Loss of Functional Connectivity in Patients with Parkinson Disease and Visual Hallucinations.

Purpose To gain more insight into the pathophysiological mechanisms of visual hallucinations (VHs) in patients with Parkinson disease (PD) by analyzing whole-brain resting-state functional connectivity in PD patients with VH (hereafter, referred to as PD + VH patients) and without VH (hereafter, referred to as PD - VH patients) and control participants. Materials and Methods For this retrospective study, 15 PD + VH patients, 40 PD - VH patients, and 15 control participants from a prospective cohort study were included, which was approved by the local ethics board and written informed consent was obtained from all participants. Functional connectivity was calculated between 47 regions of interests, of which whole-brain and region-specific means were compared by using a general linear model with false discovery rate control for multiple comparisons. Results Whole-brain mean functional connectivity was significantly lower in PD patients compared with control participants, with regional decreases involving paracentral and occipital regions in both PD + VH and PD - VH patients (mean whole-brain functional connectivity in PD + VH vs PD - VH, 0.12 ± 0.01 [standard deviation] vs 0.14 ± 0.03, respectively; control participants, 0.15 ± 0.04; P < .05, corrected). In PD + VH patients, nine additional frontal, temporal, occipital, and striatal regions showed decreased functional connectivity compared with control participants (mean of these nine regions in PD + VH, PD - VH, and control participants: 0.12 ± 0.02, 0.14 ± 0.03, and 0.16 ± 0.04, respectively; P < .05, corrected). Resting-state functional connectivity was unrelated to motor performance (r = 0.182; P = .184) and related to cognitive deficits such as attention and perception (ρ, -0.555 and -0.558, respectively; P < .05). Conclusion The findings show a PD-related effect on resting-state functional connectivity of posterior and paracentral brain regions, whereas the presence of VH is associated with a more global loss of connectivity, related to attention and perception. These findings suggest that the pathophysiological mechanisms of VH in PD may include a global loss of network efficiency, which could drive disturbed attentional and visual processing. © RSNA, 2017 Online supplemental material is available for this article.

Depressive symptoms in Parkinson's disease are related to decreased hippocampus and amygdala volume.

Depression and anxiety are common in Parkinson's disease (PD), and are among the non-motor symptoms that interfere with quality of life dramatically. Motor, cognitive, and affective features overlap in PD, hampering diagnosis. To shed more light on the contribution of structural brain changes to the presence of PD-related depressive symptoms, we conducted a Voxel-Based Morphometry (VBM) study. We hypothesized that depressive symptoms in PD are related to regional gray matter (GM) volume loss within the limbic circuit. We analyzed the T1-weigthed magnetic resonance imaging (MRI) images of 67 PD patients with a mean disease duration of 2.95 (±3.39) years. Scores on the Beck Depression Inventory (BDI) and GM probability maps were analyzed by regression analysis to study the association between GM volume and severity of depressive symptoms. Results are reported at both the uncorrected and the family-wise error (FWE) corrected level for multiple comparisons. The BDI scores correlated negatively with bilateral hippocampus and right amygdala volume and positively with the volume of the anterior cingulate cortex. These findings confirm the hypothesized involvement of the limbic circuit in PD-related depressive symptoms. We speculate that non-dopaminergic changes are essential in the pathophysiology of depressive symptoms in PD, because our findings suggest the involvement of extra-striatal brain regions.

Depressive symptoms in Parkinson's disease are related to reduced [123I]FP-CIT binding in the caudate nucleus.

BACKGROUND: Depression is a common neuropsychiatric symptom in Parkinson's disease (PD). In previous research, PD-related depression was associated with striatal dopaminergic deficits, presumably due to degeneration of brainstem dopaminergic projections. Segregated areas of the striatum are crucially involved in various parallelly arranged cortical-striatal-thalamocortical circuits and serve functions in, among others, motor control or emotion. This suggests regional specificity of dopaminergic deficits in the striatum in motor and depressive symptoms in PD. METHODS: In this cross-sectional retrospective study, we correlated severity scores of depressive and motor symptoms in 100 non-demented PD patients (median Hoehn & Yahr stage: 2) with dopamine loss in specific regions of the striatum as measured by [(123)I]FP-CIT SPECT tracer binding to the dopamine transporter (DaT). RESULTS: Depressive symptoms were related to lower DaT binding in the right caudate nucleus, while motor symptoms were associated with decreased DaT binding in the right putamen. This double dissociation was most pronounced in early-stage PD patients. CONCLUSIONS: These results suggest that depressive symptoms in PD are associated with dopamine loss in the caudate nucleus, possibly related to degeneration of dopaminergic projections from the ventral tegmental area, while motor symptoms are associated with low dopamine signalling to the putamen and loss of nigrostriatal projections. This is consistent with the neuroanatomy of partially segregated cortical-striatal-thalamocortical circuits and supports the role of dysfunctional associative and motivational circuits in PD-related depression.

Reduced dopamine transporter binding predates impulse control disorders in Parkinson's disease.

Impulse control disorders (ICD) are relatively common in Parkinson's disease (PD) and generally are regarded as adverse effects of dopamine replacement therapy, although certain demographic and clinical risk factors are also involved. Previous single-photon emission computed tomography (SPECT) studies showed reduced ventral striatal dopamine transporter binding in Parkinson patients with ICD compared with patients without. Nevertheless, these studies were performed in patients with preexisting impulse control impairments, which impedes clear-cut interpretation of these findings. We retrospectively procured follow-up data from 31 medication-naïve PD patients who underwent dopamine transporter SPECT imaging at baseline and were subsequently treated with dopamine replacement therapy. We used questionnaires and a telephone interview to assess medication status and ICD symptom development during the follow-up period (31.5 ± 12.0 months). Eleven patients developed ICD symptoms during the follow-up period, eight of which were taking dopamine agonists. The PD patients with ICD symptoms at follow-up had higher baseline depressive scores and lower baseline dopamine transporter availability in the right ventral striatum, anterior-dorsal striatum, and posterior putamen compared with PD patients without ICD symptoms. No baseline between-group differences in age and disease stage or duration were found. The ICD symptom severity correlated negatively with baseline dopamine transporter availability in the right ventral and anterior-dorsal striatum. The results of this preliminary study show that reduced striatal dopamine transporter availability predates the development of ICD symptoms after dopamine replacement therapy and may constitute a neurobiological risk factor related to a lower premorbid dopamine transporter availability or a more pronounced dopamine denervation in PD patients susceptible to ICD.

Cognition and psychopathology in myoclonus-dystonia.

OBJECTIVE: (1) To study the neuropsychological and psychopathological profile in myoclonus-dystonia (M-D) patients with and without a mutation in the DYT11 gene. (2) To explore whether cognitive and psychiatric impairments are related to severity and duration of motor symptoms. Herewith, this study may help to clarify whether neuropsychological and psychiatric symptoms are associated with the DYT11 mutation or are secondary to the burden of motor impairments that originated in early childhood. METHODS: Extensive batteries of neuropsychological tests and psychiatric questionnaires were administered to DYT11 gene mutation-carrying (MC) M-D patients (n=31), non-mutation-carrying (NMC) M-D patients (n=20) and a healthy control group (n=36). RESULTS: MC M-D patients demonstrated mild impairments in executive functions. On the contrary, with the exception of one type of verbal fluency, no evident cognitive impairments were found in NMC M-D patients. Further, increased rates of anxiety disorders were found only in MC M-D patients, whereas increased rates of depressive symptoms were observed in both M-D groups. Correlation analyses yielded modest associations between severity of myoclonus and executive functions. No relationships were found between neuropsychological test performance and scores on the psychiatric assessments. CONCLUSIONS: The findings of this study suggest that anxiety disorders and executive dysfunctions may be part of the phenotype of M-D patients with a DYT11 mutation, whereas depressive symptoms and semantic fluency impairments may be secondary to suffering from a chronic movement disorder, regardless of DYT11 gene mutation.

Rivastigmine for minor visual hallucinations in Parkinson's disease: A randomized controlled trial with 24 months follow-up.

BACKGROUND: Visual hallucinations are common in patients with Parkinson's disease and represent probably the major independent predictor for cognitive deterioration and nursing home placement. OBJECTIVE: To investigate if treatment of minor visual hallucinations in Parkinson's disease with rivastigmine delays the progression to psychosis. METHODS: A multicenter, randomized, double-blind, placebo-controlled trial was conducted which aimed to recruit 168 patients with Parkinson's disease reporting minor visual hallucinations 4 weeks before it. Important exclusion criteria were Parkinson's disease dementia, current delirium, and treatment with antipsychotics or drugs that have significant anti-cholinergic side effects. Subjects were randomized to rivastigmine capsules, 3-6 mg twice a day, or placebo for 24 months. The primary outcome was the time to Parkinson's disease psychosis, which was defined as the need to start with antipsychotics. RESULTS: The trial was stopped prematurely because of slow recruitment. Ninety-one patients were randomized: 46 patients were assigned to rivastigmine and 45 patients to placebo. No effect of rivastigmine could be demonstrated on the transition time to psychosis or dementia during the 24-month follow-up period. After 6 months of study treatment, cognition, mood, motor performance, and non-motor performance did not differ significantly between the rivastigmine-group and the placebo-group. CONCLUSIONS: Because the study was terminated early, it was insufficiently powered to properly evaluate the primary outcome. The limited data of the study favor a wait and see approach instead of early treatment with rivastigmine in PD patients with minor VH.

Late-onset Huntington disease with intermediate CAG repeats: true or false?

Huntington disease (HD) is a neurodegenerative disorder associated with an expanded CAG trinucleotide repeat length in the huntingtin gene. 'Intermediate alleles' with 27 to 35 CAG repeats generally do not cause HD but are unstable upon germ-line transmission. Insights in CAG repeat mosaicism and enhanced trinucleotide expansion in postmitotic neurons indicate that in the intermediate range, other factors than the CAG repeat length in diagnostic tests have to be considered. Here, we report two patients with mild, late onset HD and an intermediate repeat allele. The authors anticipate that intermediate repeats can cause late-onset HD due to disease modifiers and may be more common than previously stated.

DYT6 dystonia: mutation screening, phenotype, and response to deep brain stimulation.

Mutations in THAP1, a gene encoding a nuclear pro-apoptotic protein, have been associated with DYT6 dystonia. First reports on the phenotype of DYT6 dystonia show an early onset dystonia with predominant cranio-cervical and laryngeal involvement. Here we assessed the frequency and phenotype of THAP1 mutation carriers in a large Dutch cohort of adult-onset (≥26 years) dystonia (n = 388) and early-onset dystonia (n = 67) patients. We describe the phenotype of DYT6 dystonia patients and their response on GPi DBS. Overall, 3 nonsynonymous heterozygous mutations were detected in the early-onset group (4.5%). Two DYT6 families were identified, showing a heterozygous phenotype. All patients had segmental or generalized dystonia, often associated with profound oromandibular and laryngeal involvement. No nonsynonymous mutations were found in patients with adult-onset focal dystonia. Rare synonymous variants were identified in conserved regions of THAP1, two in the adult-onset cervical dystonia group and one in the control group. Four DYT6 dystonia patients were treated with GPi DBS with moderate to good response on motor function but marginal benefit on speech.

Long-term experience with intraoperative microrecording during DBS neurosurgery in STN and GPi.

BACKGROUND: Intraoperative microelectrode recording (MER) for targeting during deep brain stimulation (DBS) procedures has been evaluated over a period of 4 years, in 57 consecutive patients with Parkinson's disease, who received DBS in the subthalamic nucleus (STN-DBS), and 28 consecutive patients with either dystonia (23) or Parkinson's disease (five), in whom the internal segment of the globus pallidus (GPi-DBS) was targeted. METHODS: The procedure for DBS was a one-stage bilateral stereotactic approach using a combined electrode for both MER and macrostimulation. Up to five micro/macro-electrodes were used in an array with a central, lateral, medial, anterior, and posterior position. Final target location was based on intraoperative test stimulation. FINDINGS: For the STN, the central trajectory was chosen for implantation in 50% of the cases and for the globus pallidus internus (GPi) in 57% of the cases. Furthermore, in 64% of the cases, the channel selected for the permanent electrode corresponded with the trajectory having the longest segment of STN MER activity. For the GPi, this was the case in 61%. The mean and standard deviation of the deepest contact point with respect to the magnetic resonance imaging (MRI)-based target for the STN was 2.1 ± 1.5 mm and for the GPi was -0.5 ± 1.2 mm. CONCLUSIONS: MER facilitates the selection of the final electrode location in STN-DBS and GPi-DBS, and based on the observed MER activity, a pre-selection could be made as to which channel would be the best candidate for macro-test stimulation and at which depth should be stimulated. The choice of the final location is based on intraoperative test stimulation, and it is demonstrated that regularly it is not the central channel that is chosen for implantation. On average, the target as defined by MER activity intensity was in accordance with the MRI-based targets both for the STN and GPi. However, the position of the best MER activity did not necessarily correlate with the locus that produced the most beneficial clinical response on macroelectrode testing intraoperatively.

Anterior insular network disconnection and cognitive impairment in Parkinson's disease.

BACKGROUND: The insula is a central brain hub involved in cognition and affected in Parkinson's disease (PD). The aim of this study was to assess functional connectivity (FC) and betweenness centrality (BC) of insular sub-regions and their relationship with cognitive impairment in PD. METHODS: Whole-brain 3D-T1, resting-state functional MRI and a battery of cognitive tests (CAMCOG) were included for 53 PD patients and 15 controls. The insular cortex was segmented into ventral (vAI) and dorsal (dAI) anterior and posterior sub-regions. Connectivity between insular sub-regions and resting-state networks was assessed and related to cognition; BC was used to further explore nodes associated with cognition. RESULTS: Cognitive performance was significantly lower in PD patients compared to controls (p < 0.01) and was associated with FC of the dAI with default mode network (DMN) (adjusted R2 = 0.37, p < 0.001). In controls, cognitive performance was positively related to FC of the dAI with the fronto-parietal network (FPN) only (adjusted R2 = 0.5, p = 0.003). Regionally, FC of the dAI with the anterior cingulate cortex (ACC) was significantly reduced in PD (F(1,65) = 11, p = 0.002) and correlated with CAMCOG (r = 0.4, p = 0.001). DMN and FPN showed increased BC in PD which correlated with cognition and reduced connectivity of dAI with the ACC (rs = -0.33, p = 0.014 and rs = -0.44, p = 0.001 respectively). CONCLUSIONS: These results highlight the relevance of the insula in cognitive dysfunction in PD. Disconnection of the dAI with ACC was related to altered centrality in the DMN and FPN only in patients. Disturbance in this network triad appears to be particularly relevant for cognitive impairment in PD.

Hallucinations and other psychotic experiences across diagnoses: A comparison of phenomenological features.

Although psychotic experiences are prevalent across many psychiatric, neurological, and medical disorders, investigation of these symptoms has largely been restricted to diagnostic categories. This study aims to examine phenomenological similarities and differences across a range of diagnoses. We assessed frequency, severity and phenomenology of psychotic experiences in 350 outpatients including; participants with schizophrenia spectrum disorders, hearing impairment, Parkinson's disease, Lewy Body Dementia, Alzheimer's disease, visual impairment, posttraumatic stress disorder, borderline personality disorder, and participants with recent major surgery. Psychotic phenomena were explored between these groups using the Questionnaire for Psychotic Experiences (QPE). Participants with major psychiatric disorders reported a combination of several psychotic experiences, and more severe experiences compared to all other disorders. Participants with recent major surgery or visual impairment experienced isolated visual hallucinations. Participants with hearing impairment reported isolated auditory hallucinations, whereas the neurodegenerative disorders reported visual hallucinations, occasionally in combination with hallucinations in another modality or delusions. The phenomenology between neurodegenerative disorders, and within major psychiatric disorders showed many similarities. Our findings indicate that the phenomenology of psychotic experiences is not diagnosis specific, but may rather point to the existence of various subtypes across diagnoses. These subtypes could have a different underlying etiology requiring specific treatment.

Is psychopathology part of the phenotypic spectrum of myoclonus-dystonia?: a study of a large Dutch M-D family.

BACKGROUND: Myoclonus-dystonia (M-D) is a movement disorder frequently caused by mutations in the epsilon-sarcoglycan gene (SGCE, DYT11). In several M-D families, psychiatric symptoms accompanying the motor symptoms have been reported, but a shared genetic etiology remains unclear. OBJECTIVE: To assess neuropsychologic functioning and psychopathology in DYT11 mutation carriers (MC) and their family members using standardized neuropsychologic and psychiatric measures. METHODS: Cognitive and behavioural characteristics of 27 DYT11 MC (14 symptomatic and 13 asymptomatic) and 42 control subjects from 1 large Dutch M-D family were studied. Neuropsychologic tests encompassed memory, language, mental speed, concentration, visuospatial function, and executive functions. Psychiatric assessment addressed qualitative (according to Diagnostic and Statistical Manual-IV criteria) as well as quantitative measures of depression, anxiety, panic attacks, and obsessive-compulsive disorder (OCD), using selfadministered and interview-based scales. RESULTS: No differences were observed on tests of cognitive functioning between DYT11 MC and controls. The frequency of Diagnostic and Statistical Manual-IV diagnoses was higher in the symptomatic DYT11 MC than in controls. The symptomatic DYT11 MC showed more depressive and anxiety symptoms, including panic attacks but no increase of OCD compared with controls. No differences were found between asymptomatic DYT11 MC and controls on any of the psychopathologic tests. CONCLUSIONS: Neither cognitive dysfunction nor OCD seems to be associated with the DYT11 phenotype in this large Dutch pedigree. Depressive and anxiety symptoms are increased in symptomatic, but not in asymptomatic DYT11 MC. Future research has to be carried out to determine whether the psychiatric symptoms are part of or secondary to the DYT11 phenotype.

Clinical and genetic characterization of a large Dutch family with primary focal dystonia.

We describe a large family with a primary focal dystonia from a small Dutch village on a former island. Twenty-four individuals spanning three generations were examined by two movement-disorder neurologists. Two other movement-disorder neurologists evaluated the videos independently. Subjects were classified as "affected," "possibly affected," or "not affected." A diagnosis was defined if all the neurologists agreed on the definition. Eight definitely affected and four possibly affected subjects were detected. Clinical presentation consisted of mild cranio-cervical-brachial dystonia. Mean age at onset was 45.5 years (range, 39-56). Mean BFMDRS motor score was 4.4 (range, 1-8). Mean TWSTRS score (part I) was 11.3 (range, 8-23). Mutations in DYT1 gene and in the epsilon-sarcoglycan (SGCE) genes were not detected. We could not find linkage to the dominant DYT6, DYT7, DYT13, or the recessive DYT16 loci. The identification and accurate clinical evaluation of large dystonia families not linked to known genes is crucial for further advancement in molecular genetic characterization of focal dystonia.

Abnormal low frequency drive in myoclonus-dystonia patients correlates with presence of dystonia.

The pathophysiology of Myoclonus-Dystonia (M-D), an autosomal dominantly inherited movement disorder is largely unknown. In different forms of dystonia abnormal intermuscular coherence is present. The objective of this study was to investigate whether the myoclonic and dystonic features are the result of an abnormal common drive to the muscles in M-D. Coherence analysis was performed in 20 DYT11 mutation carriers (MC) and 13 healthy controls during resting condition and during weak isometric contraction of the arm and neck. The EMG-EMG coherence analysis showed significantly increased intermuscular 3 to 10 Hz coherence in 4 DYT11 MC with clinical pronounced (mobile and static) dystonia. This coherence was not present in DYT11 MC with mild (static) dystonia and/or predominating myoclonus. The EEG-EMG analysis showed significant 15 to 30 Hz coherence during weak isometric contraction of the arm in five healthy controls, but in none of the DYT11 MC. The intermuscular coherence in the low frequency band in DYT11 MC with predominant dystonia is concordant with the previously described coherence in dystonia and suggests that the pathophysiology of M-D shares common pathophysiological features with dystonia. The absence of 15 to 30 Hz EEG-EMG coherence in DYT11 MC may reflect abnormal motor activation caused by an altered cortical drive because of the basal ganglia dysfunction.

Damaged fiber tracts of the nucleus basalis of Meynert in Parkinson's disease patients with visual hallucinations.

Damage to fiber tracts connecting the nucleus basalis of Meynert (NBM) to the cerebral cortex may underlie the development of visual hallucinations (VH) in Parkinson's disease (PD), possibly due to a loss of cholinergic innervation. This was investigated by comparing structural connectivity of the NBM using diffusion tensor imaging in 15 PD patients with VH (PD + VH), 40 PD patients without VH (PD - VH), and 15 age- and gender-matched controls. Fractional anisotropy (FA) and mean diffusivity (MD) of pathways connecting the NBM to the whole cerebral cortex and of regional NBM fiber tracts were compared between groups. In PD + VH patients, compared to controls, higher MD values were observed in the pathways connecting the NBM to the cerebral cortex, while FA values were normal. Regional analysis demonstrated a higher MD of parietal (p = 0.011) and occipital tracts (p = 0.027) in PD + VH, compared to PD - VH patients. We suggest that loss of structural connectivity between the NBM and posterior brain regions may contribute to the etiology of VH in PD. Future studies are needed to determine whether these findings could represent a sensitive marker for the hypothesized cholinergic deficit in PD + VH patients.

Profiling cognitive and neuropsychiatric heterogeneity in Parkinson's disease.

BACKGROUND: Parkinson's disease (PD) is a highly heterogeneous disease, in which motor symptom subtypes are often-described. While it is recognized that motor, cognitive and affective neuropsychiatric symptoms negatively influence the patients' quality of life, it is currently unknown how these symptoms contribute to phenotypic subtypes. The objective of this study was to assess subtypes of motor, cognitive and affective symptoms in PD. METHODS: A hierarchical cluster analysis was conducted on clinical data of 226 PD patients screened at the VU University Medical Center using comprehensive assessment of cognitive, affective and motor symptoms. Subsequent linear discriminant analyses were conducted to investigate discriminating constructs between clusters. RESULTS: The cluster analysis yielded four clusters: (1) a young-age (59.9 years), mildly affected cluster (N = 86), (2) an old-age (72.3 years) cluster with severe motor and non-motor symptoms (N = 15), (3) a cluster (age 64.7 years) with mild motor symptoms, below-average executive functioning and affective symptoms (N = 46) and (4) a cluster (age 64.8 years) with severe motor symptoms, affective symptoms and below-average verbal memory (N = 79). CONCLUSIONS: Cluster 1 and 2 seem to represent opposite ends of the PD disease stages. Patients in clusters 3 and 4 had similar age, educational level and disease duration but different symptom profiles - we therefore suggest that these clusters represent different pathways of disease progression, presumably with distinct underlying pathology localization. Future research on the neuropathophysiological characteristics of these two clusters and monitoring of disease progression is required.

Cortical Thickness, Surface Area and Subcortical Volume Differentially Contribute to Cognitive Heterogeneity in Parkinson's Disease.

Parkinson's disease (PD) is often associated with cognitive deficits, although their severity varies considerably between patients. Recently, we used voxel-based morphometry (VBM) to show that individual differences in gray matter (GM) volume relate to cognitive heterogeneity in PD. VBM does, however, not differentiate between cortical thickness (CTh) and surface area (SA), which might be independently affected in PD. We therefore re-analyzed our cohort using the surface-based method FreeSurfer, and investigated (i) CTh, SA, and (sub)cortical GM volume differences between 93 PD patients and 45 matched controls, and (ii) the relation between these structural measures and cognitive performance on six neuropsychological tasks within the PD group. We found cortical thinning in PD patients in the left pericalcarine gyrus, extending to cuneus, precuneus and lingual areas and left inferior parietal cortex, bilateral rostral middle frontal cortex, and right cuneus, and increased cortical surface area in the left pars triangularis. Within the PD group, we found negative correlations between (i) CTh of occipital areas and performance on a verbal memory task, (ii) SA and volume of the frontal cortex and visuospatial memory performance, and, (iii) volume of the right thalamus and scores on two verbal fluency tasks. Our primary findings illustrate that i) CTh and SA are differentially affected in PD, and ii) VBM and FreeSurfer yield non-overlapping results in an identical dataset. We argue that this discrepancy is due to technical differences and the subtlety of the PD-related structural changes.

Distribution and Load of Amyloid-ß Pathology in Parkinson Disease and Dementia with Lewy Bodies.

Parkinson disease (PD), Parkinson disease with dementia (PDD), and Dementia with Lewy bodies (DLB) differ clinically with regard to the presence and timing of dementia. In this postmortem study, we evaluated whether the burden and distribution pattern of amyloid-ß (Aß) pathology differs among these disease entities. We assessed Aß phases and neuritic plaque scores in 133 patients fulfilling clinical diagnostic criteria for PD, PDD, and DLB, and determined the presence and load of Aß pathology in 5 cortical and 4 subcortical regions in a subset of patients (n = 89) using a multispectral imaging system. Aß phases and neuritic plaque scores were higher in DLB versus PDD (both p < 0.001) and in PDD vs PD patients (p = 0.020 and 0.022, respectively). Aß pathology was more often observed in the entorhinal cortex, amygdala and putamen in DLB versus PDD patients; Aß load was higher in both cortical and subcortical regions. PDD patients had more frequent Aß pathology in temporal cortex and higher Aß load in cortical regions and striatum versus PD patients. Our findings suggest that the load and extent of Aß pathology may contribute to cognitive dysfunction in PDD and the early-stage severe dementia in DLB.

Psychiatric disorders, myoclonus dystonia and SGCE: an international study.

OBJECTIVE: Myoclonus-dystonia (M-D) is a hyperkinetic movement disorder, typically alcohol-responsive upper body myoclonus and dystonia. The majority of autosomal dominant familial cases are caused by epsilon-sarcoglycan gene (SGCE) mutations. Previous publications have observed increased rates of psychiatric disorders amongst SGCE mutation-positive populations. We analyzed the psychiatric data from four international centers, forming the largest cohort to date, to further determine the extent and type of psychiatric disorders in M-D. METHODS: Psychiatric data from SGCE mutation-positive M-D cohorts, collected by movement disorder specialists in the Netherlands, United Kingdom, United States, and Germany, were analyzed. These data were collected using standardized, systematic questionnaires allowing classification of symptoms according to Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV) criteria. Based on motor findings and SGCE mutation analysis, participants were classified into one of three groups: manifesting carriers, nonmanifesting carriers and noncarriers. RESULTS: Data from 307 participants were evaluated (140 males, 167 females, mean age at examination: 42.5 years). Two-thirds of motor affected mutation carriers (n = 132) had ≥1 psychiatric diagnosis, specific, and social phobias being most common followed by alcohol dependence and obsessive-compulsive disorder (OCD). Compared to familial controls, affected mutation carriers had significantly elevated overall rates of psychiatric disorders (P < 0.001). The most significant differences were observed with alcohol dependence (P < 0.001), OCD (P < 0.001), social and specific phobias (P < 0.001). INTERPRETATION: M-D due to SGCE mutations is associated with specific psychiatric disorders, most commonly OCD, anxiety-related disorders, and alcohol dependence. These suggest either a potential pleiotropic function for SGCE within the central nervous system or a secondary effect of the motor disorder.