Transcranial Doppler in the Detection and Management of Arterial Vasospasm after Aneurysmal Subarachnoid Haemorrhage

Delayed cerebral ischaemia (DCI) and cerebral infarction is a much-feared complication of aneurysmal subarachnoid haemorrhage (aSAH). It has been largely attributed to focal hypoperfusion from reversible cerebral arterial narrowing, "vasospasm," from the effects of prolonged exposure of the arteries to perivascular blood and oxy-haemoglobin. Transcranial Doppler (TCD) provides a non-invasive method for detecting and monitoring vasospasm. We report a 38-year-old lady who developed sudden dizziness and catastrophic generalised headache with neck pain (Pain Score 10/10) while voiding her bowels. She subsequently became drowsy and was brought to hospital. On examination, she was already alert and orientated. Blood pressure was 175/109 mm Hg. Her neurological examination was normal but for severe neck stiffness to passive flexion. Computed tomography of the brain showed extensive SAH. Cerebral angiography revealed a 6 x 3 mm aneurysm along the posteromedial aspect of the supraclinoid left internal carotid artery. She underwent aneurysm coiling that night. She was given intravenous and then oral nimodipine. TCD monitoring of the circle of Willis on day 14 detected very high velocities in the right and left middle cerebral arteries, mean velocity 187 and 141 cm/s, middle cerebral artery/internal carotid artery ratio 6.03 and 4.15, suggestive of severe and moderate vasospasm, respectively. She did not develop any related neurological symptoms or deficits. She was maintained in a euvolemic state and given high volumes of intravenous saline (2.4 L/day). Repeat TCD 7 days later was normal. The intravenous saline was gradually tailed off and she was subsequently discharged. TCD has an important role in the non-invasive detection and monitoring of vasospasm after aSAH.