PT  - JOURNAL ARTICLE
AU  - Oppenheim, C
AU  - Galanaud, D
AU  - Samson, Y
AU  - Sahel, M
AU  - Dormont, D
AU  - Wechsler, B
AU  - Marsault, C
TI  - Can diffusion weighted magnetic resonance imaging help differentiate stroke from stroke-like events in MELAS?
AID  - 10.1136/jnnp.69.2.248
DP  - 2000 Aug 01
TA  - Journal of Neurology, Neurosurgery & Psychiatry
PG  - 248--250
VI  - 69
IP  - 2
4099  - http://jnnp.bmj.com/content/69/2/248.short
4100  - http://jnnp.bmj.com/content/69/2/248.full
SO  - J Neurol Neurosurg Psychiatry2000 Aug 01; 69
AB  - The precise mechanism of neurological symptoms in patients with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) is still controversial. The diffusion weighted MR findings at the acute phase of a neurological event in MELAS are described and the pathophysiology of stroke-like lesion in the light of diffusion changes is discussed. Brain MRI was performed 2 days after the sudden onset of cortical blindness in a 25 year old patient with MELAS. Fluid attenuated inversion recovery (FLAIR) images showed multifocal cortical and subcortical hyperintensities located bilaterally in the frontobasal and the temporo-occipital lobes. Diffusion weighted images showed normal to increased apparent diffusion coefficient values in the acute left temporooccipital lesion and increased values in the older stroke-like lesions. These diffusion weighted findings support the metabolic rather than the ischaemic pathophysiological hypothesis for stroke-like episodes occurring in MELAS. Normal or increased apparent diffusion coefficient values within 48 hours of a neurological deficit of abrupt onset should raise the possibility of MELAS, especially if conventional MR images show infarct-like lesions.