Clinical problem-solving. A creeping suspicion

Polymerase Chain Reaction (PCR)-Negative Herpes Simplex Virus (HSV) Encephalitis in a 62-Year-Old Woman With p-ANCA Vasculitis

We present the case of a 62-year-old woman with a past medical history significant for p-ANCA vasculitis (on immunosuppression) who was found to have polymerase chain reaction (PCR)-negative herpes simplex virus (HSV) encephalitis. We also present a review of all identifiable reports of PCR-negative HSV encephalitis in the past 20 years. To our knowledge, this is the first case of PCR-negative HSV encephalitis in a patient with p-ANCA vasculitis and the thirteenth overall in this timeframe. The patient presented with new-onset fever, encephalopathy, and a first-in-lifetime focal motor seizure progressing to status epilepticus. Cerebrospinal fluid (CSF) PCR was negative for HSV on three separate instances between the first and thirteenth days since symptom onset, and the CSF profile was not typical for HSV encephalitis. The patient underwent a brain biopsy, which confirmed the presence of HSV. She continued to worsen despite aggressive seizure control and six days of empiric acyclovir. Unfortunately, she expired despite the reinitiation of acyclovir. When faced with the classical features of encephalitis in the immunocompromised, the suspicion of HSV should remain high despite negative PCR results. The completion of a full course of acyclovir in the absence of clinical improvement should be considered.

Twice Negative PCR in a Patient With Herpes Simplex Virus Type 1 (HSV-1) Encephalitis

Untreated herpes simplex virus type 1 (HSV-1) encephalitis is associated with high mortality. Missed cases can have devastating consequences. Detection of HSV-1 in cerebrospinal fluid (CSF) with polymerase chain reaction (PCR) is reported to have high sensitivity and specificity and is considered the diagnostic gold standard for HSV-1 encephalitis. In this article, we report a case of autopsy-confirmed HSV-1 encephalitis where CSF PCR returned negative on 2 occasions. A 64-year-old man presented with fever, left-sided weakness, and altered level of consciousness. Magnetic resonance imaging demonstrated right mesial temporal lobe diffusion restriction and electroencephalography showed right lateralized periodic discharges. Lumbar puncture was performed on day 1 for which CSF PCR returned negative for HSV-1. Empiric antiviral and antibiotic treatments were continued due to high clinical suspicion of HSV-1 encephalitis. Repeat lumbar puncture on day 5 was unchanged and empiric treatments were discontinued. On day 13, he developed status epilepticus requiring intensive care unit admission. A third CSF sample returned positive for HSV-1. Acyclovir was restarted but he continued to clinically worsen and supportive care was withdrawn. Autopsy confirmed widespread HSV-1 meningoencephalitis. Negative CSF PCR should be interpreted with caution in cases where there is high clinical suspicion of HSV-1 encephalitis. Current guidelines suggest repeating CSF HSV-1 PCR within 3 to 7 days in suspicious cases while continuing empiric therapy. However, missed cases can occur even with repeated testing. Empiric treatment with acyclovir should be considered in cases with high clinical suspicion of HSV-1 encephalitis, while investigations for alternate treatable diagnoses are continued.

Travel-associated neurological disease terminated in a postmortem diagnosed atypical HSV-1 encephalitis after high-dose steroid therapy - a case report

Background

Human encephalitis can originate from a variety of different aetiologies, of which infection is the most common one. The diagnostic work-up is specifically challenging in patients with travel history since a broader spectrum of unfamiliar additional infectious agents, e. g. tropical disease pathogens, needs to be considered. Here we present a case of encephalitis of unclear aetiology in a female traveller returning from Africa, who in addition developed an atypical herpes simplex virus (HSV) encephalitis in close temporal relation with high-dose steroid treatment.

Case presentation

A previously healthy 48-year-old female presented with confusion syndrome and impaired vigilance which had developed during a six-day trip to The Gambia. The condition rapidly worsened to a comatose state. Extensive search for infectious agents including a variety of tropical disease pathogens was unsuccessful. As encephalitic signs persisted despite of calculated antimicrobial and antiviral therapy, high-dose corticosteroids were applied intravenously based on the working diagnosis of an autoimmune encephalitis. The treatment did, however, not improve the patient’s condition. Four days later, bihemispheric signal amplification in the insular and frontobasal cortex was observed on magnetic resonance imaging (MRI). The intracranial pressure rapidly increased and could not be controlled by conservative treatment. The patient died due to tonsillar herniation 21 days after onset of symptoms. Histological examination of postmortem brain tissue demonstrated a generalized lymphocytic meningoencephalitis. Immunohistochemical reactions against HSV-1/2 indicated an atypical manifestation of herpesviral encephalitis in brain tissue. Moreover, HSV-1 DNA was detected by a next-generation sequencing (NGS) metagenomics approach. Retrospective analysis of cerebrospinal fluid (CSF) and serum samples revealed HSV-1 DNA only in specimens one day ante mortem.

Conclusions

This case shows that standard high-dose steroid therapy can contribute to or possibly even trigger fulminant cerebral HSV reactivation in a critically ill patient. Thus, even if extensive laboratory diagnostics including wide-ranging search for infectious pathogens has been performed before and remained without results, continuous re-evaluation of potential differential diagnoses especially regarding opportunistic infections or reactivation of latent infections is of utmost importance, particularly if new symptoms occur.

Herpes encephalitis : a stroke mimicker

Background: HSV-1 encephalitis (HSVE) usually presents with fever, altered mental status or focal seizures. Aphasia can also be a presenting symptom of HSVE but rarely occurs as the primary symptom. We present a case where aphasia was the primary presenting symptom of HSVE.

Case: A 72-year-old physician with a history of hyperlipidemia and obstructive sleep apnea presented to the emergency room with sudden onset of speech difficulty lasting an hour. He did not have a fever, photophobia, neck stiffness, weakness, or numbness. The patient was brought in by the family within an hour to the emergency department. On exam, the only neurological deficit that was found was the use of inappropriate words in sentences and inability to name certain objects. He was diagnosed with an embolic stroke and received tPA. MRI brain that was done 24-hour post tPA showed an increased FLAIR and T2 signal hyperintensity within the medial left temporal lobe with slight effacement of the cysts sulci which was concerning for encephalitis. This was later confirmed by serology. The patient was started on IV Acyclovir and recovered fully after 3 weeks of acute neuro rehabilitation.

Conclusion: Aphasia primarily is an unusual presentation of HSVE. It should be considered as one of the possibilities in patients presenting with features suggestive of a stroke involving the language areas of the brain.

MRI diagnosis of herpes simplex encephalitis in an elderly man with nonspecific symptoms

A 78-year-old male presented to the Emergency Department complaining of a 1-week onset of increasing fatigue and anorexia. The patient was previously well but had a history of depression, chronic diarrhea, and hypertension. His examination was remarkable for mild fever (100.1°F). He had no acute neurologic deficits. The patient felt better after intravenous fluids and was discharged to follow-up with the primary care provider. With no resolution of symptoms and new memory loss, the patient's primary care doctor ordered an MRI which revealed abnormal signal/patchy enhancement of the left temporal lobe indicative (pathognomonic) of herpes simplex encephalitis. This case emphasizes the importance of early consideration of herpes simplex encephalitis in the differential of patient's with these symptoms.