Vasospasm diagnosis: theoretical and real transcranial Doppler sensitivity

Area of Science:

• Neurology
• Vascular Surgery
• Radiology

Background:

• Cerebral vasospasm is a common complication after subarachnoid hemorrhage.
• Early detection of vasospasm is crucial for timely intervention and improved patient outcomes.
• Transcranial Doppler (TCD) is a non-invasive tool used to assess cerebral blood flow velocity.

Purpose of the Study:

• To evaluate the diagnostic accuracy of TCD in detecting middle cerebral artery (M1) vasospasm.
• To compare TCD findings with cerebral angiography in patients with vasospasm post-aneurysm rupture.
• To determine the reliability of TCD based on the aneurysm location.

Main Methods:

• Retrospective analysis of 54 patients with vasospasm after aneurysm rupture.
• Comparison of TCD measurements of M1 flow velocity with findings from carotid angiography.
• Assessment of TCD sensitivity and specificity for vasospasm detection.

Main Results:

• Angiographic vasospasm was present in the M1 segment in 41 out of 54 cases.
• The overall sensitivity of TCD for detecting M1 vasospasm was 70%, with a theoretical sensitivity of 76%.
• TCD demonstrated lower sensitivity for vasospasm after anterior communicating artery aneurysm rupture (55%) compared to middle cerebral artery aneurysm rupture (93%).

Conclusions:

• Transcranial Doppler is a useful but not infallible tool for diagnosing cerebral vasospasm.
• Angiography should be considered when TCD is negative in the presence of clinical deterioration or during the high-risk period for vasospasm.
• The accuracy of TCD varies depending on the location of the ruptured aneurysm.