Clinical Review

Thunderclap headache

BMJ 2013; 346 doi: (Published 09 January 2013) Cite this as: BMJ 2013;346:e8557

Re: Thunderclap headache

The authors have advocated the practice of visual inspection of cerebrospinal fluid (CSF) to detect if CSF blood pigments are present, which may indicate the occurrence of sub-arachnoid haemorrhage. This practice is highly subjective and generates false positive and false negative results, which could ultimately result in miss-treatment of patients and may prove fatal and therefore is not recommended.

The Revised National Guidelines for analysis of cerebrospinal fluid for bilirubin in suspected subarachnoid haemorrhage state that visual inspection is not a reliable method for detecting bilirubin in CSF samples. These guidelines are utilised by the laboratories that perform the analysis of bilirubin CSF testing nationally.

We therefore recommend the following:
“A lumbar puncture is needed in patients with a thunderclap headache after normal brain imaging. Yellow coloration (xanthochromia) on visual inspection of the supernatant is not a reliable test for subarachnoid haemorrhage and spectrophotometry for detecting bilirubin formed in vivo is required to make a diagnosis of subarachnoid haemorrhage.”

References relevant to this matter are as follows:

Revised National Guidelines for analysis of cerebrospinal fluid for bilirubin in suspected subarachnoid haemorrhage. Cruickshank A, Auld P, Beetham R, Burrows G, Egner W, Holbrook I, Keir G, Lewis E, Patel D, Watson I, White P, UK NEQAS Specialist Advisory Group for External Quality Assurance of CSF Proteins and Boichemistry. Ann Clin Biochem 2008 May; 45 (Pt3): 238-44

Kjellin KG, Soderstrom CE. Diagnostic significance of CSF spectrophotometry in cerebrovascular diseases. J Neurol Sci 1974;23 :359-69

Marden NA, Thomas PH, Syansbie D. Is the naked eye as sensitive as the spectrophotometer for detecting xanthochromia in cerebrospinal fluid? In: Martin SM, ed. Proceedings of the National Meeting, 30 April-4 May 2001, London. London: Association of Clinical Biochemists 2001:53.

Competing interests: No competing interests

17 January 2013
Carrie Chadwick
Clinical Scientist
Charles van Heyningen
Aintree University Hospital
Lower Lane, Liverpool, L9 7AL