The spectrum of orolingual tremor—A proposed classification system

Orolingual tremors include tremors of the jaw, tongue, pharynx, and face. There is currently no accepted classification scheme for such tremors. A proper classification scheme for orolingual tremors should aid in providing more accurate diagnoses and permit future research studies assessing important aspects such as pathogenesis or novel therapies using more uniformly defined and characterized populations. In this review, we propose a classification system for orolingual tremor based on the consensus statement of the Movement Disorder Society on tremor. We also present cases of orolingual tremor and include these cases in the classification system. © 2007 Movement Disorder Society     

Bayesian Interpretation of Essential Tremor Plus

Essential tremor (ET) plus is a new tremor classification that was introduced in 2018 by a task force of the International Parkinson and Movement Disorder Society. Patients with ET plus meet the criteria for ET but have one or more additional systemic or neurologic signs of uncertain significance or relevance to tremor (“soft signs”). Soft signs are not sufficient to diagnose another tremor syndrome or movement disorder, and soft signs in ET plus are known to have poor interrater reliability and low diagnostic sensitivity and specificity. Therefore, the clinical significance of ET plus must be interpreted probabilistically when judging whether a patient is more likely to have ET or a combined tremor syndrome, such as dystonic tremor. Such a probabilistic interpretation is possible with Bayesian analysis. This review presents a Bayesian analysis of ET plus in patients suspected of having ET versus a dystonic tremor syndrome, which is the most common differential diagnosis in patients referred for ET. Bayesian analysis of soft signs provides an estimate of the probability that a patient with possible ET is more likely to have an alternative diagnosis. ET plus is a distinct tremor classification and should not be viewed as a subtype of ET. ET plus covers a more-comprehensive phenotyping of people with possible ET, and the clinical interpretation of ET plus is enhanced with Bayesian analysis of associated soft signs.     

Therapeutic Advances in the Treatment of Holmes Tremor: Systematic Review

ObjectiveWe aimed to formulate a practical clinical treatment algorithm for Holmes tremor (HT) by reviewing currently published clinical data.Materials and MethodsWe performed a systematic review of articles discussing the management of HT published between January 1990 and December 2018. We examined data from 89 patients published across 58 studies detailing the effects of pharmacological or surgical interventions on HT severity. Clinical outcomes were measured by a continuous 1-10 ranked scale. The majority of studies addressing treatment response were case series or case reports. No randomized control studies were identified.ResultsOur review included 24 studies focusing on pharmacologic treatments of 25 HT patients and 34 studies focusing on the effect of deep brain stimulation (DBS) in 64 patients. In the medical intervention group, the most commonly used drugs were levetiracetam, trihexyphenidyl, and levodopa. In the surgically treated group, the thalamic ventralis intermedius nucleus (VIM) and globus pallidus internus (GPi) were the most common brain targets for neuromodulation. The two targets accounted for 57.8% and 32.8% of total cases, respectively. Overall, compared to the medically treated group, DBS provided greater tremor suppression (p = 0.025) and was more effective for the management of postural tremor in HT. Moreover, GPi DBS displayed greater benefit in the resting tremor component (p = 0.042) and overall tremor reduction (p = 0.022).ConclusionsThere is a highly variable response to different medical treatments in HT without randomized clinical trials available to dictate treatment decisions. A variety of medical and surgical treatment options can be considered for the management of HT. Collaborative research between different institutions and researchers are warranted and needed to improve our understanding of the pathophysiology and management of this condition. In this review, we propose a practical treatment algorithm for HT based on currently available evidence.     

Tremor in Parkinson disease: acute response to oral levodopa

A single blind placebo-controlled study has been performed in order to investigate objectively the acute tremorolytic effect of oral L-Dopa in ten parkinsonians chronically treated with L-Dopa. Finger tremor was assessed by means of a computerized accelerometer method, at rest and during maintenance of a fixed posture. Both resting and postural tremor were significantly influenced by L-Dopa. An “acute test” with oral L-Dopa, especially when different tremor components are investigated, may be useful for identifying objectively parkinsonians whose tremor does not respond to drug therapy or shows a deterioration of drug-responsiveness.

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Sommario Uno studio controllato con placebo è stato condotto su 10 pazienti affetti da morbo di Parkinson idiopatico, in trattamento cronico con L-Dopa, allo scopo di valutare in modo obiettivo l'effetto tremorolitico della L-Dopa. Il tremore è stato valutato alle mani mediante una metodica di accelerometria computerizzata, sia in condizioni di riposo che di postura. In entrambe le condizioni l'effetto tremorolitico della L-Dopa si è rivelato significativo. Un “test acuto” con L-Dopa orale, in particolare con l'esplorazione di componenti diverse del tremore, può risultare utile per una valutazione obiettiva di casi di Parkinson che non rispondano alla terapia farmacologica o che manifestino un deterioramento della risposta alla L-Dopa.

     

Tremor in multiple sclerosis

Tremor is estimated to occur in about 25 to 60 percent of patients with multiple sclerosis (MS). This symptom, which can be severely disabling and embarrassing for patients, is difficult to manage. Isoniazid in high doses, carbamazepine, propranolol and gluthetimide have been reported to provide some relief, but published evidence of effectiveness is very limited. Most trials were of small size and of short duration. Cannabinoids appear ineffective. Tremor reduction can be obtained with stereotactic thalamotomy or thalamic stimulation. However, the studies were small and information on long-term functional outcome is scarce. Physiotherapy, tremor reducing orthoses, and limb cooling can achieve some functional improvement. Tremor in MS remains a significant challenge and unmet need, requiring further basic and clinical research. Received in revised form: 2 May 2006     

Keep smiling!

Introduction Emotional contagion is a common phenomenon in verbal and nonverbal communication between individuals. Perception and mimicry of facial movements play an important role in this process. Several studies have demonstrated impaired facial expression recognition in patients with schizophrenia and differences in their facial behavior compared to healthy subjects, but so far, the relationship between facial mimicry and emotional contagion has not been studied in this group. Methods Seventeen schizophrenic patients and an equal number of matched healthy controls were presented with digital versions of happy, sad and neutral faces from the “Pictures of facial affect” (Ekman and Friesen, Consulting Psychologists Press, Palo Alto, 1976) and were asked to pull their lip corners up or down (like in smiling or showing a sad face) according to the direction of two arrows that were presented simultaneously. In healthy subjects, congruous movements (i.e. pulling the lip corners up when seeing a happy face or pulling them down when seeing a sad face) are facilitated and dissonant movements are inhibited; these tendencies were considered as indicators of emotional contagion. Results In schizophrenic patients, these tendencies were significantly diminished. The patients were more apt to display a smile as a reaction to a sad face. We found a positive correlation between these effects and the PANSS—Scores for General Psychopathology. Discussion Patients’ tendencies towards positive reactions even when a negative stimulus was presented could function as a protective mechanism against overwhelming emotional experiences.     

家族性皮质肌阵挛震颤伴癫(痫)研究进展

家族性皮质肌阵挛震颤伴癫(痫)是种常染色体显性遗传、成年起病、良性病程的罕见癫(痫)综合征.主要临床表现为肌阵挛样震颤、伴或不伴癫(痫)发作.依据临床表现及神经电生理检查显示肌阵挛样震颤源于大脑皮质可做诊断.抗癫(痫)药物可有效控制患者的肌阵挛样震颤和癫(痫).近期研究已提出数个可能的致病基因位点及机制,文中对其临床表现及发病机制的研究进行综述.     

Tremor dominant parkinsonism: Clinical description and LRRK2 mutation screening

Tremor dominant parkinsonism (TDP) is characterized by initial prominent resting and action tremor, mild parkinsonism, unpredictable response to medication, and a better prognosis than idiopathic Parkinson's disease (PD). We report on clinical features and longitudinal course of 26 patients suffering from TDP. Mean disease duration was 6.5 ± 3 years, 61.5% of patients had a positive family history of tremor, 73% did not need drug treatment, performance of 123I‐Ioflupane SPECT showed reduced striatal tracer uptake in 65.4% of patients, and odor identification testing was pathologic in all the patients tested (n = 22). Co‐occurrence of action and resting tremor were the most annoying and disabling symptoms in all the patients, whereas rigidity and/or bradykinesia were clinically irrelevant in most of them. We also sequenced the full coding region of the Leucine‐rich repeat kinase 2 gene (LRRK2) in all patients. We found a novel Val2390Met mutation that was not found in 864 chromosomes. Our results suggest a broader clinical heterogeneity related to LRRK2 mutations and points towards TDP as a subtype within the spectrum of PD, in which disabling tremor but otherwise mild parkinsonian signs and a better prognosis are the main characteristics. © 2007 Movement Disorder Society     

Epicranial Direct Current Stimulation Suppresses Harmaline Tremor in Rats

IntroductionEssential tremor (ET) is the most common neurologic movement disorder worldwide. It is characterized by a postural tremor, mostly in the upper extremities, causing difficulties in daily activities that may lead to social exclusion. Some patients with ET do not respond well to or do not tolerate medication. Thus, deep brain stimulation can be offered. In a recent study, we proposed a novel neuromodulation technique called epicranial current stimulation (ECS) that works in a minimally invasive way by placing the electrodes subcutaneously under the skin and directly over the skull. In this study, we investigated the feasibility of using epicranial direct current stimulation (EDCS) to suppress tremor in a rat harmaline ET model.Materials and MethodsIn experiment 1, seven Sprague Dawley rats were implanted with ECS electrodes placed over the motor cortex (MC) and the cerebellum to investigate whether stimulating between them could suppress tremor. In experiments 2 and 3, eight rats were implanted with ECS electrodes placed over the MC, cerebellum, and the rostral skull to separate the effects on tremor caused by stimulating each target. During each experiment, the rats were injected with harmaline, which induced tremor that was quantified using an accelerometer. EDCS was then applied through the different electrode configurations to evaluate their tremor suppression effectiveness.ResultsResults from experiment 1 showed that MC_cathode-Cerebellar_anode suppressed tremor compared with stimulation-OFF but MC_anode-Cerebellar_cathode did not. Furthermore, experiments 2 and 3 showed that it was the cerebellar anodal electrode that was driving tremor suppression.ConclusionCerebellar EDCS suppressed harmaline tremor in rats in a polarity-dependent manner. EDCS could be a promising neuromodulation method for patients with ET.     

Tremor in neuropathies of different origin

Background and purposeTremor accompanies some polyneuropathies, but its prevalence and its clinical and electrophysiological manifestations are not well known. The aim of the study was to assess the occurrence and characteristics of hand tremor in patients with polyneuropathy of different origins, as well as relations between the occurrence of tremors and clinical and neurographic findings of polyneuropathy.Material and methodsEighty-nine patients diagnosed with polyneuropathy of known aetiology, and 50 age- and sex-matched healthy volunteers were included in the study. All subjects were interviewed regarding the occurrence of tremor. Tremor was assessed clinically and objectively using a triaxial accelerometer and electromyographic (EMG) recordings. A load test with a weight of 500 g was performed in order to differentiate between enhanced physiological tremor (EPT) and essential tremor-like (ET-L) tremor.ResultsTremor was found in 59.5% of patients in clinical assessment and in 74% of patients in objective evaluation, significantly more often than in controls (12%). Tremor was detected in all types of polyneuropathy apart from paraproteinaemic IgM polyneuropathy. Tremor was postural (70%), but resting (51%) or kinetic (32%) tremor was also present. In the majority of cases, the severity of the tremor was mild. Essential tremor-like tremor prevailed in the study group. The occurrence of hand tremor was not related to the axonal or demyelinating type of polyneuropathy, nor to the conduction velocity or other electrophysiological findings of the investigated upper limb nerves.ConclusionTremor accompanies 60–70% of patients with polyneuropathy; it is mostly postural, ET-L type with mild severity, and unrelated to other typical clinical and electrophysiological findings of neuropathy.