Biomedical subjects
Publications and source records attributed to Elan D Louis.
We report on a woman with idiopathic Meige's syndrome whose dystonia improved with the use of levetiracetam (LEV, Keppra, UCB Pharma, Smyrna, GA). This report and data from an animal model of paroxysmal dystonia suggest that LEV might be helpful in the treatment of dystonia.
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In a multi-ethnic cohort we analyzed the Saitohin (STH) gene 'Q7R' polymorphism in 200 late-onset Alzheimer's disease cases (LOAD), 60 Parkinson's disease cases with dementia (PDD), 84 Parkinson's disease cases without dementia and 458 controls. We found no significant differences in genotype or allele frequencies when LOAD or PD cases were compared to controls. Ethnic differences in STH genotype frequencies for cases and controls were observed and these were statistically significant (cases n=344, P<0.03; controls n=458, P<0.001). We also observed a trend in non-Hispanic white PDD cases with the STH 'QQ' (Tau H1/H1) genotype increased (76%) compared to PD cases without dementia (61.7%) and controls (56.6%); however, this difference was not statistically significant (PDD vs. controls OR 2.1; 95% CI: 0.8-5.8, P=0.2).
BACKGROUND: Cigarette smoking and coffee consumption may reduce the risk of PD. Parkinsonian signs (tremor, rigidity, bradykinesia) occur in 30 to 40% of the elderly. OBJECTIVE: To determine whether there was an association between cigarette smoking, coffee consumption, and parkinsonian signs in a community population of older people. METHODS: Data on smoking were collected and a neurologic examination performed on 1,339 residents > or = 65 years of age in the Washington Heights-Inwood community in northern Manhattan, NY. Parkinsonian signs were rated with an abbreviated Unified Parkinson's Disease Rating Scale, resulting in a parkinsonian sign score. Coffee consumption was assessed with a semiquantitative food-frequency questionnaire, and caffeine consumption was determined. Analyses were cross-sectional. RESULTS: Mean age was 76.6 years. Parkinsonian signs were present in 537 (40.1%). The odds for presence of parkinsonian signs was lower in smokers than nonsmokers (odds ratio [OR] = 0.58, 95% CI = 0.47 to 0.73). Smokers had a lower mean parkinsonian sign score than nonsmokers (p < 0.001). Coffee drinking and caffeine consumption were not associated with the presence of parkinsonian signs. The odds for presence of parkinsonian signs remained lower in smokers (OR = 0.75, 95% CI = 0.57 to 0.99) after adjusting for age, gender, ethnicity, years of education, adjusted daily caffeine consumption, and dementia. CONCLUSION: The reduced risk of parkinsonian signs in cigarette smokers could reflect a protective effect of smoking on age-related parkinsonian signs in the elderly or an aversion to smoking in elderly persons with mild parkinsonism.
BACKGROUND: Isolated rest tremor, which is observed in some patients with essential tremor (ET), poses a diagnostic challenge. The phenomenon has been examined in few studies and is poorly understood. OBJECTIVES: To determine the prevalence and study the clinical correlates of rest tremor in ET and to examine the electrophysiologic features in a subgroup of patients. METHODS: Sixty-four patients with ET cared for at a tertiary referral center underwent neurologic examination. Five of 12 patients with rest tremor also underwent quantitative computerized tremor analysis using accelerometry and handwritten spiral analysis. RESULTS: Twelve of 64 patients with ET had rest tremor (prevalence, 18.8%; 95% confidence interval, 9.2%-28.4%). Compared with the 52 patients with ET without rest tremor, these 12 had disease of longer duration and greater severity. Also, their ET was more widely disseminated, as evidenced by a larger proportion with head tremor. None had clinical signs of bradykinesia or rigidity. The 5 patients with rest tremor who underwent electrophysiologic study had electrophysiologic features consistent with parkinsonism (eg, slow spiral speed and increased decrement of spiral speed with radius). CONCLUSIONS: In our sample, 1 in 5 patients with ET had rest tremor. The tremor was associated with disease that was more severe, more disseminated, and of longer duration. Some of these patients had electrophysiologic features consistent with parkinsonism. The basis for the rest tremor could be basal ganglia involvement, raising the possibility that the pathologic process responsible for ET may extend to these structures.
The role of heredity in early- versus late-onset Parkinson's disease (PD) is controversial. We estimated the degree of increased risk of PD in first-degree relatives of 221 PD probands with age of onset 50 years or younger and 266 PD probands with age of onset older than 50 years compared with the first-degree relatives of 409 control probands. Risk of PD was similar among first-degree relatives of early-onset PD probands (risk ratio [RR], 2.9; 95% confidence interval [CI], 1.6-5.0; p = 0.0002) and late-onset PD probands (RR, 2.7; 95% CI, 1.6-4.4; p = 0.0002) when each was compared with first-degree relatives of controls. However, siblings of early-onset PD probands were at markedly increased risk of PD compared with siblings of controls (RR, 7.9; 95% CI, 2.5-25.5; p = 0.0005), whereas parents of early-onset PD probands were not at significantly increased risk compared with parents of controls (RR, 1.7; 95% CI, 0.9-3.3; p = 0.2). In late-onset families, both siblings (RR, 3.6; 95% CI, 1.3-10.3; p = 0.02) and parents (RR, 2.5; 95% CI, 1.4-4.6; p = 0.003) were at increased risk compared with control relatives. This pattern is consistent with an autosomal recessive contribution to the inheritance of early but not late-onset PD. Genetic factors are important in both early- and late-onset PD, but specific genes and mode of inheritance may differ between the two groups.
The pathophysiology of essential tremor (ET) is not well understood, although the tremor often worsens over time. Several processes could contribute, including the inherent worsening of the underlying disease with increasing disease duration and the effects of aging on the nervous system. Our objective was to examine the associations of disease duration and age with tremor severity in ET. Cases were ascertained from a community-based study of ET in northern Manhattan, New York. A neurologist rated tremor severity using a clinical rating scale and assigned a total tremor score (0-36 [maximum]). Analyses were repeated in a sample of cases from a tertiary referral center, the Neurological Institute of New York. There were 55 cases from the community-based study (mean age, 72.1 years, mean disease duration, 13.2 years). Disease duration was associated with the total tremor score (r = 0.30; P = 0.02). Age was associated with the total tremor score (r = 0.30; P = 0.025). In a linear regression analysis the dependent variable was the total tremor score and independent variables were disease duration, age gender. Duration (beta = 0.11; P = 0.02) and age (beta = 0.10; P = 0.02) were independently associated with the total tremor score. Results were similar in 79 ET cases from the Neurological Institute. Disease duration and age were independently associated with tremor severity in ET. This suggests that the reported increase in tremor severity may be related to the inherent worsening of the disease with increasing duration that this is independent of age and age-related processes like neuronal attrition and change in tremor frequency.
Head tremor is one of the major expressions of essential tremor (ET). It is not well understood why some patients develop head tremor, whereas others do not. A study of the characteristics of patients with head tremor has not been undertaken. Our goal was to estimate the prevalence of head tremor and to identify demographic and clinical characteristics associated with an increased risk of head tremor in ET. Cases were ascertained from a community-based study of ET in northern Manhattan, New York. Arm tremor severity was rated with a total tremor score. Logistic regression analyses resulted in odds ratios (OR). Head tremor was present in 37 (34.9%) of 106 ET cases. Female gender was associated with a fourfold increased risk of head tremor (OR = 3.73; P = 0.005). Total tremor score was divided into quartiles; individuals in the lowest or highest quartile were four times more likely to have head tremor (OR = 4.16; P = 0.001). Individuals with both risk factors (female gender and lowest or highest total tremor score quartile) were 16 times more likely to have head tremor (OR = 15.88; P = 0.0006). Being related to a proband with head tremor marginally increased the risk of head tremor (OR = 11.30; P = 0.08). Age and tremor duration did not influence the risk of head tremor. We identified several factors that were associated with an increased risk of head tremor in ET; female gender, coexisting arm tremor that was either very mild or extremely severe, and relation to an ET case with head tremor. These disease associations require further exploration, and might provide insight into the mechanisms underlying head tremor.
For reasons that are unclear, prevalence estimates of essential tremor (ET) differ considerably across the United States. Separate communities have never been sampled within the framework of the same study to substantiate these differences. We estimated the prevalence of physician-diagnosed ET in the elderly in four communities in the United States in whom the same screening questions were used, and examined whether this prevalence differed between Caucasians and African Americans. The Cardiovascular Health Study recruited a sample of Medicare beneficiaries >/=65 years of age from four communities in different regions of the United States. In 1998 to 1999, 3,494 participants (mean age, 80.0 years; range, 70-103 years) answered a 12-question screen for ET, including the question, "has a doctor diagnosed you as having familial tremor or benign essential tremor?" Fifty-four participants reported that a doctor had diagnosed them as having ET (1.5%; 95% confidence interval, [CI], 1.1-2.0%). Prevalence was similar across the four communities (1.1-2.0%). A larger proportion of Caucasians than African Americans reported a diagnosis of ET (1.7% vs. 0.4%; odds ratio = 4.9; 95% CI, 1.2-20.2; P = 0.028). In a logistic regression analysis, physician-diagnosed ET was associated with Caucasian ethnicity (P = 0.038) but not with age, gender, education, mental status or depression scores, income, smoking status, or alcohol consumption. When a standardized screening question was used, the proportion of participants with physician-diagnosed ET was similar across four communities, suggesting that the prevalence of this condition may be less variable than is often reported. Caucasians were five times more likely to have physician-diagnosed ET than were African Americans. This study does not provide an explanation for this difference, which deserves further study.
An olfactory deficit is present in patients with essential tremor (ET), but it is often milder than that in patients with Parkinson's disease (PD). In both, the deficit occurs early in the disease. Isolated rest tremor without other signs of parkinsonism can occur in patients with ET. If the rest tremor in these patients represents a manifestation of ET rather than early PD, we hypothesized that their University of Pennsylvania Smell Identification Test (UPSIT) scores would be similar to those of ET patients without rest tremor. The mean UPSIT score in 13 ET patients with isolated rest tremor did not differ from that of 58 ET patients without rest tremor (29.3 +/- 4.3 vs. 29.4 +/- 6.4; P = 0.69). Several ET patients with rest tremor had UPSIT scores that fell outside of the range that is seen in 95% of patients with PD. These data raise the possibility that some ET patients with isolated rest tremor may not have early PD and that the pathological process that is responsible for their ET is also involving the basal ganglia.
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Whipple disease is a rare disease caused by infection with the bacterium Tropheryma whippelii. Humans are the only known host for the infection. The signs of systemic infection include gastrointestinal problems, weight loss, and arthritis. Signs of central nervous system infection include cognitive changes, supranuclear gaze palsy, altered level of consciousness, and movement disorders. The diagnosis is based on clinical findings as well as microscopic examination of biopsy specimens and, more recently, polymerase chain reaction (PCR) analysis, which has high sensitivity and specificity. Although the organism historically has been difficult to culture, several recent attempts have been successful. Antibiotic treatment is recommended for 1 year while monitoring the clinical signs and cerebrospinal fluid PCR results.
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James Ramsay Hunt (1874-1937) was one of the pioneers of early-twentieth-century American neurology. The James Ramsay Hunt Case Books, Columbia University, were created by Hunt and chronicle his experience with private patients from 1903 until 1937. This resource is not widely known to scholars and the content of these 30 volumes has not been described in detail. The purpose of this report is to describe this resource in terms of its organization, general contents and special features. The books contain the clinical records of 5,019 consecutive patients. The largest proportion had neurasthenia or psychiatric diagnoses, followed by those with neuropathies, manifestations of neurosyphilis, migraine and epilepsy. The books, through the enclosed correspondence, photographs, and poetry sent by patients, reveal a close relationship between the patients and their physician. Hunt's drawings are a special feature of the early volumes, including his original unpublished drawing of the lesions associated with his herpetic geniculate ganglion syndrome. The Case Books, by providing an indexed and permanent record of cases, would have made it easier for Hunt to cross-reference patients with similar clinical characteristics when he was in the process of describing a new syndrome. These Case Books provide a valuable perspective of the practice of neurology in early-twentieth-century America.
James Ramsay Hunt (1874-1937) was a pre-eminent twentieth-century American neurologist. The name of Ramsay Hunt is known today because several neurological disorders bear his name, including the herpetic geniculate ganglion syndrome and a form of ataxia and myoclonus. Despite his importance in the field of neurology, few biographical details have been recorded about Hunt's life. One of the authors of this report recently located Hunt's daughter. This biographical sketch was based on interviews conducted with her and review of documents in her possession, including letters written by Hunt. Details are depicted about Hunt's family background and childhood, medical education and early professional development, courtship and marriage, wartime experiences, family and social life, daily routine and professional development, as well as illness and death.
Lead is a ubiquitous toxicant that causes tremor and cerebellar damage. Essential tremor (ET) is a highly prevalent neurologic disease associated with cerebellar involvement. Although environmental toxicants may play a role in ET etiology and their identification is a critical step in disease prevention, these toxicants have received little attention. Our objective was to test the hypothesis that ET is associated with lead exposure. Therefore, blood lead (BPb) concentrations were measured and a lifetime occupational history was assessed in ET patients and in controls. We frequency matched 100 ET patients and 143 controls on age, sex, and ethnicity. BPb concentrations were analyzed using graphite furnace atomic absorption spectrophotometry. A lifetime occupational history was reviewed by an industrial hygienist. BPb concentrations were higher in ET patients than in controls (mean +/- SD, 3.3 +/- 2.4 and 2.6 +/- 1.6 microg/dL, respectively; median, 2.7 and 2.3 microg/dL; p = 0.038). In a logistic regression model, BPb concentration was associated with diagnosis [control vs. ET patient, odds ratio (OR) per unit increase = 1.21; 95% confidence interval (CI), 1.05-1.39; p = 0.007]. BPb concentration was associated with diagnosis (OR per unit increase = 1.19; 95% CI, 1.03-1.37; p = 0.02) after adjusting for potential confounders. Prevalence of lifetime occupational lead exposure was similar in ET patients and controls. We report an association between BPb concentration and ET. Determining whether this association is due to increased exposure to lead or a difference in lead kinetics in ET patients requires further investigation.
Because olfactory dysfunction is a feature of neurodegenerative diseases, the authors hypothesized that it would be present in essential tremor. Thirty-seven cases and control subjects underwent the University of Pennsylvania Smell Identification Test. Mean score was lower in cases than in control subjects (29.0 +/- 6.1 vs 31.9 +/- 4.6, p = 0.02) and was not correlated with tremor severity or duration.
The pathological basis for essential tremor (ET) is unknown. We used proton magnetic resonance spectroscopic imaging (1H MRSI) in 16 ET patients and 11 controls to measure levels of intracellular metabolites, including N-acetyl-L-aspartate (NAA) and total choline, relative to total creatine (tCR), in several brain regions (cerebellum, thalamus, basal ganglia). Multislice 1H MRSI data were acquired on a 1.5 T GE Signa Scanner by prescribing four 15-mm axial-oblique slices. The mean (standard deviation) cerebellar cortical NAA/tCR was reduced in cases compared to controls (1.53 [0.36] versus 1.91 [0.49], P = 0.03). There was an inverse association between cerebellar cortical NAA/tCR and dominant arm tremor severity (r = -0.59, P = 0.02). The reduction in cerebellar cortical NAA/tCR indicates that there is neuronal damage or loss in ET, suggesting that ET may be a neurodegenerative disease.