Multiple system atrophy (MSA) is a rare, progressive neurodegenerative disorder that involves the gradual loss of nerve cells in specific brain areas, affecting both movement and the body’s involuntary functions. MSA begins to show symptoms in adulthood, most often when individuals are in their 50s or 60s. The disorder’s effects on the nervous system lead to a combination of issues impacting balance, muscle control, and autonomic processes like blood pressure regulation.
Symptoms and Types of MSA
The clinical presentation of multiple system atrophy involves three main categories of symptoms. A prominent feature is autonomic dysfunction, which is the malfunction of the body’s automatic processes. This frequently results in orthostatic hypotension, a sharp drop in blood pressure upon standing that can cause dizziness or fainting. Bladder control problems, such as urinary urgency or incontinence, and severe constipation are also common manifestations of this autonomic failure.
Another group of symptoms is parkinsonism, which resembles those seen in Parkinson’s disease. These include slowed movement (bradykinesia) and muscle rigidity, which can cause trouble bending limbs and issues with posture. While tremors can occur, they are often different from the typical resting tremor associated with Parkinson’s disease.
The third symptom category is cerebellar ataxia, stemming from damage to the cerebellum, a part of the brain that coordinates voluntary movements. This leads to a loss of muscle coordination, making walking and maintaining balance difficult. Speech may become slurred, slow, or soft, a condition called dysarthria. Some individuals also experience changes in vision, such as blurriness or difficulty focusing.
Based on which symptoms are most dominant at diagnosis, MSA is classified into two main types. The parkinsonian type (MSA-P) is the more common form, where symptoms like muscle stiffness and slow movement are primary. The cerebellar type (MSA-C) is characterized by problems with coordination, gait, and balance. Most individuals will eventually develop a mixture of parkinsonian, cerebellar, and autonomic symptoms as the disease progresses.
The Diagnostic Process
Diagnosing multiple system atrophy is challenging because no single test can definitively confirm the condition in a living person. The process relies on a clinical evaluation by a neurologist, who assesses the combination of symptoms. A common difficulty is that the early signs of MSA, particularly parkinsonian symptoms, can be mistaken for those of Parkinson’s disease, leading to an initial misdiagnosis.
To support a diagnosis and exclude other neurological conditions, physicians use several diagnostic tools. A neurological examination evaluates motor skills, balance, reflexes, and autonomic functions. Specific tests for autonomic dysfunction, such as the tilt-table test, can provide objective evidence of orthostatic hypotension by measuring blood pressure and heart rate responses to changes in body position.
Brain imaging, particularly Magnetic Resonance Imaging (MRI), plays a role in the diagnostic process. While an MRI cannot directly visualize MSA, it can reveal certain characteristic changes in the brain that are suggestive of the disease. For instance, in some individuals with MSA-C, an MRI may show a “hot cross bun” sign, which reflects atrophy in a part of the brainstem called the pons. The imaging also helps rule out other potential causes of the symptoms.
A definitive diagnosis of MSA can only be achieved through a post-mortem examination of brain tissue. This examination looks for the specific pathological hallmarks of the disease. The combination of clinical findings and supportive tests allows for a probable diagnosis while the person is alive.
Underlying Causes and Brain Changes
The underlying cause of multiple system atrophy is the abnormal accumulation of a protein called alpha-synuclein within the brain. This protein misfolds and clumps together inside specific brain cells. Unlike in Parkinson’s disease where these clumps are primarily in neurons, in MSA they are found in glial cells, specifically the oligodendrocytes that support and insulate nerve cells.
These protein aggregates form structures known as glial cytoplasmic inclusions (GCIs), which are the pathological signature of MSA. These inclusions disrupt the normal function of the glial cells, which in turn leads to the degeneration and death of nerve cells. The affected regions include the basal ganglia, cerebellum, and brainstem.
The precise trigger that initiates the misfolding and accumulation of alpha-synuclein remains unknown. Research has not identified a clear genetic link for the vast majority of cases. MSA is considered a sporadic disorder, meaning it occurs randomly in the population without a pattern of inheritance and is not typically passed down from a parent to a child.
Managing Symptoms and Prognosis
As there is no cure for multiple system atrophy or any treatment that can halt its progression, medical care focuses on managing symptoms to enhance quality of life. The approach to management is tailored to the individual’s specific set of symptoms and often requires a multidisciplinary team of healthcare professionals.
For the parkinsonian symptoms of slowness and rigidity, medications like Levodopa may be tried. However, the response in MSA is often limited and not as sustained as it is in Parkinson’s disease. Managing orthostatic hypotension is a primary component of care and involves non-pharmacological methods first, such as increasing salt and fluid intake, wearing compression stockings, and learning to change positions slowly.
Physical, occupational, and speech therapies are important for maintaining function and safety. Physical therapy can help with mobility and balance, while occupational therapy can assist in finding new ways to perform daily activities. Speech therapy can address difficulties with swallowing (dysphagia) and changes in speech to improve communication.
Multiple system atrophy is a progressive condition, and symptoms worsen over time, though the rate of progression can differ from one person to another. After the onset of symptoms, the average life expectancy is approximately 10 years, but this varies. The disease leads to disability, eventually requiring assistance with most daily activities and increasing the risk of complications like falls and respiratory infections.