Multiple system atrophy | L’atrophie multisystématisée
Article in French
Multiple system atrophy (MSA) is a sporadic neurodegenerative disorder of unknown
etiology. It is the most frequent disorder among atypical parkinsonism with an
estimated prevalence of 2 to 5 per 100 000 inhabitants. The clinical symptoms are
rapidly progressing with a mean survival ranging between 6 to 9 years. The
diagnosis is based on consensus criteria that have been revised in 2008. The
diagnostic criteria allow defining “possible”, “probable” and “definite” MSA. The
latter requires post mortem confirmation of striatonigral and
olivopontocerebellar degeneration with alpha-synuclein containing glial
cytoplasmic inclusions. The diagnosis of “possible” and “probable” MSA is based
on the variable presence and severity of parkinsonism, cerebellar dysfunction,
autonomic failure and pyramidal signs. According to the revised criteria, atrophy
of putamen, pons, middle cerebellar peduncle (MCP) or cerebellum on brain
magnetic resonance imaging are considered to be additional features for the
diagnosis of “possible” MSA. T2-weighted brain imaging may further reveal a
putaminal hypointensity, a hyperintense lateral putaminal rim, the so called “hot
cross bun sign” and MCP hyperintensities. Cardiovascular examination, urodynamic
testing and anal sphincter electromyography may be helpful for the diagnosis of
autonomic failure. Some patients may respond to levodopa, but usually to a lesser
extent than those suffering from Parkinson’s disease, and high doses are already
required in early disease stages. No specific therapy is available for cerebellar
dysfunction, while effective treatments exist for urinary and cardiovascular
autonomic failure. Physical therapy may help to improve the difficulties of gait
and stance, and to prevent their complications. In later disease stages, speech
therapy becomes necessary for the treatment of dysarthria and dysphagia.
Percutaneous gastrostomy is sometimes necessary in patients with severe
dysphagia. Beyond these strategies, psychological support, social care and
occupational therapy to adapt the environment to the patient’s disability are
prerequisites for improving the quality of life in MSA patients.