Diffusion-negative MRI in acute ischemic stroke: a case report.
BACKGROUND
Diffusion-weighted magnetic resonance imaging is a very sensitive tool for the early diagnosis of acute ischemic stroke. This is employed in some stroke centers as the primary screening tool to select patients eligible for thrombolysis.


METHODS
We present the case of a 49-years old Chinese man whose diffusion-weighted magnetic resonance imaging performed 12 hours of symptom onset was negative.


RESULTS
Although the initial diffusion-weighted magnetic resonance imaging was negative, the imaging repeated after 4 days despite static neurological symptoms and signs, could demonstrate an acute medullary infarction.


CONCLUSIONS
Diffusion-weighted imaging may not be100% sensitive in very early stages, especially in posterior circulation strokes. Our case serves as a reminder that clinical assessment still retains priority until a diagnostic modality offering 100% sensitivity and specificity is discovered.
Rathakrishnan
Rahul
R
Division of Neurology, Department of Medicine, National University Hospital, Singapore. drvijay@singnet.com.sg.
Sharma
Vijay K
VK
Chan
Bernard Pl
BP