|
|
|
|
Multiple system atrophy
|
| |
|
| |
Multiple system atrophy (MSA) is a rare, degenerative neurological disorder. MSA is associated with the degeneration of nerve cells in specific areas of the brain. This cell degeneration causes problems with movement, balance and autonomic functions of the body such as bladder control. The cause of MSA is unknown and no specific risk factors have been identified. Around 55% of cases occur in men, with typical age of onset in the late 50s to early 60s.
The overall prevalence of MSA is estimated at 4.6 cases per 100,000 people.
is characterized by a combination of the following:
When autonomic failure predominates, the term Shy-Drager syndrome is often used, although this term is no longer current, given the recent terminology changes which are explained below.
most common first sign of MSA is the appearance of an "akinetic-rigid syndrome" (i.e.
Discussion
Ask a question about 'Multiple system atrophy' Start a new discussion about 'Multiple system atrophy' Answer questions from other users |
Encyclopedia
Multiple system atrophy (MSA) is a rare, degenerative neurological disorder. MSA is associated with the degeneration of nerve cells in specific areas of the brain. This cell degeneration causes problems with movement, balance and autonomic functions of the body such as bladder control. The cause of MSA is unknown and no specific risk factors have been identified. Around 55% of cases occur in men, with typical age of onset in the late 50s to early 60s.
The overall prevalence of MSA is estimated at 4.6 cases per 100,000 people.
Presentation
MSA is characterized by a combination of the following:
- Progressive damage to the autonomic nervous system, commonly leading to low blood pressure when standing (postural hypotension), incontinence, difficulty urinating (dysuria), and/or abnormal breathing during sleep
- Muscle rigidity +/ tremor and slow movement (Parkinsonism)
- Poor coordination / unsteady walking (ataxia)
When autonomic failure predominates, the term Shy-Drager syndrome is often used, although this term is no longer current, given the recent terminology changes which are explained below.
Symptoms
The most common first sign of MSA is the appearance of an "akinetic-rigid syndrome" (i.e. slowness of initation of movement resembling Parkinson's disease) found in 62% at first presentation. Other common signs at onset include problems with balance (found in 22%), followed by genito-urinary problems (9%). For men, the first sign can be erectile dysfunction (unable to achieve or sustain an erection). Both men and women often experience problems with their bladders including urgency, frequency, incomplete bladder emptying or an inability to pass urine (retention). About 1 in 5 MSA patients will suffer a fall in their first year of disease.
As the disease progresses three groups of symptoms predominate. These are:
- parkinsonism (slow, stiff movement, writing becomes small and spidery)
- cerebellar dysfunction (difficulty coordinating movement and balance)
- autonomic dysfunction (impaired automatic body functions) including:
- — postural or orthostatic hypotension, resulting in dizziness or fainting upon standing up
- — urinary incontinence
- — impotence
- — constipation
- — dry mouth and skin
- — trouble regulating body temperature due to abnormal sweating
- — abnormal breathing during sleep
Not all patients experience all of these symptoms.
Prognosis
MSA usually progresses more quickly than Parkinson's disease.There is no remission from the disease. The remaining lifespan after the onset of symptoms is on average about 9 years. Almost 80% of patients are disabled within 5 years of onset of the motor symptoms, and only 20% survive past 12 years. Rate of progression differs in every case and speed of decline may vary widely in individual patients.
Treatment
There is no discovered cure for MSA, so treatment involves treating the symptoms.
Management by rehabilitation professionals (physiotherapists, occupational therapists, speech therapists, and others) for problems with walking/movement, daily tasks, and speech problems is essential. Also social workers can help with coping with disability and access to health care services, both for the person with MSA as well as his/her family caregivers.
Ongoing care from a neurologist specialized in "movement disorders" is recommended as the complex symptoms of MSA are often not familiar to less-specialized health care professionals.
One particularly serious problem, the drop in blood pressure upon standing up (with risk of fainting thus injury from falling) often responds to fludrocortisone, a synthetic mineralocorticoid. Another common drug treatment is midodrine (an alpha-agonist.) Non-drug treatments include "head-up tilt" (elevating the head of the whole bed by about 10 degrees), salt tablets, generous intake of fluids, and pressure (elastic) stockings. Avoidance of triggers of low blood pressure (e.g. hot weather, alcohol, dehydration) are crucial.
Hospice/homecare services can be very useful as disability progresses.
Levdopa (L-Dopa) (a drug used in the treatment of Parkinson's disease)fails to improve the parkinsonian symptoms of most MSA patients. A recent trial reported that only 1.5% of MSA patients experienced a >50% improvement when taking levodopa, and even this was a transient effect lasting less than one year. Poor response to L-Dopa has been suggested as a possible element in the differential diagnosis of MSA from Parkinson's disease.
A recent study conducted in Europe failed to find an effect for the drug riluzole in treating MSA or PSP.
Histopathology
In some cases, a diagnosis of MSA can only be confirmed post-mortem. When brain tissue of a person with MSA is examined under a microscope, structures called glial cytoplasmic inclusion bodies are visible. The presence of these inclusions (also known as Papp-Lantos bodies) in the movement, balance and automatic control centres of the brain are the defining histopathologic hallmark of MSA. Recent studies have shown that major fillamentous component of glial and neuronal cytoplasmic inclusions is alpha-synuclein
Terminology
Other terms have been used to refer to this disorder, based on the predominant systems presented. These terms and their distinctions have been dropped in recent (1996 onwards) medical usage and replaced with MSA subtype naming, but are helpful to understanding the older literature about this disease:
| Name | Characteristics | Abbreviation
>-
| Striatonigral degeneration | predominating Parkinson's-like symptoms | -
| Shy-Drager syndrome | characterized by Parkinsonism plus a more pronounced failure of the autonomic nervous system | -
| Sporadic Olivopontocerebellar atrophy (OPCA) | characterized by progressive ataxia (an inability to coordinate voluntary muscular movements) of the gait and arms and dysarthria (difficulty in articulating words) | MSA - c, "c" = cerebellar dysfunction subtype |
See also
External links
- at Vanderbilt University
- The , a UK registered charity providing information about MSA.
- The , an Innsbruck based European MSA Study Group comprising 20 academic centres of excellence dedicated to MSA research
- The , A US-based non-profit for people with MSA
|
| |
|
|
