multiple system atrophy

Imaging
biomarkers in Parkinson’s disease and Parkinsonian syndromes: current and emerging concepts. MRI of a patient with a clinical diagnosis of Multiple System Atrophy-C. a Axial proton density sequence at the level of the pons demonstrates cruciform pontine T2 hyperintensity consistent with the ‘hot cross bun’ sign secondary to selective vulnerability of the pontocerebellar tract in Multiple System Atrophy-C. Disproportionate atrophy of the pons and partially visualized cerebellar hemispheres is also evident. b Axial FLAIR sequence with cruciform T2 hyperintensity within the pons and middle cerebellar peduncles (i.e., ‘Middle Cerebellar Peduncle sign’) with marked atrophy. Cerebellar hemispheric and vermian atrophy is also seen with ex vacuo dilatation of the fourth ventricle. c Sagittal T1 sequence showing marked atrophy of the brainstem and cerebellar vermis
translationalneurodegeneration.biomedcentral.com • CC-by-4.0
Multiple
system atrophy parkinsonian type (MSA-P) • Multiple system atrophy (MSA-P) - Ganzer Fall bei Radiopaedia
Dixon A, Multiple system atrophy (MSA-P). Case study, Radiopaedia.org (Accessed on 23 Nov 2022) https://doi.org/10.53347/rID-14451 • CC by-nc-sa 3.0 (modified)
Radiopaedia • CC-by-nc-sa 3.0 • de

Multiple system atrophy (MSA) is a sporadic neurodegenerative disease (one of the synucleinopathies) characterized by varying degrees of cerebellar ataxia, autonomic dysfunction, parkinsonism, and corticospinal dysfunction.

Epidemiology

Multiple systemic atrophy is a sporadic disease, with a prevalence of 4 per 100,000 . Typically symptoms begin between 40 and 60 years of age .

Clinical presentation

Clinical presentation is variable, but typically presents in one of three patterns (initially described as separate entities) :

In a 2007 consensus paper MSA has been divided clinically into two forms according to the dominant non-autonomic symptoms:

  • MSA-C: predominance of cerebellar symptoms (olivopontocerebellar atrophy)
  • MSA-P: predominance of parkinsonian signs and symptoms (striatonigral degeneration)

    • Some older texts refer to MSA-A to denote Shy-Drager syndrome. In the latest consensus however autonomic symptoms are considered part of both MSA-C and MSA-P and thus the term MSA-A is no longer used.

    Pathology

    Like other synucleinopathies, multiple systemic atrophy results from abnormalities of alpha-synuclein metabolism, resulting in intracellular deposition. Unlike Parkinson disease and Lewy body dementia (two other synucleinopathies) these intracellular deposits are found not only in neurons but also in oligodendroglia .

    Radiographic features

    MRI is the modality of choice for imaging patients with suspected multiple system atrophy (MSA).

    MRI
    • T2: hyperintensities typically present in the pontocerebellar tracts
    • putaminal findings in MSA-P :
      • reduced volume
      • reduced GRE and T2 signal relative to globus pallidus
      • reduced GRE and T2 signal relative to the red nucleus
      • abnormally high T2 linear rim surrounding the putamen (putaminal rim sign), seen at 1.5 T (this is normal at 3 T) (see case 3)
    • MSA-C
      • disproportionate atrophy of the cerebellum and brainstem (especially olivary nuclei and middle cerebellar peduncle)
    • ADC values: higher in the pons, cerebellum, and putamen than in Parkinson disease or controls
    • fractional anisotropy (FA): lower in the pons, cerebellum, and putamen than in Parkinson disease or controls
    Nuclear medicine

    On SPECT/CT with I-123 ioflupane, there is loss of the normal comma- or crescent-shaped tracer uptake in the striatum. Instead, a period- or oval-shaped uptake is seen within the caudate nucleus head without tracer uptake in the putamen. Quantitative assessment reveals reduced uptake in the putamen compared to norms.

    Treatment and prognosis

    Unfortunately, no effective treatment is currently available. The disease progresses relentlessly culminating in death usually within 10 years of diagnosis .

    Siehe auch:
    und weiter:
    Assoziationen und Differentialdiagnosen zu Multisystematrophie:
    Morning glory
    Zeichen Mittelhirn
    translationalneurodegeneration.biomedcentral.com • CC-by-4.0
    Morbus
    Parkinson
    Wikipedia • CC BY-SA 3.0
    Olivopontozerebelläre
    Atrophie
    translationalneurodegeneration.biomedcentral.com • CC-by-4.0
    hot-cross bun
    sign of multiple system atrophy
    translationalneurodegeneration.biomedcentral.com • CC-by-4.0