Disappearing basal ganglia sign

Case contributed by Nafisa Shakir Batta


Young lady with rheumatic heart disease, presented with neurological deficit

Patient Data

Age: 25 years
Gender: Female

CT done at 4 hours, with a subsequent followup 24 hours CT


CT done within 4 hours demonstrates the blurring of grey white matter differentiation at the left insular cortex, with loss of the insular ribbon, obscuration of the lentiform nucleus and abnormally hypodense left basal ganglia showing absence of normal contour (disappearing basal ganglia sign).

CT repeated at 24 hours, (after thrombolytic therapy) reveals more prominent hypoattenuating left basal ganglia and insular cortex, as the infarct has matured.

MRI done at 24 hours from the onset of neurological symptoms.


Diffusion-weighted MRI images show the bright signal in the left MCA circulation territory, consistent with an acute infarct.

MRA sequences in coronal and axial planes show a short-segment abruption of the proximal left MCA M2 branches, with attenuation in caliber of the M2 and M3 segments, with visualization of fewer opercular and sylvian branches of the distal M3. These findings are highly suggestive of a thromboembolic episode.

Case Discussion

A focused look at the basal ganglia is absolutely essential on early CT scans in a patient with acute neurological deficit. The subtle signs of early MCA infarction are demonstrated in this case, and their careful detection can aid immensely in induction of thrombolytic therapy for it to be of timely benefit within the window period.

This case clearly delineates the early signs of MCA infarction: namely, loss of the insular ribbon sign, obscured lentiform nucleus sign, and disappearing basal ganglia sign. A hyperdense MCA can be seen at times when thrombosed, but in the event of an embolic phenomenon this may not be demonstrated.

This patient had complete recovery and reversal of neurological deficit post-thrombolysis.

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