Autoimmune glial fibrillary acidic protein (GFAP) astrocytopathy
General description
Autoimmune glial fibrillary acidic protein (GFAP) astrocytopathy is an autoimmune disease where the patient's immune system attacks glial fibrillary acidic protein (GFAP), a protein in the nervous system. This inflammatory central nervous system disorder can affect any region from the optic nerve to the spinal cord, though meningoencephalitis is most common. Diagnosis relies on detecting GFAP-reactive IgG in the CSF.
Common symptoms include myelitis, headache, abnormal vision, fever, ataxia, psychosis, dyskinesia, dementia, and seizures. Flu-like symptoms often precede the neurological manifestations.
T2WI and FLAIR hyperintensity
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CerebrumCerebral white matter
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Caudate nucleus
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Putamen
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Globus pallidus
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Thalamus
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Brainstem
T2WI and FLAIR demonstrate bilateral hyperintensity in the periventricular white matter, which may extend to the thalamus, basal ganglia, and brainstem.
Perivascular enhancement
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CerebrumCerebral white matter
Contrast enhanced T1WI demonstrates characteristic bilateral linear enhancement along the perivascular spaces of the cerebral white matter, extending radially from the periventricular surface throughout the white matter.
Perivascular enhancement
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Thalamus
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Putamen
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Globus pallidus
Perivascular enhancement may also be seen in the thalamus and basal ganglia.
Leptomeningeal enhancement
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Leptomenix
Spinal lesion
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Spinal cord
A characteristic feature of autoimmune GFAP astrocytopathy is the presence of longitudinally extensive, hyperintense lesions near the central canal of the spinal cord on T2-weighted MRI.
Bloomy rind sign
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LeptomenixBrainstem leptomenix
FLAIR reveals hyperintensity along the leptomeninges of the brainstem, referred to as the 'bloomy rind sign.'