Diffusion-weighted MR imaging characteristics of an acute strokelike form of multiple sclerosis

Abstract

The characteristics of multiple sclerosis (MS) lesions on diffusion-weighted sequences and apparent diffusion coefficient (ADC) mapping at the very early phase of symptoms have not been clearly described. We report the case of a young woman who presented with a sudden pseudostroke form of MS resulting in hemiplegia and sudden aphasia. MR imaging showed a lesion of the left internal capsule with reduced ADC, which suggests an ischemic stroke. This case shows that very acute MS lesions may have reduced ADC on MR imaging, reflecting cytotoxic and not vasogenic edema.

Fig 1.

Brain MR imaging, T2-weighted sequence: high-intensity white matter images, 2 of which are periventricular.

Fig 2.

Brain MR imaging 2 hours after onset of symptoms. A, FLAIR sequence, showing high signal intensity of left internal capsule. B, DWI, showing high signal intensity of left internal capsule. C, ADC mapping, showing reduced ADC of the left internal capsule lesion.

Fig 3.

Brain MR imaging on day 10. A, FLAIR sequence, showing extension of the left internal capsule lesion. B, DWI, showing extension of the left internal capsule lesion. C, ADC mapping, showing heterogeneous ADC of the left internal capsule lesion.

Fig 4.

Brain MR imaging at 3 months. A, FLAIR sequence, showing regression of the high signal intensity of the left internal capsule. B, Gadolinium-enhanced T1-weighted image, showing no contrast enhancement of the lesion.