Case Presentation: A previously healthy 25-year-old woman presented with 3 weeks of headache. Headaches were bilateral, daily, of a severe squeezing quality, and were described as the worst pain of her life. She reported associated fever to 102°F, pressure behind her eyes, photophobia, neck stiffness, nausea, and vomiting. Temperature was 99.7°F, heart rate 99 beats per minute, blood pressure 112/76 mmHg, and respiratory rate 18 breaths per minute. She appeared mildly distressed from pain and had no neurologic deficits.MR head was normal. MR venography showed moderate bilateral transverse dural sinus stenosis consistent with elevated intracranial pressure. Lumbar puncture showed opening pressure of 34 cmH2O, WBC 313 cells/uL (95% lymphocytes), protein 93 mg/dL, and glucose 51 mg/dL. Her headache and nausea greatly improved after lumbar puncture. Workup revealed negative CSF cultures, viral PCR, cytology, VDRL, and cryptococcal antigen and negative serum HIV Ab, Rickettsia Ab, ANA, and anti RNP. She had positive serum Borrelia burgdorferi IgM Ab. Her family noted her house contained many ticks, and they suspected that she was bitten. She also had traveled to New York two months prior. She was diagnosed with Lyme meningitis and treated with doxycycline and ceftriaxone with resolution of symptoms.A week into outpatient treatment she had recurrence of severe headache with retroorbital pressure, blurry vision, and tinnitus and presented to the hospital. Vital signs were normal. She was well-appearing. Fundoscopy showed blurring of left inferior optic disc and remainder of the exam was normal. Lumbar puncture showed opening pressure of 50 cmH2O, WBC 12 cells/uL (93% lymphocytes), glucose 41 mg/dL, and protein 23 mg/dL. Symptoms resolved after large volume lumbar puncture. Her resolving CSF inflammation supported prior Lyme meningitis responding to treatment. She was diagnosed with post-Lyme disease intracranial hypertension (PLIH). She subsequently completed meningitis treatment. At her 2-month follow-up visits she had resolution of symptoms and no optic disc edema.
Discussion: Elevated opening pressure with a lymphocytic pleocytosis is rarely consistent with viral meningitis and never consistent with idiopathic intracranial hypertension (IIH). These findings should prompt further evaluation in the hospital setting, where hospitalists are often responsible for the initial workup. Alternative infectious etiologies include Cryptococcus, Tuberculosis, Syphilis, Borrelia burgdorferi, Rickettsia, and Leptospirosis. Non-infectious etiologies include meningeal carcinomatosis, lymphoma, paraneoplastic encephalitis, and SLE.PLIH is a well-documented phenomenon in children but rare in adults. PLIH mimics IIH by presenting with headache, visual changes, tinnitus, and papilledema. Persistent headache in patients with Lyme disease should prompt the consideration of intracranial hypertension.The treatment of intracranial hypertension due to infection is antimicrobials and serial lumbar punctures, whereas treatment of IIH is acetazolamide and removal of risk factors such as oral contraceptives, Vitamin A, and weight loss.
Conclusions: It is critical that a hospitalist keeps a broad differential diagnosis for lymphocytic pleocytosis with an elevated opening pressure including malignancy, autoimmune disorders, and atypical infections such as Lyme meningitis. A rare but important complication of Lyme meningitis is intracranial hypertension, which can mimic IIH.