Case Presentation: A 70-year-old gentleman with no known medical issues was brought in to the emergency department after experiencing sudden onset unresponsiveness and respiratory arrest. He had been intubated by paramedics on arrival.
Upon transfer to the emergency department, he was found to have unstable atrial fibrillation with rapid ventricular response necessitating cardioversion. Initial labs were largely unremarkable and his CPK level was 152. While the patient was stabilized on initial presentation, all attempts at extubation during his hospitalization were unsuccessful. Physical examination was notable for a resting tremor, cogwheel rigidity, dysarthria, and multi-directional nystagmus. However muscular weakness in the extremities was only mild, with all limbs described as 4/5 to 5/5 strength.
History from the patient’s wife revealed that the patient over the past 4 years had progressive weakness requiring the use of a walker or wheelchair. He had also developed a pill-rolling tremor, dysarthria, imbalance, recurrent falls and intermittent urinary retention over the past few months. His wife said he had become homebound. The patient had a neurological evaluation three years previously with magnetic resonance imaging of the brain showing no significant findings. During that time, Carbidopa-Levodopa was trialed for suspicion of Parkinson’s disease with no relief of symptoms.
On review of his past MRI, no acute cerebrovascular process or focal lesions were evident; however, our neurology team noted notable olivopontocerebellar atrophy which was out of proportion to global volume loss, which are findings consistent with multiple system atrophy. After extensive discussion with the patient and his family, the patient ultimately decided against tracheostomy and wished for comfort measures only with terminal extubation.
Discussion: Multiple system atrophy (MSA) is a rare, progressive neurodegenerative condition which affects the central nervous system by causing accumulation of alpha-synuclein protein in the cytoplasm of oligodendrocytes. MSA often presents with signs of Parkinsonism that are resistant to Carbidopa-Levodopa. The condition is often classified as one of the Parkinson-plus syndromes, and is divided into three different subtypes: olivopontocerebellar atrophy, striatonigral degeneration, or a mixed subtype. Mixed MSA such as seen in our patient presents with autonomic dysfunction, progressive muscle weakness and Parkinsonian manifestations.
Our patient’s initial presentation with sudden respiratory muscle compromise is usually a consequence of late stages of the disease rather than initial presentation, however the patient had a reported progressive decline in his status prior to this event. To date, no effective disease-modifying therapies are available for MSA and the treatment is supportive. The survival rate is around 50% six years after disease onset. Therefore recognition of the disease is critical for timely discussion of goals of care.
Conclusions: MSA may resemble Parkinson’s disease with tremors and motor slowing as well as signs of cerebellar and autonomic dysfunction. MSA presents a complex diagnostic challenge given both the rarity of the condition as well as shared features of other neurological conditions. The prognosis is generally poor and treatment is limited to supportive management.