Brainstem auditory evoked potential (BAEP) abnormalities in brucellosis

Brucellosis

Brucellosis is a common Zoonosis affecting half a million people annually. The most common mode of infection is by consuming unpasteurized milk or milk products. The general manifestations are those of fever with generalized symptoms. The nervous system is affected in 4-7% of cases. The manifestations are protean and include meningo-encephalitis as well as peripheral nervous system involvement. The diagnosis relies on culture, which is cumbersome and can be falsely negative. Agglutination tests for the various species of the organism are the mainstay for diagnosis. Treatment is for 3-6 months with combination therapy including Doxycycline, Rifampicin and ceftriaxone. The main issue is prevention and better animal husbandry.

EVALUATION OF BRAINSTEM AUDITORY POTENTIAL IN BRUCELLOSIS PATIENTS WITH AND WITHOUT NEUROLOGICAL INVOLVEMENT

This study investigated the changes in brainstem auditory evoked potentials (BAEPs) in acute phase of brucellosis. Twenty-two patients with brucellosis without neurologic involvement and seven patients with neurobrucellosis were included. BAEPs were evaluated before treatment. No patient had a symptom of hearing loss. Patients who had neurologic involvement did not show any abnormalities in their BAEPs recording. This study suggests that patients with brucellosis who are in the acute phase of the disease with or without neurological involvement may have normal BAEPs. BAEPs do not seem to be a sensitive method for central nervous system involvement of brucella patients in the acute phase of the disease.

Diagnostic role of brain-stem auditory evoked potentials in neurobrucellosis

Evoked potential audiometry and brain-stem auditory evoked potentials were evaluated in 15 patients with systemic brucellosis in whom brucella meningitis was suspected clinically. In 8 patients cerebrospinal fluid (CSF) was abnormal with high brucella titre, and evoked potentials were abnormal in all of them. In 7 patients the CSF was normal and evoked potentials were also normal. Brain-stem auditory evoked potential abnormalities were categorised into 4 types: (1) abnormal wave I, (2) abnormal wave V, both irreversible, (3) prolonged I-III interpeak latencies, and (4) prolonged I-V interpeak latencies, both reversible. These findings are of important diagnostic value and correlate well with the clinical features, aetiopathogenesis and final outcome.