multiple system atrophy

1. MULTIPLE SYSTEM ATROPHY

2. The term Multiple System Atrophy(MSA) was introduced by graham and oppenheimer (1969) Patients with this neurologic syndrome are characterized by parkinsonism, cerebellar ataxia, and autonomic failure. The disorder was previously known as striatonigral degeneration, sporadic olivopontocerebellar atrophy, and Shy-Drager syndrome. Prominent autonomic failure, including OH, neurogenic bladder is a characteristic feature of MSA. The presence of autonomic failure is a required clinical criterion for the diagnosis of MSA.

3. Prevalence of MSA range from 1.9 to 4.9 per 100.000 in the population(32,147). The annual incidence of MSA was estimated to be about 0.6 cases per 100.000 persons or 3.0/100.000 people over the age of 50 years. MSA is regarded as a sporadic disease. MSA has two phenotypes: parkinsonian (MSA-P) and cerebellar (MSA-C). MSA-P presents with progressive bradykinesia, rigidity, postural instability, and a peculiar dysarthria with quivering high-pitched speech, jerky postural tremor, and, much less commonly, tremor at rest.

4. MSA-C presents with gait and limb ataxia, scanning speech, and cerebellaroculomotor disturbances Autonomic failure is widespread in patients with MSA and affects the control of blood pressure and heart rate, automatic respiration, sleep, and endocrine function as well as bladder and gastrointestinal motility. MSA is characterized neuropathologically by cytoplasmic inclusions in oligodendroglial cells and the absence of Lewy bodies. Oligodendroglial cells responsible for producing the myelin sheath that wraps around neurons in the central nervous system.

5. In patients with MSA, the accumulation of GSIs in the basal ganglia, cortex, and spinal cord oligodendroglial cells leads to the death of adjacent neurons that depend on these glial cells for their survival. Parkinsonism is the predominant motor abnormality in most cases of MSA (i.e., MSA-P), and the striatonigral system is the main site of pathology. Autonomic failure in MSA is primarily due to degeneration of autonomic neurons in the central nervous system.

6. Many patients with MSA have hypertension when they are supine, as well as impaired circadian variation of arterial pressure and impaired reflex release of argininevasopressin(AVP) in response to hemodynamic stimuli. In patients with MSA, respiratory abnormalities including laryngeal stridor (158,193), sleep apnea, and respiratory dysrhythmia are common and can be life-threatening Laryngeal stridor has been attributed to laryngeal abductor palsy.