Acute Cerebellitis With a Cross-Reactivity of COVID-19 and Influenza A.

This is a case report of a previously healthy three-year-old male who was admitted to the emergency department (ED) of the Pediatric Intensive Care Unit in King Salman Armed Forces Hospital in Tabuk. The patient presented to the ED with an acute inability to stand, associated with two episodes of non-bilious, non-bloody vomiting and abdominal pain that began approximately four hours prior to presentation. This was preceded by a nine-day history of upper respiratory tract symptoms, for which he had received oral antibiotics. On the day of presentation, the patient developed vertigo, dysarthria, and gait instability. There was no history of fever, seizures, altered consciousness, trauma, or toxin exposure. On examination, the patient was hemodynamically stable and appeared non-toxic. Growth parameters were appropriate for age. Neurological examination revealed truncal ataxia, intention tremor, dysarthria, and bilateral hypotonia. Deep tendon reflexes were intact, with hyperreflexia noted at the knees. Cranial nerve examination was normal, and no meningeal signs were present. Laboratory investigations were largely within normal limits, with mild elevation in inflammatory markers. Cerebrospinal fluid (CSF) analysis demonstrated mild pleocytosis, normal glucose, and mildly elevated protein. Blood, urine, and CSF cultures showed no microbial growth. CT done at presentation showed no fractures with good differentiation of gray and white matter and no central deviation. A nasopharyngeal swab was sent for viral panel, which came positive for both COVID-19 and Influenza A; thus, he was started on oseltamivir along with acyclovir, ceftriaxone, and vancomycin pending culture results. Upon stabilization of the condition and improvement of the symptoms, the patient was transferred to the floor to continue his active treatment and observation. Acute cerebellitis should be considered in children presenting with acute ataxia, particularly following viral illness. This case highlights the potential association between SARS-CoV-2 and influenza A co-infection and cerebellar involvement. While the exact mechanism remains unclear, immune-mediated processes are likely contributory. Early recognition, appropriate investigation, and timely management are essential to ensure optimal outcomes. Further research is needed to better understand the role of viral co-infection and immune mechanisms in acute cerebellitis.