[False negative diffusion in acute ischemic stroke].
BACKGROUND
The new techniques of magnetic resonance imaging have produced a important advance in the early diagnosis of acute ischemic stroke. The diffusion weighted imaging (DWI) has a high sensitivity and specificity in the acute ischemia.


METHODS
70 years old woman with previous history of hypertension and dyslipemia. The patient presented sudden vertigo with cervical neck pain and gaze problems. The physical exploration revealed right miosis, nistagmus, IX and X cranial nerve affection and ataxia. The clinical diagnosis was Wallenberg s syndrome and a medulla lateral infarction. However DWI was normal (10 hours). The neurological deficit was persistent and a repeated study disclosed a lateral infarction of the medulla.


CONCLUSIONS
The sensitivity of DWI is reduced during the first 24 hours. There are false negative diagnosis mainly in small infarctions of posterior territory.
Unidad de RM-IDI, Servicio de Radiología, Hospital Josep Trueta, Girona, España. spedraza@retemail.es
S
S
Pedraza
M T
MT
Osuna
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A
Dávalos
J
J
Teruel
J
J
Vera-Sancho
L
L
Inaraja
D000368:Aged; D002545:Brain Ischemia / Q000175:diagnosis*; D001933:Brain Stem / Q000098:blood supply / Q000473:pathology; D005188:False Negative Reactions; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D012680:Sensitivity and Specificity; D020521:Stroke / Q000175:diagnosis*