Multiple system atrophy
1 . General outline
Multiple system atrophy (MSA) with postural hypotension, also called Shy-Drager
syndrome, 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 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.
Parkinsoninan-like mild cognitive impairment can be observed, but no dementia.
2) Synonyms: Shy-Drager syndrome, olivopontocerebellar atrophy, striatonigral
3 . Course :
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.
3. CAUSES AND RISK FACTORS :
Neurodegeneration in subcortical nuclei is mainly affecting oligodendrocytes.
A simultaneous synucleopathy and tauopathy is observed.
4. EPIDEMILOGICAL DATA :
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.
6. 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.
What is the prognosis?
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.
10. Further reading
Gilman et al, J.Neurol.Sci, 1999, 163:94-98
EMSA-SG The European Multiple System
Atrophy Study Group