varicella zoster virus ( vzv ) is a neurotropic dna alpha herpesvirus that infects more than 95% of the world population . usually , varicella results from primary infection . the virus then becomes latent in ganglion neurons along the entire neuroaxis , and after reactivation , vzv moves transaxonally to the skin resulting in zoster . less often , vzv reactivation leads to neurologic complications more common in immunocompromised patients , such as vzv vasculopathy . vasculitis has , however , been reported in patients with dermatomal herpes zoster infection without trigeminal nerve involvement . the average time from rash to neurologic symptoms and signs is 4.1 months , but sporadically the patient can present with rash and stroke simultaneously . nonetheless , approximately one third of patients have no history of rash . in recent years , the number of recognized vzv vasculopathies has grown , but the diagnosis is not easy because , frequently , clinical presentation and imaging features are not specific of this entity . antiviral and antithrombotic treatment should probably be considered in stroke associated with vzv vasculopathy , but data on which to base therapeutic decisions are lacking . a 31-year - old right - handed female was admitted to the emergency department because of headache associated with visual disturbance . she had no previous history of headache and no known vascular risk factors but she used an oral contraceptive pill . on admission , she reported a 9-hour progressive pulsatile headache , with nausea and photophobia , followed by a sudden left visual field defect . neurological examination a head computed tomography ( ct ) scan was judged to be normal ( fig . the next day , the patient was observed at an outpatient consultation and subsequently admitted in the neurology ward because the headache had worsened and she felt weakness and numbness of the left limbs . she also recalled a history of thoracic rash 1 month before and she reported having had varicella at the age of 7 years . neurological examination at that time revealed slight drowsiness , mild left hemiparesis , left hemihypesthesia and homolateral homonymous hemianopia . a new ct scan showed an ischemic infarct on the territory of the right posterior cerebral artery ( fig . two days after admission , the neurological picture worsened with acute onset of left central facial palsy , visual and tactile inattention and worsening of the left motor deficit . a new ct scan showed enlargement of the ischemic lesion with involvement of the right thalamus ( fig . 1c ) and new areas of infarction involving different arterial territories , further depicted on mri ( fig . mr angiography showed an occlusion of the right posterior cerebral artery 5 mm after its origin ( fig . 2c ) . transthoracic and transesophageal echocardiography and holter ecg were within the norms , as were the of laboratory blood tests ( including hiv antibodies ) . clinical deterioration continued with further motor compromise , and although no cardiac or large vessel embolic source had been documented , facing neurological worsening , acetylsalicylic acid was substituted by low molecular weight heparin ( 60 mg subcutaneously twice a day ) 6 days after admission . the patient remained stable for a week , but then a new episode occurred , with headache and slight drowsiness associated with hemorrhagic transformation involving the thalamus but sparing the cortical territory of the posterior cerebral artery ( fig . because of the medical history of recent vzv reactivation , it was then hypothesized that the stroke could be secondary to vzv vasculopathy . however , at that time , evidence of increased intracranial pressure contraindicated the lumbar puncture . acyclovir and prednisolone were started empirically ( acyclovir 750 mg three times daily , and prednisolone 60 mg once a day for 21 days ) , with slow but steady improvement . digital subtraction angiography ( dsa ) showed narrowing at the origin of the right posterior cerebral artery and demonstrated an irregular lumen of the posterior segment of the pericallosal artery with beading - like pattern appearance ( fig . she underwent a lumbar puncture 11 days after initiation of therapy ( 27 days after admission ) . cerebrospinal fluid ( csf ) protein content was slightly increased ( 48 mg / dl ) , glucose 59 mg / dl , and a discrete mononuclear pleocytosis was detected ( 6 cells ) . vzv - dna was not detected by polymerase chain reaction , but there was an increased csf / serum ratio of vzv igg ( 3.3 ) , confirming intrathecal production of anti - vzv antibodies . motor function improved , but the patient was discharged with persistent left homonymous hemianopia and spatial inattention , unable to walk without assistance [ modified rankin scale ( mrs ) score 4 ] . after antiviral therapy , she restarted acetylsalicylic acid 150 mg once a day . on the 6-month follow - up , only a mild to moderate paresis of the left limbs was present . the patient was able to walk unassisted and look after her own affairs ( mrs score 2 ) . recognition of vzv vasculopathy was not straightforward because this is an uncommon entity and strokes of other etiologies may present with a similar neurologic picture and imaging abnormalities . on the other hand , finally , vzv - induced central nervous system ( cns ) disease seems to be rare in immunocompetent patients . despite no previous history of headache and sudden presentation of the visual deficit , migrainous infarction could be considered in our patient on account of presentation with pulsatile progressive headache in a young female and the known predilection of this complication for the posterior circulation . cryptogenic stroke , which may be responsible for as much as 50% of strokes in young adults [ 6 , 7 ] , was also considered in the absence of findings that supported cardiac embolism , atherosclerosis , arterial dissection , inflammatory or drug - induced etiologies . although there was no evidence to support the decision , anticoagulation was considered because of the stepwise deterioration of the neurological status under aspirin , with new ischemic areas in different territories , and a mr angiography not indicative of vasculitis . looking backwards , anticoagulation may not have been the most suitable therapeutic choice and should probably be avoided with in - patients with stroke and recent vzv infection , as hemorrhagic transformation occurred probably in the context of vessel wall damage but may also have been triggered by anticoagulation . the biological mechanisms are probably multifactorial : inflammation associated with systemic infection may lead to endothelial dysfunction ; in addition , the vzv virus spreads along nerve fibers and directly involves the vessels . vasculitis has been described in patients with dermatomal herpes zoster infection without trigeminal nerve involvement , as in our case . the vasculopathy typically involves the anterior circulation , but vzv vasculitis involvement of the vertebrobasilar system has also been reported . these studies suggest that vzv may enter the cns not only from trigeminal ganglia but also from other pathways . as suggested in previous reports , this case highlights the usefulness of dsa and csf / serum ratio of vzv igg for the diagnosis of vzv vasculopathy . vzv dna was not present in csf , but several studies with serial analysis revealed its presence only during the first 2 weeks of disease , while anti - vzv igg antibodies become detectable during the second week after infection . the diagnostic value of detecting anti - vzv igg antibody in csf is greater than that of detecting vzv dna . the multifocal nature of vzv vasculopathy makes biopsy a test with low sensitivity and high morbidity . when the diagnosis of vzv vasculopathy was considered , a lumbar puncture was contraindicated due to increased intracranial pressure ; nevertheless , we began treatment with intravenous acyclovir and steroids . although there are no controlled trials to access the optimal treatment schemes , we continued treatment during 21 days . duration of antiviral treatment as well as acyclovir dosage and benefit of steroids are issues that deserve further research . in conclusion , our case underlines that vasculopathy and stroke related to vzv infection should be borne in mind when dealing with stroke in young adults . in fact , available data suggest that this complication of a frequent infection may be more common than usually reported , not only after herpes zoster or varicella but also in cases of a stroke of unknown origin [ 1 , 2 ] . dsa seems to be important to the diagnosis of vzv vasculopathy , which is confirmed by intrathecal synthesis of anti - vzv igg antibody . the authors declare that there are no conflicts of interest and that no funding was received for this report .