Essential Head Tremor Research Articles

Clinical Conditions Targeted by OnabotulinumtoxinA in Different Ways in Medicine.

OnabotulinumtoxinA (BT-A) is used in different medical fields for its beneficial effects. BT-A, a toxin originally produced by the bacterium Clostridium botulinum, is widely known for its ability to temporarily paralyze muscles by blocking the release of acetylcholine, a neurotransmitter involved in muscle contraction. The literature continually reports new hypotheses regarding potential applications that do not consider blockade of acetylcholine release at the neuromuscular junction as a common pathway. In this opinion article, it is our aim to investigate the different pathway targets of BT-A in different medical applications. First of all, the acetylcholine effect of BT-A is used to reduce wrinkles for cosmetic purposes, in the treatment of urological problems, excessive sweating, temporomandibular joint disorders, obesity, migraine, spasticity in neurological diseases, and in various cases of muscle overactivity such as cervical dystonia, blepharospasm, and essential head tremor. In another potential pathway, glutamate A, CGRP, and substance P are targeted for pain inhibition with BT-A application in conditions such as migraine, trigeminal neuralgia, neuropathic pain, and myofascial pain syndrome. On the other hand, as a mechanism different from acetylcholine and pain mediators, BT-A is used in the treatment of hair loss by increasing oxygenation and targeting transforming growth factor-beta 1 cells. In addition, the effect of BT-A on the apoptosis of cancer cells is also known and is being developed. The benefits of BT-A applied in different doses to different regions for different medical purposes are shown in literature studies, and it is also emphasized in those studies that repeating the applications increases the benefits in the long term. The use of BT-A continues to expand as researchers discover new potential therapeutic uses for this versatile toxin.

Effect of Thalamic versus Pallidal Deep Brain Stimulation on Head Tremor in Dystonic and Essential Tremor Patients-A Retrospective Video-Blinded Study.

Head tremor is common in dystonia syndromes and difficult to treat. Deep brain stimulation (DBS) is a therapeutic option in medically-refractory cases. In most DBS-centers, the globus pallidus internus (GPi) is targeted in patients with predominant dystonia and the ventrointermediate nucleus of the thalamus (Vim) in predominant tremor. The aim of the study was to evaluate the effect of GPi- versus Vim-DBS in dystonic or essential head tremor. All patients with dystonia or essential tremor (ET) (n = 381) who underwent DBS surgery at our institution between 1999 and 2020 were screened for head tremor in our database according to predefined selection criteria. Of the 33 patients meeting inclusion criteria tremor and dystonia severity were assessed at baseline, short- (mean 10 months) and long-term follow-up (41 months) by two blinded video-raters. Twenty-two patients with dystonic head tremor received either GPi- (n = 12) or Vim-stimulation (n = 10), according to the prevailing clinical phenotype. These two groups were compared with 11 patients with ET, treated with Vim-stimulation. The reduction in head tremor from baseline to short- and long-term follow-up was 60-70% and did not differ significantly between the three groups. GPi-DBS effectively and sustainably reduced head tremor in idiopathic dystonia. The effect was comparable to the effect of Vim-DBS on head tremor in dystonia patients with predominant limb tremor and to the effect of Vim-DBS on head tremor in ET.

Trial of Botulinum Toxin for Isolated or Essential Head Tremor

BackgroundLocal injections of botulinum toxin type A have been used to treat essential head tremor but have not been extensively studied in randomized trials.MethodsIn 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.ResultsA 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.ConclusionsInjection 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.)

A Case Report of Acupotomy and Herbal Medicine Treatment for Patient with Essential Head Tremor

A Case Report of Acupotomy and Herbal Medicine Treatment for Patient with Essential Head Tremor

Oral propranolol for treatment of the subgroups of essential tremor: a systematic review and meta-analysis protocol

IntroductionEssential tremor (ET), a tremor disorder, is one of the most common movement disorders. Only oral drugs (propranolol, primidone, topiramate, etc）are still the first-line treatment recommended by the Food and...

Dystonic Head Tremor and the Coexistence of Headache

<strong>Background:</strong> Head tremor may be observed in the presence of cervical dystonia and sometimes coexists with headache. We wished to investigate the presence of headache in dystonic head tremor. <strong>Methods:</strong> We studied the files of 19 patients from our outpatient clinic (1997–2017) with dystonic head tremor and assessed the co-occurrence of headache. We also performed a literature search of the topic. <strong>Results:</strong> Cervicogenic headache was present in nearly 37% of patients with dystonic head tremor. More than 85% of our patients presented with a ‘‘no-no’’ head tremor. <strong>Discussion:</strong> Headache is common in dystonic head tremor. Cervicogenic headache seems to be more frequent in patients with dystonic head tremor than in the general population. Future studies should compare the presence of cervicogenic headache in essential head tremor patients with that in patients suffering from dystonic head tremor.

Triggering essential head tremor with sustained phonation: A clinical phenomenon with potential diagnostic value

Here we report a clinical phenomenon that we have observed repeatedly in clinical research settings; namely, a triggering and/or exacerbation of head tremor during or immediately following sustained phonation. To our knowledge, it has not been reported previously nor has it been the subject of study. Here we: 1) report the phenomenon, 2) provide several visual illustrations, 3) estimate its prevalence, and 4) analyze its clinical correlates. Head tremor was assessed qualitatively, and scores were assigned pre-, during, and post-sustained phonation using the Tremor Research Group Essential Tremor Rating Assessment Scale. Seventy (68.6%) of 102 essential tremor (ET) patients exhibited a qualitative increase in head tremor amplitude during and/or immediately after sustained phonation; in 5 (4.9%), head tremor would not have been detected without the voice activation maneuver (i.e., it was not visible at any other point in the videotape aside from the period during/immediately following sustained phonation). Women were more likely than men to exhibit this phenomenon (p = 0.05), whereas age, age at onset, duration of tremor, and total tremor score did not predict responsiveness of head tremor to sustained phonation. Sustained voice activation is a useful examination maneuver that may elicit or amplify head tremor in ET. Head tremor is not reported to occur in patients with enhanced physiological tremor. Thus, this maneuver, by triggering head tremor, may be a useful diagnostic supplement, particularly in research/clinical settings where arm tremor is mild and the diagnosis (mild ET vs. enhanced physiological tremor) would otherwise be ambiguous.

Effect of lead trajectory on the response of essential head tremor to deep brain stimulation

BackgroundEssential tremor (ET) is one of the most common movement disorders. Normally ET affects the distal upper extremities, but it can also be accompanied by midline symptoms. Ventralis intermedius (VIM) thalamic deep brain stimulation (DBS) has been shown to be effective in reducing hand tremor, but its effects on head tremor have been inconsistent. MethodsTwenty-nine DBS patients with a diagnosis of ET met inclusion criteria. All implantations targeted VIM. The factors examined included age, gender, disease duration, presence or absence of head tremor, handedness, and the Fahn-Tolosa-Marin rating scale (TRS). This analysis specifically focused on TRS head tremor sub-scores at baseline, 6 months and 12 months post-DBS. Additionally, DBS lead entry angles were examined. ResultsTwenty-three ET patients underwent unilateral DBS and six underwent staged bilateral DBS. At both 6 and 12 months following DBS, stimulation resulted in diminished head tremor (ON vs OFF; p < 0.0001). The most important predictor of head tremor suppression was the entry angle of the DBS lead in the sagittal projection relative to the AC–PC axial plane (AC–PC angle). Head tremor reduction was greater among more vertical AC–PC angles. ConclusionA more vertical AC–PC angle of the DBS lead trajectory was associated with improved head tremor suppression. Further studies will be necessary to confirm this potentially important finding.

Factors Predicting Improvement in Essential Head Tremor Following Deep Brain Stimulation (P04.048)

Factors Predicting Improvement in Essential Head Tremor Following Deep Brain Stimulation (P04.048)

Warren Buffett, Black–Scholes, and the Valuation of Long-Dated Options

We describe three patients with spontaneous pendular oscillation of the eye during funduscopy. All patients had blurred, shimmering vision or oscillopsia, exacerbated by concentration, reading, or trivial head movements, and had a history of unsteadiness. Examination revealed a fine head tremor, mild unsteadiness, absent vestibulo-ocular reflex (VOR), and otherwise normal neurologic and ocular motor findings. Rigid immobilization of the head abolished the retinal oscillations. Simultaneous precision recordings of head and eye movements showed that the eye movement was in the compensatory direction to the head tremor but that, in contrast to normal VOR, it was in phase error. We conclude that the essential head tremor was provoking oscillopsia and retinal oscillation because of the absence of VOR. Recognizing the association of head tremor with absent VOR is important since in all these patients the presence of this pendular pseudonystagmus on ophthalmoscopy raised the diagnostic possibility of brain-stem disease.

Essential Head Tremor Is Associated with Cerebellar Vermis Atrophy: A Volumetric and Voxel-Based Morphometry MR Imaging Study

Our aim was to investigate the presence of brain gray matter (GM) abnormalities in patients with different forms of essential tremor (ET). We used optimized voxel-based morphometry (VBM) and manually traced single region-of-interest analysis in 50 patients with familial ET and in 32 healthy subjects. Thirty patients with ET had tremor of the arms (a-ET), whereas the remaining 20 patients had both arm and head tremor (h-ET). VBM showed marked atrophy of the cerebellar vermis in the patients with h-ET with respect to healthy subjects (P(corrected) < .001). Patients with a-ET showed a trend toward a vermal GM volume loss that did not reach a significant difference with respect to healthy controls (P(uncorrected) < .01). The region-of-interest analysis showed a reduction of the cerebellar volume (CV) in the h-ET group (98.2 +/- 13.6 mm(3)) compared with healthy controls (110.5 +/- 15.5 mm(3), P < .012) as well as in the entire vermal area (790.3 +/- 94.5 mm(2), 898.6 +/- 170.6 mm(2), P < .04 in h-ET and control groups, respectively). Atrophy of the cerebellar vermis detected in patients with h-ET strongly supports the evidence for the involvement of the cerebellum in the pathophysiology of ET. The lack of a significant CV loss observed in patients with a-ET suggests that a-ET and h-ET might represent distinct subtypes of the same disease.

Quantification of sensory trick impact on tremor amplitude and frequency in 60 patients with head tremor.

Head tremor with an obvious head deviation is the typical clinical picture of tremulous cervical dystonia (TCD), whereas head tremor without any significant head deviation allows for the differential diagnosis of dystonic head tremor (DHT) as well as essential head tremor (EHT). Clinical and polyelectromyographic (poly-EMG) studies have shown a suppression of dystonic muscle activity in patients with TCD performing a maneuver called geste antagonistique. The effect of these trick maneuvers on head tremor has not been investigated in patients with DHT and EHT. We studied the impact of sensory trick maneuvers on head tremor amplitude and frequency clinically by using the tremor subscore of the Tsui scale and by means of computer-based accelerometry in 60 patients with head tremor as their major disorder. Based on clinical data (modified Tsui scale: rating of spontaneous head deviation [rotation + lateroflexion + ante-/retroflexion]), pharmacologic response of tremor (propranolol, primidone, or alcohol), family history (postural hand tremor in first-degree relatives), and poly-EMG findings (reciprocal inhibition in neck muscles during voluntary head rotation), 34 patients were diagnosed as having TCD, 14 were classified as having DHT, and 12 patients were diagnosed as having EHT. Using a clinical rating scale, head tremor amplitudes showed a significant decrease compared with baseline during the performance of sensory trick maneuvers in patients with TCD and DHT, but not in patients with EHT. This clinically observed effect was accompanied by a significant reduction in the mean peak power of the dominant frequency in patients with TCD (decrease by 83%, p = 0.0001) and DHT (decrease by 90%, p = 0.01), but not in patients with EHT (decrease by 6%, p = 0.6). Head tremor frequencies showed no significant changes in relation to the trick maneuvers. We conclude that a significant reduction of head tremor amplitude during a sensory trick maneuver is a useful quantitative criterion to distinguish TCD and DHT from EHT.

Neurophysiological investigations in patients with head tremor.

We studied 30 patients whose primary complaint was head tremor in an attempt to characterize neurophysiological aspects of their abnormal movement. Based on family medical history and physical examination, 23 patients had definite or probable essential tremor (essential head tremor, EHT). The remaining seven had mild dystonic signs accompanying their head tremor (head tremor plus dystonic signs, HT + DS). We recorded head movement and the electromyographic (EMG) activity of the sternomastoid and splenius capitis muscles, determined the spontaneous blinking rate, and measured the excitability recovery curve of the blink reflex and of the masseteric inhibitory reflex. All patients had tremor bursts at a frequency ranging between 3 and 9 Hz in at least one of the muscles examined. The predominant pattern seen when patients were sitting relaxed and facing forward was that of synchronized EMG bursts in both splenius capitis muscles. Maintenance of extreme head postures demonstrated two types of additional abnormalities: type 1 (enhancement of tremor), which was observed in 11 patients (47.8%) with EHT and in two (28.5%) with HT + DS; and type 2 (activation of neck muscles not required for maintenance of the posture), which was observed in two patients (8.7%) with EHT and in five (71.5%) with HT + DS (chi 2 = 26.4; p < 0.001). Mean blinking rate per minute was 24.9 +/- 14.6 in patients with EHT and 42.3 +/- 10.5 in patients with HT + DS (paired t test, p = 0.001). The blink reflex and masseteric inhibitory reflex excitability recovery curves showed an abnormal interneuronal excitability enhancement in seven (30.4%) of the 23 patients with EHT and in two (28.5%) of the seven with HT + DS (chi 2 = 3.1; p > 0.05). Abnormal patterns of EMG activity of the neck muscles correlated well with the presence of mild dystonic signs. However, the analysis of brainstem interneuronal excitability did not enable recognition of those patients with head tremor who could potentially develop cervical dystonia. The enhancement of brainstem interneuronal excitability found in approximately 30% of patients with head tremor could be related to plastic changes triggered by increased activity of the cranial muscles.

Botulinum toxin treatment of essential head tremor

We examined in a double-blind, placebo-controlled study the effects of botulinum toxin in 10 patients with essential head tremor. Each subject received two treatments approximately 3 months apart, one with botulinum toxin injections and another with normal saline injections into the sternocleidomastoid and splenius capitis muscles. The subjects were assessed before each treatment and at 2, 4, and 8 weeks after injections. There was moderate to marked improvement in clinical ratings in five subjects after botulinum toxin injections and in one subject after placebo. There was moderate to marked subjective improvement in five patients with botulinum toxin as compared with three subjects with placebo. Side effects were mild and transient. We conclude that botulinum toxin may be useful for patients with essential head tremor who have failed to benefit from oral medications.

Effect of Propranolol in Head Tremor

The effect of the beta-adrenoceptor antagonist propranolol has been investigated in nine patients suffering from isolated (six patients) or prominent (three patients) essential tremor of the head. In a double-blind, placebo-controlled study the tremorolytic efficacy of propranolol has been assessed by a quantitative accelerometric method after a single oral dose (120 mg) and following 2 weeks of sustained treatment with two different dosage regimens of the drug (120 and 240 mg daily). As compared with placebo, a significant reduction in tremor magnitude was found following a single oral dose but not on sustained administration of the beta-blocker at either dosage. The results suggest that the efficacy of sustained propranolol on isolated or prominent essential head tremor is less predictable and satisfactory than expected on the basis of the single-dose response, as compared with hand tremor.