Kinetic tremor : differences between smokers and non-smokers

Tremor is among the acute effects of nicotine exposure. Published studies have focused on smoking-related postural (static) hand tremor rather than kinetic tremor (tremor during hand use), and gender differences in smoking-related tremor have not been examined. In a group of adults who were sampled from a population (mean ± S.D. = 65.7 ± 11.5 years, range = 18–92 years), the investigator assessed whether the severity of postural and kinetic tremors differed in smokers versus non-smokers, and whether this difference was influenced by gender. Twenty-seven (9.9%) of 273 subjects were current smokers. Greater tremor was observed in smokers than non-smokers during a variety of activities (drawing a spiral, using a spoon, finger–nose–finger maneuver, all p < 0.05) and smokers had a higher total tremor score than non-smokers (5.15 ± 3.06 versus 3.41 ± 2.88, p < 0.01), even after adjusting for age, caffeine intake and other potential confounding factors. The difference between smokers and non-smokers in terms of hand tremor was more apparent in women than in men. In women, the number of cigarettes smoked on the day of testing was weakly correlated with the total tremor score (r = 0.17, p = 0.03). In summary, smokers had more kinetic hand tremor than non-smokers. This difference between smokers and non-smokers was more apparent in women than in men. These results suggest that smoking habits should be considered carefully in order to avoid over- or underestimating the effects of occupational and non-occupational exposures to other tremor-producing neurotoxins

Essential tremors : a family of neurodegenerative disorders?

Essential tremor (ET) is the most common pathologic tremor in humans. The traditional view of ET, as a monosymptomatic condition, is being replaced by an appreciation of the spectrum of clinical features, with both motor and nonmotor elements. These features are not distributed homogeneously across patients. In addition, postmortem studies are now demonstrating distinct structural changes in ET. There is growing evidence that ET may be a family of diseases rather than a single entity. Furthermore, this aging-associated, progressive disorder is associated with neuronal loss and postmortem changes that occur in traditional neurodegenerative disorders

Functional correlates of lower cognitive test scores in essential tremor

Although motor features have been the defining element of essential tremor (ET), lower neurocognitive test scores are increasingly being recognized. However, the clinical correlates, if any, of these lower test scores remain largely unexplored. The aim of this study was to determine whether cognitive test scores in ET have any functional correlates. The Modified Mini Mental Status Examination (MMSE), Katz Activities of Daily Living (ADL) scale and Lawton Instrumental (I) ADL scale were administered to 95 cases. The Katz ADL score (rho = 0.26, P = 0.01) and Lawton IADL score (rho = 0.32, P = 0.001) were correlated with MMSE scores, such that poorer cognitive performance indicated greater dysfunction. Furthermore, cognitive test scores were a better predictor of functional disability than was tremor severity. Poorer cognitive performance in ET was associated with greater functional deficit. Cognition should enter the clinical dialog with ET patients as an issue of clinical significance

Treatment of Essential Tremor: Are there Issues We are Overlooking?

Background: Essential tremor (ET) is one of the most common neurological diseases. Although a large number of medications have been tested, there are only two first-line medications, primidone and propranolol, which is a situation that has not changed in approximately 30 years. Several recent reviews have summarized the current pharmacotherapeutic options for ET and the approach to the management of ET patients. Yet there remain a number of important issues, both scientific and clinical, that have not been broached in the literature and that have therapeutic implications. Objectives: To introduce several clinical and scientific issues that have not formally entered the published literature on the treatment of ET. Methods: In September 2011, materials for this article were gathered during a literature search of PubMed using the following terms: ET, clinical, clinical trial, treatment, medications, therapeutics. English-language articles were selected for further review. Results: The paper focuses on several topics that have received scant or no discussion in the published literature on ET therapeutics. These topics are as follows: the nature of the underlying disease pathophysiology, the presence of pathological heterogeneity, the complexity of cellular and neurochemical changes which may be underlying this disorder, the presence of clinical heterogeneity, the selection of treatment endpoints, the effects of diagnostic uncertainty, the presence of cognitive and psychiatric features in ET, the identification of possible modifiable risk factors, and the absence of any neuroprotective therapies. Conclusion: The author has identified several topics that have received scant or no discussion in the published literature on ET therapeutics. Further discussion of the issues raised here may lead to improvements in clinical trial methodologies as well as facilitate the development of fresh approaches to pharmacotherapy

Index Finger Pointing (Likely a Subtle Form of Hand Dystonia): Prevalence Across Movement Disorders

Objective: To investigate the prevalence of index finger pointing (IFP) while walking, which is likely a subtle form of hand dystonia, in cranio-cervical focal dystonia syndromes, Parkinson's disease (PD), essential tremor (ET), and controls.Methods: We recruited patients with an established diagnosis of PD, dystonia, or ET and healthy controls. All participants were videotaped while walking. Videotapes were evaluated by the authors, blinded to diagnosis, to assess the presence or absence of IFP.Results: Two-hundred-fifty participants included 50 dystonia, 50 PD, 80 ET and 70 controls. IFP was present in 29/250 (11.6%) participants: 10 dystonia (20.0%), 8 PD (16.0%), 8 ET (10.0%), and 3 controls (3.8%) (p = 0.03). There was a significant evidence of a trend in the odds of having this sign among disorders with higher risk of dystonic features (dystonia&gt;PD&gt;ET&gt;control; test for trend = 0.004). Among the 180 patients (dystonia, PD, and ET, i.e., excluding the 70 controls), IFP was present in 26 (14.4% prevalence).Conclusion: IFP during gait, likely a subtle form of hand dystonia, was observed in 14.4% of movement disorder patients. The highest prevalence was in dystonia, the second highest in a disease that is often accompanied by dystonia (PD), a lower prevalence among individuals with a disease that is rarely accompanied by dystonia (ET), and the lowest in controls