Herpes Simplex Encephalitis Presenting with Bilateral Hippocampal Lesions on Magnetic Resonance Imaging, Simultaneously Complicated by Small Cell Lung Carcinoma

Abstract

We report a 75-year-old man who developed herpes simplex encephalitis (HSE), presenting with bilateral hippocampal lesions on magnetic resonance imaging, and this case was simultaneously complicated by small cell lung carcinoma. We identified a new anti-neuronal antibody in the cerebrospinal fluid of this patient. Our findings suggest that HSE and paraneoplastic limbic encephalitis (PLE) can overlap, and we discuss the relationships of HSE, PLE, and related disorders.

A Herpes simplex virus-1 fatal encephalitis following chemo-radiotherapy, steroids and prophylactic cranial irradiation in a small cell lung cancer patient

“…In our case we discarded the hypothesis of a paraneoplastic focal encephalitis because the electroencephalogram was not specific and MRI imaging was suggestive of a typical viral encephalitis whereas Hirai et al [18] and Fadul et al [19] case reports revealed focal findings on brain MRI and electroencephalogram. The absence of pleocytosis, radiation induced lymphopenia and the positive HSV-1 consensus test in cerebrospinal fluid suggested that HSE should be accounted in a immunosuppressed subject as in our patient.…”

“…Rarely HSE may be an expression of a paraneoplastic syndrome: recently have been reported two cases on untreated cancer patients complicated by a paraneoplastic limbic HSE [18] and by a paraneoplastic encephalitis combined to an organic epilepsy [19]. Anyway the pathogenesis underlying the reactivation of latent Herpes simplex virus in the brain may be multifactorial and remains undefined.…”

“…Dragoje and colleagues [10] reported a case of HSE on a 52-year-old woman 2 months after brain irradiation and dexamethasone administration. Authors commented that, as suggested by experimental evidence on mouse trigeminal ganglia [18] HSE could be resulted by reactivation of endogenous latent Herpes simplex virus. Brain irradiation together with corticosteroid therapy might had exhibited a trigger mechanism on virus replication and on a new lytic virus cycle.…”

Limbic encephalitis: Experience of a moroccan center

“…This could be explained by the fact that infectious causes are more common in our study because these etiologies usually have an acute onset of symptoms (Geisler et al, 2013;Hirai et al, 2005). Brain MRI shows on T2-weighted images (a) and FLAIR sequences (b) bilateral hyperintensity in temporo-insular regions predominant on the right.…”

“…Diagnosis of herpetic LE was made after the biological investigations onset was acute (1-7 days) in 64.5% of cases. This could be explained by the fact that infectious causes are more common in our study because these etiologies usually have an acute onset of symptoms (Geisler et al, 2013;Hirai et al, 2005). The autoimmune LE most often has a subacute onset of symptoms.…”