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This 62 year old man came to the emergency room after suffering a first seizure, a tonic-clonic convulsion with focal onset, witnessed by his wife.
He suddenly became quiet, had eye deviation to the left, and began to
twitch in the left face. He became unresponsive to verbal commands, and
had generalized jerking movements of arms and legs, lasting for a few minutes.
There was a history of carcinoma of the colon, with recent metastasis to
the liver and lung.
MR images show a lesion involving the right second frontal convolution and another in the cerebellum, near the fourth ventricle, also visible on the sagittal imagemap.
There is contrast enhancement of the rim of both lesions. Metastatic brain lesions are typically but not always multiple. The low signal on
T2-weighted images of the frontal lesion is remarkable, since metastases are often associated with high signal. There is very little surrounding edema or distortion of the frontal cortical architecture. In contrast, the cerebellar lesion is quite swollen and displaces the underlying brainstem, a potentially dangerous situation because of the proximity of vital brainstem centers involved in regulation of basic functions such as ventilation. This lesion required prompt attention and careful monitoring.
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