Case report:
A previously healthy 12-year-old girl presented with a 12-month history of intermittent right facial paresthesias which occasionally extended to the right superior and inferior limbs, associated with variable tonic-clonic movements, headaches, and aphasia. Video-EEG monitoring showed left temporal/parietal ictal activity. A brain and spine magnetic resonance imaging (MRI) identified a lesion involving the left insular cortex and frontal operculum with extension into the deep white matter suspicious of low-grade glioma (Fig1A, 1B). The patient was started on 3 different AED without efficacy in seizures control. Furthermore, and secondary to her poor controlled epilepsy, she developed panic attacks and symptoms of anxiety and depression, isolating herself at home from friends and family. Ten days after the first scan, a functional MRI for language localization with diffuse tensor imaging (DTI) was performed. The lesion had significantly increased in size (Fig1C) and depicted a close relationship with language areas and major white matter tracts (arcuate fasciculus and corticospinal tract, Fig1D). Because of the high risk associated with a radical surgery, a stereotactic biopsy was performed without complications. The pathology review was consistent with a WHO grade 1 ganglioglioma. The BRAF p.V600E mutation, in addition to monoallelic CDKN2A deletion was identified by using droplet digital PCR (ddPCR).
Treatment was initiated with dabrafenib at 150 mg BID. A few weeks into therapy, seizures frequency decreased and two months later, they stopped. After 4 months on dabrafenib, a follow-up MRI showed no evidence of disease (Fig2). After 14 months, AED were discontinued with no clinical signs nor epileptic activity in the EEG. Anxiety and depression symptoms decreased, and the patient was able to go back to her normal activities including school and sports. Therapy was overall well tolerated. However, because of fatigue and headaches, the dosage had to be decreased progressively to 75 mg BID with further good tolerance and compliance. She is still in complete remission and seizures free 30 months after diagnosis.