Background 
The etiology behind stroke in younger patients may differ from the well-known of the old. Standard work up is often normal and other considerations and exams should be conducted.
 
Aim 
We present three cases where an infectious etiology is suspected. 
 
Cases 
32-year-old male presenting with continuous nautic vertigo, nystagmus, vomiting and a broad-based gait. Truncal herpes zoster infection four weeks earlier. MRI: left-sided cerebellar ischemia corresponding to the PICA territory. 
 
19-year-old male presenting with headache, dysphagia, progressing to left-sided hemiparestesia and right-side Horner’s syndrome. Primary HSV-1 infection four weeks earlier. MRI: right-sided ischemia in medulla oblongata and cerebellum. 
 
32-year-old female with known anxiety, two years of relapsing skin infections and unknown promiscuity presenting with right-sided hemiparesis, dysphagia, dysartria, discrete vertigo and imbalance. 
MRI: left-sided pontine infarction. 
 
In all three cases, stroke was verified by MRI, and standard work up including cerebral CT-angiography and cardiac evaluation with 72 hours telemetry, TTE and TEE, and a thrombophilia screening was normal.

Discussion 
Clinically and radiologically, in the two first cases, embolic stroke was suspected; in the latter case, a pontine perforant stroke. As angiography and cardiac evaluation were negative, infectious vasculitis was considered. 
Lumbar puncture revealing monocytary pleocytosis supported the diagnosis despite a normal angiography, as all three agents can cause vasculopathy in small or large vessels of the brain.
 
Conclusion 
Through thorough examinations of young stroke cases and more frequent CSF analysis, the chance of identifying an infectious and potentially treatable etiology is increased.

INFECTIOUS ETIOLOGY BEHIND STROKE IN THE YOUNG: THREE CASES