Sudden onset blindness as a presenting feature of chronic subdural haematoma: case report

Abstract

We present a rare case report of a patient with chronic subdural haematoma presenting with sudden onset blindness secondary to severe acute bilateral papilloedema. Following prompt surgical evacuation, the patient’s visual acuity returned back to almost normal. Previous reported cases in the literature of blindness following subdural haematomas were related to bilateral homonymous hemianopia due to compression of the posterior cerebral artery following tentorial herniation. These patients were either left blind or developed significant visual deficit despite surgical evacuation. Our case is the first in the literature where the blindness was reversible and due to severe acute papilloedema. There was also no evidence of posterior cerebral artery territory ischaemia. We discuss the importance of visual symptoms in subdural haematoma and emphasize the importance of prompt early intervention. CLINICAL PRESENTATION A 21 years old man was transferred as an emergency from the regional district general hospital after he presented with sudden onset of complete blindness in both eyes in the early hours of the day of transfer. Prior to this, he has been complaining of severe progressive headache with episodic visual blurring over the previous seven weeks. There was nothing of note in previous background history. On examination, he was alert, confused and obeying commands. He was eye opening spontaneously and there were no lateralizing signs. He was completely blind in both eyes and there was evidence of gross papilloedema bilaterally. CT (computerized axial tomography) scan showed a significant left sided acute on chronic subdural haematoma with 1 cm midline shift and also a left middle fossa arachnoid cyst. These findings were confirmed on MR (magnetic resonance) imaging (Fig 1) with MRA (magnetic resonance angiography) ruling out an underlying vascular abnormality. Figure 1 Fig 1: MRI scan showing chronic subdural haematoma causing midline shift. There is also a left temporal arachnoid cyst Considering the papilloedema and scan appearances, he underwent emergency burrhole drainage of subdural haematoma on the evening of transfer. He had significant recovery of his vision within 24 hours of his surgery. Visual acuity has been recorded as 6/9 right eye, 6/12 left eye with good fields in Goldman perimetry but with enlarged blind spots bilaterally. He was subsequently discharged home and at the time of discharge, he was self caring, alert, oriented and had not suffered any deficits a result of the surgery. On review in the outpatient clinic in 6 weeks time, his visual acuity in the right eye was 6/6+2 and left eye 6/9+1. Repeat CT scan (Fig 2) showed that the Sudden onset blindness as a presenting feature of chronic subdural haematoma: case report 2 of 4 subdural haematoma had resolved and the arachnoid cyst was unchanged.