Morbus Parkinson/Multiple System Atrophy
Multiple system atrophy (MSA) is another α-synucleinopathy, although much rarer than MP. There are a range of associated clinical features, which include parkinsonism, cerebellar ataxia, autonomic failure, urogenital dysfunction, and corticospinal involvement. There is a relative preservation of cognition. It is subdivided into MSA with predominant parkinsonism (MSA-P) and MSA with predominant cerebellar ataxia (MSA-C).
The parkinsonism of MSA tends to be rapidly progressive and poorly responsive to levodopa. Bradykinesia and rigidity are usually predominant; a classic pillrolling tremor is rarely seen. In the initial stages, MSA can be difficult to distinguish from MP, as symptoms are invariably asymmetric and up to 30% of patients do show an initial good response to levodopa treatment. MSA patients treated with levodopa can also exhibit dyskinesias, although these are often atypical and can manifest as prolonged facial dystonia or torticollis (22). Autonomic failure is virtually always a feature at presentation, which tends to occur later in the disease course in MP. This is seen as an orthostatic drop in blood pressure, urinary incontinence, or erectile dysfunction. Additional features which point toward MSA and are not seen in MP are stridor, a positive Babinski sign, and cerebellar ataxia, which can manifest as a gait or limb ataxia, dysarthria, or oculomotor dysfunction. Myoclonus is also seen, particularly as “poly-mini-myoclonus”: stretch-sensitive jerks affecting the fingers. This is unusual in MP.
Imaging can be useful in discriminating MP and MSA. Structural imaging using MRI can reveal changes in the brainstem and basal ganglia which are supportive of MSA, including the “hot cross bun” sign, although this feature is only normally recognized by radiologists familiar with these types of syndrome.
Overall, the clue that the patient has MSA rather than MP is the poor response to levodopa and the involvement of systems outside the striatum and thus the prominent gait and autonomic problems early on in the disease course.
The parkinsonism of MSA tends to be rapidly progressive and poorly responsive to levodopa. Bradykinesia and rigidity are usually predominant; a classic pillrolling tremor is rarely seen. In the initial stages, MSA can be difficult to distinguish from MP, as symptoms are invariably asymmetric and up to 30% of patients do show an initial good response to levodopa treatment. MSA patients treated with levodopa can also exhibit dyskinesias, although these are often atypical and can manifest as prolonged facial dystonia or torticollis (22). Autonomic failure is virtually always a feature at presentation, which tends to occur later in the disease course in MP. This is seen as an orthostatic drop in blood pressure, urinary incontinence, or erectile dysfunction. Additional features which point toward MSA and are not seen in MP are stridor, a positive Babinski sign, and cerebellar ataxia, which can manifest as a gait or limb ataxia, dysarthria, or oculomotor dysfunction. Myoclonus is also seen, particularly as “poly-mini-myoclonus”: stretch-sensitive jerks affecting the fingers. This is unusual in MP.
Imaging can be useful in discriminating MP and MSA. Structural imaging using MRI can reveal changes in the brainstem and basal ganglia which are supportive of MSA, including the “hot cross bun” sign, although this feature is only normally recognized by radiologists familiar with these types of syndrome.
Overall, the clue that the patient has MSA rather than MP is the poor response to levodopa and the involvement of systems outside the striatum and thus the prominent gait and autonomic problems early on in the disease course.
