Systematrophie

Systematrophie, commonly referred to in English as multiple system atrophy (MSA), is a rare neurodegenerative disorder characterized by progressive autonomic failure combined with motor dysfunction. It can present with parkinsonism, cerebellar ataxia, or a combination of both.

Forms and features: The two main clinical variants are MSA-P, which resembles Parkinson’s disease with bradykinesia and rigidity, and MSA-C, which is dominated by cerebellar ataxia such as gait instability and limb incoordination. Autonomic symptoms often appear early and may include orthostatic hypotension, urinary incontinence, constipation, and erectile dysfunction. Parkinsonian features in MSA respond poorly to levodopa compared with typical Parkinson’s disease, and cerebellar signs may be prominent in MSA-C.

Pathology and pathophysiology: Pathologically, MSA is characterized by glial cytoplasmic inclusions containing alpha-synuclein, with degeneration affecting multiple systems including the striatonigral pathway, olivopontocerebellar regions, and autonomic circuits. The disease is considered a synucleinopathy.

Diagnosis: Diagnosis is clinical and supported by imaging and autonomic testing. MRI may show putaminal atrophy with a hyperintense rim on T2-weighted images and the pontine “hot cross bun” sign. DaT-SPECT (dopamine transporter imaging) can indicate presynaptic dopaminergic deficit but does not reliably distinguish MSA from other parkinsonian disorders.

Treatment and prognosis: There is no disease-modifying therapy. Management is symptomatic and multidisciplinary, including dopaminergic medication with variable benefit, strategies for orthostatic hypotension, physical and speech therapy, and treatment of constipation and sleep disturbances. The condition typically follows a progressive course, with median survival of about 6–10 years after onset. Epidemiology shows it as a rare disorder, with incidence estimated at a few per 100,000 people and a slight male predominance in some studies.