The Presence of Bilateral Dilated Pupils is Not a Death Sentence in a Stroke Patient: A Case Report

Bilateral dilated pupils are an ominous clinical sign of brainstem dysfunction, which uniformly leads to a bad prognosis for the patient. In some rare instances in adult patients, it could be reversible. We present a clinical case of an elderly stroke patient with bilateral dilated pupils with a surprisingly favorable clinical outcome. An 80-year-old female patient presented in the emergency department in a coma, areflexia, and bilaterally dilated non-reactive pupils. One and a half hours ago the patient suddenly lost consciousness and became unresponsive. A computed tomography (CT) scan showed a hyperdense basilar tip, and CT angiography confirmed the presence of a defect in the filling of the basilar tip and the bilateral P1 segments of the posterior cerebral arteries (PCA). The patient was ineligible for intravenous thrombolysis. Endovascular treatment was performed with partial recanalization of the basilar artery thrombolysis in cerebral ischemia (TICI) 2a. The diameter and light reactivity of patients' pupils are important parts of the neurological exam. A dilated pupil is an ominous sign associated with a severe prognosis and even worse if both pupils are dilated. Bilateral fixed dilated pupils could be present in basilar artery occlusion (BAO), i.e., basilar tip occlusion. This is explained by ischemia in the mesencephalon, where the nucleus of the oculomotor nerve lies. This ischemic stroke has the highest mortality rate, greater than 85%. The only proven treatment for BAO patients is recanalization with intravenous r-tPA (recombinant tissue plasminogen activator), intra-arterial r-tPA, or endovascular treatment. With adequate treatment, a good outcome can be obtained in up to 35%, and the mortality can be dropped to 40%. Patients with posterior circulation stroke, especially BAO, are still one of the hardest to diagnose on time. They require timely and coordinated efforts by an interdisciplinary team of neurologists, neuroradiologists and neurosurgeons. Timely recanalization within 12 hours and potentially up to 24 hours is the goal. This could lead to a favorable outcome. Loss of consciousness and bilateral fixed dilated pupils could be present in patients with BAO and shouldn't be accepted as a sign of a definite bad outcome. This definitely should not discourage treating physicians. All efforts should be focused on finding the right diagnosis in a timely manner. The differential diagnosis is crucial and may be the difference between life and death, especially in the context of BAO.