Bilateral ophthalmoplegia: an unusual sign of the top of the basilar artery syndrome.

Bilateral ophthalmoplegia may be an unusual sign of vertebrobasilar ischemia. We report the cases of two patients (75 and 73 years old), who suddenly developed drowsiness, bilateral ophthalmoplegia with bilateral ptosis and mild right hemiparesis. In both patients, MRI revealed bilateral thalamic and midbrain infarcts, ECG showed the presence of atrial fibrillation and Doppler study of the extracranial and intracranial vertebral arteries found no significant alterations. Ischemia involving the midbrain and thalamic paramedian regions may cause bilateral ophthalmoplegia and consciousness disturbances. In these two cases, the most plausible etiologic mechanism was cardiac embolism, and the prognosis for bilateral ocular palsy was poor.