Dados do Trabalho

Título

Rabies Encephalitis: Follow-up with Electroencephalogram

RESUMO

Case report:

A 2-years-old boy from the interior of Maranhão was referred for suspected encephalitis. He had a history of fox scratch on the left leg without rabies prophylaxis 2 months ago of symptoms onset (fever, irritability, spasms and incoordination). The diagnosis of rabies was made through splitte and PCR test. CSF (9th day) and brain MRI (15th day) were initially normal. The CSF (16th day) showed WBC 106; PMN: 76% Prot:117; Glucose: 35. Serial evaluations were performed with electroencephalogram (EEG), which showed:

The EEG was performed under continuous sedation on the 15th, 18th and 22nd day.
15th day: Diffuse slowing with the presence of frontocentral spindles.
18th day: Burst-suppression pattern, consisting of delta and theta activity with frontal accentuation and maximum interburst interval of up to 5 seconds.
22nd day: Activity suppression. Patient evolved with the absence of brain stem reflexes.
32nd day: Burst-suppression. Its bursts were constituted of rhythmic theta activity (5 to 7 Hz) in the frontocentral region, with a lack of alpha and beta rhythms. The maximum interburst interval was 10 seconds.
38th day: Activity suppression and occasional bursts of rhythmic theta activity in the left frontocentral region.

The last brain MRI showed: areas of diffuse hyperintensity in the cortex and basal ganglia on T2 and Flair without expression in the diffusion sequence. The patient died on the 51st day of symptoms onset.

Discussion:

Rabies encephalitis is caused by a Lyssavirus. It is transmitted through the bite or scratch of mammals carrying the disease. Despite reports of survivors, the mortality of the disease is close to 100%. There are descriptions of multiple EEG patterns of this encephalitis, such as: slowing, periodic discharges, isoelectric pattern mimicking brain death, among others. None of them are specific to the disease. In the present case, it was possible to follow, through the electroencephalogram, the catastrophic evolution of the disease, being observed patterns of progressive hypometabolism, as respectively: diffuse slowing, burst-suppression and activity suppression. The EEG is not indicated for the diagnosis of brain death in this population.

Conclusions:

In rabies encephalitis, there are no specific findings on EEG. It is used as a non-invasive method at the bedside to identify subclinical seizures, monitor the level of sedation and follow-up the patient's clinical course.

Palavras Chave

encephalitis, electroencephalogram, rabies

Área

Neurofisiologia Clínica