Associations Among Tremor Amplitude, Activities of Daily Living, and Quality of Life in Patients with Essential Tremor.

Background: Essential tremor (ET) is a disabling syndrome consisting of tremor, primarily in the upper limbs. We assessed the correlation of The Essential Tremor Rating Assessment Scale (TETRAS) Performance Item 4 ratings of upper limb tremor with the TETRAS activities of daily living (ADL) subscale and with 2 quality of life (QoL) scales.

Methods: This noninterventional, cross-sectional, point-in-time survey of neurologists(n = 60), primary care physicians (n = 38), and their patients with ET (n = 1,003) used real-world data collected through the Adelphi ET Disease Specific Programme™.

A Randomized Phase 2 KINETIC Trial Evaluating SAGE-324/BIIB124 in Individuals with Essential Tremor.

Background: SAGE-324/BIIB124 is an investigational positive allosteric modulator of GABA receptors.

Objective: KINETIC (NCT04305275), a double-blind, randomized, placebo-controlled, phase 2 study, evaluated SAGE-324/BIIB124 in individuals with essential tremor (ET).

Methods: Individuals aged 18 to 80 years were randomly assigned 1:1 to orally receive 60 mg of SAGE-324/BIIB124 or placebo once daily for 28 days.

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.

Tremor rating scales and laboratory tools for assessing tremor.

The purpose of this review is to characterize and compare validated clinical rating scales and transducers that are used in the clinical assessment of tremor disorders. Tremor is an involuntary oscillatory movement of a body part. Tremor can be characterized in terms of amplitude and frequency of oscillation, and these kinematic properties vary randomly and with activities of daily living.

The clinical and electrophysiological investigation of tremor.

The various forms of tremor are now classified in two axes: clinical characteristics (axis 1) and etiology (axis 2). Electrophysiology is an extension of the clinical exam. Electrophysiologic tests are diagnostic of physiologic tremor, primary orthostatic tremor, and functional tremor, but they are valuable in the clinical characterization of all forms of tremor.

From null to midline: changes in head posture do not predictably change head tremor in cervical dystonia.

Introduction: A common view is that head tremor (HT) in cervical dystonia (CD) decreases when the head assumes an unopposed dystonic posture and increases when the head is held at midline. However, this has not been examined with objective measures in a large, multicenter cohort.

Methods: For 80 participants with CD and HT, we analyzed videos from examination segments in which participants were instructed to 1) let their head drift to its most comfortable position (null point) and then 2) hold their head straight at midline.

Do We Belittle Essential Tremor by Calling It a Syndrome Rather Than a Disease? No.

A task force of the International Parkinson and Movement Disorder Society (MDS) recently published a tremor classification scheme that is based on the nosologic principle of two primary axes for classifying an illness: clinical manifestations (Axis 1) and etiology (Axis 2). An Axis 1 clinical syndrome is a recurring group of clinical symptoms, signs (physical findings), and possibly laboratory results that suggests the presence of at least one underlying Axis 2 etiology. Syndromes must be defined and used consistently to be of value in finding specific etiologies and effective treatments.

Development and Validation of the Orthostatic Tremor Severity and Disability Scale (OT-10).

Background: Limited tools are available for the assessment of orthostatic tremor severity and disability.

Objectives: To develop and validate a self-administered orthostatic tremor scale.

Methods: After expert consensus and literature review generating a list of 42 items, the scale was developed and modified for validation after a patient focus group, multiple rounds of Delphi panels, and cognitive interviews.

A Pilot Double-Blind Randomized Trial of Perampanel for Essential Tremor.

Background: Perampanel is a noncompetitive antagonist of alpha-amino-3-hydroxy-5-methylisoxazole propionic acid glutamate receptors suggested to modulate tremor.

Objectives: To assess the efficacy and tolerability of perampanel for essential tremor.

Methods: This was a double-blind, placebo-controlled, randomized, cross-over trial involving 26 patients titrated to 8 mg/day or a lower maximally tolerated dose as monotherapy or adjunct to antitremor medication.

Oculopalatal tremor following sequential medullary infarcts that did not cause hypertrophic olivary degeneration.

Background: The syndrome of oculopalatal tremor is a known consequence of lesions in the dentate-olivary pathway. Hypertrophic degeneration of the inferior olive is a recognized pathological correlate of these lesions and hypothesized to cause tremorogenic olivary hypersynchrony. However, oculopalatal tremor also occurs in Alexander disease, which produces severe inferior olive degeneration without intervening hypertrophy.

Estimating Change in Tremor Amplitude Using Clinical Ratings: Recommendations for Clinical Trials.

Tremor rating scales are the standard method for assessing tremor severity and clinical change due to treatment or disease progression. However, ratings and their changes are difficult to interpret without knowing the relationship between ratings and tremor amplitude (displacement or angular rotation), and the computation of percentage change in ratings relative to baseline is misleading because of the ordinal nature of these scales. For example, a reduction in tremor from rating 2 to rating 1 (0-4 scale) should not be interpreted as a 50% reduction in tremor amplitude, nor should a reduction in rating 4 to rating 3 be interpreted as a 25% reduction in tremor.

Current Opinions and Consensus for Studying Tremor in Animal Models.

Tremor is the most common movement disorder; however, we are just beginning to understand the brain circuitry that generates tremor. Various neuroimaging, neuropathological, and physiological studies in human tremor disorders have been performed to further our knowledge of tremor. But, the causal relationship between these observations and tremor is usually difficult to establish and detailed mechanisms are not sufficiently studied.

Surgical treatments for essential tremor.

Essential tremor is the most common form of pathologic tremor. Surgical therapies disrupt tremorogenic oscillation in the cerebellothalamocortical pathway and are capable of abolishing severe tremor that is refractory to available pharmacotherapies. Surgical methods are raspidly improving and are the subject of this review.

Consensus Statement on the classification of tremors. from the task force on tremor of the International Parkinson and Movement Disorder Society.

Background: Consensus criteria for classifying tremor disorders were published by the International Parkinson and Movement Disorder Society in 1998. Subsequent advances with regard to essential tremor, tremor associated with dystonia, and other monosymptomatic and indeterminate tremors make a significant revision necessary.

Objectives: Convene an international panel of experienced investigators to review the definition and classification of tremor.

Pure akinesia with gait freezing: a clinicopathologic study.

Background: Pure akinesia with gait freezing is a rare syndrome with few autopsied cases. Severe freezing of gait occurs in the absence of bradykinesia and rigidity. Most autopsies have revealed progressive supranuclear palsy.

Digitizing Tablet and Fahn-Tolosa-Marín Ratings of Archimedes Spirals have Comparable Minimum Detectable Change in Essential Tremor.

Background: Drawing Archimedes spirals is a popular and valid method of assessing action tremor in the upper limbs. We performed the first blinded comparison of Fahn-Tolosa-Marín (FTM) ratings and tablet measures of essential tremor to determine if a digitizing tablet is better than 0-4 ratings in detecting changes in essential tremor that exceed random variability in tremor amplitude.

Methods: The large and small spirals of FTM were drawn with each hand on two consecutive days by 14 men and four women (age 60±8.

Assessment of Head Tremor with Accelerometers Versus Gyroscopic Transducers.

Background: Accelerometers and gyroscopes are used commonly in the assessment of hand tremor, but their validity in the assessment of head tremor has not been studied. We hypothesized that gyroscopy would be superior to accelerometry because head tremor is rotational motion, and gyroscopes record rotational motion, free of gravitational artifact. We also hypothesized a strong logarithmic relationship between 0 to 4-point tremor ratings and the transducer measures of tremor amplitude, similar to those previously reported for hand tremor.

Transducer-based evaluation of tremor.

The International Parkinson and Movement Disorder Society established a task force on tremor that reviewed the use of transducer-based measures in the quantification and characterization of tremor. Studies of accelerometry, electromyography, activity monitoring, gyroscopy, digitizing tablet-based measures, vocal acoustic analysis, and several other transducer-based methods were identified by searching PubMed.gov.

The essential tremor syndromes.

Purpose Of Review: Essential tremor has not been defined or used consistently in clinical diagnosis and research. Other monosymptomatic disorders are often referred to as essential tremor variants.

Recent Findings: There is now solid evidence that essential tremor, however defined, is a syndrome with multiple causes.

Using Portable Transducers to Measure Tremor Severity.

Background: Portable motion transducers, suitable for measuring tremor, are now available at a reasonable cost. The use of these transducers requires knowledge of their limitations and data analysis. The purpose of this review is to provide a practical overview and example software for using portable motion transducers in the quantification of tremor.