A 35 years old male presents with a partial seizure involving jerky movements of his right side of his face. He reports having had left-sided headaches for a few months and clumsiness of his right hand, and on further questioning, admits others have the past few months. On examination, he is awake and oriented. He has a subtle facial droop and pronator drift on the right side. What potential sequelae do you need to be concerned about?