants that might be linked to ET open the way towards primary disease prevention through a reduction in exposure to these factors.

Essential Tremor↗
PubMed2005

Levetiracetam for the treatment of generalized dystonia.

We report the case of a woman with generalized dystonia whose symptoms improved with the use of levetiracetam. Improvements were noted in blepharospasm, cervical, and truncal dystonia. The patient has been on LEV for a total of 20 weeks, and has experienced sustained improvement of symptoms.

Anticonvulsants↗
PubMed2005

Incidence of essential tremor in three elderly populations of central Spain.

OBJECTIVE: To estimate the incidence of essential tremor (ET) in three populations in central Spain using data from the Neurologic Disorders in Central Spain (NEDICES), a population-based survey of elderly subjects (65 years and older). METHODS: Individuals were evaluated at baseline (1994 to 1995) and at follow-up (a median of 3.3 years later in 1997 to 1998). The evaluation included a screening question for ET and a neurologic examination, when possible. RESULTS: Of 5,278 subjects evaluated at baseline, there were 256 prevalent ET cases. Eighty-three incident ET cases were identified among 3,942 individuals assessed at follow-up. The adjusted annual incidence rate (per 100,000 person-years) in the population aged 65 years and older was 616 (95% CI: 447 to 784). Sixty-four (77.1%) of 83 incident cases had not been diagnosed before our assessment. CONCLUSIONS: The incidence of ET may be higher than previously recognized because a large proportion of patients with ET may never seek medical attention.

Age Factors↗
PubMed2005

Factor structure of motor signs in essential tremor.

Motor signs in essential tremor (ET) are varied. Patients may have limb tremors, including postural, kinetic (e.g. writing, pouring), and rest tremors, head tremor, voice tremor, or chin tremor. Factor analysis allows one to determine whether these signs fall into a smaller number of discrete domains. Such an analysis has not been performed on a group of ET cases. ET cases (n = 168) were recruited from the Neurological Institute of New York and a videotaped examination was performed. A factor analysis was performed on 17 motor items. Four distinct factors emerged, explaining 68.7% of the total variance. These were factor I (action tremor in the dominant arm), factor II (action tremor in the nondominant arm), factor III (tremor at rest) and factor IV (chin tremor, head tremor, and voice tremor). The demonstration of these four factors will be of potential use for pathological and genetic studies as well as interventional studies, as will be discussed.

Aged↗
PubMed2005

Case-control study of nutritional antioxidant intake in essential tremor.

The theory that oxidative stress is involved in the pathogenesis of neurodegenerative diseases has received considerable attention and studies have linked these diseases to the diminished use of antioxidant vitamins (vitamins E and C) and other dietary antioxidants. Essential tremor (ET) is a chronic, progressive disease. One possible disease mechanism is neurodegenerative. Whether nutritional antioxidant use differs between ET cases and controls is not known. Using a case-control design, we conducted detailed dietary assessments and tested the hypothesis that diminished use of nutritional antioxidants is associated with ET. Data on diet were collected on 156 ET cases and 220 controls using a semi-quantitative food-frequency questionnaire. There was no evidence that current nutritional antioxidant exposure differs in ET cases and controls. This does not exclude the possibility that nutritional antioxidant exposure was lower in ET cases prior to their disease onset.

Acetic Acid↗
PubMed2005

Clinical characteristics of essential tremor in Mersin, Turkey--a population-based door-to-door study.

OBJECTIVE: To describe the clinical features of essential tremor (ET) in a population. BACKGROUND: With few exceptions, clinical data on ET are derived from patients who attend specialty clinics. Most (> 90%) population-dwelling ET cases do not seek neurological attention. METHODS: 89 ET cases living in the Mersin province, Turkey were matched to 89 controls from the same population. All were examined by neurologists. Standardized scales included the Hamilton Depression Scale (HDS) and Hamilton Anxiety Scale (HAS). RESULTS: Eight-one (91%) of 89 cases previously had not been diagnosed as ET and 96.6% were untreated. Despite this,more than half (51.7%) of the cases answered "yes" to the question "are you disabled in some way by your tremor". Cases had more psychiatric symptomatology than controls (mean HDS scores = 11.4 +/- 8.2 vs. 7.9 +/- 6.1, p = 0.003 and mean HAS scores = 12.0 +/- 8.8 vs. 6.9 +/- 7.1, p < 0.001). Among ET cases, HDS scores (r = 0.24, p = 0.03) and HAS scores (r = 0.27, p = 0.01) were correlated with tremor severity. CONCLUSIONS: We present the clinical findings of a group of largely undiagnosed and untreated population-dwelling ET cases that would not otherwise have come to neurological attention. Approximately one-half reported functional difficulty and psychiatric symptoms were over-represented in these ET cases compared with matched controls. These findings suggest that ET, as it exists in the population, is not a completely benign entity.

Aged↗
PubMed2005

Functional correlates and prevalence of mild parkinsonian signs in a community population of older people.

BACKGROUND: Mild parkinsonian signs (MPS) are associated with incident dementia and an increased risk of mortality. To our knowledge, the functional correlates of MPS have not been studied. OBJECTIVES: To study the functional correlates of MPS, including self-reported and performance-based measures of function, and to determine the prevalence of MPS in a cohort of community-dwelling older people (aged >or=65 years). DESIGN: Participants (N = 1866) in the Washington Heights-Inwood Columbia Aging Project underwent a neurological assessment that included a modified motor portion of the Unified Parkinson's Disease Rating Scale, which yielded a parkinsonian sign score (range, 0-40) and parkinsonian sign subscores (axial function, rigidity, and tremor). A functional assessment included 3 self-reported measures of function and 2 performance-based tests. Participants with Parkinson disease were excluded. RESULTS: Mild parkinsonian signs were present in 469 (25.1%) of the 1866 participants. The parkinsonian sign score was correlated with functional and performance-based test scores (r = 0.24-0.32, P<.001). The axial function and rigidity subscores correlated to a greater extent with functional and performance-based test scores than did the tremor subscore. In analysis of covariance models, excluding participants with dementia and adjusting for age, sex, ethnicity, education, depressive symptoms, and medical illnesses (eg, arthritis), the parkinsonian sign score and age were strongly and independently associated with functional scores. CONCLUSIONS: Mild parkinsonian signs, and particularly axial dysfunction, were associated with functional disability, including self-reported and performance-based measures of functional difficulty. Given the high prevalence of these signs in elderly persons, MPS may be a significant indicator of disability in elderly persons.

Activities of Daily Living↗
PubMed2005

Contribution of aging to the severity of different motor signs in Parkinson disease.

BACKGROUND: Evidence does not support the view that Parkinson disease (PD) represents an accelerated aging process; however, the additional contribution of aging to the severity of different motor signs in patients with PD is not known. This knowledge may have implications for clinical trials of neuroprotective agents in PD. OBJECTIVE: To investigate the contribution of aging to the severity of the different motor signs of idiopathic PD. SETTING: Center for Parkinson Disease and Other Movement Disorders of the Columbia University Medical Center and a neurology clinic that primarily served individuals from the Washington Heights-Inwood community in New York City. PATIENTS: Sample of patients with a wide range of disease duration and age. DESIGN: Cross-sectional clinic-based study. Patients with PD were evaluated using the Unified Parkinson Disease Rating Scale (UPDRS). The total UPDRS motor score was divided into 6 motor domains (tremor, rigidity, bradykinesia, facial expression, speech, and axial impairment) and 2 subscores that represented predominantly dopaminergic (subscore A: tremor, rigidity, bradykinesia, and facial expression) and nondopaminergic (subscore B: speech and axial impairment) deficiency. Analyses were performed using linear regression models with the UPDRS motor domains and subscores as the outcomes. The variation (adjusted R(2)) of the outcome variables explained by the inclusion of disease duration in the models, adjusting for sex, years of education, levodopa dosage, and use of other antiparkinsonian medications, was calculated. The additional variation explained by adding age at examination to the models was used to gauge the contribution of aging to each motor domain and subscore of the UPDRS. RESULTS: A total of 451 patients participated in the study. Mean age at examination was 62.0 years (SD, 12.6 years; median, 62.0 years; range, 18-93 years), and mean disease duration was 7.2 years (SD, 5.9 years; median, 5.6 years; range, 0.1-41.6 years). The additional variation of the outcome variable explained by including age in the models was higher for subscore B (14.3%; 95% confidence interval [CI], 9.9%-20.4%) than subscore A (4.7%; 95% CI, 2.0%-9.1%). Among the 6 motor domains, the additional variation of the outcome variable explained by including age in the models was highest for axial impairment (13.6%; 95% CI, 9.4%-19.6%). CONCLUSION: Axial (gait and postural) impairment in PD may result from the combined effect of the disease and the aging process on nondopaminergic subcortical structures.

Adolescent↗
PubMed2005

Essential tremor associated with focal nonnigral Lewy bodies: a clinicopathologic study.

BACKGROUND: Essential tremor is one of the most common neurological diseases. Its links with Parkinson disease (PD) are often debated. There have been few published postmortem studies. OBJECTIVE: To study our first case of essential tremor through the recently established Essential Tremor Centralized Brain Repository. DESIGN: Report of a case of a patient with a diagnosis of severe essential tremor for 46 years who exhibited no signs of parkinsonism. RESULTS: On postmortem examination, gross brain sections showed no abnormalities. Results of microscopic examination of hematoxylin-eosin-stained sections revealed that the locus coeruleus contained multiple Lewy bodies (LBs), although none were found in the substantia nigra, dorsal vagal nuclei, thalamus, substantia innominata, inferior olivary nucleus, or cerebellum. Immunochemical staining using antibodies directed against alpha-synuclein confirmed the presence of many LBs in the locus ceruleus and showed rare LBs in the substantia innominata and dorsal vagal nuclei. There were no LBs in the substantia nigra. CONCLUSIONS: Our patient had a very focal presence of LBs in the locus ceruleus, an anatomically restricted form of LB disease. This study provides support for the link between essential tremor and LB disease and raises the question as to what proportion of patients with essential tremor might have unusual forms of LB disease.

Aged↗
PubMed2005

Pilot association study of the beta-glucocerebrosidase N370S allele and Parkinson's disease in subjects of Jewish ethnicity.

Mutations in the beta-glucocerebrosidase gene cause Gaucher's disease, one of the most common lysosomal lipid storage diseases in the Ashkenazi Jewish population. The occurrence of parkinsonism in patients with Type 1 Gaucher's disease has been noted previously. In this pilot study, we evaluated a possible association between Parkinson's disease (PD) and the beta-glucocerebrosidase gene N370S allele (nt.1226 A>G) in 160 Parkinson's disease patients and 92 controls of Jewish ethnicity. We observed a higher frequency of the N370S genotype in PD cases (NS and SS, 10.7%) compared to controls (NS and SS 4.3%); however, the difference was not statistically significant (chi(2) = 3.4, P = 0.2). A total of 17 PD cases carry the N370S allele, including 2 homozygotes and 15 heterozygotes. The N370S allele (nt.1226 A>G) may be associated with PD in patients of Jewish ethnicity and should be examined in a larger study.

Aged↗
PubMed2005

Feasibility and validity of a modified finger-nose-finger test.

In essential tremor (ET) research, it is important to obtain standardized, objective data on tremor severity. Often, it is not possible to carry out in-person or videotaped neurological examinations. In place of these, handwriting samples can be collected, but they do not capture all of the variance in tremor severity. Although additional tests of tremor severity (finger-nose-finger [FNF] test) might be of use, these would need to be modified to allow ET patients to mail their results to the study investigator for rating. We modified the standard FNF test (sFNF) by asking subjects to hold a pen during this activity and mark a paper target. The purpose of this report was to determine whether the modified FNF (mFNF) test was feasible and valid. Of 70 subjects, 65 (92.9%) were able to complete the mFNF, demonstrating that it was feasible. The scores of the mFNF correlated highly with those of the sFNF (r = 0.56-0.85; all P < 0.001), indicating the mFNF is a valid measure of tremor severity. In addition, using the regression equation, sFNF = 0.174(mFNF) + 0.743, a sFNF score can be derived easily from the mFNF score. The mFNF may be used to collect valuable data on tremor severity in pathological, genetic, and epidemiological field studies of ET, in which in-person or videotaped neurological examinations are not possible.

Essential Tremor↗
PubMed2005

Association between male gender and pediatric essential tremor.

Approximately 5% of new essential tremor (ET) cases arise during childhood. The goal of the current report was to examine the possible association between male gender and pediatric ET, using data from 95 pediatric ET cases seen at three medical centers (two in the United States and one in Spain). The odds of ET in our sample of cases were threefold higher in boys compared to girls. Whether this association between male gender and pediatric ET represents a selection bias or a true gender-mediated biological difference in disease expression is not known, although some data support the latter possibility.

Adolescent↗
PubMed2005

Interaction between blood lead concentration and delta-amino-levulinic acid dehydratase gene polymorphisms increases the odds of essential tremor.

Blood lead (BPb) concentrations are elevated in essential tremor (ET) cases. The delta-amino-levulinic acid dehydratase (ALAD) gene codes for ALAD, the principal enzyme involved in lead kinetics. Carriers of the ALAD-2 allele may be more susceptible to lead toxicity. The objective of this study was to test, using a case-control design, whether an interaction between BPb concentration and ALAD allele status increases the odds of ET. Mean log BPb concentration was significantly higher in 63 cases than 101 controls (0.47+/-0.26 vs. 0.35+/-0.25 microg/dl). Eighteen (28.6%) cases vs. 17 (16.8%) controls had an ALAD-2 allele (OR=1.98; 95% CI=0.93--4.21). In an adjusted logistic regression analysis, the interaction term (ALAD allele status x log BPb concentration) was associated with increased odds for ET. In stratified analyses, log BPb concentration was not associated with odds of ET in individuals with two ALAD-1 alleles (OR=2.69; 95% CI=0.61--11.82), but in individuals with an ALAD-2 allele, BPb concentration was significantly associated with odds of ET (OR=80.29; 95% CI=3.08--2,096.36). There was an interaction between BPb concentration and ALAD allele status; the odds of ET were greatly elevated in individuals with both an ALAD-2 allele and an elevated BPb concentration. The presence of increased circulating BPb concentrations along with a greater potential for lead toxicity (ALAD-2 allele) could result in greater cerebellar damage, thereby increasing the risk of developing tremor.

Adult↗
PubMed2005

Validity of a modified Parkinson's disease screening questionnaire in India: effects of literacy of participants and medical training of screeners and implications for screening efforts in developing countries.

The prevalence of Parkinson's disease (PD) is low among Indians, except in the Parsis. Data for Indians come from studies using different screening tools and criteria to detect PD. An epidemiological study in India, which has nearly a billion people, more than 18 spoken languages, and varying levels of literacy, requires development and validation of a screening tool for PD. The objectives of this study are to (1) validate a modified version of a widely used screening questionnaire for PD to suit the needs of the Indian population; (2) compare the use of a nonmedical assistant (NMA) with the use of a medical person during screening; and (3) compare the effect of literacy of participants on the validity of the screening tool. The validity of the questionnaire was tested on 125 participants from a home for the elderly. NMAs of similar background and medical personnel administered the modified screening questionnaire. A movement disorder neurologist blind to the responses on the questionnaire, examined participants independently and diagnosed if participants had PD. The questionnaire was validated in the movement disorders clinic, on known PD patients and their family members without PD. In the movement disorders clinic, sensitivity and specificity of the questionnaire were 100% and 89%, respectively. Fifty-seven participants were included for analysis. The questionnaire had a higher sensitivity when NMAs (75%) rather than the medical personnel (61%) administered it, and its specificity was higher with the medical personnel (61%) than with NMAs (55% and 25%). The questionnaire had a higher specificity in literates than illiterates, whereas sensitivity varied considerably. The modified questionnaire translated in a local Indian language had reasonable sensitivity and can be used to screen individuals for PD in epidemiological studies in India. This questionnaire can be administered by NMAs to screen PD and this strategy would reduce manpower costs. Literacy may influence epidemiological estimates when screening PD.

Aged↗
PubMed2005

Essential tremor centralized brain repository: diagnostic validity and clinical characteristics of a highly selected group of essential tremor cases.

We studied essential tremor (ET) cases enrolled in the Essential Tremor Centralized Brain Repository to (1) assess the validity of their diagnoses and (2) characterize the clinical features in a group of highly selected cases who might reflect a far end of the disease spectrum. Our over-arching goal was to provide a perspective of ET that complements that derived from population-based and clinic-based studies. Based on a history and videotaped examination, 94 of 100 ET cases had their diagnoses confirmed; most of the remainder had Parkinson's disease. When compared with ET cases ascertained through populations and clinics, a large proportion had been prescribed medication for tremor (87.2%), had a family history of tremor (88.3%), had rest tremor (33.0%), or had neck tremor (60.6%). One patient had facial tremor, which has not been reported previously. As has been reported once before, a large proportion wore hearing aids (26.9% of the 67 participants age>or=70). In summary, diagnostic validity was high. In terms of their clinical characteristics, the high proportion of cases with severe tremor and varied disease manifestations (neck tremor, rest tremor) make these cases a valuable resource in pathological studies; the high proportion with familial tremor would provide an enriched sample for genetic studies.

Age of Onset↗