a 57-year - old man was referred to samsung medical center with abrupt confusion , fever , and loss of vision in both eyes .
the patient was in his usual state of health until two weeks prior , when he began to develop sudden loss of vision in his right eye . in another hospital , he was diagnosed with retinal vasculitis in his right eye and was prescribed oral prednisolone , 60 mg / day for three days , followed by 120 mg / day for three days .
the retinal vasculitis did not respond to oral prednisolone , so he was treated with intravenous methylprednisolone , 1 g / day for five days .
two days after initiation of intravenous methylprednisolone , he complained of decreased vision in his left eye .
one week after initiation of intravenous methylprednisolone , he became drowsy and high fever occurred , and he was then referred to samsung medical center . on neurological examination , he was drowsy and confused to time and place orientation .
his brain magnetic resonance imaging ( mri ) showed a hyper - intense lesion in the left medial temporal and bilateral medial occipital areas on t2-weight images , suggestive of hse ( fig .
cerebrospinal fluid ( csf ) study revealed 11 cells / ml ( lymphocytes 90% ) , low protein ( 19.3 mg / dl ) , and normal range glucose concentration ( 63 mg / dl compared to 110 mg / dl in serum ) . an empirical antiviral agent
one week later pcr of the csf was revealed to be positive for hsv-1 dna . on the night of admission ,
his electroencephalography showed sharp waves in left or right anterior temporal areas ( f7t7 , f8t8 maximum ) with a frequency of 1/min and diffuse slow waves .
an antiepileptic drug ( phenytoin 300 mg / d ) was administered and no more epileptic seizure recurred . on the day of admission , his visual acuity was perception of light in both eyes .
fundus examination showed retinal hemorrhage , confluent retinal necrosis affecting almost the whole retina , vascular sheathing involving both arterioles and venules , optic disc swelling , and exudative retinal detachment in both eyes ( fig .
infectious retinitis including acute retinal necrosis was suspected , but in terms of the location of necrosis , his clinical features were not typical of arn diagnostic vitrectomy confirmed the presence of hsv-1 .
after administration of intravenous acyclovir for 14 days , his systemic symptoms consistent with encephalitis slowly resolved , but his vision was not restored . on follow - up examination ,
retinal necrosis did not progress , but he still suffered from severe bilateral ocular pain with partial improvement of the exudative retinal detachment ( fig . 2c , d ) .
thus , intravitreal ganciclovir injection ( 5,000/0.05 g / ml ) causes pain relief and decreased intraocular inflammation .
atrophy was found six weeks later , thus vitrectomy with silicone oil tamponade was done in the right eye .
cases with arn following hse have been uncommonly reported,59 and to our knowledge , this is the first report of the reverse situation , hse following arn , in even an immune - competent patient .
arn associated with hse is known to be caused by axonal transmission of a reactivated latent virus from the brain to the retina , and retinitis occasionally occurs after the encephalitis . as shown by our patient ,
this is consistent with the finding that herpes virus uses bidirectional fast - axonal transport in neurons.11 arn usually presents as retinal necrosis with discrete borders located in the peripheral retina , rapid progression , circumferential spread , occlusive vasculopathy with arterial involvement , and a prominent inflammatory reaction in the vitreous and anterior chamber.3 our patient was initially diagnosed with retinal vasculitis and treated with a high - dose systemic corticosteroid , which was not effective .
corticosteroids are known to affect cellular immunity and may promote viral replication . intraocular or systemic corticosteroids may induce retinal necrosis in patients with viral infection .
thus , it is recommended that corticosteroids should be used in combination with antiviral agents or after beginning antiviral therapy.12 in this patient , the contralateral eye became infected , and hse occurred during initial corticosteroid therapy without antiviral medication . in cases with an unusual clinical course , especially in retinal vasculitis with arterial involvement ,
, arn may be a risk factor for hse , even in an immune - competent patient .
the virus may reach the brain from the eye by a trans - axonal route .
systemic steroid therapy may have exacerbated herpes viral infection in the retina , with subsequent spread to the contralateral eye and brain .
 acute retinal necrosis ( arn ) , a viral retinal disease with poor visual prognosis , following herpes simplex encephalitis ( hse ) are uncommonly seen , and there has been no case yet reported of the reverse situation . 
 we herein present the reverse situation , an immune - competent patient with hse following arn . 
 a 57-year - old man who had been under steroid therapy for retinal vasculitis the prior two weeks , presented with abrupt confusion and high fever . 
 his cerebrospinal fluid study and brain magnetic resonance imaging revealed typical hse . 
 ophthalmic examination and polymerase chain reaction of the vitreous specimen revealed arn by herpes simplex virus type 2 . intravenous acyclovir treatment improved his encephalitis symptoms and retinal necrosis . 
 this case implies that arn may be a risk factor for hse and the virus may reach the brain from the eye . 
 inappropriate administration of a systemic steroid may exacerbate herpes viral infection in the retina , with subsequent spread to the brain . 
Case Report
Discussion