Multiple System Atrophy
Multiple System Atrophy (MSA) is a group of conditions with a common feature of prominent autonomic dysfunction.
The autonomic nervous system controls the internal organs, affecting heart rate, blood pressure, gut, and urinary system, among others. Symptoms that may sometimes be due to autonomic dysfunction include orthostatic hypotension (blood pressure dropping upon standing up), urinary symptoms (urgency, frequency, or incontinence), constipation (because the gut slows down as well), sexual dysfunction, and dysfunctional sweating.
There are 3 subtypes of MSA:
- Autonomic MSA (MSA-A), previously known as Shy-Drager syndrome. This manifests with the symptoms listed above, in addition to postural instability, falls, stridor (difficulty with breathing in), head tilt (usually forward), dysphagia (trouble swallowing), dysphonia (abnormal quality of voice, often with a quivering component), and emotional variability.
- Cerebellar MSA (MSA-C), previously known as Olivopontocerebellar atrophy (OPCA) or olivopontocerebellar degeneration (OPCD). This combines parkinsonism, autonomic dysfunction as above, and cerebellar findings such as imbalance, staggering gait, lack of coordination, and eye movement abnormalities. The cerebellar findings may precede the parkinsonism.
- Parkinsonian MSA (MSA-P), previously known as striatonigral degeneration (SND), manifests with parkinsonism (moving slowly, tremor and stiffness) and autonomic dysfunction. Other symptoms associated with MSA include REM sleep behavior disorder (RBD), which is where there is an absence of the usual paralysis during dream sleep (rapid eye movement REM), resulting in acting out dreams; contractures; leaning to one side; depression and anxiety.
The diagnosis of MSA is often made based on typical findings on MRI, particularly cerebellar atrophy (shrinking in the size of the cerebellum), the “hot-cross bun” sign in the pons (part of the brainstem) or other areas of increased signal in the MRI such as a linear rim adjacent to the putamen. These can be quite subtle at times so our specialists will perform an independent review of all MRIs done on patients with PD or suspected MSA.