Title : Eastern equine encephalitis: A rare case with minimal drama in brain’s theater
Abstract:
Introduction: Eastern Equine Encephalitis (EEE) is a rare zoonotic viral disease caused by the Eastern Equine Encephalitis Virus (EEEV), which belongs to the Togaviridae family. While human infections are uncommon, they carry a high mortality rate of approximately 33%. Survivors often experience significant neurological sequelae. We present a rare case of EEE in a 91-year-old patient who showed a rapid improvement in symptoms with only minor neurological consequences.
Case Report: A 91-year-old female with a past medical history of coronary artery disease (CAD), osteoporosis, hyperlipidemia, and a right frontoparietal meningioma, presented with a few days of new onset slurred speech, drooling, headache, and mild dysphagia. On initial evaluation, she exhibited flattening of the left nasolabial fold and persistent slurred speech, without expressive or receptive aphasia, or focal strength or sensory deficits. A Level 2 Code Stroke was activated.
Initial imaging, including CT head and CTA head and neck, showed no acute pathology but confirmed the presence of her known meningioma with mass effect on the right ventricle. She was admitted to the medicine floor. The patient, an avid gardener, was suspected of possible tick-borne illness, so a viral panel was sent, which returned negative.
During her hospitalization, she developed worsening left-sided motor weakness, although repeated imaging showed no acute changes. Her condition was complicated by high-grade fevers, and she was empirically started on IV Unasyn. A lumbar puncture was performed due to concern for meningitis, revealing elevated protein levels in the cerebrospinal fluid (CSF). The CSF and serum was sent to the CDC for further analysis, and testing confirmed the presence of Eastern Equine Encephalitis Virus and powassan virus in the serum but only positive for IgM antibodies against EEEV in CSF.
After a 7-day course of Unasyn, the antibiotic was discontinued. The patient actively participated in speech and swallow therapy, leading to significant improvement in her dysphagia and dysarthria, and she eventually was started on a diet. Regular physical therapy contributed to gradual improvement in her left-sided motor weakness. She was discharged to a subacute rehabilitation facility.
Upon re-evaluation during her stay in the rehabilitation facility, the patient showed significant recovery in motor and bulbar functions. However, mild cognitive issues persisted.
Discussion: Eastern Equine Encephalitis Virus (EEEV) is known to have high mortality and significant neurological sequela. However, as illustrated by this case, some individuals may experience a much milder course with minimal neurological effects. Our patient, despite being 91 years old with multiple comorbidities, showed rapid improvement after treatment, with only mild cognitive impairment remaining. This suggests that factors such as the patient’s immune response, viral load, and the timeliness of intervention might influence the severity of disease.
This case also highlights the potential for co-infection with other arboviruses, such as Powassan virus, which was detected alongside EEEV in the patient’s serum. Co-infections could complicate the clinical picture and impact disease progression, though our patient’s rapid recovery suggests that prompt diagnosis and supportive care, including physical and speech therapy, can result in favorable outcomes even in elderly patients with underlying health conditions.
In conclusion, while EEE is typically associated with severe outcomes, some cases may present with milder symptoms and better prognoses. Further research is needed to identify factors that contribute to these variations in disease severity and to improve management strategies for patients with less severe manifestations of EEE.
