To report the first documented case of Bell's palsy occurring concurrently with acute open-angle glaucoma (OAG) following methamphetamine use, expanding our understanding of the drug’s potential neurologic complications.

Methamphetamine use is associated with various neurological and ocular complications thought to be related to direct neurotoxicity, neuroinflammation and vasoconstriction, including cerebrovascular events, seizures, retinopathy and acute closed-angle glaucoma. However, neither OAG nor Bell's palsy have been previously reported as drug-related complications in the literature.

Case report and literature review.

A 39-year-old male with history of well-controlled HIV, methamphetamine use disorder and family history of glaucoma presented with 1 day of right-sided facial droop and left eye painless vision loss, 1 week after heavy relapse in intravenous and intranasal methamphetamine use. Examination revealed complete right-sided peripheral cranial nerve VII palsy, bilateral elevated intraocular pressures (IOP; left 43 mmHg, right 23 mmHg), as well as no light perception, afferent pupillary defect and deep cupping with complete rim loss of the optic disc in the left eye. MRI revealed left optic nerve atrophy and mild segmental enhancement of the right facial nerve. The patient was treated with IOP-lowering medications, oral corticosteroids and valacyclovir, and completed drug rehabilitation. At 3-month follow up, he experienced improvement of facial palsy but had persistent left eye blindness.

This case is the first to report an association between methamphetamine use and Bell's palsy, occurring alongside an acute exacerbation of previously undiagnosed OAG. Possible pathophysiological mechanisms for this presentation include vascular dysregulation and neuroinflammation affecting the facial nerve vasa nervorum and optic nerve head perfusion. This case expands our understanding of methamphetamine's potential neurologic and ocular complications and highlights the need for further investigations into their underlying mechanisms.