Introduction-Embarrassment is commonly reported in essential tremor (ET) patients yet there is no formal tool to assess embarrassment in ET. Our aim was to develop such a tool and to assess its clinimetric properties. A quantitative measure of embarrassment could be used to assess response to treatment in clinical practice and clinical trials.

Introduction-Harmane, a potent tremor-producing β-carboline alkaloid, may play a role in the etiology of essential tremor (ET). Blood harmane concentrations are elevated in ET cases compared with controls yet the basis for this elevation remains unknown. Decreased metabolic conversion (harmane to harmine) is one possible explanation. Using a sample of >500 individuals, we hypothesized that defective metabolic conversion of harmane to harmine might underlie the observed elevated harmane concentration in ET, and therefore expected to find a higher harmane to harmine ratio in familial ET than in sporadic ET or controls.Methods-Blood harmane and harmine concentrations were quantified by high performance liquid chromatography.Results-There were 78 familial ET cases, 187 sporadic ET cases, and 276 controls. Blood harmane and harmine concentrations were correlated with one another (Spearman's r = 0.24, p < 0.001). The mean (±SD) harmane/harmine ratio = 23.4 ± 90.9 (range = 0.1 -987.5). The harmane/harmine ratio was highest in familial ET (46.7 ± 140.4 Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.Financial disclosure: The National Institutes of Health played no role in the study design, the collection of data, the analysis and interpretation of data, the writing of the report or in the decision to submit the paper for publication. Statistical Analyses:The statistical analyses were conducted by Dr. Louis. Conflict of Interest StatementThe authors declare that there are no conflicts of interest. NIH Public Access Author ManuscriptNeurotoxicology. Author manuscript; available in PMC 2011 December 1. NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscript controls (13.5 ± 50.3)(p = 0.03). In familial ET cases, there was no association between this ratio and tremor severity (Spearman's r = 0.08, p=0.48) or tremor duration (Spearman's r = 0.14, p = 0.24).Conclusion-The basis for the elevated blood harmane concentration, particularly in familial ET, is not known, although the current findings (highest harmane/harmine ratio in familial ET cases) lends support to the possibility that it could be the result of a genetically-driven reduction in harmane metabolism.

Background Tremor in the dominant arm is often the focus of clinical attention in essential tremor (ET) yet many daily activities require both arms. The functional relevance of non-dominant arm tremor has rarely been studied. Methods In 181 right-handed ET patients, action tremor in each arm was rated using a clinical ratings scale. Tremor disability was self-reported and a performance-based test of function was administered. Results Independently of tremor on the right, greater tremor severity on the left was associated with greater self-reported disability (p=0.02) and greater performance-based dysfunction (p<0.001). In 5.0% of patients, tremor was largely restricted to the non-dominant arm. Conclusions Non-dominant arm tremor, independent of dominant arm tremor, had a significant functional correlate, contributing to both greater perceived and greater observable functional difficulty. In 5% of patients, tremor in the non-dominant arm was the likely motivator for seeking care, which is another indication of its functional significance.

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