This term abbreviated MSA defines a specific syndrome within the larger less well defined category of multiple system degenerations. The features of
the MSA include: parkinsonism, cerebellar or corticospinal signs, orthostatic hypotension, impotence, and urinary incontinence or retention, usually preceding or within two years after the onset of the motor
symptoms. The previous division into Shy Drager Syndrome (SDS), Striato Nigral Degeneration (SND), and Olivopontocerebellar Atrophy (OPCA) has been dropped. Immunohistochemistry demonstrates that these three
disorders share a common pathology. The latest diagnostic criteria are shown in the table below.Wenning et. al. determined that the combination of autonomic insufficiency, speech or bulbar
dysfunction, absence of dementia, postural instability with falls, poor response to levodopa, and absence of levodopa-induced confusion gave a diagnostic sensitivity and specificity greater than 90%. Median age of onset of MSA is about age 55 years (range of 33 to 76). It affects men slightly more than women. Nearly half of patients are disabled or wheelchair bound within 5 years of the onset
of motor symptoms. Mean survival is 6 to 7 years. 80% of MSA patients develop predominant parkinsonism (MSA-P) and 20% develop predominant cerebellar signs (MSA-C). The latter statistics are likely skewed by
referral patterns to movement disorder centers. There is considerable overlap. Cerebellar features are present in over 40% of patients with SND type, and parkinsonism is detectable in 50% of OPCA type
patients. 30% and 65% of MSA patients had a good levodopa response at some stage. Between 13% and 30% maintained some response through the course of the illness. 25% to 50% of those treated
with levodopa had dyskinesias (particularly orofacial) and dystonia, even if they did not experience improvement in motor state. Autonomic symptoms were the initial feature in 41% of patients,
but ultimately 97% of patients developed some degree of autonomic dysfunction. The most frequent autonomic symptom in men was impotence and in women urinary incontinence. Orthostatic hypotension occurred in
68%. A mild restriction of downgaze may develop in about 10% of MSA cases.. Anterior horn cell loss may occur but is uncommon. Anal sphincter EMG (90% have an abnormality) is a sensitive and
specific diagnostic test for MSA. Even less frequently seen is a mild sensory neuropathy. Classic rest tremor is uncommon (29%) Cerebellar signs occurred in 54% of patients and upper motor neuron signs in
49% of the cases. SND type generally demonstrates more tremor, pyramidal signs, and myoclonus than OPCA type. Severe dementia is uncommon Respiratory stridor (which ultimately occurs in 1/3 of
cases) in combination with parkinsonism is highly suggests MSA until proved otherwise; although stridor can also occur in PD, it is exceptionally rare.
Multiple System Atrophy: Clinical Diagnostic Criteria |
STRIATONIGRAL DEGENERATION Type (predominant parkinsonism)Sporadic adult-onset (age 30 years or above) Possible
Non/poorly levodopa responsive parkinsonism* Probable Above**, plus severe symptomatic autonomic failure*** or cerebellar signs or pyramidal signs or
pathological sphincter EMG Definite
Post mortem confirmed |
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OLIVOPONTOCEREBELLAR Type (predominantly cerebellar)Sporadic adult-onset (age 30 years or above) Possible
Cerebellar syndrome with parkinsonism Probable
Sporadic adult-onset cerebellar syndrome* (with or without parkinsonism or pyramidal signs) plus severe symptomatic autonomic failure*** or pathological sphincter EMG Definite Post mortem confirmed |
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* Without DSM III dementia, generalised tendon areflexia, downgaze PSNP or other identifiable cause.
** Moderate or good, but often waning, response to levodopa may occur, in which case multiple atypical features need to be present.
*** Postural syncope or presyncope and/or urinary incontinence or retention not due to other causes.
Sporadic: one other case of typical clinical IPD among 1st or 2nd degree relatives allowable. |
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Frequency of individual clinical features in 203 cases of MSA |
From Wenning, et al, MSA: A Review of 203 Pathologically proven Cases Movement Disorders Vol 12 No 2
1997 – 133-147 |
Autonomic symptoms
Urinary incontinence 55%
Postural faintness 51%
Impotence 47%
Recurrent syncope 18%
Fecal incontince 12% Parkinsonism
Akinesia 83%
Tremor 67%
Rigidity 63%
Best L-Dopa response
Poor 72%
Good 28%
Last L-Dopa response
Poor 95%
Good 5% Dyskinesias
Orofacial 15%
Limbs 10% Fluctuations 24% |
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Cerebellar Signs
Gait ataxia 49%
Limb ataxia 47%
Intention Tremor 24%
Nystagmus 23%
Pyramidal signs
Hyperreflexia 46%
Babinski 41%
Spasticity 10% Other features
Intellectual deterioration
Mild 22%
Moderate 2%
Severe 0.5%
Stridor 13%
Dystonia 12%
Anisocoria 8% Contractures 7% |
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