Epidemiological evidence on multiple system atrophy

Summary. Multiple system atrophy (MSA), is a sporadic neurodegenerative disorder characterized clinically by any combination of parkinsonian, autonomic, cerebellar or pyramidal symptoms and signs. The frequence of disease is estimated for the incidence rate to 0.6 cases per 100.000 person-years, while the prevalence rate is included between 1.86 and 4.9 cases per 100.000 pop. A risk factor seems to be the occupational history of farming also if the occupational exposure to pesticides is not associated with MSA. Smoking is probably a protective factor in MSA as Parkinson’s disease. MSA seems a sporadic disease also if recently a German family with two MSA cases has been reported. The polymorphism association studies support a role for inflammation-related genes in risk for MSA. The current epidemiological and clinical evidence suggests that likely the etiopathogenesis of MSA is complex, and that many genetic as well as environmental factors are involved. Unfortunately, the most of studies in MSA are lacking in a sample size estimate to test the hypothesis, then the scientific evidence is poor. Then, much larger numbers of cases and controls are necessary for these studies to reach sufficient power, but collecting such large numbers is feasible only in the framework of multicentric consortia.     

Functional imaging with positron emission tomography in multiple system atrophy

Summary. Although the current guidelines for the clinical diagnosis of multiple system atrophy (MSA) do not require structural or functional brain imaging, investigations utilizing positron emission tomography (PET) have been helpful diagnostically in differentiating between MSA and primary autonomic failure; idiopathic Parkinson’s disease; and sporadic olivopontocerebellar atrophy. These investigations have demonstrated different patterns of cerebral glucose utilization and of nigrostriatal projection abnormalities among these disorders and between the cerebellar and parkinsonian forms of MSA. Most of the studies have focused upon patients with well-established disease and none have examined the utility of PET imaging in early stage patients with follow-up of clinical course and autopsy verification to ensure accuracy of diagnosis and to determine the sensitivity and specificity of PET techniques for diagnosis. Recent PET studies have revealed denervation of myocardial post-ganglionic sympathetic neurons in some MSA patients, indicating that this disorder can affect the peripheral autonomic as well as the central nervous system. Investigations utilizing ligands to quantify central nervous system dopaminergic and cholinergic terminals have begun to provide insight into the neurochemical disorders that may underlie two of the sleep disturbances common in MSA, rapid eye movement sleep behavior disorder and obstructive sleep apnea.     

Computed tomography,magnetic resonance imaging and positron emission tomography with [18F] fluorodeoxyglucose in multiple system atrophy and pure autonomic failure

We studied 45 patients who had autonomic failure with computed tomography, magnetic resonance imaging and positron emission tomography with [¹⁸F]fluorodeoxyglucose to characterize the neuroimaging features of multiple system atrophy and pure autonomic failure and determine the utility of these techniques in distinguishing multiple system atrophy from pure autonomic failure. There were 30 patients with multiple system atrophy and 15 with pure autonomic failure. In the multiple system atrophy group, eight patients had mainly cerebellar signs, seven extrapyramidal and 15 had combinations of cerebellar and extrapyramidal signs. Cerebellar atrophy on computerized tomography and magnetic resonance imaging, signal hypointensity in the posterolateral putamen on magnetic resonance imaging and a generalized reduction in glucose utilization rate with positron emission tomography with [¹⁸F]fluorodeoxyglucose, were the main findings and were seen only in the patients with multiple system atrophy. Decreased glucose utilization (hypometabolism) was most prominent in the cerebellum, brainstem, striatum and frontal and motor cortices. These results indicate clear differences, using neuroimaging studies, between multiple system atrophy and pure autonomic failure.     

Sleep disorders in multiple system atrophy

Summary. Complaints about sleep disorders and excessive daytime sleepiness are common among patients with multiple system atrophy. The diffuse neurodegenerative process that encompasses the key structures involved in the regulation of the sleep/wake transition and respiratory function may account for these complaints and for the most frequent polysomnographic findings in MSA, i.e., sleep-related breathing disturbances and REM sleep behaviour disorder, which are both treatable conditions. Nocturnal stridor is an inspiratory sound produced by complex vocal cord muscle dysfunction. Often occurring with sleep apnoea, stridor is associated with decreased survival. REM sleep behaviour disorder, a parasomnia characterized by loss of normal skeletal muscle atonia during REM sleep with prominent motor activity, is detected in almost all patients. The pathophysiology of both disorders is partially elucidated but increasing evidence points to the role of basal ganglia dysfunction.     

Management of multiple system atrophy: state of the art

Summary. Multiple system atrophy (MSA) is a sporadic neurodegenerative disease of undetermined aetiology presenting with parkinsonian, autonomic, cerebellar, and pyramidal signs. Despite the lack of any effective therapy to reverse MSA, some of the symptoms may be improved with adequate symptomatic therapies. Medical treatment is largely aimed at mitigating the parkinsonian and autonomic features. The therapeutic results of levodopa therapy in cases of MSA are difficult to interpret because of their variability. Nevertheless, the simple statement that patients with MSA do not respond to levodopa is false. Clinical and pathologically proven series document levodopa efficacy in about 40-60% of patients with MSA and predominant parkinsonian features. Other antiparkinsonian compounds (dopamine agonists, amantadine) may also be employed, but they are not more effective than levodopa. Orthostatic hypotension (OH) can be suspected from the patient s history and subsequently documented in the clinic by measuring lying and standing blood pressure. The diagnosis ideally should be confirmed with additional laboratory tests to determine the cause and evaluate the functional deficit, so as to aid treatment. A number of pharmacological agents with different mechanisms of action have been used in MSA to reduce OH when this is symptomatic. OH can also be alleviated by avoiding aggravating factors, such as the effects of food, micturition, exposure to a warm environment, and physiological diurnal changes, and by using other non-pharmacological strategies. The treatment of the very common genitourinary symptoms (incontinence, retention, impotence) should also be considered in order to improve the quality of life of these patients.     

多系统萎缩的临床分型和影像学改变特点分析

目的探讨多系统萎缩（multiple system atrophy，MSA）的临床表现类型与神经影像学改变新特征（脑桥“十字征”和“壳核裂隙征”）的关系，为临床尽早做出诊断提供依据。方法按照Gilman诊断标准回顾性分析11例MSA患者的临床表现、分型和头颅MRI资料。结果本组诊断为很可能MSA11例，其中橄榄体脑桥小脑萎缩（MSA-C型）8例。2例在发病后3年头颅MRI脑桥“十字征”达Ⅰ期；1例在病后2年达Ⅱ期；3例分别在病后1年、3年、5年达Ⅲ期；另外2例分别在病后2年和7年达Ⅳ期。8例“壳核裂隙征”均为0期。黑质纹状体变性（MSA-P型）2例：1例病后6年脑桥“十字征”0期，“壳核裂隙征”Ⅰ期，另1例发病后9年“壳核裂隙征”Ⅱ期，脑桥“十字征”Ⅳ期。Shy-Drager综合征（MSA-A型）1例：病程5年，MRI检查脑桥“十字征”和“壳核裂隙征”分期均为0期。结论临床表现与头颅MRI检查发现的脑桥“十字征”和“壳核裂隙征”可作为及早识别MSA-C型的神经影像学改变特征，“壳核裂隙征”可作为识别MSA-P型的神经影像学改变特征。     

多系统萎缩患者的临床表现、MRI、肛门括约肌肌电图分析

目的分析多系统萎缩患者(MSA)临床表现、头部MRI、肛门括约肌肌电图改变特点,探讨它们在MSA诊断的价值。方法按Gilman诊断标准,回顾性分析46例MSA患者的临床资料、头部MRI及肛门括约肌肌电图检查结果。结果符合很可能MSA39例,可能MSA7例,其中MSA-A型24例,主要临床表现为自主神经功能障碍;MSA-C型16例,主要表现为小脑性共济失调;MSA-P型6例,主要表现为锥体外系症状。MRI显示部分MSA-A患者出现大脑皮质萎缩,小脑改变较轻;MSA-C型主要表现为延髓、脑桥、小脑萎缩;MSA-P主要病变在壳核和苍白球,而小脑、脑桥、延髓病变早期可以不明显。部分患者出现脑桥十字征和壳核裂隙征。36例患者做肛门括约肌肌电图检查,全部出现神经源性损害。结论 MSA早期诊断难度大,结合临床表现、头部MRI检查及肛门括约肌肌电图检查,可提高MSA的诊断准确率。     

Pain in multiple system atrophy

Pain is a recognized feature of idiopathic Parkinson’s disease (IPD) but has never been studied in multiple system atrophy (MSA), the commonest cause of atypical parkinsonism. We retrospectively analysed histories of pain in 100 consecutive cases of clinically probable MSA. Details were obtained from the medical records of 100 patients with MSA, comprising 82 with the striatonigral degeneration (SND) type and 18 with the olivopontocerebellar atrophy (OPCA) type of MSA. Pain was reported in 47% of the MSA patients. It was classified as rheumatic in 64% of MSA patients reporting pain, sensory in 28%, dystonic in 21%, and levodopa-related in 16%, mostly related to off-period or diphasic dystonias. There was a mixed pain syndrome in 19% of these patients. Pain was significantly more commonly reported by females (P=0.02), and by patients with levodopa-induced dyskinesias (P=0.02). No other clinical feature differentiated MSA patients who reported pain from those who did not. The mean delay between disease onset and onset of pain was 2.9 years, but pain was reported at the time of, or before, disease onset in about 30% of patients. The overall prevalence of pain in MSA was similar to that reported in IPD, but the distribution of pain categories was different.     

High-field-strength magnetic resonance imaging and SPECT of multiple system atrophy]

Two cases of multiple system atrophy (MSA) showing similar abnormalities by magnetic resonance (MR) imaging and SPECT are reported. The clinical diagnoses of the two cases were striatonigral degeneration (SND) and sporadic olivopontocerebellar atrophy (OPCA). In addition, one case of sporadic OPCA without parkinsonism was used for comparison. The MR images were obtained using a 1.5-T MR system and included spin-echo transverse sections with T1-weighted images (TR = 450 ms and TE = 15 ms) and T2-weighted images (TR = 2500 ms and TE = 90 ms). The T1-weighted images demonstrated atrophy of cerebellum and pons, with increased signal intensity in the bilateral putamen. The T2-weighted images demonstrated decreased signal intensity in the putamen, as reported recently. SPECT demonstrated reduced uptake in the celleberum, basal ganglia and frontal lobe cortex. The putaminal changes evident on T1-weighted images may have resulted from deposition of pigments such as neuromelanin and lipofuscin, related to parkinsonism. Both T1- and T2-weighted MRI seem to be useful clinical diagnosis of MSA.     

Three Years On Clomipramine: Before and After Brain SPECT Study

A case is presented of a patient diagnosed with attention deficit disorder, obsessive thinking, anger outbursts, and depression who had a SPECT study prior to treatment and after 3 years of treatment on clomipramine. The follow-up SPECT study showed marked improvement overall in the cerebral perfusion of the brain. At rest marked overactivity was noted in the anterior medial aspects of the frontal lobes, along with patchy (increased and decreased) uptake throughout the cortical and subcortical areas of the brain. After treatment for 3 years on clomipramine at 225 mg a day, the follow-up SPECT study revealed a normalization of activity in the anterior medial aspects of the frontal lobes as well as no patchy uptake cortically and subcortically as noted in the study prior to treatment. The clinical usefulness of the SPECT study as it relates to this case is discussed.     

Statistical parametric mapping demonstrates asymmetric uptake with Tc-99m ECD and Tc-99m HMPAO SPECT in normal brain

Tc-99m ethyl cysteinate diethylester (ECD) and Tc-99m hexamethyl propylene amine oxime (HMPAO) are commonly used for single-photon emission computed tomography (SPECT) studies of a variety of neurologic disorders. Although these tracers have been very helpful in diagnosing and guiding treatment of neurologic disease, data describing the distribution and laterality of these tracers in normal resting brain are limited. Advances in quantitative functional imaging have demonstrated the value of using resting studies from control populations as a baseline to account for physiologic fluctuations in cerebral perfusion. Here, we report results from 30 resting Tc-99m ECD SPECT scans and 14 resting Tc-99m HMPAO scans of normal volunteers with no history of neurologic disease. Scans were analyzed with regions of interest and with statistical parametric mapping, with comparisons performed laterally (left vs. right), as well as for age, gender, and handedness. The results show regions of significant asymmetry in the normal controls affecting widespread areas in the cerebral hemispheres, but most marked in superior parietotemporal region and frontal lobes. The results have important implications for the use of normal control SPECT images in the evaluation of patients with neurologic disease.     

Multiple system atrophy masking multiple sclerosis

Multiple system atrophy (MSA) and multiple sclerosis (MS) are progressive neurological disorders with overlapping clinical signs and symptoms. However, due to the course of the disease and the age of onset both disorders are rarely differential diagnosis for each other. We here report the remarkable association of the two diseases in one patient. As MSA dominated the clinical presentation, diagnosis and therapy of MS were delayed. We discuss the clinical symptoms in our patient and highlight the features that allow to differentiate both diseases.     

Magnetic resonance imaging distinguishes progressive supranuclear palsy from multiple system atrophy

Summary. To establish diagnostic magnetic resonance imaging (MRI) criteria for differentiating progressive supranuclear palsy (PSP) from multiple system atrophy (MSA), magnetic resonance images from eight patients with probable PSP, 30 with probable MSA {nine striatonigral degeneration (MSA-P) and 21 olivopontocerebellar atrophy (MSA-C)}, and ten age-matched controls were retrospectively studied. Anteroposterior diameters in the midline sagittal T1-weighted image of the rostral (RMT) and caudal midbrain tegmentum (CMT), caudal pons and medulla were measured. Divergence of the red nuclei (RN) in the axial T2-weighted image was judged. All PSP images had a smaller RMT diameter than the lower limit of the normal range, showed RN divergence, and had a pontine diameter within the normal range. All MSA images had a CMT diameter within the normal range; no MSA images showed divergence of RN. Forty-four percent (4/9) of MSA-P and 76% (16/21) of MSA-C images had a pontine diameter smaller than the lower limit of the normal range. On basis of the results, we propose MRI diagnostic criteria for differentiating PSP from MSA. Received March 23, 2000; accepted June 7, 2000     

磁共振脑径线测量对多系统萎缩的诊断价值

目的 研究磁共振脑径线测量对于多系统萎缩(MSA)的诊断价值.方法 11例MSA患者,可能MSA 2例,拟诊MSA 9例.其中以帕金森综合征为主要表现(MSA-P)5例,以小脑性共济失调为主要表现(MSA-C)6例.健康对照组6名,病例对照组9例(帕金森病1例、其他类型的帕金森综合征8例).选取反映脑干、小脑和基底节形态学的径线进行测量,计算全脑三维体积,比较各项参数的组间差异.结果 MSA组的脑桥横径(mm,下同)明显短于健康对照组和病例对照组(27.6±2.0、30.5±0.6、29.9±1.1),MSA患者的四脑室前后径(11.9±2.8)明显长于健康对照(9.0±2.1).MSA-C组的脑桥横径明显短于健康对照组和病例对照组(27.2±2.1、30.5±0.6、29.9±1.1).MSA-C患者的四脑室前后径和横径(12.8±2.6和9.0±2.1)明显长于健康对照(17.3±2.1和13.8±1.7).MSA-P患者的脑桥横径较健康对照组短(28.2±1.8、30.5±0.6).MSA-P患者的苍白球最长径(23.7±5.0)和红核直径(6.6±0.8)明显较MSA-C患者(29.7±2.4和8.2±0.4)短.MSA-C患者的第四脑室横径较MSA-P患者宽(17.3±2.1、12.6±2.7),小脑中脚宽度较MSA-P患者缩短(13.3±1.9、15.8±1.2).结论 磁共振脑体积径线测量对于MSA患者脑组织局部萎缩的程度提供了量化的手段.脑桥的横径缩短可以客观地反映MSA患者脑桥的萎缩,但不能用于区分MSA-P和MSA-C.MSA-C患者更易出现第四脑室的扩大和MCP的萎缩,MSA-P患者更易出现红核萎缩.     

多系统萎缩患者143例临床和影像学特征分析

目的 探讨多系统萎缩(MSA)不同亚型的临床和影像学特征及其相关性.方法 对143例符合1999年Gilman诊断标准的MSA患者进行临床分型和诊断分级,根据Horimoto分期对108例影像学出现异常的患者脑桥十字征和壳核裂隙征进行分析,并探讨不同临床亚型及病程与影像学异常的相关性.结果 143例MSA患者男女比例为1.3:1,其中MSA小脑萎缩型(MSA-C)93例,MSA帕金森型(MSA-P)39例,两者同时出现的即为MSA-P+C型11例;很可能的MSA 90例,可能的MSA 53例.108例MSA患者影像学出现异常,其中MSA-C型患者36例(36/76,47%)出现脑桥十字征,10例(10/76,13%)出现壳核裂隙征;MSA-P型患者6例(6/24,25%)出现脑桥十字征,6例(6/24,25%)出现壳核裂隙征.MSA-C型中病程较短的患者脑桥十字征分期较早.结论 本组病例中MSA-C型患者明显多于MSA-P型,可能与种族遗传背景有关.脑桥十字征和壳核裂隙征为MSA患者的显著影像学特征,MSA临床分型与影像学特征具有一定的相关性,其中脑桥十字征在MSA-C型较为显著,壳核裂隙征在MSA-P型较为显著.     

Subcortical atrophy and perfusion patterns in Parkinson disease and multiple system atrophy

BackgroundThe clinical differentiation between Parkinson disease (PD) and multiple system atrophy (MSA) is difficult.ObjectivesArterial spin labeling (ASL) is an advanced MRI technique that obviates the use of an exogenous contrast agent for the estimation of cerebral perfusion. We explored the value of ASL in combination with structural MRI for the differentiation between PD and MSA.MethodsNinety-four subjects (30 PD, 30 MSA and 34 healthy controls) performed a morphometric and ASL-MRI to measure volume and perfusion values within basal ganglia and cerebellum. A region-of-interest analysis was performed to test for structural atrophy and regional blood flow differences between groups.ResultsMSA patients showed higher subcortical atrophy than both PD patients and HC, while no differences were observed between the latter. MSA and PD showed lower volume-corrected perfusion values than HC in several cerebellar areas (Crus I, Crus II, right VIIb, right VIIIa, right VIIIb), right caudate and both thalami. MSA and PD patients displayed similar perfusion values in all aforementioned areas, but the right cerebellar area VIIIb (lower in MSA) and right caudate and both thalami (lower in PD). Similar results were obtained when comparing PD and MSA patients with the parkinsonian variant.ConclusionsA perfusion reduction was equally observed in both MSA and PD patients in cerebellar areas that are putatively linked to cognitive (i.e., executive) rather than motor functions. The observed hypo-perfusion could not be explained by atrophy, suggesting the involvement of the cerebellum in the pathophysiology of both MSA and PD.     

Subtraction brain SPECT imaging in a patient with gait ignition failure.

The precise anatomical location and pathophysiology of gait ignition failure (GIF) is poorly understood. We investigated the cerebral perfusion patterns using subtraction brain single photon emission computed tomography (SPECT) in a patient with GIF. Subtraction brain SPECT imaging revealed an increased activity in the region of right ventrolateral midbrain and ventral medulla.