Abstract | March 5, 2024

Atypical Presentation of Mumps Encephalitis: A Case Report

Ferdusy Dia, MD, Internal Medicine, PGY2, Novant Health, Wilmington, NC

Katherine M. Ruiz, MD, Internal Medicine, PGY2, Novant Health, Wilmington, NC; Bhumi Patak, MD, Internal Medicine, PGY2, Novant Health, Wilmington, NC; Charin Hanlon, MD FACP, Internal Medicine, Program Director, Novant Health, Wilmington, NC

Learning Objectives

  1. Understand the importance of the differential diagnosis when a patient presents to the Emergency Department with neurologic symptoms
  2. Identify when a patient requires a more thorough evaluation when the symptoms are not getting better

Introduction: Bilateral hyperintense lesions of the brain can be seen with multiple pathologies, but the most concerning one is encephalitis. There are many causes of encephalitis and when the patient is unable to provide any history, it becomes a true challenge. Mumps as a cause for encephalitis is an exceedingly rare diagnosis in the era of vaccination. Here, we present a case of atypical presentation of mumps encephalitis without evidence of parotitis.

Case presentation: A 63-year-old female presented to the ED due to headache, difficulty speaking and abnormal gait. Initial workup was remarkable for leukocytosis, abnormal right extraocular movements, and inability to follow two-step commands on examination. She was up to date in all vaccinations. Patient was admitted for concerns of stroke. CAT scan was negative for any ischemic changes or hemorrhages. Overnight, she developed a temperature of 103 and her neurologic status continued to decline. Given concerns of meningitis, she was started on broad-spectrum antibiotics while waiting for further imaging. MRI of the brain revealed abnormal flair hyperintensity within the bilateral basal ganglia, midbrain, and pons. Due to rapid decline in neurological status, the patient was intubated for airway protection and was transferred to the ICU. A lumbar puncture was completed, and infectious disease was consulted. Antiviral therapy with Acyclovir was started, along with steroids. Lumbar puncture showed pleocytosis with total neutrophil count of 680, mainly lymphocytes. Encephalitis molecular panel and meningitis PCR were negative. Tick borne infection was also ruled out. West Nile serum Ab and CSF West Nile were negative. Given unknown cause and ongoing symptoms, a repeat lumbar puncture was done 3 days later and was positive for IgM mumps on CSF.

Final diagnosis: Atypical mumps encephalitis

Management / Follow-up: There is no treatment for this disease in the literature. She was able to be extubated, but unfortunately, required a PEG tube for nutrition. She was non-verbal at the time of discharge and given her acute decline secondary to the disease, she went to a long-term rehabilitation facility to work on her neuromuscular recovery. She continues to follow up with Neurology in the outpatient setting.

References and Resources

  1. Chee, Y. C., & Ong, B. H. (2019). Mumps encephalitis with bilateral hippocampal lesions preceding parotitis. Neurology. Clinical practice, 9(6), 475–477. https://doi.org/10.1212/CPJ.0000000000000665
  2. TAYLOR FB, TORESON WE. Primary Mumps Meningo-Encephalitis. Arch Intern Med. 1963;112(2):216–221. doi:10.1001/archinte.1963.03860020114015
  3. W.L. Donohue, F.D. Playfair, L. Whitaker, Mumps encephalitis: Pathology and pathogenesis, The Journal of Pediatrics, Volume 47, Issue 4, 1955, Pages 395-412, ISSN 0022-3476,
    https://doi.org/10.1016/S0022-3476(55)80051-0. (https://www.sciencedirect.com/science/article/pii/S0022347655800510)s://www.sciencedirect.com/science/article/pii/S0022347655800510)
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