Continuous in-home monitoring of essential tremor.

BACKGROUND: Essential tremor (ET) is typically measured in the clinic with subjective tremor rating scales which require the presence of a clinician for scoring and are not appropriate for measuring severity throughout the day. Motion sensors can accurately rate tremor severity during a set of predefined tasks in a laboratory. METHODS: We evaluated the ability of motion sensors to quantify tremor during unconstrained activities at home. 20 ET subjects wore a wireless sensor continuously for up to 10 h daily on two days and completed hourly standardized tremor assessments involving pre-defined tasks. Mathematical models were used to predict tremor rating scores from the sensor data. RESULTS: At home tremor scores from hourly standardized assessments correlated with at home tremor scores estimated during unconstrained activities immediately following the standardized assessments. The hourly standardized assessments did not significantly fluctuate throughout the day, while fluctuations in the continuous assessments tended to follow changes in voluntary activity level. Both types of tremor ratings (standardized and continuous) showed high day-to-day test-retest reliability with intraclass correlation coefficients ranging from 0.67 to 0.90 for continuous ratings and 0.77 to 0.95 for standardized ratings. CONCLUSIONS: Results demonstrate the feasibility of continuous monitoring of tremor severity at home, which should provide clinicians with a measure of the temporal pattern of tremor in the context of daily life and serve as a useful tool for the evaluation of novel anti-tremor medications in clinical trials.

P-wave duration in a clinically normal hound population.

Electrocardiogram (ECG) analysis is a common noninvasive technique used for diagnosis of cardiac disease in the clinical and research branches of veterinary medicine. Accurate analysis of P-wave duration, amplitude, and morphology is crucial to identification of morphologic and functional changes of the atria. The published accepted maximal normal value for P-wave duration in the dog is < or = 40 milliseconds. We looked at P-wave duration in ECG obtained as part of routine quarantine health screening over a period of 1 year in 364 clinically normal hounds weighing 13 to 35 kg. The dogs were neither anesthetized nor sedated and were placed in standard position. P-wave duration was classically determined from the lead-II recording. Mean P-wave duration for all dogs (44.9 +/- 6.1 milliseconds) was greater than published accepted normal values for the dog. There was a significant difference in mean P-wave duration by body weight (P < 0.001); dogs weighing > or = 20 kg had longer mean P-wave durations than dogs weighing < 20 kg (45.3 and 41.6 milliseconds respectively). There were also significant differences in mean P-wave duration by sex (P < 0.01), with a greater mean duration for females (45.4 milliseconds) than for males (43.8 milliseconds). All other ECG parameters were within published accepted normal values. A P-wave of prolonged duration leads to a diagnosis of abnormalities in cardiac morphology and/or function. Published accepted normal values for P-wave duration, at least for a clinically normal hound population, appear to be shorter than the true normal values. An error in published accepted normal standards may lead to overdiagnosis of cardiac abnormalities, as well as to erroneous results in cardiovascular studies. Therefore we recommend that the standard for P-wave duration be increased above the currently accepted standard of < or = 40 milliseconds.

Enforcement of drunken driving laws in cases involving injured intoxicated drivers.

STUDY OBJECTIVE: To determine the frequency of driving while impaired (DWI) charges among alcohol-intoxicated drivers injured in motor vehicle crashes (MVCs) and any differences in the group of those charged compared with those not charged. METHODS: We performed a retrospective analysis of linked data from medical and judicial sources. Our setting was an urban emergency department of a trauma center serving a population of 1 million. We studied consecutive drivers injured in MVCs over a period of 15 months who had measured serum ethanol (BAC) levels of 100 mg/dL or higher. BAC, Trauma Score (TS), demographics, and crash data were linked to court records of charges, outcome, and prior convictions. The group of individuals who were charged with DWI were compared with those who were not charged. RESULTS: One hundred eighty-seven patients were studied; 53 (28%) were charged with DWI, and 32 (17% of total) were convicted. Two (7%) of 29 patients with severe injuries, 9 (28%) of 32 with moderate injuries, and 42 (33%) of 126 with nonsevere injuries were charged (P = .004). Eighteen (16%) of 112 patients with no prior convictions were charged; 20 (56%) of 36 patients with one, 11 (52%) of 21 with two, 3 (25%) of 12 with three, and 0 of 5 with four or more prior DWI convictions were charged (P < .001). There were no significant differences in BAC, demographics, or other measures between the two groups. CONCLUSION: Alcohol-impaired drivers who require ED treatment for injuries sustained in an MVC are infrequently charged with DWI. The likelihood of a DWI charge diminishes with increasing severity of injury. Repeat offenders are charged more often, but the frequency of charges does not increase with increasing number of prior DWI convictions.