Orthostatic Tremor: An Update on a Rare Entity

Background: Orthostatic tremor (OT) remains among the most intriguing and poorly understood of movement disorders. Compared to Parkinson’s disease or even essential tremor, there are very few articles addressing more basic science issues. In this review, we will discuss the findings of main case series on OT, including data on etiology, pathophysiology, diagnostic approach, treatment strategies, and outcome. Methods: Data for this review were identified by searching PUBMED (January 1966 to August 2016) for the terms “orthostatic tremor” or “shaky leg syndrome,” which yielded 219 entries. We did not exclude papers on the basis of language, country, or publication date. The electronic database searches were supplemented by articles in the authors’ files that pertained to this topic. Results: Owing to its rarity, the current understanding of OT is limited and is mostly based on small case series or case reports. Despite this, a growing body of evidence indicates that OT might be a progressive condition that is clinically heterogeneous (primary vs. secondary cases) with a broader spectrum of clinical features, mainly cerebellar signs, and possible cognitive impairment and personality disturbances. Along with this, advanced neuroimaging techniques are now demonstrating distinct anatomical and functional changes, some of which are consistent with neuronal loss. Discussion: OT might be a family of diseases, unified by the presence of leg tremor, but further characterized by etiological and clinical heterogeneity. More work is needed to understand the pathogenesis of this condition

Population-based study of baseline ethanol consumption and risk of incident essential tremor

Recent postmortem studies have demonstrated pathological changes, including Purkinje cell loss, in the cerebellum in essential tremor (ET). Toxic exposures that compromise cerebellar tissue could lower the threshold for developing ET. Ethanol is a well-established cerebellar toxin, resulting in Purkinje cell loss

Population-based prospective study of cigarette smoking and risk of incident essential tremor

Background: Smoking cigarettes is associated with lower risk of Parkinson disease (PD). Despite the clinical links between PD and essential tremor (ET), there are few data on smoking in ET. One study showed an association between smoking and lower ET prevalence. We now study whether baseline smoking is associated with lower risk of incident ET. Methods: Using a population-based, cohort design, baseline cigarette smoking habits were assessed in 3,348 participants in an epidemiologic study in Spain, among whom 77 developed incident ET. Results: There were 3,348 participants, among whom 397 (11.9%) were smokers at baseline. Five (6.5%) of 77 incident ET cases had been smokers at baseline, compared with 392 (12.0%) of 3,271 controls (p = 0.14). Baseline pack-years were lower in incident ET cases than in controls (9.2 ± 17.7 vs 15.7 ± 28.4, p = 0.002). Participants were stratified into baseline pack-year tertiles, and few incident ET cases were in the highest tertile (4 [5.2%] cases vs 431 [13.2%] controls, p = 0.039). In Cox proportional hazards models, the highest baseline pack-year tertile was associated with lower risk of incident ET; those in the highest pack-year tertile were one-third as likely to develop ET when compared with nonsmokers (relative risk [RR] 0.37, 95% CI 0.14—1.03, p = 0.057 [unadjusted model] and RR 0.29, 95% CI 0.09—0.90, p = 0.03 [adjusted model]). Conclusions: We demonstrated an association between baseline heavy cigarette smoking and lower risk of incident essential tremor. The biologic basis for this association requires future investigation

Philadelphia Geriatric Morale Scale in essential tremor : a population-based study in three Spanish communities

Essential tremor (ET) is associated with both functional disability and depression. Each could contribute to a poor sense of well-being and low morale. We hypothesized that morale would be lower in ET cases than controls. Using a population-based, cross-sectional design, morale was assessed in 187 ET cases and 561 matched controls living in three communities in central Spain using the Philadelphia Geriatric Center Morale Scale (PGCMS) (range = 0 [low morale]-17), which included three-dimensions of psychological well-being: agitation, lonely dissatisfaction, and attitude toward own aging. The PGCMS score was lower in ET cases than controls (9.41 ± 3.21 vs. 10.39 ± 2.92, P < 0.001), as were the Agitation subscore (3.17 ± 1.71 vs. 3.78 ± 1.67, P < 0.001) and Lonely Dissatisfaction subscore (3.75 ± 1.34 vs. 4.02 ± 1.24, P < 0.05). Nearly one-half of the ET cases were classified as having low morale compared with only one-third of controls (P = 0.006). In a linear regression analysis adjusting for demographic factors and multiple comorbid conditions, ET cases had a lower log PGCMS score than controls (P < 0.001). Exclusion of participants on antidepressant medication did not change the results. Our results indicate that morale is significantly lower in community-dwelling ET cases than in matched controls. This lower morale could in part be a proxy for mild, untreated depression. It therefore seems important to detect and then possibly treat this problem to improve the psychological well-being of patients with this disease

Statins and cognitive functioning in the elderly: a population-based study

In a 2009 Cochrane review, the authors concluded that there is good evidence that statins, given in late life to people at risk of vascular disease, have no effect in preventing Alzheimer's disease or dementia. A related issue, which remains unclear, is whether statins improve cognitive function. While some studies have shown a beneficial effect of statins on cognitive function, others have observed mild detrimental effects on cognition. Our aim was to assess cognitive function in community-dwelling elderly participants treated with statins compared with their untreated counterparts (i.e., controls) living in the same population. 137 population-dwelling participants who were receiving statins and 411 matched controls age ⩾ 65 years (median=72 years) in central Spain (the Neurological Disorders in Central Spain [NEDICES] study) underwent a neuropsychological assessment, including tests of global cognitive performance, frontal-executive function, verbal fluency, and memory. Median duration of statin treatment was 2 years. Of 137 participants receiving statins, 53 (38.7%) were taking pravastatin, 38 (27.7%) simvastatin, 37 (27.0%) lovastatin, 6 (4.4%) fluvastatin, and 3 (2.2%) atorvastatin. Although initial univariate analyses indicated some differences, after adjusting for age, gender, education, depressive symptoms, premorbid intelligence, medications that potentially affect cognitive function, and blood cholesterol levels, statin users and controls performed similarly on all neuropsychological tests. In this population-based sample, elderly participants treated with statins and untreated controls performed similarly in all tested cognitive areas. These results do not support a positive benefit of statins on cognition

Biomechanical Loading as an Alternative Treatment for Tremor: A Review of Two Approaches

Background: Tremor is the most common movement disorder and strongly increases in incidence and prevalence with aging. Although not life threatening, upper-limb tremors hamper the independence of 65% of people suffering from them affected persons, greatly impacting their quality of life. Current treatments include pharmacotherapy and surgery (thalamotomy and deep brain stimulation). However, these options are not sufficient for approximately 25% of patients. Therefore, further research and new therapeutic options are required to effectively manage pathological tremor. Methods: This paper presents findings of two research projects in which two different wearable robots for tremor management were developed based on force loading and validated. The first consisted of a robotic exoskeleton that applied forces to tremulous limbs and consistently attenuated mild and severe tremors. The second was a neuroprosthesis based on transcutaneous neurostimulation. A total of 22 patients suffering from parkinsonian or essential tremor (ET) of different severities were recruited for experimental validation, and both systems were evaluated using standard tasks employed for neurological examination. The inclusion criterion was a postural and/or kinetic pathological upper-limb tremor resistant to medication. Results: The results demonstrate that both approaches effectively suppressed tremor in most patients, although further research is required. The work presented here is based on clinical evidence from a small number of patients (n = 10 for robotic exoskeleton and n = 12 for the neuroprosthesis), but most had a positive response to the approaches. In summary, biomechanical loading is non-invasive and painless. It may be effective in patients who are insufficiently responsive (or have adverse reactions) to drugs or in whom surgery is contraindicated. Discussion: This paper identifies and evaluates biomechanical loading approaches to tremor management and discusses their potential

Electrical Stimulation of Afferent Pathways for the Suppression of Pathological Tremor

Pathological tremors are involuntary oscillatory movements which cannot be fully attenuated using conventional treatments. For this reason, several studies have investigated the use of neuromuscular electrical stimulation for tremor suppression. In a recent study, however, we found that electrical stimulation below the motor threshold also suppressed tremor, indicating involvement of afferent pathways. In this study, we further explored this possibility by systematically investigating how tremor suppression by afferent stimulation depends on the stimulation settings. In this way, we aimed at identifying the optimal stimulation strategy, as well as to elucidate the underlying physiological mechanisms of tremor suppression. Stimulation strategies varying the stimulation intensity and pulse timing were tested in nine tremor patients using either intramuscular or surface stimulation. Significant tremor suppression was observed in six patients (tremor suppression > 75% was observed in three patients) and the average optimal suppression level observed across all subjects was 52%. The efficiency for each stimulation setting, however, varied substantially across patients and it was not possible to identify a single set of stimulation parameters that yielded positive results in all patients. For example, tremor suppression was achieved both with stimulation delivered in an out-of-phase pattern with respect to the tremor, and with random timing of the stimulation. Overall, these results indicate that low-current stimulation of afferent fibers is a promising approach for tremor suppression, but that further research is required to identify how the effect can be maximized in the individual patient.This work has been supported by the Commission of the European Union through the grant ICT-2011-287739 (NeuroTREMOR).Peer reviewedPeer Reviewe

Psychometric attributes of the DISC Predictive Scales

Introduction: This study was designed to evaluate the psychometric attributes and screening efficiency of a Spanish version of the Children Predictive Scales (DPS) against the Spanish Diagnostic Interview Schedule for Children (DISC-IV). Method: This pilot cross-sectional study included 61 children aged 9 to 14 years in a mainstream school. The following psychometric attributes were analyzed: acceptability, scale assumptions, internal consistency, and precision, as well the predictive validity (AUC). Results: The scale did not show ceiling or floor effects (6.4%, 1.3%, respectively). The internal consistency was high (α±=0.92), and the standard error of measurement was adequate (SEM=1.54). The overall DPS AUC was 0.72 against DISC IV corresponding diagnosis. Conclusion: The Spanish version of the DPS-4.32 seems to be a reliable and precise tool for screening mental health disorders in a school-age population

A protective personal factor against disability and dependence in the elderly: an ordinal regression analysis with nine geographically-defined samples from Spain

Background Sense of Coherence (SOC) is defined as a tendency to perceive life experiences as comprehensible, manageable and meaningful. The construct is split in three major domains: Comprehensibility, Manageability, and Meaningfulness. SOC has been associated with successful coping strategies in the face of illness and traumatic events and is a predictor of self-reported and objective health in a variety of contexts. In the present study we aim to evaluate the association of SOC with disability and dependence in Spanish elders. Methods A total of 377 participants aged 75 years or over from nine locations across Spain participated in the study (Mean age: 80.9 years; 65.3% women). SOC levels were considered independent variables in two ordinal logistic models on disability and dependence, respectively. Disability was established with the World health Organization-Disability Assessment Schedule 2.0 (36-item version), while dependence was measured with the Extended Katz Index on personal and instrumental activities of daily living. The models included personal (sex, age, social contacts, availability of an intimate confidant), environmental (municipality size, access to social resources) and health-related covariates (morbidity). Results High Meaningfulness was a strong protective factor against both disability (Odds Ratio [OR] = 0.50; 95% Confidence Interval [CI] = 0.29–0.87) and dependence (OR = 0.33; 95% CI = 0.19–0.58) while moderate and high Comprehensibility was protective for disability (OR = 0.40; 95% CI = 0.22–0.70 and OR = 0.39; 95%CI = 0.21–0.74), but not for dependence. Easy access to social and health resources was also highly protective against both disability and dependence. Conclusions Our results are consistent with the view that high levels of SOC are protective against disability and dependence in the elderly. Elderly individuals with limited access to social and health resources and with low SOC may be a group at risk for dependence and disability in Spain.This project was partially funded by a research contract in support of the project “Epidemiological Study of Dementia in Spain” signed by the Pfizer Foundation and Carlos III Institute of HealthS