Bedside clinical assessment of patients with common upper limb tremor and algorithmic approach.

The diagnostic approach for patients with tremor is challenging due to the complex and overlapping phenotypes among tremor syndromes. The first step in the evaluation of tremor is to identify the tremulous movement and exclude the tremor mimics. The second step is to classify the tremor syndrome based on the characteristics of tremor from historical clues and focused examination (Axis 1). Comprehensive tremor examinations involve the assessment of tremor in different conditions (rest, action or mixed, position or task-specific), distribution of tremor (upper limb, lower limb, head, jaw), positive signs for functional tremor (FT) if suspected (distractibility, entrainment, co-contraction), and associated neurological signs including parkinsonism, dystonic posture, cerebellar/brainstem signs, neuropathy, and cognitive impairment. A pivotal feature in this step is to determine any distinct feature of a specific isolated or combined tremor syndrome. In this review, we propose an algorithm to assess upper limb tremors. Ancillary testing should be performed if clinical evaluation is unclear. The choice of investigation depends on the types of tremors considered to narrow down the spectrum of etiology (Axis 2). Laboratory blood tests are considered for acute onset and acute worsening of tremors, while structural neuroimaging is indicated in unilateral tremors with acute onset, nonclassical presentations, and a combination of neurological symptoms. Neurophysiological study is an important tool that aids in distinguishing between tremor and myoclonus, etiology of tremor and document specific signs of FT. Treatment is mainly symptomatic based depending on the etiology of the tremor and the patient's disabilities.

Clinical features, pathophysiology, treatment, and controversies of tremor in dystonia.

Dystonia and tremor frequently co-occur. In some cases, they have shared biological mechanisms, while in others dystonia and tremor are two comorbid conditions. The term "dystonic tremor" is used to describe tremor in those who have dystonia. Two mutually exclusive definitions of "dystonic tremor" were proposed. According to one definition, dystonic tremor is the tremor in the dystonic body part. An alternate definition of dystonic tremor entails irregular and jerky oscillations that have saw tooth appearance with or without overt dystonia. This paper outlines the differences in two definitions of dystonic tremor and identifies their limitations. Given the diverse views defining "dystonic tremor", this paper will use the term "tremor in dystonia". In addition, we will outline different ways to separate the subtypes of tremor in dystonia. Then we will discuss pathophysiological mechanisms derived from the objective measures and single neuron physiology analyses of tremor in dystonia. This article is part of the Special Issue "Tremor" edited by Daniel D. Truong, Mark Hallett, and Aasef Shaikh.

Orofacial dystonia and asssociated bulbar symptoms in multiple system atrophy: A blinded video analysis.

BACKGROUND: Orofacial dystonia (OFD) is considered a supporting feature for a diagnosis of Multiple System Atrophy (MSA). However, the association of OFD with other adjacent symptoms has not been explored. OBJECTIVES: To identify clinical characteristics of OFD and associated bulbar symptoms in MSA patients. METHODS: In this blinded trial, video clips of 24 MSA patients were reviewed by two movement disorder neurologists who rated the presence of OFD. Analysis was performed to determine correlations between the presence of OFD and clinical demographics as well as associated bulbar symptoms. RESULTS: There were 14 patients with MSA-P and 10 patients with MSA-C. OFD was identified in seven patients (29.16%) and MSA-P as the majority (85.71%). Oromandibular dystonia (OMD) was hardly ever identified in isolation with the most frequent combination being OMD with upper facial dystonia, blepharospasm and platysma dystonia. All OMD patients had the jaw-closing subtype. Mean onset of OFD was 1.7 (SD = 0.5) years after the first symptom onset and 1.1 years (SD = 0.4) after the introduction of levodopa. Patients with OFD used significantly higher levodopa equivalent daily dosage (LEDD) than those without (p = 0.02). There were moderate correlations between the presence of OFD and LEDD (r = 0.458, p = 0.02), and dysarthria (r = 0.639, p = 0.001) while a strong correlation was demonstrated between the presence of OFD and dysphagia (r = 0.9, p < 0.001). CONCLUSION: OFD is probably a manifestation of motor fluctuations in MSA and its presence is significantly associated with bulbar symptoms. Neurologists should inquire about dysphagia when encountering MSA patients with OFD for early recognition and appropriate management.