Corticobasal syndrome (CBS)
General description
Corticobasal syndrome (CBS) is a slowly progressive neurodegenerative disorder resistant to Levodopa treatment. Motor symptoms include akinetic rigidity, myoclonus, and asymmetric dystonia. Cortical motor sensory features comprise limb apraxia, alien limb syndrome, and cortical sensory loss. Speech and language are also impaired, alongside executive dysfunction and visuospatial deficits.
Cerebral atrophy
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CerebrumFrontal lobePrecentral gyrus
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CerebrumParietal lobe
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Cerebral peduncle
The imaging study reveals asymmetric cerebral atrophy, notably characterized by the frontal to parietal lobe degeneration, particularly evident in the precentral gyrus contralateral to the clinically symptomatic side. In addition to the atrophic changes observed in the cerebral hemisphere, involvement of the contralateral cerebral peduncle is also noted.
T2WI and FLAIR hyperintensity
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CerebrumFrontal lobeCerebral white matter
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CerebrumParietal lobeCerebral white matter
In corticobasal syndrome, abnormal hyperintense signal may be observed on T2WI and FLAIR sequences within the white matter underlying the atrophic gyri in the cerebral hemisphere contralateral to the symptomatic side. Additionally, these hyperintense signal abnormalities can extend over a large area, involving subcortical and deep white matter regions spanning from the frontal to the parietal lobes.
Atrophy of midbrain and corpus callosum
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BrainstemMidbrainMidbrain tegmentum
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Corpus callosum
Atrophy of the corpus callosum and midbrain is evident upon examination.
CBF SPECT
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Cerebrum
In corticobasal syndrome, cerebral blood flow single-photon emission computed tomography (CBF SPECT) imaging reveals reduced perfusion in the cerebral hemisphere contralateral to the symptomatic side. The degree of asymmetry observed on SPECT is more pronounced compared to findings on MRI.