Dados do Trabalho

Título

Oligodendroglial and neuronal clusters in a patient with temporal lobe epilepsy and amygdala enlargement

Apresentação do caso

A 21 years old right-handed male with uncontrolled seizures since age ten was surgically treated in our center. He had no history of initial precipitant injury, presented normal neuropsychomotor development, and had no family history of epilepsy. Seizure semiology included a description of out-of-body sensation and déja-vu, followed by behavioral arrest, presenting with 30 seizures/month, half of which evolving to bilateral tonic-clonic episodes. Brain MRI showed increased volume and FLAIR hypersignal in the left amygdala, without calcifications or contrast enhancement. The left hippocampus was normal, with only a slight increase in FLAIR signal. VideoEEG showed asymmetric base activity, bitemporal slow wave burst predominantly to the left and epileptiform paroxysms in the left temporal region. Histopathology evaluation revealed neuron clusters and a single focus of clustered oligodendroglial cells spanning several consecutive sections in the amygdala. Eight years after surgery, the patient remained with seizures (Engel 2A/ILAE4) and is currently under carbamazepine (800 mg) and clobazam (10 mg).

Discussão

Among mesial temporal lobe epilepsy cases, amygdala enlargement (AE) is sometimes the only abnormality seen in the patients. Although most could expect a low-grade tumor as the etiology in these cases, but this hypothesis was ruled out in our patient after a comprehensive anatomopathological evaluation. Moreover, most studies indicate gliosis and malformations as the main etiologies in AE cases. The presence of oligodendroglial abnormalities together with neuronal clusters is rare, as we only found one case described presenting with oligodendroglia-like clusters in AE. Regarding seizure outcome, a review of 8 studies describing more than 100 cases revealed that several are well controlled with antiseizure medications, and most of the surgically-treated AE patients were Engel I, including the case with oligodendroglial atypia. Only around 11% are Engel II, as is our patient.

Comentários finais

The presence of malformation with oligodendroglial clusters was only described once among AE patients, and T2/FLAIR hypersignal in AE is not a pathognomonic sign of low-grade tumor.