Familial Spinocerebellar Ataxia Type 2 Parkinsonism Presenting as Intractable Oromandibular Dystonia

We have previously described a Korean family afflicted with spinocerebellar ataxia type 2 (SCA2) parkinsonism in which genetic analysis revealed CAG expansion of 40 repeats in the ATXN2 gene.1 The affected members presented with levodopa-responsive parkinsonism without cerebellar ataxia. Some showed motor fluctuation and dyskinesia, further mimicking idiopathic Parkinson’s disease (PD). Herein, we report a member of this family who developed jaw-opening and lingual-protrusion dystonia as the chief presentation

Practical Tips on Botulinum Toxin Injections

Botulinum toxin injections are effective for hyperactivities of muscles and glands that are mediated by acetylcholine (Ach) release in neuronal terminal. The effects of botulinum toxin are reversible because the involved nerves build new sprouts and synapses with time. Thus, botulinum toxin is relatively safe and repeated applications are needed. To maximize effects of botulinum toxin without side effects, understanding the action mechanism of botulinum toxin and determining appropriate target sites are very important. Many guidelines have already been published and provided useful information for these. Therefore, in this chapter, we concentrate more on practical tips for botulinum toxin injections

Hypothyroidism-induced Reversible Encephalopathy as a Cause of Aggravation of Parkinsonism and Myoclonus in Parkinson’s Disease

Background: Myoclonus and encephalopathy are unusual in patients with Parkinson’s disease (PD). Case report: We describe the case of a 59-year-old male with PD who developed myoclonus and encephalopathy. Underlying hypothyroidism was revealed after admission and treated with levothyroxine. Myoclonus and encephalopathy were completely resolved following thyroid hormone replacement. Discussion: Hypothyroidism can cause reversible myoclonus and encephalopathy along with unusual aggravation of parkinsonism symptoms in patients with PD

Longitudinal evolution of cortical thickness signature reflecting Lewy body dementia in isolated REM sleep behavior disorder: a prospective cohort study

Background The isolated rapid-eye-movement sleep behavior disorder (iRBD) is a prodromal condition of Lewy body disease including Parkinson's disease and dementia with Lewy bodies (DLB). We aim to investigate the longitudinal evolution of DLB-related cortical thickness signature in a prospective iRBD cohort and evaluate the possible predictive value of the cortical signature index in predicting dementia-first phenoconversion in individuals with iRBD. Methods We enrolled 22 DLB patients, 44 healthy controls, and 50 video polysomnography-proven iRBD patients. Participants underwent 3-T magnetic resonance imaging (MRI) and clinical/neuropsychological evaluations. We characterized DLB-related whole-brain cortical thickness spatial covariance pattern (DLB-pattern) using scaled subprofile model of principal components analysis that best differentiated DLB patients from age-matched controls. We analyzed clinical and neuropsychological correlates of the DLB-pattern expression scores and the mean values of the whole-brain cortical thickness in DLB and iRBD patients. With repeated MRI data during the follow-up in our prospective iRBD cohort, we investigated the longitudinal evolution of the cortical thickness signature toward Lewy body dementia. Finally, we analyzed the potential predictive value of cortical thickness signature as a biomarker of phenoconversion in iRBD cohort. Results The DLB-pattern was characterized by thinning of the temporal, orbitofrontal, and insular cortices and relative preservation of the precentral and inferior parietal cortices. The DLB-pattern expression scores correlated with attentional and frontal executive dysfunction (Trail Making Test-A and B: R = − 0.55, P = 0.024 and R = − 0.56, P = 0.036, respectively) as well as visuospatial impairment (Rey-figure copy test: R = − 0.54, P = 0.0047). The longitudinal trajectory of DLB-pattern revealed an increasing pattern above the cut-off in the dementia-first phenoconverters (Pearsons correlation, R = 0.74, P = 6.8 × 10−4) but no significant change in parkinsonism-first phenoconverters (R = 0.0063, P = 0.98). The mean value of the whole-brain cortical thickness predicted phenoconversion in iRBD patients with hazard ratio of 9.33 [1.16–74.12]. The increase in DLB-pattern expression score discriminated dementia-first from parkinsonism-first phenoconversions with 88.2% accuracy. Conclusion Cortical thickness signature can effectively reflect the longitudinal evolution of Lewy body dementia in the iRBD population. Replication studies would further validate the utility of this imaging marker in iRBD

A Meta-Analysis of α-Synuclein Multiplication in Familial Parkinsonism

Chronic alpha-synuclein (SNCA) overexpression is a relatively homogenous and well-defined cause of parkinsonism and dementia. Parkinson's disease (PD), PD with dementia, dementia with Lewy bodies and multiple system atrophy all manifest in SNCA multiplication families. Herein we summarize genealogic, clinical and genetic data from 59 families (25 not previously published) with parkinsonism caused by SNCA multiplications. Longitudinal clinical assessments and genealogic relationships were documented for all family members. All probands were genotyped with an Illumina MEGA high-density genotyping array to identify copy number variants (CNV) and enable SNCA multiplication breakpoints to be defined. Three SNCA short tandem repeat (STR) markers were genotyped in all available samples to validate genomic dosage and inheritance. A web-application was built as a forum for future data sharing. CNV analysis identified 49 subjects with heterozygous SNCA duplication (CNV3), 2 with homozygous duplication (CNV4) and 7 with a triplication mutation (CNV4). Clinical presentations varied greatly throughout the cohort. SNCA dosage correlates with disease onset (mean age of onset CNV3: 46.9 ± 10.5 years vs. 34.5 ± 7.4 CNV4, p = 0.003). Atypical or more severe clinical courses were described in several patients and dementia was noted in 50.9% of the probands. Neither the multiplication size (average 2.05 ± 2.45 Mb) nor the number of genes included (range 1–50) was associated with motor symptom onset or dementia. Families with SNCA multiplication are rare and globally-distributed. Nevertheless, they may both inform and benefit from the development of SNCA targeted therapeutic strategies relevant to the treatment of all alpha-synucleinopathies

The mortality of patients with Parkinson's disease with deep brain stimulation

BackgroundDeep brain stimulation (DBS) of the subthalamic nucleus (STN) is effective in improving motor function in patients with Parkinson's disease (PD). This study aimed to investigate mortality associated with bilateral STN DBS in patients with PD and to assess the factors associated with mortality and causes of death after DBS.MethodsWe reviewed the medical records of 257 patients with PD who underwent bilateral STN DBS at the Movement Disorder Center at Seoul National University Hospital between March 2005 and November 2018. Patients were evaluated preoperatively, at 3, 6, and 12 months after surgery and annually thereafter. The cause and date of death were obtained from interviews with caregivers or from medical certificates at the last follow-up.ResultsOf the 257 patients with PD, 48 patients (18.7%) died, with a median time of death of 11.2 years after surgery. Pneumonia was the most common cause of death. Older age of disease onset, preoperative falling score while on medication, and higher preoperative total levodopa equivalent daily dose were associated with a higher risk of mortality in time-dependent Cox regression analysis.ConclusionThese results confirm the mortality outcome of STN DBS in patients with advanced PD

Functional Characterization of Rare RAB12 Variants and Their Role in Musician's and Other Dystonias

Mutations in RAB (member of the Ras superfamily) genes are increasingly recognized as cause of a variety of disorders including neurological conditions. While musician's dystonia (MD) and writer's dystonia (WD) are task-specific movement disorders, other dystonias persistently affect postures as in cervical dystonia. Little is known about the underlying etiology. Next-generation sequencing revealed a rare missense variant (c.586A> G; p.Ile196Val) in RAB12 in two of three MD/WD families. Next, we tested 916 additional dystonia patients; 512 Parkinson's disease patients; and 461 healthy controls for RAB12 variants and identified 10 additional carriers of rare missense changes among dystonia patients (1.1%) but only one carrier in non-dystonic individuals (0.1%; p = 0.005). The detected variants among index patients comprised p.Ile196Val (n = 6); p.Ala174Thr (n = 3); p.Gly13Asp; p.Ala148Thr; and p.Arg181Gln in patients with MD; cervical dystonia; or WD. Two relatives of MD patients with WD also carried p.Ile196Val. The two variants identified in MD patients (p.Ile196Val; p.Gly13Asp) were characterized on endogenous levels in patient-derived fibroblasts and in two RAB12-overexpressing cell models. The ability to hydrolyze guanosine triphosphate (GTP), so called GTPase activity, was increased in mutants compared to wildtype. Furthermore, subcellular distribution of RAB12 in mutants was altered in fibroblasts. Soluble Transferrin receptor 1 levels were reduced in the blood of all three tested p.Ile196Val carriers. In conclusion, we demonstrate an enrichment of missense changes among dystonia patients. Functional characterization revealed altered enzyme activity and lysosomal distribution in mutants suggesting a contribution of RAB12 variants to MD and other dystonias

Defining the causes of sporadic Parkinson's disease in the global Parkinson's genetics program (GP2)

The Global Parkinson’s Genetics Program (GP2) will genotype over 150,000 participants from around the world, and integrate genetic and clinical data for use in large-scale analyses to dramatically expand our understanding of the genetic architecture of PD. This report details the workflow for cohort integration into the complex arm of GP2, and together with our outline of the monogenic hub in a companion paper, provides a generalizable blueprint for establishing large scale collaborative research consortia

Multi-ancestry genome-wide association meta-analysis of Parkinson?s disease

Although over 90 independent risk variants have been identified for Parkinson’s disease using genome-wide association studies, most studies have been performed in just one population at a time. Here we performed a large-scale multi-ancestry meta-analysis of Parkinson’s disease with 49,049 cases, 18,785 proxy cases and 2,458,063 controls including individuals of European, East Asian, Latin American and African ancestry. In a meta-analysis, we identified 78 independent genome-wide significant loci, including 12 potentially novel loci (MTF2, PIK3CA, ADD1, SYBU, IRS2, USP8, PIGL, FASN, MYLK2, USP25, EP300 and PPP6R2) and fine-mapped 6 putative causal variants at 6 known PD loci. By combining our results with publicly available eQTL data, we identified 25 putative risk genes in these novel loci whose expression is associated with PD risk. This work lays the groundwork for future efforts aimed at identifying PD loci in non-European populations

A case report of thoracolumbar paraspinal myopathy as the cause of camptocormia in a patient with atypical parkinsonism

Abstract Background Camptocormia is severe flexion of the thoracolumbar spine, exaggerated during standing and walking but minimized in supine position. Even though camptocormia is a relatively common condition during the course of Parkinson’s disease, there is ongoing controversy concerning its mechanisms. The most widely accepted and yet still disputed one is dystonia. However, based on myopathic changes observed in the paraspinal muscle biopsies of some PD patients with camptocormia, the attempt to attribute camptocormia to myopathy has continued. This case presents evidence for paraspinal myopathy as the cause of camptocormia in a patient with atypical parkinsonism. Case presentation A patient presented with a relatively acute onset of camptocormia and new-onset back pain. Upon examination, she had asymmetric parkinsonism. Magnetic resonance imaging of the lumbar spine revealed alterations in muscle signal intensity in the right paraspinal muscles at the L1–2 level. In the presence of persistent back pain, repeat imaging done two months later showed diffuse enlargement and patchy enhancement of the paraspinal muscles on T1-weighted imaging from T4 through sacrum bilaterally. About fifteen months after the onset of camptocormia, she underwent ultrasound-guided gun biopsy of the paraspinal muscles for evaluation of focal atrophy of the back muscles on the right. The biopsy revealed unmistakable myopathic changes, marked endomysial and perimysial fibrosis of the muscles, and merely mild infiltration of inflammatory cells but no clues regarding the cause of myopathy. On account of persistent back pain and MRI results indicative of ongoing inflammation, she was prescribed glucocorticoid, which she refused to take. Now merely two and a half years after the onset of camptocormia, she is in Hoehn and Yahr stage 4. Conclusions The coincidence of back pain with the appearance of camptocormia and the imaging and pathology findings supportive of myopathy give strong evidence for paraspinal myopathy as the cause of the deformity in this patient. When a patient presents with a relatively acute onset of camptocormia accompanied by back pain, the clinician should not overlook the possibility of myopathy of paraspinal muscles, which may be one of the few treatable causes of camptocormia