Corticobasal syndrome (CBS) is characterised by asymmetric apraxia, cortical sensory loss, extrapyramidal features and cognitive decline. Although CBS is classically described as a taupathy, heterogeneity of its aetiology is increasingly recognised. Clinical presentation of CBS appears to reflect areas of the brain involved and not necessarily the nature of the underlying pathology.1

CBS is associated with asymmetric cortical atrophy on brain imaging, a feature that is typical of focal neurodegenerative disorders. Rarely, atrophy of ipsilateral cortical areas has been reported with slowly growing subcortical lesions.2 We report a patient in whom resolution of a thalamic tuberculoma was associated with progressive atrophy of the parietotemporal cortex, resulting in an unusual presentation of CBS.

Case report

A 49-year-old, right-handed geologist presented with progressive stiffness and numbness of the right arm and leg for 6 months. On clinical evaluation, he had rigidity of his right-sided limbs with mild right hemisensory loss. A magnetic resonance imaging (MRI) scan of the brain showed contrast-enhancing, coalescing lesions involving the left thalamus (fig 1A). A firm cervical lymph node was detected and biopsy revealed caseating granulomas consistent with tuberculosis. The granulomatous lesion on brain imaging, which was associated with histopathological evidence of lymph-nodal tuberculosis suggested the diagnosis of thalamic tuberculoma, and anti-tubercular treatment was started. After 6 months, the patient’s sensory symptoms improved, and a …