A 19-year-old heavy metal singer with a history of congenital micrognathia, post-traumatic stress disorder, and anxiety developed isolated movements of the soft palate after lower mandible corrective surgery (osteotomy and genioplasty). He endorsed ear clicks and control over the movements. On examination, there were rhythmic movements of the distal soft palate, characteristic of essential palatal tremor (EPT). However, their change in frequency and amplitude on command (video on the Neurology® Web site at www.neurology.org) indicated volitional control. Unlike psychogenic EPT, whereby variability and entrainability must be present1 and endorsed as involuntary (“a-volitional”), patients with volitional EPT admit to full control and no disability (figure). They have also been categorized as the “voluntary/special skill” EPT variant.2 No neurologic investigations are warranted in patients with volitional EPT.
Advances in functional neurosurgery have expanded the treatment of Parkinson’s disease (PD), from early lesional procedures to targeted electrical stimulation of specific nodes in the basal ganglia circuitry. Deep brain stimulation (DBS), applied to selected patients with Parkinson’s disease (PD) and difficult-to-manage motor fluctuations, yields substantial reductions in off time and dyskinesia. Outcomes for DBS targeting the two major studied targets in PD, the subthalamic nucleus (STN) and the internal segment of the globus pallidus (GPi), appear to be broadly similar and the choice is best made based on individual patient factors and surgeon preference. Emerging concepts in DBS include examination of new targets, such as the potential efficacy of pedunculopontine nucleus (PPN) stimulation for treatment of freezing and falls, the utilization of pathologic oscillations in the beta band to construct an adaptive “closed-loop” DBS, and new technologies, including segmented electrodes to steer current toward specific neural populations.
Parkinson disease; deep brain stimulation; patient selection; beta band oscillations
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Purpose of Review
This review describes the main clinical features of psychogenic (functional) movement disorders and reports recent advances in diagnosis, pathophysiology, and treatment.
The terminology and definition of patients with psychogenic movement disorders remain subjects of controversy; the term “functional” has been used more frequently in the literature in recent years regarding the neurobiological substrate underpinning these disorders. Correct diagnosis of psychogenic movement disorders should rely not on the exclusion of organic disorders or the sole presence of psychological factors but on the observation or elicitation of clinical features related to the specific movement disorder (ie, a positive or inclusionary rather than exclusionary diagnosis). Sudden onset, spontaneous remissions, and variability over time or during clinical examination are useful “red flags” suggestive of a psychogenic movement disorder. Imaging studies have demonstrated impaired connectivity between limbic and motor areas involved in movement programming and hypoactivity of a brain region that compares expected data with actual sensory data occurring during voluntary movement. Treatment of psychogenic movement disorders begins with ensuring the patient’s acceptance of the diagnosis during the initial debriefing and includes nonpharmacologic (cognitive-behavioral therapy, physiotherapy) and pharmacologic options.
Psychogenic movement disorders represent a challenging disorder for neurologists to diagnose and treat. Recent advances have increased understanding of the neurobiological mechanism of psychogenic movement disorders. Treatment with cognitive strategies and physical rehabilitation can benefit some patients. As short duration of disease correlates with better prognosis, early diagnosis and initiation of treatment are critical.
Background: Oral therapies and chemodenervation procedures are often unrewarding in the treatment of focal, task-specific hand disorders such as writer’s cramp or primary writing tremor (PWT).
Methods: A portable writing orthotic device (WOD) was evaluated on 15 consecutively recruited writer’s cramp and PWT subjects. We measured overall impairment at baseline and after 2 weeks of at-home use with the Writer’s Cramp Rating Scale (range = 0–8, higher is worse) and writing quality and comfort with a visual analog scale (range = 0–10).
Results: Compared to regular pen, the WOD improved the Writer’s Cramp Rating Scale scores at first-test (p = 0.001) and re-test (p = 0.005) as well as writing quality and device comfort in writer’s cramp subjects. Benefits were sustained at 2 weeks. PWT subjects demonstrated no improvements.
Conclusion: WODs exploiting a muscle-substitution strategy may yield immediate benefits in patients with writer’s cramp.
orthotic devices; medical devices; writer’s cramp; primary writing tremor; task-specific hand dystonia; writer’s cramp rating scale
The substantial proportion of individuals with Parkinson’s disease (PD) who have or are expected to develop concomitant cognitive impairment emphasizes the need for large, well-characterized participant cohorts to serve as a basis for research into the causes, manifestations, and potential treatments of cognitive decline in those with PD.
To establish a multi-site clinical core that cognitively and clinically characterizes patients with PD by obtaining quality longitudinal clinical, neuropsychological, and validated biomarker data.
Six hundred nineteen participants with idiopathic PD (68.0 ± 9.1 years, 7.1 ± 6.2 years since diagnosis, 70% males) were enrolled in the Pacific Northwest Udall Center (PANUC), one of the Morris K. Udall Centers of Excellence for Parkinson’s Research, Clinical Consortium and underwent comprehensive clinical and neuropsychological assessment. Participants were diagnosed with no cognitive impairment (PD-NCI), mild cognitive impairment (PD-MCI), or dementia (PDD) at a diagnostic consensus conference.
A substantial proportion of the overall sample was diagnosed with cognitive impairment at baseline: 22% with PDD and 59% with PD-MCI. A higher rate of cognitive impairment was observed in men than women (87% vs. 68%, p<0.0001), despite a higher level of education. Most patients older than 50 years at the time of diagnosis and with disease duration greater than 10 years were cognitively impaired or demented.
The PANUC Clinical Consortium is a clinically and cognitively well-characterized cohort of patients with PD. Baseline cohort characteristics demonstrate a high rate of cognitive impairment in the sample, as well as potential sex differences with regard to cognitive diagnosis. The PANUC Clinical Consortium, with its access to biomarker, genetic, and autopsy data, provides an excellent foundation for detailed research related to cognitive impairment in PD.
cognition; cohort studies; dementia; mild cognitive impairment; movement disorders; Parkinson disease
Bradykinesia encompasses slowness, decreased movement amplitude, and dysrhythmia. Unified Parkinson’s Disease Rating Scale–based bradykine-sia-related items require that clinicians condense abnormalities in speed, amplitude, fatiguing, hesitations, and arrests into a single score. The objective of this study was to evaluate the reliability of a modified bradykinesia rating scale, which separately assesses speed, amplitude, and rhythm and its correlation with kinematic measures from motion sensors. Fifty patients with Parkinson’s disease performed Unified Parkinson’s Disease Rating Scale–directed finger tapping, hand grasping, and pronation–supination while wearing motion sensors. Videos were rated blindly and independently by 4 clinicians. The modified bradykinesia rating scale and Unified Parkinson’s Disease Rating Scale demonstrated similar inter- and intrarater reliability. Raters placed greater weight on amplitude than on speed or rhythm when assigning a Unified Parkinson’s Disease Rating Scale score. Modified bradykinesia rating scale scores for speed, amplitude, and rhythm correlated highly with quantitative kinematic variables. The modified bradykinesia rating scale separately captures bradykinesia components with interrater and intrarater reliability similar to that of the Unified Parkinson’s Disease Rating Scale. Kinematic sensors can accurately quantify speed, amplitude, and rhythm to aid in the development and evaluation of novel therapies in Parkinson’s disease.
Parkinson’s disease; bradykinesia; Unified Parkinson’s Disease Rating Scale; modified bradykinesia rating scale; KinetiSense
Although movement impairment in Parkinson’s disease includes slowness (bradykinesia), decreased amplitude (hypokinesia), and dysrhythmia, clinicians are instructed to rate them in a combined 0–4 severity scale using the Unified Parkinson’s Disease Rating Scale motor subscale. The objective was to evaluate whether bradykinesia, hypokinesia, and dysrhythmia are associated with differential motor impairment and response to dopaminergic medications in patients with Parkinson’s disease. Eighty five Parkinson’s disease patients performed finger-tapping (item 23), hand-grasping (item 24), and pronation–supination (item 25) tasks OFF and ON medication while wearing motion sensors on the most affected hand. Speed, amplitude, and rhythm were rated using the Modified Bradykinesia Rating Scale. Quantitative variables representing speed (root mean square angular velocity), amplitude (excursion angle), and rhythm (coefficient of variation) were extracted from kinematic data. Fatigue was measured as decrements in speed and amplitude during the last 5 seconds compared with the first 5 seconds of movement. Amplitude impairments were worse and more prevalent than speed or rhythm impairments across all tasks (P < .001); however, in the ON state, speed scores improved exclusively by clinical (P < 10−6) and predominantly by quantitative (P < .05) measures. Motor scores from OFF to ON improved in subjects who were strictly bradykinetic (P < .01) and both bradykinetic and hypokinetic (P < 10−6), but not in those strictly hypokinetic. Fatigue in speed and amplitude was not improved by medication. Hypokinesia is more prevalent than bradykinesia, but dopaminergic medications predominantly improve the latter. Parkinson’s disease patients may show different degrees of impairment in these movement components, which deserve separate measurement in research studies.
Parkinson’s disease; bradykinesia; UPDRS; MBRS; KinetiSense
The reliability and applicability of published diagnostic criteria for psychogenic movement disorders (PMDs) have never been examined.
Eight movement disorder and six general neurologists rated 14 patients diagnosed with PMD and 14 patients diagnosed with organic movement disorders. Raters provided a dichotomous judgment (i.e., psychogenic or organic) upon review of video-based movement phenomenology and a category of diagnostic certainty based on the Fahn-Williams and Shill-Gerber criteria after accessing standardized clinical information. We measured interobserver agreement on the diagnosis and clinical certainty judgment of PMD.
In both groups of raters, agreements were “fair” on the video-based dichotomous judgment, but improved to “substantial” after access to standardized clinical information. “Slight” to “poor” agreement was reached for the “probable” and “possible” categories of diagnostic certainty corresponding to both diagnostic criteria.
Diagnosis according to clinical available criteria for PMD yields poor diagnostic agreement.
psychogenic movement disorders; diagnostic criteria; interobserver agreement; epidemiology; phenomenology
Levodopa–carbidopa intestinal gel (LCIG) delivered continuously via percutaneous endoscopic gastrojejunostomy (PEG-J) tube has been reported, mainly in small open-label studies, to significantly alleviate motor complications in Parkinson’s disease (PD). A prospective open-label, 54-week, international study of LCIG is ongoing in advanced PD patients experiencing motor fluctuations despite optimized pharmacologic therapy. Pre-planned interim analyses were conducted on all enrolled patients (n = 192) who had their PEG-J tube inserted at least 12 weeks before data cutoff (July 30, 2010). Outcomes include the 24-h patient diary of motor fluctuations, Unified Parkinson’s Disease Rating Scale (UPDRS), Clinical Global Impression-Improvement (CGI-I), Parkinson’s Disease Questionnaire (PDQ-39), and safety evaluations. Patients (average PD duration 12.4 yrs) were taking at least one PD medication at baseline. The mean (±SD) exposure to LCIG was 256.7 (±126.0) days. Baseline mean “Off” time was 6.7 h/day. “Off” time was reduced by a mean of 3.9 (±3.2) h/day and “On” time without troublesome dyskinesia was increased by 4.6 (±3.5) h/day at Week 12 compared to baseline. For the 168 patients (87.5%) reporting any adverse event (AE), the most common were abdominal pain (30.7%), complication of device insertion (21.4%), and procedural pain (17.7%). Serious AEs occurred in 60 (31.3%) patients. Twenty-four (12.5%) patients discontinued, including 14 (7.3%) due to AEs. Four (2.1%) patients died (none deemed related to LCIG). Interim results from this advanced PD cohort demonstrate that LCIG produced meaningful clinical improvements. LCIG was generally well-tolerated; however, device and procedural complications, while generally of mild severity, were common.
Parkinson’s disease; Levodopa–carbidopa intestinal gel; Motor fluctuations; PEG-J procedure; Pump administration
A mean of 10 years elapse before patients with Parkinson’s disease (PD) reach Hoehn & Yahr (H&Y) stage 4, and 14 years for stage 5. A small proportion of PD patients survive and are ambulatory for ≥20 years. We sought to identify features associated with long-duration PD (dPD).
This five-center, case–control study compared 136 PD patients with ≥20 years of duration and H&Y stage ≤4 (dPD) to 134 H&Y-, age- and gender-matched PD patients between 10 and 15 years of disease (cPD).
By study design, there were no between-group differences in age, gender and H&Y. dPD subjects were younger at onset (p < 0.0001), had more psychosis (p: 0.038), were receiving higher levodopa equivalent daily doses (p: 0.02), were predominantly left-handed (p: 0.048), and had greater frequency of left-sided onset (p: 0.015) compared to cPD subjects. Both groups had similar rates of resting tremor, dementia and REM sleep behavior disorder.
Early disease onset, left-handedness and left-sided onset are associated with long disease and ambulatory PD survival. The neurobiological basis of the prognostic value of lateralization deserves further investigation.
Parkinson’s disease; Longevity; Handedness
The facial phenotype of psychogenic movement disorders has not been fully characterized. Seven tertiary-referral movement disorders centers using a standardized data collection on a computerized database performed a retrospective chart review of psychogenic movement disorders involving the face. Patients with organic forms of facial dystonia or any medical or neurological disorder known to affect facial muscles were excluded. Sixty-one patients fulfilled the inclusion criteria for psychogenic facial movement disorders (91.8% females; age: 37.0 ± 11.3 years). Phasic or tonic muscular spasms resembling dystonia were documented in all patients most commonly involving the lips (60.7%), followed by eyelids (50.8%), perinasal region (16.4%), and forehead (9.8%). The most common pattern consisted of tonic, sustained, lateral, and/or downward protrusion of one side of the lower lip with ipsilateral jaw deviation (84.3%). Ipsi- or contralateral blepharospasm and excessive platysma contraction occurred in isolation or combined with fixed lip dystonia (60.7%). Spasms were reported as painful in 24.6% of cases. Symptom onset was abrupt in most cases (80.3%), with at least 1 precipitating psychological stress or trauma identified in 57.4%. Associated body regions involved included upper limbs (29.5%), neck (16.4%), lower limbs (16.4%), and trunk (4.9%). There were fluctuations in severity and spontaneous exacerbations and remissions (60%). Prevalent comorbidities included depression (38.0%) and tension headache (26.4%). Fixed jaw and/or lip deviation is a characteristic pattern of psychogenic facial movement disorders, occurring in isolation or in combination with other psychogenic movement disorders or other psychogenic features. © 2012 Movement Disorder Society
facial movement disorders; psychogenic movement disorders; psychogenic facial movement disorders; psychogenic dystonia; psychogenic blepharospasm; facial distortion
Our understanding of the molecular mechanisms of many neurological disorders has been greatly enhanced by the discovery of mutations in genes linked to familial forms of these diseases. These have facilitated the generation of cell and animal models that can be used to understand the underlying molecular pathology. Recently, there has been a surge of interest in the use of patient-derived cells, due to the development of induced pluripotent stem cells and their subsequent differentiation into neurons and glia. Access to patient cell lines carrying the relevant mutations is a limiting factor for many centres wishing to pursue this research. We have therefore generated an open-access collection of fibroblast lines from patients carrying mutations linked to neurological disease. These cell lines have been deposited in the National Institute for Neurological Disorders and Stroke (NINDS) Repository at the Coriell Institute for Medical Research and can be requested by any research group for use in in vitro disease modelling. There are currently 71 mutation-defined cell lines available for request from a wide range of neurological disorders and this collection will be continually expanded. This represents a significant resource that will advance the use of patient cells as disease models by the scientific community.
Frontotemporal dementia is commonly associated with parkinsonism in several sporadic (i.e., progressive supranuclear palsy, corticobasal degeneration) and familial neurodegenerative disorders (i.e., frontotemporal dementia associated with parkinsonism and MAPT or progranulin mutations in chromosome 17). The clinical diagnosis of these disorders may be challenging in view of overlapping clinical features, particularly in speech, language, and behavior. The motor and cognitive phenotypes can be viewed within a spectrum of clinical, pathologic, and genetic disorders with no discrete clinicopathologic correlations but rather lying within a dementia–parkinsonism continuum. Neuroimaging and cerebrospinal fluid analysis can be helpful, but the poor specificity of clinical and imaging features has enormously challenged the development of biological markers that could differentiate these disorders premortem. This gap is critical to bridge in order to allow testing of novel biological therapies that may slow the progression of these proteinopathies.
Frontotemporal dementia; Frontotemporal lobar degeneration; Parkinsonism; Corticobasal syndrome; Progressive supranuclear palsy; Corticobasal degeneration
Mirror movements (MM) are involuntary movements of homologous muscles during voluntary movements of contralateral body regions. While subtle mirroring can be present in otherwise healthy adults, overt MM may be common in many movement disorders. Examining these collective findings may further our understanding of MM and help define their usefulness as a clinical sign.
We sought to review English language research articles examining the presence, clinical significance, and/or pathophysiology of MM in Parkinson's disease (PD), corticobasal syndrome (CBS), essential tremor (ET), focal hand dystonia, Creutzfeldt-Jakob's disease (CJD), and Huntington's disease. When available, MM in these disorders were compared with those of healthy age-matched controls and congenital disorders such as Klippel-Feil syndrome and X-linked Kallman's syndrome.
Clinical presentation of MM is common in asymmetric parkinsonian disorders (early PD, CBS) and manifests differently depending on the side affected (less affected hand in PD, more affected hand in CBS, either hand in ET, and both hands in healthy adults and congenital disorders), stage of disease (early, asymmetric PD and CJD), and presence of concomitant mirror-like overflow phenomena (focal dystonia and CBS-associated alien hand). In general, uncrossed descending corticospinal projections (congenital MM) and/or abnormal activation of the motor cortex ipsilateral to the voluntary task (most acquired MM), i.e., activation of the normal crossed corticospinal pathway, are required for the generation of MM.
MM are common motor phenomena and present differently in several acquired (mostly neurodegenerative) and congenital movement disorders. Future studies on MM will enhance the clinical diagnosis of selected movement disorders and contribute to our understanding of the normal physiology of bimanual coordination.
Mirror movements; Parkinson's disease; essential tremor; corticobasal degeneration; focal hand dystonia