Multiple System Atrophy (MSA) is a rare, progressive neurodegenerative disorder that impacts the body’s involuntary functions and movement. It is characterized by the degeneration of nerve cells in several brain regions, including the basal ganglia, inferior olivary nucleus, and cerebellum. MSA is considered uncommon, affecting an estimated 15,000 to 50,000 Americans, and typically manifests in individuals in their 50s or 60s. This condition affects both men and women, with symptoms advancing over five to ten years.
The Two Subtypes and Their Symptoms
Multiple System Atrophy presents primarily in two forms, categorized by the most noticeable symptoms at diagnosis. The Parkinsonian type, known as MSA-P, exhibits symptoms resembling Parkinson’s disease, such as slow movement (bradykinesia), muscle rigidity, and tremors. Individuals with MSA-P may also experience issues with balance and coordination, along with a hunched posture and muffled speech. These motor symptoms often begin on one side of the body before affecting both.
The Cerebellar type, or MSA-C, is characterized by problems with balance and coordination, collectively termed ataxia. People with MSA-C may experience slurred speech (dysarthria), difficulty swallowing (dysphagia), and abnormal eye movements. Walking can become challenging, with an unsteady gait, and patients might drop objects or struggle with fine motor tasks like buttoning clothes.
Regardless of the predominant motor subtype, nearly all individuals with MSA develop severe problems with their autonomic nervous system, which controls automatic bodily functions. A common autonomic symptom is orthostatic hypotension, a sharp drop in blood pressure upon standing, leading to dizziness or fainting. Other widespread autonomic issues include bladder control problems, such as urinary urgency, frequent urination, or incomplete emptying, and bowel dysfunction like constipation. Additionally, patients may experience sexual dysfunction, reduced sweating, or difficulties regulating body temperature.
Understanding the Cause
The characteristic feature of MSA in the brain is the abnormal accumulation of a protein called alpha-synuclein within glial cells. Glial cells are specialized cells that support nerve cells, and this protein buildup forms clumps known as glial cytoplasmic inclusions (GCIs). While these inclusions are a distinguishing pathological marker for MSA, the precise reason this protein aggregation begins is not yet fully understood.
MSA is largely considered a sporadic disorder, meaning it typically occurs randomly and is not inherited. Although some genetic variations (e.g., SNCA, COQ2) have been studied as potential risk factors in specific populations, their definitive role as direct causes is not confirmed.
The Diagnostic Process
Diagnosing Multiple System Atrophy can be challenging, as there is no single test that definitively confirms the condition in living individuals. Instead, neurologists rely on a thorough clinical assessment, considering the combination of symptoms, their progression, and response to treatments, while ruling out other conditions like Parkinson’s disease.
Key clues that help differentiate MSA from other disorders include a poor or transient response to levodopa, a medication commonly used for Parkinson’s disease, and the early onset of severe autonomic symptoms. While Parkinson’s disease typically sees autonomic issues develop over many years, in MSA, these problems can appear within a year of motor symptom onset. Autonomic testing, such as blood pressure and heart rate monitoring, can detect significant drops in blood pressure when changing positions, which supports an MSA diagnosis.
Brain imaging, such as Magnetic Resonance Imaging (MRI), can sometimes show characteristic signs that support an MSA diagnosis, although these findings are not always present in early stages. For instance, individuals with MSA-C may exhibit atrophy in the pons and cerebellum, and a specific pattern called the “hot cross bun sign” can be seen on axial T2-weighted MRI images of the pons. This sign represents degeneration of specific fiber tracts in the brainstem and can be seen in other neurological conditions.
Managing the Condition
There is currently no cure for Multiple System Atrophy, so all treatments focus on managing symptoms and improving the individual’s quality of life. Management strategies are tailored to address the specific problems experienced by each patient. For orthostatic hypotension, medications like fludrocortisone or droxidopa can be prescribed to help raise blood pressure. Non-pharmacological approaches, such as increasing salt and fluid intake, wearing compression stockings, and elevating the head of the bed, also play an important role.
Motor symptoms, such as rigidity and slow movement, may be managed with medications like levodopa, which is used in Parkinson’s disease. However, the response to these medications in MSA is often less pronounced and can diminish over time compared to Parkinson’s disease. Other medications may be used to address specific issues like urinary incontinence or erectile dysfunction.
A multidisciplinary care team is often involved in managing MSA, encompassing a range of specialists to address the diverse symptoms. Physical therapy helps with mobility, balance, and gait, aiming to prevent falls and maintain independence. Occupational therapy assists with daily living activities, adapting tasks to compensate for physical limitations. Speech therapy addresses difficulties with communication and swallowing, helping to reduce the risk of aspiration pneumonia.