Dysfunction In Multiple System Atrophy Research Articles

Ocular vestibular-evoked myogenic potential assists in differentiation of multiple system atrophy from Parkinson's disease.

Vestibular-evoked myogenic potentials (VEMPs) can help assess otolithic neural pathway in the brainstem that may also participate in cardiovascular autonomic function. Parkinson's disease (PD) is associated with altered VEMP responses; however, the association between VEMP abnormalities and multiple system atrophy (MSA) remains unknown. Therefore, we compared the extent of otolith dysfunction using ocular (oVEMP) and cervical VEMP (cVEMP) between MSA and PD. We analyzed the clinical features and VEMP and head-up tilt table test (HUT) findings using the Finometer in 24 patients with MSA and 52 with de-novo PD, who had undergone neurotologic evaluation in a referral-based university hospital in South Korea from January 2021 to March 2023. MSA was associated with bilateral oVEMP abnormality (odds ratio [95% confidence interval] = 9.19 [1.77-47.76], p=0.008). n1-p1 amplitude was negatively correlated with Unified Multiple System Atrophy Rating Scale I-II scores in patients with MSA (r=-0.571, p=0.033), whereas it did not correlate with Movement Disorder Society-Unified Parkinson's Disease Rating Scale-III scores in patients with PD (r=-0.051, p=0.687). n1 latency was negatively correlated with maximum changes in systolic blood pressure within 15 s during HUT in patients with PD (r=-0.335, p=0.040) but not in those with MSA (r=0.277, p=0.299). In conclusion, bilaterally abnormal oVEMP responses may indicate the extent of brainstem dysfunction in MSA. oVEMP reflects the integrity of otolith-autonomic interplay, reliably assists in differentiating between MSA and PD, and helps infer clinical decline.

Cerebral Small Vessel Disease Is Associated with Motor, Cognitive, and Emotional Dysfunction in Multiple System Atrophy.

Cerebral small vessel disease (CSVD) has not been systematically studied in patients with multiple system atrophy (MSA). We sought to explore whether MSA patients suffer from a heavier CSVD burden relative to healthy individuals and whether CSVD has a relationship with motor, cognitive, and emotional dysfunction in patients with MSA. This study consecutively recruited 190 MSA patients and 190 matched healthy controls whose overall CSVD burden and single CSVD imaging markers (including white matter hyperintensity (WMH), microbleeds, lacunes, and enlarged perivascular spaces (EPVS)) were measured. Of the MSA patients, 118 completed multi-dimensional outcome assessments. Spearman's correlations and multivariable linear regressions were performed. We observed a greater burden of overall CSVD, WMH, and EPVS in MSA patients compared with controls, but not for microbleeds and lacunes. Motor dysfunction and cognitive impairment were significantly worse in subjects with severe CSVD than those with none-to-mild CSVD. In patients with MSA, the severity of CSVD burden was positively associated with motor impairments as measured by the Unified Multiple System Atrophy Rating Scale-II (β= 2.430, p = 0.039) and Scale for the Assessment and Rating of Ataxia (β= 1.882, p = 0.015). Of CSVD imaging markers, different associations with MSA outcomes were displayed. WMH was associated with motor, cognitive, and emotional deficits, while the EPVS in the centrum semiovale, basal ganglia, and hippocampus regions was correlated only with motor severity, anxiety, and cognition, respectively. Similar findings were noted in MSA-cerebellar and MSA-parkinsonian patients. Concomitant CSVD may be correlated with worse multi-dimensional dysfunction in patients with MSA.

Non-pharmacological and drug treatment of autonomic dysfunction in multiple system atrophy: current status and future directions.

Multiple system atrophy (MSA) is a sporadic, fatal, and rapidly progressive neurodegenerative disease of unknown etiology that is clinically characterized by autonomic failure, parkinsonism, cerebellar ataxia, and pyramidal signs in any combination. Early onset and extensive autonomic dysfunction, including cardiovascular dysfunction characterized by orthostatic hypotension (OH) and supine hypertension, urinary dysfunction characterized by overactive bladder and incomplete bladder emptying, sexual dysfunction characterized by sexual desire deficiency and erectile dysfunction, and gastrointestinal dysfunction characterized by delayed gastric emptying and constipation, are the main features of MSA. Autonomic dysfunction greatly reduces quality of life and increases mortality. Therefore, early diagnosis and intervention are urgently needed to benefit MSA patients. In this review, we aim to discuss the systematic treatment of autonomic dysfunction in MSA, and focus on the current methods, starting from non-pharmacological methods, such as patient education, psychotherapy, diet change, surgery, and neuromodulation, to various drug treatments targeting autonomic nerve and its projection fibers. In addition, we also draw attention to the interactions among various treatments, and introduce novel methods proposed in recent years, such as gene therapy, stem cell therapy, and neural prosthesis implantation. Furthermore, we elaborate on the specific targets and mechanisms of action of various drugs. We would like to call for large-scale research to determine the efficacy of these methods in the future. Finally, we point out that studies on the pathogenesis of MSA and pathophysiological mechanisms of various autonomic dysfunction would also contribute to the development of new promising treatments and concepts.

New MDS Criteria for the Diagnosis of Multiple System Atrophy: An Autonomic Viewpoint

We reviewed the autonomic dysfunction in multiple system atrophy (MSA) with reference to the new MDS criteria. MSA is a major neurodegenerative disorder that presents with autonomic and motor dysfunctions (cerebellar ataxia and/or parkinsonism). Autonomic dysfunction in MSA affects urinary, cardiac, gastrointestinal, otorhinolaryngologic, and respiratory functions. Therefore, autonomic dysfunction in MSA should be recognized, collaborating with each faculty for the treatment and care of the patients. Moreover, it is highly recommended that neurologists request for an ultrasound measurement of the post-void residual urine volume. MSA has no cure; hence, active participation in the treatment and care of autonomic dysfunction in MSA patients is warranted.

Bedside Assessment of Autonomic Dysfunction in Multiple System Atrophy.

Multiple system atrophy (MSA) is a rare, rapidly progressive neurodegenerative disorder of the adulthood, characterized by autonomic failure, parkinsonian and cerebellar features in various combinations. Distinguishing MSA from common clinical look-alikes such as Parkinson's disease, other atypical parkinsonian disorders or alternative causes of sporadic adult-onset cerebellar ataxia may be difficult, especially at early disease stages. Nonetheless, some simple and cost-effective screening tools help detecting important red flags guiding towards a MSA diagnosis. Here we outline which clinical pearls and bedside tests may disclose autonomic dysfunction in multiple domains, enabling an early MSA diagnosis and, even more importantly, personalized treatment.

Alterations in electrochemical skin conductance as a marker of autonomic dysfunction in multiple system atrophy

BackgroundMultiple System Atrophy (MSA) is a rare neurodegenerative disease with pronounced autonomic failure (AF). Severe cardiovascular AF is associated with poor prognosis. Since sweating dysfunction is less well known, we investigated the interest of a quick and non-invasive assessment of sweating using electrochemical skin conductance (ESC) as a marker for AF in MSA. Methods138 MSA patients of the French Reference center for MSA with an annual follow-up including the Unified MSA Rating Scale (UMSARS), COMPASS (autonomic symptoms) and measurements of foot and hand ESC (Sudoscan®) participated to this study (age 65 ± 8 years, 66% probable MSA, 72% AMS-P). Statistical analysis included: (i) correlations between ESC and MSA type, age, disease duration, severity, blood pressure (BP), COMPASS, (ii) comparisons between groups with normal or abnormal ESC, and (iii) multivariate analysis by logistic regression. Relationships between severity progression during follow-up with ESC and other variables were modeled by Generalized Estimating Equation. ResultsHands and feet ESCs were abnormal in 81/138 (59%) and 93/138 (67%) cases, respectively. Abnormal ESCs were significantly correlated to disease severity and several features of AF. ESCs worsening over time was more pronounced than other autonomic features such as orthostatic hypotension. Abnormal ESCs at baseline were significantly associated with a higher progression of UMSARS's score during follow-up. ConclusionSweating dysfunction assessed by ESC is frequent in MSA and is significantly related to disease severity and AF. The gradual decrease in ESC with disease duration could be useful as a quantitative marker of autonomic dysfunction.

The Frontal and Cerebellar Metabolism Related to Cognitive Dysfunction in Multiple System Atrophy.

BackgroundCognitive dysfunctions have been reported in multiple system atrophy (MSA). However the underlying mechanisms remain to be elucidated. This study aimed to explore the possible cerebral metabolism associated with domain-specific cognitive performances in MSA.MethodsA total of 84 patients were diagnosed as probable or possible MSA, comprised of 27 patients as MSA with predominant parkinsonism (MSA-P) and 57 patients as MSA with predominant cerebellar ataxia (MSA-C). The comprehensive neuropsychological tests and 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) imaging were performed. Z-score was calculated to non-dimensionalize and unify indicators of different tests in the domains of executive function, attention, language, memory, and visuospatial function. Correlations between specific Z-score and cerebral 18F-FDG uptake were analyzed using statistical parametric mapping. The cognition-related metabolic differences between patients with MSA-P and MSA-C were analyzed using the post-hoc test.ResultsZ-scores of the domains including attention, executive function, and language correlated positively with the metabolism in the superior/inferior frontal gyrus and cerebellum, but negatively with that in the insula and fusiform gyrus (p < 0.001). No significant differences in neuropsychological performances and frontal metabolism were found between patients with MSA-P and MSA-C. Only lower metabolism in the cerebellum was observed in MSA-C.ConclusionMetabolic changes in the frontal lobe and cerebellum may participate in the cognitive impairments of patients with MSA. Nevertheless, cognitive and corresponding metabolic differences between the two subtypes of MSA still need more exploration.

Excessive Daytime Sleepiness Is Associated With Non-motor Symptoms of Multiple System Atrophy: A Cross-Sectional Study in China.

Objectives: Excessive daytime sleepiness (EDS) in multiple system atrophy (MSA) has received scant attention in the literature, thus the present cross-sectional study aimed to investigate the prevalence of EDS and its potential risk factors among Chinese patients with MSA.Methods: A total of 66 patients with MSA (60.6% males) were consecutively recruited. Eighteen patients (27.3%, 13 men) with Epworth Sleepiness Scale score >10 were defined as having EDS. Demographic, motor [Unified Multiple-System Atrophy (UMSARS)] and non-motor symptoms [Non-Motor Symptoms Scale (NMSS)], and sleep parameters [polysomnography (PSG)] were compared between patients with MSA with and without EDS. A logistic regression analysis was used to calculate the risk factors of EDS in patients with MSA.Results: There were no significant differences in age, sex, MSA onset age, disease duration, MSA sub-type, and motor symptom severity between MSA patients with and without EDS. However, compared with the MSA patients without EDS, their counterparts with EDS had higher scores of NMSS (65.3 ± 23.1 vs. 43.4 ± 25.3, P = .0002), Hamilton Anxiety (HAMA) [15.3 (10.3–20.0) vs. 9.5 (3.0–15.0), P = 0.006], Hamilton Depression (HAMD) [13.7 (12.5–17.8) vs. 9.0 (4.0–13.0), P = 0.015], and Fatigue Severity Scale (FSS) [29.8 (17.3–47.8) vs. 18.7 (10.3–21.8), P = 0.040]. Conversely, the patients with EDS had lower score of Mini-Mental State Examination (MMSE) [23.3 (20.3–27.0) vs. 25.7 (22.0–29.0), P = 0.023]. Similarly, there was a significantly lower percentage of N3 sleep (%) [0.3 (0–0) vs. 2.0 (0–0), P = 0.007] and a higher apnea-hypopnea index (AHI/h) [30.5 (14.5–47.8) vs. 19.3 (5.0–28.7), P = 0.034] in patients with EDS. After adjusting for age, sex, disease duration, MSA sub-type, and UMSARS score, the odds ratio (OR) (95% CI) of EDS was higher while increasing scores in FSS [1.06 (1.02–1.11)], HAMA [1.16 (1.04–1.28)], HAMD [1.13 (1.02–1.25)], NMSS [1.04 (1.01–1.07)], and AHI [1.03 (1.00–1.10)]. The OR of EDS was lower while the MMSE score was increasing [0.85 (0.72–1.00)].Conclusions: The presence and severity of EDS may be significantly associated with the non-motor dysfunction, including fatigue, anxiety, depression, cognitive dysfunction, and sleep-related breathing disorder, but not with the motor dysfunction in MSA.

Female sexual dysfunction in multiple system atrophy: a prospective cohort study

PurposeThe diagnosis of probable multiple system atrophy relies on the presence of severe cardiovascular or urogenital autonomic failure. Erectile dysfunction is required to fulfil the latter criterion in men, whereas no corresponding item is established for women. In this study, we aimed to investigate sexual dysfunction in women with multiple system atrophy.MethodsWe administered the Female Sexual Function Index questionnaire and interviewed women with multiple system atrophy and age-matched controls regarding the presence of “genital hyposensitivity.”ResultsWe recruited 25 women with multiple system atrophy and 42 controls. Female Sexual Function Index scores in sexually active women with multiple system atrophy were significantly lower (multiple system atrophy = 10; 15.4, 95% CI [10.1, 22.1], controls = 37; 26.1 [24.1, 28.1], p = 0.0004). The lowest scores concerned the domains of desire, arousal and lubrication. Genital hyposensitivity was reported by 56% of the patients with multiple system atrophy and 9% controls (p < 0.0001).ConclusionsSexual dysfunction is highly prevalent in women with multiple system atrophy. Screening for disturbances in specific sexual domains should be implemented in the clinical evaluation of women with suggestive motor symptoms.

Relationship Between Orthostatic Hypotension and Cognitive Functions in Multiple System Atrophy: A Longitudinal Study.

Introduction: The aim of this study is to investigate the impact of orthostatic hypotension (OH) on cognitive functions in patients with multiple system atrophy (MSA) followed over time.Methods: Thirty-two MSA patients were enrolled and underwent a comprehensive neuropsychological battery; at baseline (T0) 15 out of 32 patients presented OH, assessed by means of orthostatic standing test. All patients underwent a follow-up (T1) evaluation 12 months after baseline. Thirteen out of 32 patients also underwent a second follow-up (T2) evaluation at 24 months. Changes over time on different neuropsychological tasks were compared between patients with and without OH by means of Mann-Whitney's U-test. Moreover, clinical categories of normal cognition, mild cognitive impairment, and dementia were determined, and changes at T1 and T2 in global cognitive status were compared between patients with and without OH.Results: At T0, patients with OH had better performance on words/non-words repetition task (p = 0.02) compared to patients without OH. Compared to patients without OH, patients with OH performed worse on semantic association task (p < 0.01) at T1 and on Stroop test-error effect (p = 0.04) at T2. The percentage of patients with worsened cognitive status at T1 was higher among patients with OH than among patients without OH (93 vs. 59%, p = 0.03). OH (β = −4.67, p = 0.01), education (β = 0.45, p = 0.02), age (β = 0.19, p = 0.03), and Montreal Cognitive Assessment battery (MOCA) score at T0 (β = −0.26, p = 0.04) were significant predictors of global cognitive status worsening at T1.Discussion: We found that global cognitive status worsened at 1-year follow-up in 93% of patients with OH, and OH, along with age, education, and MOCA score, predicted cognitive worsening over time. To clarify the relationship between OH and cognitive dysfunction in MSA, we suggest the use of clinical categories of normal cognition, mild cognitive impairment, and dementia in further longitudinal studies on MSA patients with and without OH.

Urodynamic Evaluation in Multiple System Atrophy: A Retrospective Cohort Study.

ABSTRACTBackgroundUrological dysfunction in patients with multiple system atrophy (MSA) is one of the main manifestations of autonomic failure. Urodynamic examination is clinically relevant since underlying pathophysiology of lower urinary tract (LUT) dysfunction can be variable.ObjectiveEvaluation of the pathophysiology of urological symptoms and exploration of differences in urodynamic patterns of LUT dysfunction between MSA‐P and MSA‐C.MethodsRetrospective study of patients with possible and probable MSA who were referred for urodynamic studies between 2004 and 2019. Demographic data, medical history, physical examination and urodynamic studies assessing storage and voiding dysfunction were obtained.ResultsSeventy‐four patients were included in this study (MSA‐P 64.9% n = 48; median age 62.5 (IQR 56.8–70) years). Detrusor overactivity during filling phase was noted in 58.1% (n = 43) of the patients. In the voiding phase, detrusor sphincter dyssynergia and detrusor underactivity were observed in 24.6% (n = 17) and in 62.1% (n = 41) of the patients, respectively. A postmicturition residual volume of over 100 ml was present in 71.4% (n = 50) of the patients. Comparison of MSA subtypes showed weaker detrusor contractility in MSA‐P compared to MSA‐C [pdetQmax 26.2 vs. 34.4 cmH20, P = 0.04]. In 56.2% (n = 41) of patients pathophysiology of LUT dysfunction was deemed to be neurogenic and consistent with the diagnosis of MSA. In 35.6% (n = 26) urodynamic pattern suggested other urological co‐morbidities.ConclusionUrodynamic evaluation is an important tool to analyze the pattern of LUT dysfunction in MSA. Impaired detrusor contractility was seen more in MSA‐P which needs to be investigated in further studies.

Postganglionic Sudomotor Dysfunction and Brain Glucose Hypometabolism in Patients with Multiple System Atrophy.

Sudomotor dysfunction is common in patients with multiple system atrophy (MSA). Postganglionic sudomotor dysfunction in MSA, which can be assessed using quantitative sudomotor axon reflex testing (QSART), results from the degeneration of preganglionic sympathetic neurons and direct loss of postganglionic fibers. We investigate whether abnormal QSART responses in patients with MSA are associated with disease severity. In this retrospective study, patients with probable MSA who underwent both 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG-PET/CT) and autonomic function tests were included. Autonomic function test results were integrated divided into three sub-scores, including sudomotor, cardiovagal, and adrenergic sub-scores. The sudomotor sub-score represented postganglionic sudomotor function. Unified Multiple System Atrophy Rating Scale (UMSARS) Part I, Part II, and sum of Part I and II scores (Part I + II) to reflect disease severity and 18F-FDG-PET/CT results were collected. Of 74 patients with MSA, 62.2%demonstrated abnormal QSART results. The UMSARS Part I + II score was significantly higher in the abnormal QSART group than in the normal QSART group (p = 0.037). In the regression analysis, both UMSARS Part I (β= 1.185, p = 0.013) and Part II (β= 1.266, p = 0.021) scores were significantly associated with the sudomotor sub-score. On 18F-FDG-PET/CT, the abnormal QSART group exhibited more severely decreased metabolic activity in the cerebellum and basal ganglia in patients with MSA-P and MSA-C, respectively. The sudomotor sub-score was significantly associated with regional metabolism in these areas. Patients with MSA and postganglionic sudomotor dysfunction may have worse disease severity and greater neuropathological burden than those without.

Intraocular pressure and choroidal thickness postural changes in multiple system atrophy and Parkinson\u2019s disease

To evaluate intraocular pressure (IOP) and choroidal thickness (ChT) postural changes in multiple system atrophy (MSA), Parkinson’s disease (PD) patients and healthy controls (HC). 20 MSA patients, 21 PD patients and 14 HC, were examined. All subjects underwent a complete examination, including corneal thickness, ChT, IOP and axial length (AL) measurements. IOP measurement was performed in supine, sitting, and standing positions, whereas ChT in sitting and standing positions. Supine to standing IOP variations were significantly higher in MSA vs PD(p = 0.01) and in MSA vs HC (p < 0.0001), whereas no significant differences were observed between PD and HC (p = 0.397). Mean sub-foveal ChT in MSA was 240 ± 92 μm in sitting position, and 215 ± 94 μm in standing position with a significant reduction (p = 0.008). Mean sub-foveal ChT in PD was 258 ± 79 μm in sitting position, and 259 ± 76 μm in standing position (p = 0.887). In HC it was 244 ± 36 μm in sitting position, and 256 ± 37 μm in standing position with a significant increase (p = 0.007). The significant IOP and ChT postural changes can be considered additional hallmarks of autonomic dysfunction in MSA and further studies are needed to consider them as biomarkers in the differential diagnosis with PD.

Autonomic dysfunction in multiple system atrophy

Autonomic dysfunction in multiple system atrophy

Signs of early cellular dysfunction in multiple system atrophy.

Multiple system atrophy (MSA) is a fatal neurodegenerative disease that belongs to the family of α-synucleinopathies. At post mortem examination, intracellular inclusions of misfolded α-synuclein are found in neurons and oligodendrocytes and are considered to play a significant role in the pathogenesis. However, the early steps of the disease process are unknown and difficult to study in tissue derived from end-stage disease. Induced pluripotent stem cells (iPSCs) were generated from patients' and control skin fibroblasts and differentiated into NCAM-positive neural progenitor cells (NPCs). The mitochondrial morphology and function were assessed by immunocytochemistry and high resolution respirometry. The ability to cope with exogenous oxidative stress was tested by exposure to different doses of luperox. The expression of α-synuclein was studied by immunocytochemistry. We identified increased tubulation of mitochondria with preserved respiration profile in MSA-derived NPCs. Exposure of these cells to exogenous oxidative stress even at low doses, triggered an excessive generation of reactive oxygen species (ROS) and cleavage of caspase-3. MSA-derived NPCs did not present changed levels of SNCA gene expression nor intracellular aggregates of α-synuclein. However, we identified disease-related translocation of α-synuclein to the nucleus. Our results show early cellular dysfunction in MSA-derived NPCs. We identified changes in the redox homeostasis which are functionally compensated at baseline but cause increased susceptibility to exogenous oxidative stress. In addition, nuclear translocation of α-synuclein in MSA-derived NPCs supports an early cellular stress response which may precede the neurodegenerative process in this disorder.

Laryngeal Movement Disorders in Multiple System Atrophy: A Diagnostic Biomarker?

BackgroundMultiple system atrophy (MSA) is a rare neurodegenerative disorder, and its parkinsonian variant can be difficult to delineate from Parkinson's disease (PD). Despite laryngeal dysfunction being associated with decreased life expectancy and quality of life, systematic assessments of laryngeal dysfunction in large cohorts are missing.ObjectivesThe objective of this study was to systematically assess laryngeal dysfunction in MSA and PD and identify laryngeal symptoms that allow for differentiating MSA from PD.MethodsPatients with probable or possible MSA underwent flexible endoscopic evaluation of swallowing performing a systematic task protocol. Findings were compared with an age‐matched PD cohort.ResultsA total of 57 patients with MSA (64 [59–71] years; 35 women) were included, and task assessments during endoscopic examination compared with 57 patients with PD (67 [60–73]; 28 women). Patients with MSA had a shorter disease duration (4 [3–5] years vs 7 [5–10]; P < 0.0001) and higher disease severity (Hoehn & Yahr stage 4 [3–4] vs 3 [2–4]; P < 0.0001). Of the patients with MSA, 43.9% showed clinically overt laryngeal dysfunction with inspiratory stridor. During endoscopic task assessment, however, 93% of patients with MSA demonstrated laryngeal dysfunction in contrast with only 1.8% of patients with PD (P < 0.0001). Irregular arytenoid cartilages movements were present in 91.2% of patients with MSA, but in no patients with PD (P < 0.0001). Further findings included vocal fold motion impairment (75.4%), paradoxical vocal fold motion (33.3%), and vocal fold fixation (19.3%). One patient with PD showed vocal fold motion impairment.ConclusionLaryngeal movement disorders are highly prevalent in patients with MSA when assessed by a specific task protocol despite the lack of overt clinical symptoms. Our data suggest that irregular arytenoid cartilage movements could be used as a clinical marker to delineate MSA from PD with a specificity of 1.0 and sensitivity 0.9. © 2020 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society

Early autonomic and cognitive dysfunction in PD, DLB and MSA: blurring the boundaries between α-synucleinopathies.

Differential diagnosis between Parkinson's disease, dementia with Lewy bodies and multiple system atrophy can be difficult, especially because in early phase they might present with overlapping clinical features. Notably, orthostatic hypotension and cognitive dysfunction are common nonmotor aspects of parkinsonian syndromes and can be both present from the earliest stages of all α-synucleinopathies, indicating a common neurobiological basis in their strong relationship. In view of the increasing awareness about the prevalence of mild cognitive dysfunction in multiple system atrophy, the relevance of autonomic dysfunction in demented parkinsonian patients, the critical role of non-motor symptoms in clustering Parkinson's disease patients and the shift to studying patients in the prodromal phase, we will discuss some intrinsic limitations of current clinical diagnostic criteria, even when applied by movement disorder specialists. In particular, we will focus on the early coexistence of autonomic and cognitive dysfunction in the setting of overt or latent parkinsonism as pitfalls in the differential diagnosis of α-synucleinopathies. As early and accurate diagnosis remains of outmost importance for counselling of patients and timely enrolment into disease-modifying clinical trials, a continuous effort of research community is ongoing to further improve the clinical diagnostic accuracy of α-synucleinopathies.

Hippocampal α-synuclein pathology correlates with memory impairment in multiple system atrophy.

Recent post-mortem studies reported 22-37% of patients with multiple system atrophy can develop cognitive impairment. With the aim of identifying associations between cognitive impairment including memory impairment and α-synuclein pathology, 148 consecutive patients with pathologically proven multiple system atrophy were reviewed. Among them, 118 (79.7%) were reported to have had normal cognition in life, whereas the remaining 30 (20.3%) developed cognitive impairment. Twelve of them had pure frontal-subcortical dysfunction, defined as the presence of executive dysfunction, impaired processing speed, personality change, disinhibition or stereotypy; six had pure memory impairment; and 12 had both types of impairment. Semi-quantitative analysis of neuronal cytoplasmic inclusions in the hippocampus and parahippocampus revealed a disease duration-related increase in neuronal cytoplasmic inclusions in the dentate gyrus and cornu ammonis regions 1 and 2 of patients with normal cognition. In contrast, such a correlation with disease duration was not found in patients with cognitive impairment. Compared to the patients with normal cognition, patients with memory impairment (pure memory impairment: n = 6; memory impairment + frontal-subcortical dysfunction: n = 12) had more neuronal cytoplasmic inclusions in the dentate gyrus, cornu ammonis regions 1-4 and entorhinal cortex. In the multiple system atrophy mixed pathological subgroup, which equally affects the striatonigral and olivopontocerebellar systems, patients with the same combination of memory impairment developed more neuronal inclusions in the dentate gyrus, cornu ammonis regions 1, 2 and 4, and the subiculum compared to patients with normal cognition. Using patients with normal cognition (n = 18), frontal-subcortical dysfunction (n = 12) and memory impairment + frontal-subcortical dysfunction (n = 18), we further investigated whether neuronal or glial cytoplasmic inclusions in the prefrontal, temporal and cingulate cortices or the underlying white matter might affect cognitive impairment in patients with multiple system atrophy. We also examined topographic correlates of frontal-subcortical dysfunction with other clinical symptoms. Although no differences in neuronal or glial cytoplasmic inclusions were identified between the groups in the regions examined, frontal release signs were found more commonly when patients developed frontal-subcortical dysfunction, indicating the involvement of the frontal-subcortical circuit in the pathogenesis of frontal-subcortical dysfunction. Here, investigating cognitive impairment in the largest number of pathologically proven multiple system atrophy cases described to date, we provide evidence that neuronal cytoplasmic inclusion burden in the hippocampus and parahippocampus is associated with the occurrence of memory impairment in multiple system atrophy. Further investigation is necessary to identify the underlying pathological basis of frontal-subcortical dysfunction in multiple system atrophy.

Impact of depressive symptoms on self-perceived severity of autonomic dysfunction in multiple system atrophy: relevance for patient-reported outcomes in clinical trials.

To assess the relationship between depressive symptoms and self-perceived severity of autonomic dysfunction in patients with multiple system atrophy (MSA). Cross-sectional evaluation of patients with MSA who underwent autonomic testing, Unified MSA Rating Scale (UMSARS)-1 and -2, rating of the presence and severity of depressive symptoms (Zung scale), quality of life (SF-36), body vigilance, anxiety (Spielberger's anxiety scale), severity of autonomic dysfunction with the Composite Autonomic Symptoms Score (COMPASS-31), and severity of orthostatic hypotension (OH) symptoms with the Orthostatic Hypotension Questionnaire (OHQ). Fifty-eight patients (32 women) with probable MSA (aged 61.8 ± 8.6years; disease duration 4.3 ± 2.1years) were studied. Forty patients (69%) had symptoms of depression in the Zung scale. Age, disease duration, and motor disability were similar in those with and without symptoms of depression. Despite a similar orthostatic blood pressure fall, the severity of orthostatic symptoms was higher in patients with symptoms of depression (p = 0.004). Depression scores were associated with higher burden of autonomic symptoms (R = 0.401, p = 0.02), specifically with the COMPASS-31 items related to orthostatic intolerance (R = 0.337, p = 0.045), and with the OHQ (R = 0.529; p < 0.001). A multivariable regression model including age, sex, UMSARS, and drop in systolic blood pressure upon head-up tilt as covariates showed that the burden of depressive symptoms was independently associated with the OHQ score: for every 1-unit increase in the Zung depression score, there was a 1.181-point increase in the total OHQ score. In patients with MSA, depressive symptoms worsen the perceived severity of autonomic symptoms in general and orthostatic hypotension in particular. Our findings have implications for clinical trial design.

Sympathetic outflow to skin predicts central autonomic dysfunction in multiple system atrophy.

To find out the physiological method for evaluating the severity of central autonomic dysfunction, we performed detailed evaluation of cutaneous vasomotor neural function in a comparatively large sample of multiple system atrophy (MSA). We evaluated cutaneous vasomotor neural function in 24 MSA patients. Skin sympathetic nerve activity (SSNA) and sympathetic skin response (SSR) and skin blood flow (skin vasomotor reflex [SVR]) were recorded at rest, as well as reflex changes after electrical stimulation. The parameters investigated were SSNA frequency at rest, reflex latency and amplitude of SSNA reflex bursts, absolute decrease and percent reduction of SVR, recovery time, and spontaneous SVR and SSR frequency. There were negative correlations between resting SSNA and disease duration or the SCOPA-AUT score, but these were not significant. SSNA reflex latency displayed significant positive correlations with disease duration and SCOPA-AUT score (p < 0.001 and p < 0.01, respectively). In all five patients who underwent the same examination twice, SSNA reflex latency was significantly longer at the second examination than at the first examination (p < 0.005). A significant positive correlation was identified between recovery time of skin blood flow and SCOPA-AUT score or reflex latency (p < 0.05). Significant correlations were not observed between SCOPA-AUT score or disease duration and other parameters. These results suggest that some MSA patients with a comparatively short duration of disease potentially have impaired thermoregulatory function. Measurement of sympathetic outflow to the skin is potentially a useful tool for predicting the severity of central autonomic dysfunction in MSA.