Tremor and Other Hyperkinetic Movements最新文献

Background: Anecdotal evidence suggests paradoxical caffeine overuse in individuals with Huntington's disease (HD). A small retrospective study associated caffeine intake over 190 grams daily to earlier onset of HD symptoms. However, specific data on consumption habits is limited. This study aims to gather pilot data on caffeine use in people with HD, exploring motivations and consequences.

Methods: Thirty adults with HD completed a survey on daily caffeine intake, its impact on symptoms, and consumption motivations through multiple-choice and open-ended questions. Descriptive statistics were used to analyze findings and compare them to general population data.

Results: Caffeine intake ranged from 0 to 1400.4 mg/day, with a median of 273.2 mg/day and a mean of 382.5 mg/day. Seventy percent of participants with HD consumed more caffeine than the average for their age group in the general population. Additionally, 20% of participants and 38% of family members believed caffeine influenced HD symptoms, primarily anxiety.

Discussion: People with HD typically consume more caffeine than the general U.S. population. Contrary to the hypothesis, higher caffeine intake was not associated with significant subjective worsening of HD symptoms. Further research with objective measures and multiple HD centers is necessary to guide screening and counseling on caffeine use in this population.

Highlights: Participants with Huntington's disease (HD) had increased caffeine intake compared to the general population, supporting previous anecdotal observations. Anxiety was the most affected HD symptom. Further research using objective measures of symptom burden and including multiple HD centers can help inform screening and counseling regarding caffeine use in this population.

Clinical vignette: A 23-year-old woman with pantothenate kinase-associated neurodegeneration (PKAN) presented with medication-refractory generalized dystonia and an associated gait impairment.

Clinical dilemma: Bilateral globus pallidus internus (GPi) deep brain stimulation (DBS) can be an effective treatment for dystonia. However, outcomes for PKAN DBS have been variable and there are no standardized criteria for patient selection.

Clinical solution: Bilateral GPi DBS implantation resulted in improvement in dystonia and gait. The benefit has persisted over one year after implantation.

Gap in knowledge: PKAN is a rare neurodegenerative disorder and evidence supporting the use of PKAN DBS has been largely limited to case reports and case series. Consequently, there is a paucity of long-term data, especially on gait-related outcomes.

Expert commentary: The clinical characteristics of dystonia that respond to DBS tend to respond in PKAN. Clinicians counselling patients about the effects of DBS for PKAN should thoughtfully discuss gait and postural instability as important aspects to consider, especially as the disease will progress post-DBS.

Background: Postural tremor is an uncommon and often overlooked phenotype in skeletal myopathy, which may lead to diagnostic delays.

Case report: A 21-year-old man presented with adolescent onset postural hand tremor as the initial symptom, followed by mild limb muscle weakness. Neurological examination showed restricted ocular motility without diplopia and myopathic facial appearance. A muscle biopsy showed a decrease in type 2A fibers. Whole-exome sequencing identified two novel compound heterozygous variants in MYH2 gene (NM_017534.6): c.505+2T>C and c.3565 del C. The diagnosis was further validated via bioinformatics analysis and confirmed through familial co-segregation by Sanger sequencing.

Discussion: This report expands the mutational and phenotypic spectrum of MYH2-associated myopathy. We suggest that in the differential diagnosis of tremor, besides common neurogenic causes, myogenic etiology should also be considered.

Highlights: Hand tremor in this case expands the phenotype of MYH2-associated myopathy, enhancing our understanding of tremor origins. It underscores the importance of nuanced clinical assessment and genetic screening in complex tremor disorders.

There are myths and misperceptions about most human diseases, and neurological diseases are no exception. In many instances, myths and misconceptions reflect what is no more than the collective failure of the field to catch up with the state of the science in that field. Hence, one may perhaps refer to these as "lags" rather than myths. As the field of medicine attempts to be evidence-based, it is best to remain true to published data and the state of the science. In this paper, I review six myths and misconceptions about ET. Myth 1 relates to the natural history and prognosis of ET. Myths 2 and 3 relate to the biological basis of ET, whereas myths 4 and 5 relate to the expression of the core clinical feature of ET. Finally, myth 6 focuses on the issue of disease classification. The myths are as follows: Myth 1: "ET is not associated with a shorter life expectancy". Myth 2: "The pathophysiology of ET remains unclear". Myth 3: "There have also been studies that do not show any cerebellar degeneration". Myth 4: "ET is a postural or a kinetic tremor". Myth 5: "Action tremor in ET is usually bilateral and symmetric". Myth 6: "ET plus". As neurologists, we are not ignorant of feedback loops. A regular review of facts should help to frame one's output. As such, one's formulations and output will be firmly grounded in data.

Background: KBG syndrome is a monogenic disorder caused by heterozygous pathogenic variants in ANKRD11. A recent single-case study suggested that the clinical spectrum of KBG syndrome, classically defined by distinctive craniofacial traits and developmental delay, may include movement disorders.

Case report: We report a 24-year-old patient harboring a pathogenic de novo ANKRD11 frameshift variant. The phenotype was dominated by a progressive tremor-dominant movement disorder, characterized by rest, intention and postural tremor of the hands, voice tremor, head and tongue tremor, increased muscle tone and signs of ataxia. Additionally, the patient had a history of mild developmental delay and epilepsy.

Discussion: Adding to the recently described individual, our present patient highlights the relevance of movement disorders as a clinically relevant manifestation of KBG syndrome. ANKRD11 pathogenic variants should be considered in the differential diagnosis of combined tremor syndromes.

Background: Prior studies suggest that patients with essential tremor (ET) have increased rates of healthcare utilization, but the reason for this increased use is unknown. The objective of this study was to evaluate the reasons for healthcare use among ET patients.

Methods: This was a retrospective cross-sectional study of ET patients with an admission or emergency department (ED) visit at a tertiary health system from 2018-2023. Patients were matched on an encounter level with control patients based on propensity scores incorporating age, sex, race, and co-morbid conditions. The primary outcome was the odds of an encounter for each diagnostic category comparing ET patients with matched controls.

Results: Only inpatient admissions for neurologic diagnoses were more likely for ET compared to control patients (odds ratio (OR) 3.73, 95% confidence interval (CI) 2.54 - 5.49, p < 0.001). Once admissions related to the surgical treatment of tremor were excluded, admissions for neurologic diagnoses were equally likely among ET and control patients (OR 0.96, 95% CI 0.59 - 1.57, p = 0.88).

Discussion: Surgical treatment of tremor appears to be a key driver of healthcare use among ET patients. Future investigations should examine the pattern of healthcare use of ET patients before and after surgery.

Highlights: Prior studies have shown increased healthcare use among essential tremor (ET) patients. The objective of this study was to evaluate the reasons for healthcare use among ET patients compared to matched control patients. Surgical treatment of tremor was found to be a key driver of healthcare use among ET patients.

Background: Deep brain stimulation for dystonia improves motor symptoms but variable and delayed responses challenge patient selection, targeting, and device programming.

Case report: Here we studied intracranial electrophysiology in a patient with primary dystonia and observed evoked resonant neural activity (ERNA) in the globus pallidus interna. These local stimulus-evoked potentials displayed refractory periods and paired-pulse facilitation at clinically relevant interstimulus intervals. Sensing from directional DBS contacts localized ERNA to an effective stimulation site in the ventral posterolateral portion of the pallidum.

Discussion: To the best of our knowledge, this is the first observation of ERNA in the globus pallidus interna in a patient with primary dystonia. Stimulus-evoked activity could eventually guide both directional and adaptive stimulation for dystonia and other complex neuropsychiatric disorders.

Deep brain stimulation of the subthalamic nucleus and globus pallidus internus is approved by the Food and Drug Administration for treating dystonia. Both targets have shown effectiveness in improving symptoms, but post-operative outcomes can vary significantly among patients. This variability has led researchers to explore alternative neuromodulation targets that might offer more consistent results. Emerging research has highlighted several promising new targets for DBS in dystonia. This review examines pre-clinical and clinical data on novel DBS targets for dystonia and explores non-invasive neuromodulation studies that shed light on the disease's underlying pathological circuitry.

Background: Spontaneous intracranial hypotension (SIH), a treatable condition that stems from spinal leakage of cerebrospinal fluid, usually presents with orthostatic headache, nausea, vomiting, dizziness, and tinnitus. A subset of patients, especially those with sagging of brain structures ("brain sagging syndrome"), develop several movement abnormalities. As SIH is treatable with epidural blood patch (EBP), movement disorders neurologists should be familiar with this syndrome.

Method: The authors performed a literature search in PubMed in July 2024 using the Boolean phrase- (("Brain sagging")OR("Intracranial hypotension"))AND(((((((((("Movement disorders")OR("Involuntary movements"))OR("Tremor"))OR("Dystonia"))OR("Chorea"))OR("Ballismus"))OR("Myorhythmia"))OR ("Tic"))OR("Ataxia"))OR("Parkinsonism")).

Result: We tabulated 21 case reports/series that highlighted the presence of movement disorders. The most reported phenomenology is gait unsteadiness. While it usually emerges in the background of the classic SIH symptoms, rarely, patients may present with isolated gait dysfunction. Tremor is the second most reported phenomenology with postural and kinetic tremor being the common subtypes. Holmes tremor has also been reported in SIH. Other reported phenomenologies are parkinsonism, chorea, and dystonia. One study reported a unique phenomenology i.e. compulsive repetitive flexion and breath holding in 35.3% of the patients. In majority of the patients, EBP resulted in substantial clinical and radiological improvement.

Discussion: Brain sagging syndrome due to SIH may present with a wide range of movement disorders. Mechanical distortion of the posterior fossa and subcortical structures result in the emergence of such movement abnormality. SIH adds to the list of conditions that result in "treatable movement disorders." Therefore, movement disorders neurologists should be versed with the diagnosis and clinical features of this condition.

Background: Essential tremor (ET) and dystonic tremor (DT) are movement disorders that cause debilitating symptoms, significantly impacting daily activities and quality of life. A poor understanding of their pathophysiology, as well as the mediators of clinical outcomes following deep brain stimulation (DBS), highlights the need for biomarkers to accurately characterise and optimally treat patients.

Objectives: We assessed the white matter microstructure of pathways implicated in the pathophysiology and therapeutic intervention in a retrospective cohort of patients with DT (n = 17) and ET (n = 19). We aimed to identity associations between white matter microstructure, upper limb tremor severity, and tremor improvement following DBS.

Methods: A fixel-based analysis pipeline was implemented to investigate white matter microstructural metrics in the whole brain, cerebello-thalamic pathways and tracts connected to stimulation volumes following DBS. Associations with preoperative and postoperative severity were analysed within each disorder group and across combined disorder groups.

Results: DBS led to significant improvements in both groups. No group differences in stimulation positions were identified. When white matter microstructural data was aligned according to the maximally affected upper limb, increased fiber density, and combined fiber density & cross-section of fixels in the left cerebellum were associated with greater tremor severity across DT and ET patients. White matter microstructure did not show associations with postoperative changes in cerebello-thalamic pathways, or tracts connected to stimulation volumes.

Discussion: Diffusion changes of the cerebellum are associated with the severity of upper limb tremor and appear to overlap in essential or dystonic tremor disorders.