Treatable Hyperkinetic Movement Disorders Not to Be Missed

Hyperkinetic movement disorders are characterized by the presence of abnormal involuntary movements, comprising most notably dystonia, chorea, myoclonus, and tremor. Possible causes are numerous, including autoimmune disorders, infections of the central nervous system, metabolic disturbances, genetic diseases, drug-related causes and functional disorders, making the diagnostic process difficult for clinicians. Some diagnoses may be delayed without serious consequences, but diagnosis delays may prove detrimental in treatable disorders, ranging from functional disabilities, as in dopa-responsive dystonia, to death, as in Whipple's disease. In this review, we focus on treatable disorders that may present with prominent hyperkinetic movement disorders.

Amelioration of L-DOPA-induced dyskinesia with vitamin D3 in Parkinsonian mice model

L-DOPA Induced Dyskinesia (LID) is associated with prolonged L-DOPA therapy. Vitamin-D receptor modulation improves motor-cognitive deficit in experimental LID Parkinsonism. Therefore, in this study, we investigated the mechanism underlying the anti-dyskinetic potential of Vitamin D3 (VD3). Dyskinesia was induced by chronic L-DOPA administration in 6-OHDA lesioned male C57BL6 mice. The experimental groups (Dyskinesia, Dyskinesia/VD3, and Dyskinesia/Amantadine) and controls were challenged with L-DOPA to determine the abnormal involuntary movements (AIMs) score during 14 days of VD3 (30 mg/kg) or Amantadine (40 mg/kg) treatment. Global behavioral Axial, Limb & Orolingual (ALO) AIMs were scored for 1 min at every 20 mins interval, over a duration of 100 mins on days 1,3,7,11 and 14 of treatment. Thereafter, brain samples were collected and processed for immunoblotting to assess striatal expression of tyrosine hydroxylase (TH), monoamine oxidase (MAO), cathecol-o-methyl transferase (COMT), dopamine decarboxylase (DDC), CD11b, BAX, P47phox, and IL-1β. VD3 significantly attenuated ALO AIMs only on days 11 & 14, with maximal reduction of 32.7% compared with dyskinetic mice but had no effect on days 1, 3 & 7, while amantadine decreased AIMs all through days 1 to 14 with maximal reduction of 64.5%. TH and MAO-B expression were not significantly different across the groups. DDC was significantly suppressed in dyskinetic mice vs control (p<0.001) but remained unchanged in VD3 mice vs dyskinetic mice. COMT was upregulated in the dyskinetic group vs control (p<0.01) and attenuated in VD3 mice (p<0.05) compared to the dyskinetic group. Interestingly, VD3 inhibited significantly (p<0.01) oxidative stress (p47phox), apoptosis (BAX), inflammation (IL-1β), and microglial activation (CD11b) in dyskinetic mice. Overall, we find that the anti-dyskinetic effects of VD3 is associated with modulation of striatal oxidative stress, microglial responses, inflammation, and apoptotic signaling.

Caregiver-Reported Burden in RE-KINECT: Data From a Prospective Real-World Tardive Dyskinesia Screening Study

Background: RE-KINECT (NCT03062033), a real-world study of possible tardive dyskinesia (TD) in antipsychotic-treated patients, included a questionnaire to assess the effects of patients’ abnormal involuntary movements on caregivers. Objective: To capture the experiences of caregivers who assisted individuals with abnormal involuntary movements that were confirmed by clinicians as being consistent with TD. Methods: Qualified (nonpaid) caregivers were invited to complete a questionnaire that included the following: caregivers’ sociodemographic characteristics, their perceptions about the impact of abnormal involuntary movements on patients, and the impact of these movements on themselves (caregivers). Results: Of the 41 participating caregivers, 25 (61.0%) were women, 20 (48.8%) were employed full time or part time, and 35 (85.4%) were family members or friends. Based on responses from caregivers who noticed patients’ abnormal involuntary movements and were caring for individuals who also noticed those movements, 48.0% of patients had “a lot” of severity in ≥1 body region and 76.0% had abnormal involuntary movements in ≥2 regions. Caregiver ratings were significantly correlated with patient ratings (but not with clinician ratings) for maximum severity of abnormal involuntary movements and the number of affected regions (both p <.05). Based on their own judgments and perceptions, caregivers reported that the patient’s movements had “some” or “a lot” of impact on their (caregiver’s) ability to continue usual activities (50.0%), be productive (58.3%), socialize (55.6%), or take care of self (50.0%). Conclusion: Caregivers as well as patients are negatively affected by TD, and the impact of TD on caregivers’ lives should be considered when determining treatment options.

Paroxysmal kinesigenic dyskinesia: a diagnostic challenge

A 10-year-old girl presented with a month long history of episodic limb movements. She had a normal neurological examination and after thorough investigation, she was thought to have possible tics. Anxiety was reported as being a trigger. Unusually, these ‘tics’ were not directly witnessed during hospital visits. Eighteen months after the initial presentation, the clinician observed dystonic posturing after the child stood up from having been seated during a consultation. Paroxysmal kinesigenic dyskinesia (PKD) was then suspected and confirmed on genetic testing. She was successfully treated with carbamazepine. In hindsight, it became apparent that her anxiety was related to a fear of uncontrolled movements, rather than it being a trigger. The abnormal involuntary movements in PKD are precipitated by sudden voluntary movement. Lack of recognition of this typical feature, normal examination and/or features such as coexisting anxiety can lead to misdiagnosis or delayed diagnosis of this easily treatable condition.