Multiple System Atrophy (MSA)
by André Delacourte
Multiple system atrophy (MSA) is a progressive disorder of the central and sympathetic nervous systems. The disorder is characterized by postural (or orthostatic) hypotension (an excessive drop in blood pressure when the patient stands up), which causes dizziness or momentary blackouts. MSA does not provoke dementia but could impair some cognitive functions.
Shy-Drager syndrome, olivopontocerebellar atrophy (OPCA), striatonigral degeneration
Symptoms and course
MSA has been classified clinically into three types, olivopontocerebellar atrophy (OPCA), which primarily affects balance, coordination, and speech; a parkinsonian form (striatonigral degeneration), which can resemble Parkinson's disease because of slow movement and stiff muscles; and a mixed cerebellar and parkinsonian form. In all three forms of MSA, the patient can have orthostatic hypotension.Orthostatic hypotension and symptoms of autonomic failure such as constipation, impotence in men, and urinary incontinence usually predominate early in the course of the disease. Constipation may be unrelenting and hard to manage.
Shy-Drager syndrome may be difficult to diagnose in the early stages. For the majority of patients, blood pressure is low when the patients stand up and high when the patients lie down. Other symptoms that may develop include impaired speech, difficulties with breathing and swallowing, and inability to sweat.Shy-Drager syndrome usually ends in the patient’s death by 7 to 10 years after diagnosis. Breathing problems such as aspiration, stridor (high-pitched breathing sounds due to airway obstruction), or cardiopulmonary arrest are common causes of death.
Causes and risk factors
Neurodegeneration in subcortical nuclei is mainly affecting oligodendrocytes. A simultaneous synucleopathy and tauopathy is observed.
The average annual incidence rate (new cases per 100,000 person-years) for ages 50 to 99 years is 3.0 for MSA (Bower 1997).
The age-adjusted prevalence for MSA is 4.4 per 100,000 (two probable and two possible cases)(Schrag, 1999).
NEUROPATHOLOGY Argyrophilic intracytoplasmic inclusions in oligodendrocytes (AGCIs) are widespread, not only in the olivopontocerebellar and striatonigral systems but also among fibers connecting their affecting lesions of MSA. Synuclein and tau proteins accumulate in AGCIs.
The diagnosis is mainly based on the specific clinical manifestations (postural or orthostatic) hypotension , rigidity, balance, coordination, impaired speech, excessive drop in blood pressure, and in general autonomic/urogenital failure. (Wenning G.k. - 2003) MRI can help to precise the diagnosis (Yekhlef F – 2003).
Care and treatment
Orthostatic hypotension in Shy-Drager syndrome is treatable, but there is not known effective treatment for the progression central nervous system degeneration.
The general treatment course is aimed at controlling symptoms. Antiparkinsonian medication, such as L-dopa, may be helpful. To relieve low blood pressure while standing, dietary increases of salt and fluid may be beneficial. Medications to elevate blood pressure, such as salt-retaining steroids, are often necessary, but they can cause side effects and should be carefully monitored by a physician.
Alpha-adrenergic medications, non-steroidal anti-inflammatory drugs, and sympathomimetic amines are sometimes used. Sleeping in a head-up position at night reduces morning orthostatic hypotension. An artificial feeding tube or breathing tube may be surgically inserted for management of swallowing and breathing difficulties.
The Multiple System Atrophy Trust
Southbank House, Black Prince Road
London, SE1 7SJ
Tel: (44) 207 940 4666
- Bower, J. H., D. M. Maraganore, et al. (1997). Incidence of progressive supranuclear palsy and multiple system atrophy in Olmsted County, Minnesota, 1976 to 1990. Neurology 49(5): 1284-8.
- Litvan, I., C. G. Goetz, et al. (1997). What is the accuracy of the clinical diagnosis of multiple system atrophy? A clinicopathologic study. Arch Neurol 54(8): 937-44.
- Schrag, A., Y. Ben-Shlomo, et al. (1999). Prevalence of progressive supranuclear palsy and multiple system atrophy: a cross-sectional study. Lancet 354(9192): 1771-5.
- Swan, L. and J. Dupont (1999). Multiple system atrophy. Phys Ther 79(5): 488-94.
- Wenning, G. K., K. Seppi, et al. (2002). A novel grading scale for striatonigral degeneration (multiple system atrophy). J Neural Transm 109(3): 307-20.
- Wenning G. K., Geser F., Stampfer-Kountchev M. and Tison F. (2003) Multiple system atrophy: an update. Mov Disord 18 Suppl 6, S34-42.
- Yekhlef F., Ballan G., Macia F., Delmer O., Sourgen C. and Tison F. (2003) Routine MRI for the differential diagnosis of Parkinson's disease, MSA, PSP, and CBD. J Neural Transm 110, 151-169.
Last Updated: vendredi 09 octobre 2009