Internuclear Ophthalmoplegia as a Sole Presentation of Acute Ischemic Stroke Involving the Midbrain with an NIH Stroke Scale of One

The National Institute of Health Sciences Scale (NIHSS) is a popular screening tool in the Emergency Department to rule out strokes. However, a small number of cases can be missed. But it is useful to remember that any sudden onset cranial nerve involvement could be a symptom of stroke and hence must be investigated thoroughly as time is brain. Internuclear ophthalmoparesis (INO) or internuclear ophthalmoplegia is very typical of a brainstem lesion. Our patient had complaints of sudden onset diplopia secondary to internuclear ophthalmoplegia with no other signs or symptoms. Though her NIHSS was only 1, given her longstanding history of hypertension, an immediate CT Brain was ordered which showed a fresh infarct of the left Medial Longitudinal fasciculus.