Subarachnoid Hemorrhage Diagnosis: Lumbar Puncture Is Still Needed When the Computed Tomography Scan Is Normal

Abstract

Objectives: To determine the sensitivity of third-generation CT scanners for diagnosed nontraumatic subarachnoid hemorrhage (SAH) and to assess the impact of symptom duration on sensitivity.Methods: A retrospective chart review was performed in a university-affiliated tertiary care hospital with an annual ED volume of >100,000 patients. The target population was all patients who presented to the ED from January 1991 to September 1994 with symptoms suggestive of SAH and who had a final diagnosis of nontraumatic SAH based on either a positive CT scan or positive spinal fluid analysis. Patients referred from outside facilities were included if they had a CT done at the study site. All C T scans were done using thirdgeneration scanners. Official CT scan reports were used to categorize scans as positive or negative.Results: There were 140 patients identified with SAH, with a mean age of 56 years (range 10-88). The sensitivity of CT in the diagnosis of nontraumatic SAH when performed at or before 12 hours of symptom duration was 100% (80/80), and 81.7% (49/60) after 12 hours of symptom duration (95% CI 95-100% and 69.5-90.4%, respectively; p c 0.0001). Eleven of the 140 patients had a negative CT and positive spinal fluid analysis, yielding an overall sensitivity of 92.1% (129/140).Conclusion: The sensitivity of third-generation CT scans for SAH decreases with time from the onset of symptoms. In this sample population, CT was able to detect all patients scanned 512 hours after symptom onset. Although the study demonstrated good sensitivity of CT scan reports for SAH when the scan was performed after 5 1 2 hours of symptom onset, additional real-time experience is needed to better define the potential risk of a missed SAH should this population not receive the customary lumbar puncture examination in the setting of a negative CT scan.Key words: subarachnoid hemorrhage; intracranial bleed; computed tomography; CT scan; neurology.

Can Computed Tomography Angiography of the Brain Replace Lumbar Puncture in the Evaluation of Acute‐onset Headache After a Negative Noncontrast Cranial Computed Tomography Scan?

“…20,[23][24][25][26][27] The 95% confidence intervals (CIs) substantially lower these sensitivities. Most clinicians estimate the sensitivity to be above 90% in the first 24 to 48 hours after headache onset.…”

“…The study by Boesiger and Shiber 20 was excluded because of the wide CIs due to study size and design. The studies by Sidman et al, 24 Sames et al, 25 and van der Wee et al 23 were felt to use outdated CT technology and are limited by patient selection bias. The specificity of CT for SAH is not reported in most studies, but is assumed to be 100%.…”

Hemorragia subaracnoidea aneurismática: guía de tratamiento del Grupo de Patología Vascular de la Sociedad Española de Neurocirugía

“…La TC es la prueba más sensible en el diagnóstico de la HSA; siempre se debe practicar lo antes posible después de la sospecha clínica de HSA ya que con el paso de los días pierde sensibilidad al irse lisando la sangre depositada en el espacio subaracnoideo. Únicamente un 2-5% de los pacientes con HSA tienen una TC normal en el primer día tras el sangrado, presentando una sensibilidad en las primeras 12 horas de entre el 98 y 100%, pasando a un 93% a las 24 horas y el 57% a los seis días 149,185,197,211 . Además del diagnóstico, la TC aporta una valiosa información sobre la extensión y localización de la sangre, presencia de …”

The Worst Headache of Life: Evaluation of Nontraumatic Subarachnoid Hemorrhage

“…The probability of detecting subarachnoid hemorrhage of CT scans performed at various intervals after the ictus is: day 0, 95%; day 3, 74%; day 7, 50%; day 14, 30%; and day 21, almost zero (8,9,10). The probability of detecting xanthochromia with spectrophotometry in the CSF at various times after a subarachnoid hemorrhage is: 12 hours, 100%; 7 days, 100%; 14 days, 100%; 21 days, more than 70%; and four weeks, more than 40% (8).…”