Hirnatrophie

Infant with
acute and chronic emesisAxial CT without contrast of the brain (upper left) shows bilateral large low density extra-axial fluid collections and a left frontal small high density extra-axial fluid collection. There is also prominence of the cortical sulci and the ventricular system. Axial T1 (upper right), T2 (lower left) and FLAIR (lower right) MRI without contrast of the brain better demonstrates the extra-axial fluid collections with the bilateral large collections being bright on T1 and T2 and the small left frontal collection being iso on T1 and dark on T2.The diagnosis was bilateral large chronic subdural hematomas with associated cerebral atrophy and a left frontal acute subdural hematoma in a child abuse patient.
pediatricimaging.org • CC-by-nc-sa 4.0
Neuroimaging
assessment in Down syndrome: a pictorial review. Coronal T1/3D reconstructions of a 48-year-old Down syndrome patient with dementia. a Grade 2 anterior cingulate gyrus atrophy (MRI visual rating scale). b Grade 2 orbito-frontal cortex volume loss. c Grade 2 anterior temporal cortex atrophy. d Grade 3 fronto-insular loss of volume. e Grade 4 medial temporal atrophy, including the amygdala and hippocampus. f Grade 3 posterior parieto-occipital cortex atrophy
insightsimaging.springeropen.com • CC-by-4.0
Neuroimaging
assessment in Down syndrome: a pictorial review. Coronal (a), sagittal (b), and axial (c) T1/3D reconstructions of a 58-year-old Down syndrome patient presenting with new-onset myoclonic seizures and showing imaging findings similar to Alzheimer disease, with diffuse atrophy predominantly involving the temporal mesial (a, c) (grade 4 in the visual rating scale) and parietal structures with ex-vacuo widening of adjacent CSF spaces (b). The clinical and radiological picture allowed the diagnosis of late-onset myoclonic epilepsy in Down syndrome (LOMEDS)
insightsimaging.springeropen.com • CC-by-4.0
Radiopaedia • CC-by-nc-sa 3.0 • de

Cerebral atrophy is the morphological presentation of brain parenchymal volume loss that is frequently seen on cross-sectional imaging. Rather than being a primary diagnosis, it is the common endpoint for range disease processes that affect the central nervous system. Though often no identifiable cause is found, certain patterns of atrophy can be helpful in certain clinical scenarios, most notably in neurodegenerative diseases.

It is a common finding in the elderly population, and so there is some controversy as to when imaging changes are labeled as cerebral atrophy, rather than simply "involutional" or "age-related" when the patient has normal cognition.

Terminology

As cerebral atrophy is simply the compensatory enlargement of the CSF spaces from reducing brain parenchymal volume, it is akin to hydrocephalus ex vacuo. However, the later term is usually reserved when referring to focal volume loss in the brain following a pathological insult (i.e. hemorrhage) rather than the often idiopathic more generalized changes seen with age.

Clinical presentation

As it is not a distinct disease entity, there is no uniform mode of presentation and the finding of atrophy is often incidental when imaging is taken for some other indication.

Cognitive dysfunction and acute confusion are common reasons patients with atrophy may undergo imaging.

Pathology

The underlying pathological causes can be broadly distinguished based on whether the atrophy is focal or generalized:

Radiographic features

CT and MRI are equally able to demonstrate cortical atrophy, but MRI is more sensitive in detecting focal atrophic changes in the nuclei. Characteristic features include prominent cerebral sulci (i.e. cortical atrophy) and ventriculomegaly (i.e. central atrophy) without bulging of the third ventricular recesses. It can be difficult to distinguish this from the changes seen in normal pressure hydrocephalus.

Certain important patterns of cerebral atrophy that are more specific include:

  • severe frontal and anterior temporal
    • Pick disease
  • head of caudate nuclei
    • Huntington disease
  • posterior parietal and frontal 
    • corticobasal degeneration
  • atrophy of tectum, globus pallidus, and frontal lobes
    • progressive supranuclear palsy
  • generalized with atrophy of substantia nigra
    • Parkinson disease
  • severe hippocampal atrophy
    • Alzheimer dementia

Differential diagnosis

Siehe auch:
und weiter:
Assoziationen und Differentialdiagnosen zu Hirnatrophie:
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Hirnatrophie
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