Unilateral Facial and Vestibulocochlear Nerve Palsy: A Case Report of a Rare Adverse Effect of Warfarin Therapy.

INTRODUCTION: Intracranial hemorrhage, most often intraparenchymal hemorrhage, is an increasingly common and fatal complication of warfarin-induced coagulopathy. Warfarin remains the anticoagulant of choice in valvular atrial fibrillation. However, warfarin has a narrow therapeutic index. Extra axial hemorrhage due to warfarin-induced coagulopathy is a rare adverse event. We present a rare case of right vestibulocochlear and lower motor neuron (LMN) facial palsy secondary to an intracranial bleed along the cerebellopontine angle.

CASE DESCRIPTION: A 36-year-old woman presented with headache, giddiness, sudden onset of right-sided hearing loss, and left-sided deviation of the angle of the mouth. Symptoms had developed acutely over 4 hours. She was diagnosed with mitral stenosis at 8 years of age and had undergone mitral valve repair 2 years before presentation, after which she was started on warfarin. She was lost to follow-up for over a year and on presentation had right-sided sensorineural hearing loss along with features such as difficulty raising her right eyebrow, inability to close her right eye, and water drooling from the right side, all consistent with a right LMN facial palsy and vestibulocochlear nerve palsy. MRI brain showed an extra-axial hemorrhage at the right cerebellopontine angle cisterns.

CONCLUSION: Warfarin-induced intracranial bleeds without involving the parenchyma are a rare event, and through this case, we would like to highlight the importance of timely monitoring of the international normalized ratio (INR) of patients on warfarin therapy.