Abstract
In young adult, the most common etiology of acute ischemic brain infarction are arterial dissections and cardiogenic embolic stroke. Vertebral artery dissection without preceding trauma history is quite rare in young ischemic stroke patients. Postural headache is even more atypical presentation for vertebral artery dissection. It is often misdiagnosed as spontaneous intracranial hypotension. We described a 37-year-old male suffering from acute onset postural headache with stroke in evolution during hospitalization. The initial brain magnetic resonance imaging (MRI) mislead to diagnosis of ischemic lesion. Nevertheless, with the aid of single photon emission computed tomography, we are confident the patient was afflicted with ischemic/hemorrhagic lesion, instead of neoplasm or demyelinating diseases. Lateral medullary syndrome was confirmed on the repeated brain MRI. His general condition improved with steady gait and clear articulation without easychoking after adequate hydration and rehabilitation training with aspirin as secondary prevention. Cranial artery dissections is a crucial differential diagnosis while thunderclap headache happens even related to postural change without obvious neurological deficit in the beginning presentations.