Hypermanganesemia related pallidal T1-hyperintensity is a rare manifestation of hereditary hemorrhagic telangiectasia (HHT).1 Levodopa-unresponsive parkinsonism has been described in HHT.1 We report a patient who presented with brain abscess–related seizures and was diagnosed with the HHT-juvenile polyposis overlap syndrome with hypermanganesemia. This report highlights the multifactorial pathogenesis of hypermanganesemia in HHT. ### Case report. A 35-year-old man was referred for embolization of pulmonary arteriovenous malformations (AVMs) which were detected on a chest CT done to investigate the cause of a left frontoparietal abscess. A month earlier he presented with recurrent generalized tonic-clonic seizures. Brain MRI showed a ring-enhancing left frontoparietal mass with edema (figure, A and B). Biopsy revealed purulent fluid which grew Streptococcus viridans and anaerobic Gram-negative rods. He had a past history of epistaxis, left eye hemorrhage, gum bleeds, iron deficiency anemia, and lower gastrointestinal bleeding. Endoscopy revealed multiple telangiectasia involving the gastroduodenal mucosa and colonic polyps. A colectomy revealed multiple tubulovillous adenomas. His family history was positive for epistaxis in his mother. His examination was unremarkable except for oral telangiectasia. Hepatic function assessed by liver enzymes was normal. Figure Coronal T1 with contrast (A), sagittal T1 with contrast (B), and axial T1 FLAIR (C, D) MRI sequences …