Project description:Electrophysiological and behavioral studies in primary dystonia suggest abnormalities during movement preparation, but this crucial phase preceding movement onset has not yet been studied specifically with functional magnetic resonance imaging (fMRI). To identify abnormalities in brain activation during movement preparation, we used event-related fMRI to analyze behaviorally unimpaired sequential finger movements in 18 patients with task-specific focal hand dystonia (FHD) and 18 healthy subjects. Patients and controls executed self-initiated or externally cued prelearnt four-digit sequential movements using either right or left hands. In FHD patients, motor performance of the sequential finger task was not associated with task-related dystonic posturing and their activation levels during motor execution were highly comparable with controls. On the other hand reduced activation was observed during movement preparation in the FHD patients in left premotor cortex / precentral gyrus for all conditions, and for self-initiation additionally in supplementary motor area, left mid-insula and anterior putamen, independent of effector side. Findings argue for abnormalities of early stages of motor control in FHD, manifesting during movement preparation. Since deficits map to regions involved in the coding of motor programs, we propose that task-specific dystonia is characterized by abnormalities during recruitment of motor programs: these do not manifest at the behavioral level during simple automated movements, however, errors in motor programs of complex movements established by extensive practice (a core feature of FHD), trigger the inappropriate movement patterns observed in task-specific dystonia.
Project description:In Response To: Frucht SJ. Focal task-specific dystonia-from early descriptions to a new, modern formulation. Tremor Other Hyperkinet Mov. 2014; 4. doi: 10.7916/D8VD6WHP.
Project description:BackgroundSkater's cramp is an involuntary lower leg movement in skilled speed skaters. We aim to evaluate whether skater's cramp is compatible with task-specific dystonia.MethodsA case-control study tested 5 speed skaters exhibiting symptoms of skater's cramp and 5 controls. Affected skaters completed a standardized questionnaire and neurological examination. Video analyses included skating normally, intensely, and with extra mass around the skater's ankles. An Inertial Motion Capturing (IMC) device mounted on both skates provided angular velocity data for both feet.ResultsMedian time of onset of skater's cramp occurred after 12 (range 3-22) years of speed skating. Skater's cramp appeared as task specific; its onset was sudden and correlated to stress and aberrant proprioception. Symptoms presented acutely and consistently during skating, unilaterally in 4 and bilaterally in 1 skater. Visually, skater's cramp was an active, patterned, and person-specific jerking of a skater's foot, either exo- or endorotationally. It presented asymmetrically, repeating persistently as the foot neared the end of the swing phase. The skater's affected leg had a longer swing phase (median, 1.37 [interquartile range {IQR}, 0.35]/1.18 [IQR, 0.24] seconds; P < 0.01), a shorter glide phase (median, 1.09 [IQR, 0.25]/1.26 (IQR, 0.29) seconds; P < 0.01), and higher angular velocity during the jerking motion. Symptoms remained constant irrespective of speed or extra mass around the ankle (P > 0.05). No significant differences between legs were detected in the control group.ConclusionsObserved clinical, visual, and kinematic data could be an early and tentative indication of task-specific dystonia.
Project description:RationaleDuring the coronavirus disease of 2019 (COVID-19) pandemic, various movement disorders associated with COVID-19 infection have been reported. However, the incidence of dystonia specifically associated with COVID-19 infection has been particularly rare.Patient concernsA 43-year-old male patient presented to the movement disorders clinic with complaints of facial grimacing while chewing and experiencing spasms during nasal breathing. These symptoms appeared 2 weeks after he tested positive for COVID-19.DiagnosesBased on normal diagnostic test results, including brain imaging and blood tests, it was concluded that task-specific facial dystonia following COVID-19 infection.InterventionsDespite treatment with clonazepam, trihexyphenidyl, and carbamazepine, his condition did not improve. Subsequently, botulinum toxin injections were administered to the affected facial muscles identified through video analysis.OutcomesBotulinum toxin injections led to a significant improvement in the patient's symptoms.LessonsTask-specific dystonia affecting the facial muscles, particularly induced by specific actions such as chewing and nasal breathing, is rare and may represent an atypical post-infectious manifestation of COVID-19.
Project description:Adult-onset, task-specific dystonia of the lower limb is a rare occurrence. In this report, the authors present 6 cases of task-specific dystonia manifested only when going down the stairs. These patients were seen by 6 different neurologists from across Canada, Australia, and New Zealand, and all videos were reviewed by 1 movement disorders specialist who made the final diagnosis. Video description of each case is also presented. All 6 patients demonstrated dystonia of 1 of their lower limbs specifically only when going down the stairs. The remainder of the neurological examination was normal, and distractibility, inconsistency, fixed dystonia, or a premonitory urge were absent, making functional movement disorder and tic disorder unlikely. These 6 patients display a distinct, adult-onset, focal isolated dystonia manifested only on going down the stairs that is recognizable as a new task-specific dystonia of the lower extremity.
Project description:Although prostate cancer is the type of cancer most commonly survived by men in the United States, it remains the second most common cause of death from cancer, largely owing to metastatic disease. Patients with metastatic castration-resistant prostate cancer (mCRPC) whose disease has progressed on standard-of-care therapies have few options and a poor prognosis. Prostate-specific membrane antigen (PSMA) is a type II integral membrane protein that is commonly expressed in prostate cancer. Expression is limited on extra-prostatic tissues other than the salivary glands, lacrimal glands, duodenal epithelium, Kupffer cells, and renal tubules. PSMA-directed theranostics has emerged to exploit the specificity of PSMA for prostate cancer cells and has demonstrated promising results in the clinic. Radionuclides linked to PSMA inhibitors/binders have resulted in US Food and Drug Administration (FDA) approval of 2 radiodiagnostics for PSMA-directed positron emission tomography/computed tomography. In addition, these radionuclides have led to the development of lutetium Lu 177PSMA-617 therapy, which is currently under priority FDA review. Multiple novel PSMA-targeted modalities have been developed and are currently under clinical investigation, including ligand-drug and cellular immune therapies. In this review, we discuss the development of PSMA-directed theranostics, along with its clinical implications, limitations, and future directions.