Case Presentation: A 60-year-old female with a history of hypertension, hyperlipidemia, migraines, and HSV-meningitis in 2004 presented with 3 days of progressively worsening bitemporal headache with associated neck stiffness and photophobia. The symptoms were not typical of her usual migraines. A few days prior she had an acute upper respiratory illness with productive cough of clear sputum and rhinorrhea. She has no known sick contacts but works at a hospital and was recently at a wedding. She denies any personal history of cold sores or genital lesions.She was afebrile with normal vital signs on presentation to the ED. On physical exam, she had limited ROM of her neck and positive Kernig sign. Laboratory workup was unremarkable with a normal CBC, BMP, cardiac markers, TSH, CRP, and urinalysis. Blood culture showed no growth. Chest x-ray, CT head/spine w/o contrast, and MRI of the brain w/ and w/o contrast were all unremarkable. On lumbar puncture, she had a lymphocytic pleocytosis, elevated protein, and a normal glucose level. CSF was positive for HSV-2 DNA on BioFire FilmArrary Meningitis/Encephalitis (ME) Panel.Her condition gradually improved with IV acyclovir. Both neurology and infectious diseases were involved throughout the patient’s hospitalization. She was transitioned to oral valacyclovir on discharge to complete her 14-day course of treatment with the recommendation to follow-up with her outpatient primary care providers.
Discussion: Mollaret’s meningitis is a rare subtype of aseptic meningitis characterized by ≥ 2 episodes of meningismus separated by complete recovery. It was first described by French neurologist Pierre Mollaret in 1944 and has been historically reported to present abruptly with typical meningitis symptoms – neck stiffness and pain, headache, nausea, vomiting, photophobia, myalgias, and fevers. Affected individuals may also have a range of temporary neurological disturbances, though persistent neurologic sequelae have not been reported. The interval between episodes can be anywhere between months to years. While HSV-2 is the most common etiology of this condition, HSV-1, EBV, sarcoidosis, SLE, and other conditions have also been described. The CSF profile in Mollaret’s meningitis mirrors what is seen for aseptic meningitis: lymphocytic predominance, mildly elevated protein levels, and normal glucose. More than 50% of patients with Mollaret’s meningitis due to HSV-2 do not report a history of genital herpetic lesions and are therefore not a reliable diagnostic finding. Risk factors for Mollaret’s are not well-studied. Acyclovir and valacyclovir have historically been used to treat Mollaret’s episodes, though it remains unclear whether such therapies are efficacious as treatment or prophylaxis against recurrence.
Conclusions: Mollaret’s meningitis is a benign syndrome with excellent prognosis, and, despite its rarity, should be suspected in all cases of recurrent lymphocytic meningitis to prevent prolonged hospitalizations as well as the unnecessary use of antimicrobial agents.