Enigmatic vessel: The persistent hypoglossal artery in a tetralogy of fallot patient with brain abscess – Report of a rare case

Persistent hypoglossal artery (PHA) is a rare vascular variant of carotid-basilar anastomosis, with persistent trigeminal artery being the more common one. It is even rarer in patients with tetralogy of Fallot (TOF) with very few cases reported in the literature. We present a case of a 9-year-old boy diagnosed with Tetralogy of Fallot who presented to the Pediatrics department of Shifa International Hospital with complaints of headache, vomiting and fits. His MRI and serial CT brain imaging were performed, and a diagnosis of brain abscess was made. An incidental note was made of the persistent right hypoglossal artery. He was given IV antibiotics, and significant improvement was seen radiologically as well as clinically. The patient is a potential candidate for Surgical repair of TOF.