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BMJ (Clinical Research Ed.) Aug 2019Essential tremor is one of the most common movement disorders in adults and can affect both children and adults. An updated consensus statement in 2018 redefined... (Review)
Review
Essential tremor is one of the most common movement disorders in adults and can affect both children and adults. An updated consensus statement in 2018 redefined essential tremor as an isolated action tremor present in bilateral upper extremities for at least three years. Tremor may also be present in other locations, commonly the neck or the vocal cords. Patients with additional neurologic symptoms are now categorized as "essential tremor plus." Additional clinical features associated with the condition include but are not limited to cognitive impairment, psychiatric disorders, and hearing loss. When treatment is needed, propranolol and primidone are considered first line treatments. Patients who are severely affected are often offered deep brain stimulation. Although the ventral intermediate nucleus of the thalamus is the traditional surgical target, the caudal zona incerta is also being studied as a possible superior alternative. Magnetic resonance imaging guided high intensity focused ultrasound is a newer surgical alternative that may be ideal for patients with substantial medical comorbidities. Current research explores novel oral treatments, chemodenervation, and noninvasive neuromodulation for treatment of essential tremor.
Topics: Adrenergic beta-Antagonists; Anticonvulsants; Antipsychotic Agents; Deep Brain Stimulation; Essential Tremor; Extracorporeal Shockwave Therapy; Humans; Nerve Block
PubMed: 31383632
DOI: 10.1136/bmj.l4485 -
Nature Reviews. Disease Primers Nov 2021Essential tremor (ET) is one of the most common movement disorders, with a reported >60 million affected individuals worldwide. The definition and underlying... (Review)
Review
Essential tremor (ET) is one of the most common movement disorders, with a reported >60 million affected individuals worldwide. The definition and underlying pathophysiology of ET are contentious. Patients present primarily with motor features such as postural and action tremors, but may also have other non-motor features, including cognitive impairment and neuropsychiatric symptoms. Genetics account for most of the ET risk but environmental factors may also be involved. However, the variable penetrance and challenges in validating data make gene-environment analysis difficult. Structural changes in cerebellar Purkinje cells and neighbouring neuronal populations have been observed in post-mortem studies, and other studies have found GABAergic dysfunction and dysregulation of the cerebellar-thalamic-cortical circuitry. Commonly prescribed medications include propranolol and primidone. Deep brain stimulation and ultrasound thalamotomy are surgical options in patients with medically intractable ET. Further research in post-mortem studies, and animal and cell-based models may help identify new pathophysiological clues and therapeutic targets and, together with advances in omics and machine learning, may facilitate the development of precision medicine for patients with ET.
Topics: Animals; Essential Tremor; Humans
PubMed: 34764294
DOI: 10.1038/s41572-021-00314-w -
Neurotherapeutics : the Journal of the... Oct 2020Essential tremor is one of the most common tremor syndromes. According to the recent tremor classification, tremor as a symptom is defined as an involuntary, rhythmic,... (Review)
Review
Essential tremor is one of the most common tremor syndromes. According to the recent tremor classification, tremor as a symptom is defined as an involuntary, rhythmic, oscillatory movement of a body part and is classified along two axes: axis 1-defining syndromes based on the clinical features such as historical features, tremor characteristics, associated signs, and laboratory tests; and axis 2-classifying the etiology (Bhatia et al., Mov Disord 33:75-87, 2018). The management of this condition has two major approaches. The first is to exclude treatable etiologies, as particularly during the onset of this condition the presentation of a variety of etiologies can be with monosymptomatic tremor. Once the few etiologies with causal treatments are excluded, all further treatment is symptomatic. Shared decision-making with enabling the patient to knowledgeably choose treatment options is needed to customize the management. Mild to moderate tremor severity can sometimes be controlled with occupational treatment, speech therapy of psychotherapy, or adaptation of coping strategy. First-line pharmacological treatments include symptomatic treatment with propranolol, primidone, and topiramate. Botulinum toxin is for selected cases. Invasive treatments for essential tremor should be considered for severe tremors. They are generally accepted as the most powerful interventions and provide not only improvement of tremor but also a significant improvement of life quality. The current standard is deep brain stimulation (DBS) of the thalamic and subthalamic region. Focused ultrasound thalamotomy is a new therapy attracting increasing interest. Radiofrequency lesioning is only rarely done if DBS or focused ultrasound is not possible. Radiosurgery is not well established. We present our treatment algorithm.
Topics: Behavior Therapy; Botulinum Toxins; Deep Brain Stimulation; Diagnosis, Differential; Disease Management; Essential Tremor; Humans; Occupational Therapy; Radiosurgery; Treatment Outcome
PubMed: 32915385
DOI: 10.1007/s13311-020-00899-2 -
CNS Drugs Aug 2022The relationship between antiseizure drugs and movement disorders is complex and not adequately reviewed so far. Antiseizure drugs as a treatment for tremor and other... (Review)
Review
The relationship between antiseizure drugs and movement disorders is complex and not adequately reviewed so far. Antiseizure drugs as a treatment for tremor and other entities such as myoclonus and restless leg syndrome is the most common scenario, although the scientific evidence supporting their use is variable. However, antiseizure drugs also represent a potential cause of iatrogenic movement disorders, with parkinsonism and tremor the most common disorders. Many other antiseizure drug-induced movement disorders are possible and not always correctly identified. This review was conducted by searching for all the possible combinations between 15 movement disorders (excluding ataxia) and 24 antiseizure drugs. The main objective was to describe the movement disorders treated and worsened or induced by antiseizure drugs. We also summarized the proposed mechanisms and risk factors involved in the complex interaction between antiseizure drugs and movement disorders. Antiseizure drugs mainly used to treat movement disorders are clonazepam, gabapentin, lacosamide, levetiracetam, oxcarbazepine, perampanel, phenobarbital, pregabalin, primidone, topiramate, and zonisamide. Antiseizure drugs that worsen or induce movement disorders are cenobamate, ethosuximide, felbamate, lamotrigine, phenytoin, tiagabine, and vigabatrin. Antiseizure drugs with a variable effect on movement disorders are carbamazepine and valproate while no effect on movement disorders has been reported for brivaracetam, eslicarbazepine, lacosamide, and stiripentol. Although little information is available on the adverse effects or benefits on movement disorders of newer antiseizure drugs (such as brivaracetam, cenobamate, eslicarbazepine, lacosamide, and rufinamide), the evidence collected in this review should guide the choice of antiseizure drugs in patients with concomitant epilepsy and movement disorders. Finally, these notions can lead to a better understanding of the mechanisms involved in the pathophysiology and treatments of movement disorders.
Topics: Anticonvulsants; Humans; Lacosamide; Levetiracetam; Movement Disorders; Tremor
PubMed: 35861924
DOI: 10.1007/s40263-022-00937-x -
Movement Disorders : Official Journal... Jul 2019Essential tremor is one of the most prevalent movement disorders. Many treatments for essential tremor have been reported in clinical practice, but it is uncertain which... (Review)
Review
BACKGROUND
Essential tremor is one of the most prevalent movement disorders. Many treatments for essential tremor have been reported in clinical practice, but it is uncertain which options have the most robust evidence. The International Parkinson and Movement Disorder Society commissioned a task force on tremor to review clinical studies of treatments for essential tremor.
OBJECTIVES
To conduct an evidence-based review of current pharmacological and surgical treatments for essential tremor, using standardized criteria defined a priori by the International Parkinson and Movement Disorder Society.
METHODS
We followed the recommendations of the International Parkinson and Movement Disorder Society Evidence Based Medicine Committee.
RESULTS
Sixty-four studies of pharmacological and surgical interventions were included in the review. Propranolol and primidone were classified as clinically useful, similar to Topiramate, but only for doses higher than 200 mg/day. Alprazolam and botulinum toxin type A were classified as possibly useful. Unilateral Ventralis intermedius thalamic DBS, radiofrequency thalamotomy, and MRI-guided focused ultrasound thalamotomy were considered possibly useful. All the above recommendations were made for limb tremor in essential tremor. There was insufficient evidence for voice and head tremor as well as for the remaining interventions.
CONCLUSION
Propranolol, primidone, and topiramate (>200 mg/day) are the pharmacological interventions in which the data reviewed robustly supported efficacy. Their safety profile and patient preference may guide the prioritization of these interventions in clinical practice. MRI-guided focused ultrasound thalamotomy was, for the first time, assessed and was considered to be possibly useful. There is a need to improve study design in essential tremor and overcome the limitation of small sample sizes, cross-over studies, short-term follow-up studies, and use of nonvalidated clinical scales. © 2019 International Parkinson and Movement Disorder Society.
Topics: Deep Brain Stimulation; Essential Tremor; Humans; Magnetic Resonance Imaging; Radiosurgery; Thalamus; Treatment Outcome
PubMed: 31046186
DOI: 10.1002/mds.27700 -
Postgraduate Medical Journal Feb 2020Essential tremor is the most common cause of tremor involving upper limbs, head and voice. The first line of treatment for limb tremor is pharmacotherapy with... (Review)
Review
Essential tremor is the most common cause of tremor involving upper limbs, head and voice. The first line of treatment for limb tremor is pharmacotherapy with propranolol or primidone. However, these two drugs reduce the tremor severity by only half. In medication refractory and functionally disabling tremor, alternative forms of therapy need to be considered. Botulinum toxin injections are likely efficacious for limb, voice and head tremor but are associated with side effects. Surgical interventions include deep brain stimulation; magnetic resonance-guided focused ultrasound and thalamotomy for unilateral and deep brain stimulation for bilateral procedures. Recent consensus classification for essential tremor has included a new subgroup, 'Essential tremor plus', who have associated subtle neurological 'soft signs', such as dystonic posturing of limbs and may require a different treatment approach. In this review, we have addressed the current management of essential tremor with regard to different anatomical locations of tremor as well as different modalities of treatment.
Topics: Acetylcholine Release Inhibitors; Adrenergic beta-Antagonists; Botulinum Toxins; Deep Brain Stimulation; Essential Tremor; GABA Modulators; High-Intensity Focused Ultrasound Ablation; Humans; Magnetic Resonance Imaging; Primidone; Propranolol; Surgery, Computer-Assisted; Thalamus; Transcranial Magnetic Stimulation
PubMed: 31575730
DOI: 10.1136/postgradmedj-2019-136647