Raised intracranial pressure marker found

CAMBRIDGE, England, Sept. 15 (UPI) -- A British study has found measurement of the optic nerve sheath's thickness by magnetic resonance imaging is a good marker for raised intracranial pressure.

The researchers, led by Thomas Geeraerts of Addenbrook's Hospital in Cambridge, discovered a retro-bulbar optic nerve sheath diameter above 5.82 millimeters predicts raised intracranial pressure in 90 percent of cases.

"Raised ICP is frequent in conditions such as stroke, liver failure and meningitis," said Geeraerts. "It is associated with increased mortality and poor neurological outcomes. As a result, the early detection and treatment of raised ICP is critical, but often challenging. Our MRI-based technique provides a useful, non-invasive solution."

The researchers said clinical signs of raised intracranial pressure such as headache, vomiting and drowsiness are not specific and are often difficult to interpret. In sedated patients, they said clinical signs frequently appear well after the internal damage has been done.

"Optic nerve sheath distension, the scientists said, "could be an early, reactive and sensitive sign of raised ICP."

The research appears in the journal Critical Care.