OVERVIEW OF COMMON MOVEMENT DISORDERS

Geospatial Analysis of Persons with Movement Disorders Living in Underserved Regions

Background

Movement disorders persons from underserved areas have increased barriers to access tertiary care. There is currently limited data on the geographic and demographic profile of movement disorders persons from underserved areas.

Methods

A retrospective chart review of the geographic and demographic profile of consecutive cases seen between 2002-2017 at the University of Florida Norman Fixel Institute for Neurological Diseases (UF-NFIND) was performed. Information collected included age, sex, diagnosis, zip code, treatment received, and insurance information. The distances between each person's home residence and the nearest movement disorders center of excellence (MDC) as well as the distance to the UF-NFIND were calculated using ArcGIS 10.3.

Results

A total of 5.2% (355/6867) of the sample population were identified as a Medicaid/self-pay population and classified as underserved. The most common diagnoses were tic disorder (19.2%), dystonia (18.3%), and Parkinson's disease (14.3%). In underserved persons, the median distances from their homes to the UF-NFIND (82.19 [45.79-176.93] km) vs. their nearest MDC (63.34 [26.91-121.43] km) were significantly different (p < 0.001).

Discussion

Underserved persons in our study travelled further to receive subspecialty care at UF-NFIND than closer MDCs. Potential reasons for underutilization of closer care could possibly include research opportunities, availability of specific treatments or procedures, insurance restrictions, and limited specialist availability. Despite this observation, underserved persons were underrepresented at our institution compared to the proportion of Medicaid/uninsured patients in Florida. Our results highlight the need for increased awareness of care options for underserved movement disorders populations.

Intranasal Carnosine Mitigates α-Synuclein Pathology and Motor Dysfunction in the Thy1-aSyn Mouse Model of Parkinson's Disease

Parkinson's disease (PD) is a debilitating neurodegenerative disorder. Early symptoms include motor dysfunction and impaired olfaction. Toxic aggregation of α-synuclein (aSyn) in the olfactory bulb (OB) and substantia nigra pars compacta (SNpc) is a hallmark of PD neuropathology. Intranasal (IN) carnosine (2 mg/d for 8 weeks) was previously demonstrated to improve motor behavior and mitochondrial function in Thy1-aSyn mice, a model of PD. The present studies evaluated the efficacy of IN carnosine at a higher dose in slowing progression of motor deficits and aSyn accumulation in Thy1-aSyn mice. After baseline neurobehavioral assessments, IN carnosine was administered (0.0, 2.0, or 4.0 mg/day) to wild-type and Thy1-aSyn mice for 8 weeks. Olfactory and motor behavioral measurements were repeated prior to end point tissue collection. Brain sections were immunostained for aSyn and tyrosine hydroxylase (TH). Immunopositive cells were counted using design-based stereology in the SNpc and OB mitral cell layer (MCL). Behavioral assessments revealed a dose-dependent improvement in motor function with increasing carnosine dose. Thy1-aSyn mice treated with 2.0 or 4.0 mg/d IN carnosine exhibited fewer aSyn-positive (aSyn(+)) cell bodies in the SNpc compared to vehicle-treated mice. Moreover, the number of aSyn(+) cell bodies in carnosine-treated Thy1-aSyn mice was reduced to vehicle-treated wild-type levels in the SNpc. Carnosine treatment did not affect the number of aSyn(+) cell bodies in the OB-MCL or the number of TH(+) cells in the SNpc. In summary, intranasal carnosine treatment decreased aSyn accumulation in the SNpc, which may underlie its mitigation of motor deficits in the Thy1-aSyn mice.

Kolaviron ameliorates behavioural deficit and injury to striatal dopaminergic terminals via modulation of oxidative burden, DJ-1 depletion and CD45R+ cells infiltration in MPTP-model of Parkinson's disease

Parkinson's disease (PD) is the second most common neurodegenerative disease. Currently, the precise pathogenic detail of PD is not entirely clear and first line therapeutics fail to attenuate the progress of the disease. In this study, we examined the neuroprotective effect of kolaviron, a natural antioxidant and anti-inflammatory biflavonoid from Garcinia kola seed, on behavioural impairment, neurodegeneration, oxidative stress and neuroinflammation in an acute MPTP-induced PD model. Kolaviron mitigated the frequently interrupted MPTP-associated hyperkinesia, inefficient gait, immobility, inability to pay attention to sizable holes on walking path, habitual clockwise rotations characterized with minimal diversion of movements and impaired balance. Also, kolaviron suppressed MPTP-mediated striatal oxidative stress, depletion as well as degeneration of dopaminergic terminals, reduced DJ-1 secretion and upregulated expression of caspase-3. Kolaviron facilitated cytoprotective antioxidant response and prevented MPTP-mediated neuroinflammation by blocking striatal infiltration of peripheral CD45R positive cells. Additionally, kolaviron reversed MPTP-induced inhibition of acetylcholinesterase activity. Together, our study provides evidence that the neuroprotective capacity of kolaviron to modulate striatal degeneration, behavioural impairment, antioxidant/redox imbalance and neuroinflammation implicated in the pathogenesis of PD may involve upregulation of DJ-1 secretion and inhibition of CD45R cells infiltration. Our data recommend kolaviron as a possible neuroprotective strategy in the management of Parkinson's disease and the associated behavioural complications, albeit the identity of MPTP-associated striatal CD45R infiltrate needs to be further characterized.

Nigral and ventral tegmental area lesioning induces testicular and sperm morphological abnormalities in a rotenone model of Parkinson's disease

Although sexual health is affected by Parkinson's disease (PD), the effect on testicular health and/or sperm quality is not well discussed. After 21 days of rotenone lesioning, we observed dopaminergic neuronal degeneration in the substantia nigra and hypothalamus. There were minimal SPACA-1-expressing epididymal spermatozoa with morphological abnormalities, scanty luminal spermatozoa and reduced testicular spermatids and post-meiotic germ cells indicating hypospermatogenesis. Occludin-expressing sertoli cells were dispersed over a wide area indicating compromised blood-testes barrier. Activated caspase-3 expression was intense while immunoreactivity of spermatogenic-enhancing SRY and GADD45 g was weak. Although serum follicle stimulating hormone level was not affected, the lesion was associated with reduced serum testosterone level, testicular oxidative damage and inhibition of acetylcholinesterase activity, even when rotenone was not detected in the testes. Together, dopaminergic lesions may mediate testicular and sperm abnormalities via the brain-hypothalamic-testicular circuit independent of the pituitary, thereby establishing a causal link between Parkinsonism and reproductive dysfunction.

Remodeling microglia to a protective phenotype in Parkinson's disease?

Parkinson's disease (PD) is the most widespread movement disorder with a prevalence of 1 in 1000 individuals above 60 years of age. Until now, understanding the pathological mechanisms of PD to translate them into therapy has remained a high research priority. In this review, we highlight evidence describing the involvement of microglial dysfunction in PD. Thereafter, we provide current knowledge suggesting that the substantia nigra pars compacta and putamen, compared to other brain regions, show a reduced microglial density, as well as altered morphological and functional properties in homeostatic conditions, while presenting dystrophic features associated with aging. Further, we describe that this defective microglial programing emerges as early as the second postnatal week, persists until adulthood and impacts negatively on their transcriptional pattern and provision of local trophic support. We emphasize the role of α-synuclein oligomers as a major dysfunctional signal underlining microglial-mediated phenotypic switch and adaptive response contributing to neurodegeneration. Moreover, we explore available avenues should microglia be considered as target for neuroprotective or restorative strategies including preventing the aggregation of α-synuclein protofibrils formation. However, we provide a note of caution regarding the success of microglial-targeted PD strategies, using minocycline as an example. In conclusion, we discuss putative neuroprotective agents that were unsuccessful in previous trials but could be reconsidered by focusing on the stage of microglial-dependent pathogenic events during PD in suitable cohorts of patients.

Cost-Effectiveness of Deep Brain Stimulation With Movement Disorders: A Systematic Review

BACKGROUND

Movement disorders (MDs) are increasingly being managed with deep brain stimulation (DBS). High-quality economic evaluations (EEs) are necessary to evaluate the cost-effectiveness of DBS. We conducted a systematic review of published EEs of the treatment of MDs with DBS. The review compares and contrasts the reported incremental cost-effectiveness ratios (ICERs) and methodology employed by trial-based evaluations (TBEs) and model-based evaluations (MBEs).

METHODS

MeSH and search terms relevant to "MDs," "DBS," and "EEs" were used to search biomedical and economics databases. Studies that used a comparative design to evaluate DBS, including before-after studies, were included. Quality and reporting assessments were conducted independently by 2 authors. Seventeen studies that targeted Parkinson's disease (PD), dystonia, and essential tremor (ET), met our selection criteria.

RESULTS

Mean scores for methodological and reporting quality were 73% and 76%, respectively. The ICERs for DBS compared with best medical therapy to treat PD patients obtained from MBEs had a lower mean and range compared with those obtained from TBEs ($55,461-$735,192 per quality-adjusted life-year [QALY] vs. $9,301-$65,111 per QALY). Pre-post ICER for DBS to treat dystonia was $64,742 per QALY. DBS was not cost-effective in treating ET compared with focused-ultrasound surgery. Cost-effectiveness outcomes were sensitive to assumptions in health utilities, surgical costs, battery life-span, model time horizons, and the discount rate.

CONCLUSIONS

The infrequent use of randomized, controlled trials to evaluate DBS efficacy, the paucity of data reporting the long-term effectiveness and/or utility of DBS, and the uncertainty surrounding cost data limit our ability to report cost-effectiveness summaries that are robust.

Neuroprotective and Therapeutic Effect of Caffeine on the Rat Model of Parkinson's Disease Induced by Rotenone

The present study aimed to investigate the protective and therapeutic effects of caffeine on rotenone-induced rat model of Parkinson's disease (PD). Rats were divided into control, PD model induced by rotenone (1.5 mg/kg intraperitoneally (i.p.) for 45 days), protected group injected with caffeine (30 mg/kg, i.p.) and rotenone for 45 days (during the development of PD model), and treated group injected with caffeine (30 mg/kg, i.p.) for 45 days after induction of PD model. The data revealed a state of oxidative and nitrosative stress in the midbrain and the striatum of animal model of PD as indicated from the increased lipid peroxidation and nitric oxide levels and the decreased reduced glutathione level and activities of glutathione-S-transferase and superoxide dismutase. Rotenone induced a decrease in acetylcholinesterase and Na⁺/K⁺-ATPase activities and an increase in tumor necrosis factor-α level in the midbrain and the striatum. Protection and treatment with caffeine ameliorated the oxidative stress and the changes in acetylcholinesterase and Na⁺/K⁺-ATPase activities induced by rotenone in the midbrain and the striatum. This was associated with improvement in the histopathological changes induced in the two areas of PD model. Caffeine protection and treatment restored the depletion of midbrain and striatal dopamine induced by rotenone and prevented decline in motor activities (assessed by open field test) and muscular strength (assessed by traction and hanging tests) and improved norepinephrine level in the two areas. The present study showed that caffeine offered a significant neuroprotection and treatment against neurochemical, histopathological, and behavioral changes in a rotenone-induced rat model of PD.

Fluoxetine Administration Exacerbates Oral Tremor and Striatal Dopamine Depletion in a Rodent Pharmacological Model of Parkinsonism

The cardinal motor symptoms of Parkinson's disease (PD) include resting tremor, akinesia, bradykinesia, and rigidity, and these motor abnormalities can be modeled in rodents by administration of the VMAT-2 (type-2 vesicular monoamine transporter) inhibitor tetrabenazine (9,10-dimethoxy-3-(2-methylpropyl)-1,3,4,6,7, 11b hexahydrobenzo[a]quinolizin-2-one; TBZ). Depression is also commonly associated with PD, and clinical data indicate that selective serotonin reuptake inhibitors (SSRIs) such as fluoxetine ((±)-N-methyl-γ-[4-(trifluoromethyl)phenoxy]benzenepropanamine hydrochloride; FLX) are frequently used to treat depression in PD patients. The aim of the present study was to characterize the effect of FLX on the motor dysfunctions induced by a low dose of TBZ (0.75 mg/kg), and investigate the neural mechanisms involved. This low dose of TBZ was selected based on studies with rat models of depressive symptoms. In rats, coadministration of FLX (2.5, 5.0, and 10.0 mg/kg) increased TBZ-induced oral tremor (tremulous jaw movements), and decreased locomotor activity compared with administration of TBZ alone. Coadministration of the serotonin 5-HT2A/2C antagonist mianserin (2.5 and 5.0 mg/kg) attenuated the increase in oral tremor induced by coadministration of TBZ (0.75 mg/kg) with FLX (5.0 mg/kg). Consistent with these behavioral data, coadministration of TBZ and FLX decreased DA tissue levels in the rat ventrolateral neostriatum compared with TBZ alone, and coadministration of mianserin with TBZ and FLX attenuated this effect, increasing DA tissue levels compared with the TBZ/FLX condition. These data suggest that SSRI administration in PD patients may result in worsening of motor symptoms, at least in part, by exacerbating existing DA depletions through 5-HT2A/2C-mediated modulation of DA neurotransmission.

Linking restless legs syndrome with Parkinson's disease: clinical, imaging and genetic evidence

Restless legs syndrome (RLS) and Parkinson's disease (PD) are both common neurological disorders. There has been much debate over whether an etiological link between these two diseases exists and whether they share a common pathophysiology. Evidence pointing towards a link includes response to dopaminergic agents in PD and RLS, suggestive of underlying dopamine dysfunction in both conditions. The extrastriatal dopaminergic system, in particular altered spinal dopaminergic modulation, may be variably involved in PD patients with RLS symptoms. In addition, there is now evidence that the nigrostriatal system, primarily involved in PD, is also affected in RLS. Furthermore, an association of RLS with the parkin mutation has been suggested. The prevalence of RLS has also been reported to be increased in other disorders of dopamine regulation. However, clinical association studies and functional imaging have produced mixed findings. Conflicting accounts of emergence of RLS and improvement in RLS symptoms after deep brain stimulation (DBS) also contribute to the uncertainty surrounding the issue. Among the strongest arguments against a common pathophysiology is the role of iron in RLS and PD. While elevated iron levels in the substantia nigra contribute to oxidative stress in PD, RLS is a disorder of relative iron deficiency, with symptoms responding to replacement therapy. Recent ultrasonography studies have suggested that, despite overlapping clinical features, the mechanisms underlying idiopathic RLS and RLS associated with PD may differ. In this review, we provide a concise summary of the clinical, imaging and genetic evidence exploring the link between RLS and PD.