A 4-year-old boy with vestibular neuritis and a serological diagnosis of adenovirus infection is reported from the University of Siena, Italy. He was admitted with paroxysmal vertigo, vomiting and unsteadiness, leaning left on attempted walking or during the Romberg test. A similar episode had occurred one year before; symptoms lasted 1 week and the patient was not hospitalized. On present examination, spontaneous horizontal nystagmus to the right decreased with visual fixation. EEG and ENT examinations were normal, and showed no evidence of seizure disorder or middle ear disease. Family history was negative for migraine. On partial recovery within a few days, a water caloric test showed no response in the left ear. Serum antibody complement fixation test for a battery of viral infections was positive only for adenovirus, the titer on admission being 1/16, 1/8 at 2 weeks, and undetectable at 4 weeks. PCR for adenovirus on lymphocytes and saliva was negative. Brain MRI was normal. Minor unsteadiness, nystagmus, and absent caloric response in the left ear persisted at 1 month. 
COMMENT. This case report is suggestive of an etiologic role for adenovirus infection in vestibular neuritis. Detection of the virus by pharyngeal culture or antigen is the preferred diagnostic method for adenovirus (AAP Red Book, 25th ed, 2000; 162-163), and the negative PCR on saliva may militate against a recent infection. A reactivation of a previous infection is possible, but biological samples from a previous episode of vertigo were unavailable for testing.
Vestibular neuritis caused by enteroviral infection is reported in a 7-year-old male, and confirmed by isolation of enteroviral RNA in CSF and nasopharyngeal washings . Other etiologies listed include mumps, rubella, herpes simplex type 1, cytomegalovirus, and Epstein-Barr virus.