Is cerebrospinal fluid spectrophotometry useful in CT scan-negative suspected subarachnoid haemorrage?

• Published in: European neurology Vol. 52; no. 4; p. 226
• Main Authors: Gunawardena, H, Beetham, R, Scolding, N, Lhatoo, S D
• Format: Journal Article
• Language: English
• Published: Switzerland 01-01-2004
• Subjects: Bilirubin - cerebrospinal fluid; Cerebrospinal Fluid - chemistry; Diagnosis, Differential; Humans; Image Processing, Computer-Assisted - methods; Methemoglobin - cerebrospinal fluid; Neurologic Examination - methods; Oxyhemoglobins - cerebrospinal fluid; Sensitivity and Specificity; Spectrophotometry - methods; Subarachnoid Hemorrhage - cerebrospinal fluid; Subarachnoid Hemorrhage - diagnosis; Tomography, X-Ray Computed
• ISSN: 0014-3022
• DOI: 10.1159/000082162

Missed cerebral aneurysms in CT-negative patients can have serious implications. We set out to determine the usefulness of cerebrospinal fluid (CSF) spectrophotometry and the individual significance of CSF oxyhaemoglobin, bilirubin and methaemoglobin in 463 CT scan-negative patients with suspected subarachnoid haemorrhage (SAH) and normal neurological examination. CSF spectrophotometry resulted in the diagnosis of an intracranial aneurysm in 2% (9/463) of patients with CT-negative suspected SAH. No aneurysms were found in patients in whom spectrophotometry was negative for haem pigments. Less than 1% of patients with oxyhaemoglobin alone had aneurysms diagnosed, whilst 21% of patients with bilirubin had an aneurysm. CSF spectrophotometry is an important investigation in patients with CT-negative suspected SAH, particularly where clinical suspicion is strong. Patients positive for bilirubin are likely to provide a high yield of aneurysmal bleed and should undergo angiography. Patients with oxyhaemoglobin alone in whom SAH is strongly suspected may benefit from angiography. Based on a small number of patients, we recommend that patients with methaemoglobin should also be investigated. Patients with negative spectrophotometry are unlikely to benefit from further investigation.