Multiple system atrophy (MSA) is an adult-onset, rare, and progressive neurodegenerative disorder characterized by a varying combination of autonomic failure, cerebellar ataxia, and parkinsonism. MSA is categorized as MSA-P with predominant parkinsonism, and as MSA-C with predominant cerebellar features. The prevalence of MSA has been reported to be between 1.86 and 4.9 cases per 100,000 individuals. In contrast, approximately 1% of the population is affected by schizophrenia during their lifetime; therefore, MSA-P comorbidity is very rare in schizophrenic patients. However, when the exacerbation or progression of parkinsonism occurs in patients with schizophrenia treated with antipsychotics, it is necessary to consider rare neurodegenerative disorders, including MSA-P, in the differential diagnosis of parkinsonism.
A 60-year-old female patient with chronic schizophrenia developed possible MSA-P. She had been treated mainly with typical antipsychotics, and presented with urinary incontinence, nocturnal polyuria, and dysarthria around 2011. In 2014, she developed worsening parkinsonian symptoms and autonomic dysfunction. Although her antipsychotic medication was switched to an atypical antipsychotic and the dose reduced, her parkinsonism was not improved. In 2015, modified electroconvulsive therapy produced slight improvements in the symptoms; however, she shortly returned to her symptomatic state. A combination of cardiac 123I-meta-iodobenzylguanidine scintigraphy and 123I-FP-CIT single-photon emission computed tomography imaging, in addition to brain magnetic resonance imaging findings, helped to discriminate MSA-P from other sources of parkinsonism. L-dopa had been prescribed, but she responded poorly and died in the spring of 2016.
This case report highlights the importance of considering MSA-P in the differential diagnosis for parkinsonism in a patient being treated with antipsychotics for chronic schizophrenia. MSA-P should be considered in patients presenting with worsening and progressing parkinsonism, especially when accompanied by autonomic dysfunction or cerebellar ataxia. Although a definite diagnosis of MSA-P requires autopsy confirmation, a combination of brain magnetic resonance imaging and nuclear medicine scans may help to differentiate suspected MSA-P from the other parkinsonian syndromes. This case also demonstrates that MSA with parkinsonism that is poorly responsive to L-dopa may improve shortly after modified electroconvulsive therapy without worsening psychiatric symptoms.