Acute glaucoma mimicking trigeminal autonomic cephalalgias: a case report

Context: Trigeminal autonomic cephalalgias (TAC) are unilateral and recurrent headache with ipsilateral cranial autonomic symptoms such as lacrimation, conjunctival injection, ptosis and changes on pupillary diameter. Acute glaucoma is a rare etiology of headache in the emergency room and can be confused with TAC because it also presents with similar symptoms in the affected eyes. Case report: We present a case report of a 50-year-old insulin-dependent diabetic woman with severe headache that started the day before admission. The headache was left hemicranial, pulsatile and associated with ipsilateral lacrimation. On physical examination we observed mild conjunctival hyperemia, ptosis, visual loss of 20/800 and fixed mydriasis in left eye. Because of the visual loss the patient was referred for urgent ophthalmological evaluation that revealed high intraocular pressure (41 mmHg) and neovascularization of the iris, suggesting the diagnosis of acute glaucoma associated with the neovascularization related to diabetes mellitus. Conclusions: Acute glaucoma should be distinguished from TAC given the overlap of severe headache and ipsilateral eye symptom. However, the presence of fixed mydriasis and progressive visual loss suggested the diagnosis of acute glaucoma, since in TAC miosis is the usual pupillary alteration, as a consequence of parasympathetic overactivation, and visual loss is uncommon.