During the study period 30 patients had been admitted with sudden severe headache or neck pain and a brain CT scan without subarachnoid blood but CSF stained with bilirubin. In total, 775 patients with SAH were admitted during this period in our hospital. Sixteen patients were men, and 14 were women. Median age was 50.9 years (range 27.3–72.9 years). On admission, WFNS score was 1 in all but one patient (who had WFNS score 2 and a slight hemiparesis). Of the total group, two patients (7%) presented early, within 3 days. Further investigation did not show any aneurysms in this group. The cause of the delay in the other patients was due to the patient (in 8), the doctor (in 11), or both (in 2) or unknown (in 7). Eighteen patients presented within 4–7 days, and eight of these (44%) had an aneurysm. Ten patients presented late (8–14 days), and five of them (50%) proved to have an aneurysm. Thus, in the total group of 30 patients, an aneurysm was found in 13 (43%) patients (Table 1).
The CT scans of patients from the outside hospitals who were referred to our hospital were judged as normal by the radiologist from the outside hospital, but after revision by the neuroradiologist in our hospital (a tertiary referral hospital) slight abnormalities in 4 of 30 included patients were detected: 1 patient had a small hyperdensity in the left cerebellum, caused by an underlying arteriovenous malformation that was confirmed by angiography. This finding was not appreciated on the initial non-contrast CT scan by the radiologist from the outside hospital. One other patient had some sedimentation of blood in the posterior horns. Two other patients had ambiguous findings: suspicion of small amount of blood in the pentagon in two patients.
One other patient had on further follow-up with MRI a small hyperdensity in the parieto-occipital gyrus (not visible on contrast CT scan). Further investigations revealed an right subcortical aberrant vein in this patient draining to the sagittal sinus, without aneurysm.
All 16 patients without an aneurysm or arteriovenous malformation of the cause of their headache were investigated with CTA, MRI or MRA or additional four-vessel angiography (11 patients). In none of these 11 patients was focal or diffuse segmental arterial vasoconstriction shown.
Haematocrit was normal in 29 patients and not known in 1 patient. Serum bilirubin was measured in only one patient (who was pregnant).
Treatment of the aneurysm was done by coiling in nine patients and clipping in two. Two patients were not treated: one patient who developed ischaemia the day after admission and was in poor clinical condition, and one other patient who refused further angiography after MRA. The arteriovenous malformation in the cerebellum in one other patient was embolized successfully.
Eleven patients with an aneurysm were alive after 3 months and two died, because of rebleeding (1 patient) and secondary ischaemia (1 patient). One patient had a poor outcome with major neurological deficits including paresis and aphasia (because of secondary ischaemia). All patients without an aneurysm detected were alive after 2–7 years of follow-up and had good outcome without further episodes of SAH (Table 1).