Trial of Botulinum Toxin for Isolated or Essential Head Tremor.

BACKGROUND: Local injections of botulinum toxin type A have been used to treat essential head tremor but have not been extensively studied in randomized trials. METHODS: In a multicenter, double-blind, randomized trial, we assigned, in a 1:1 ratio, adult patients with essential or isolated head tremor to receive botulinum toxin type A or placebo. Botulinum toxin or placebo was injected under electromyographic guidance into each splenius capitis muscle on the day of randomization (day 0) and during week 12. The primary outcome was improvement by at least 2 points on the Clinical Global Impression of Change (CGI) scale at week 6 after the second injection (week 18 after randomization). The CGI scale was used to record the patient's assessment of the degree of improvement or worsening of head tremor since baseline; scores range from 3 (very much improved) to -3 (very much worse). Secondary outcomes included changes in tremor characteristics from baseline to weeks 6, 12, and 24. RESULTS: A total of 120 patients were enrolled; 3 patients were excluded during screening, and 117 patients were randomly assigned to receive botulinum toxin (62 patients) or placebo (55 patients) and were included in the intention-to-treat analysis. Twelve patients in the botulinum toxin group and 2 patients in the placebo group did not receive injections during week 12. The primary outcome - improvement by at least 2 points on the CGI scale at week 18 - was met by 31% of the patients in the botulinum toxin group as compared with 9% of those in the placebo group (relative risk, 3.37; 95% confidence interval, 1.35 to 8.42; P = 0.009). Analyses of secondary outcomes at 6 and 12 weeks but not at 24 weeks were generally supportive of the primary-outcome analysis. Adverse events occurred in approximately half the patients in the botulinum toxin group and included head and neck pain, posterior cervical weakness, and dysphagia. CONCLUSIONS: Injection of botulinum toxin into each splenius capitis muscle on day 0 and during week 12 was more effective than placebo in reducing the severity of isolated or essential head tremor at 18 weeks but not at 24 weeks, when the effects of injection might be expected to wane, and was associated with adverse events. (Funded by the French Ministry of Health; Btx-HT ClinicalTrials.gov number, NCT02555982.).

Quantification of Head Tremors in Medical Conditions: A Comparison of Analyses Using a 2D Video Camera and a 3D Wireless Inertial Motion Unit.

This study compares two methods to quantify the amplitude and frequency of head movements in patients with head tremor: one based on video-based motion analysis, and the other using a miniature wireless inertial magnetic motion unit (IMMU). Concomitant with the clinical assessment of head tremor severity, head linear displacements in the frontal plane and head angular displacements in three dimensions were obtained simultaneously in forty-nine patients using one video camera and an IMMU in three experimental conditions while sitting (at rest, counting backward, and with arms extended). Head tremor amplitude was quantified along/around each axis, and head tremor frequency was analyzed in the frequency and time-frequency domains. Correlation analysis investigated the association between the clinical severity of head tremor and head linear and angular displacements. Our results showed better sensitivity of the IMMU compared to a 2D video camera to detect changes of tremor amplitude according to examination conditions, and better agreement with clinical measures. The frequency of head tremor calculated from video data in the frequency domain was higher than that obtained using time-frequency analysis and those calculated from the IMMU data. This study provides strong experimental evidence in favor of using an IMMU to quantify the amplitude and time-frequency oscillatory features of head tremor, especially in medical conditions.

Incobotulinum toxin A in Parkinson's disease with foot dystonia: A double blind randomized trial.

INTRODUCTION: Plantar flexion of toe dystonia is very painful and leads to difficulties in walking. The objective of this study was to investigate the effect of incobotulinum toxin A (Xeomin) in the treatment of this type of dystonia in parkinsonian patients, using a randomized, double blind, placebo-controlled trial. METHODS: 45 parkinsonian patients with painful dystonic plantar flexion of toes were injected either with incobotulinum toxin A (Btx group), or with placebo in two muscle targets: the Flexor digitorum longus and the Flexor digitorum brevis. Three groups were compared: the first group received placebo in the Flexor digitorum longus and 100UI of Btx in the Flexor digitorum brevis (n = 16); the second group received 100 UI of Btx in the Flexor digitorum longus and placebo in the Flexor digitorum brevis (n = 13); and the third group, 2 injections of placebo (n = 16). The patients were injected in the same way twice with an interval of 3 months. The primary endpoint was measured six weeks after injections with the Clinical Global Impression (CGI) of change. Dystonia severity and associated pain were also assessed. RESULTS: Mean CGI was improved in the Btx group compared to the placebo group (P = 0.039). A significant reduction of pain and dystonia severity were observed in patients treated with Btx compared to baseline but no improvement was noted when compared to placebo group. No difference of efficacy was highlighted between the two injection sites. CONCLUSIONS: Btx injections are effective for improving clinical state of parkinsonian patients with plantar flexion of toe dystonia.

Head tremor in Parkinson's disease.

Head tremor is a typical feature of essential tremor. Patients with sporadic Parkinson's disease can have tremor of the tongue, lip, or chin, but classically do not have head tremor. We describe five patients with Parkinson's disease and head tremor in whom clinical and neurophysiological findings suggested that head tremor was a manifestation of Parkinson's disease.