gms | German Medical Science

Objective: Aneurysmal subarachnoid hemorrhage (aSAH) is still associated with high morbidity and mortality. However, more sensitive radiological surrogates for DCI are lacking. The goal of the present study was to analyze safety and feasibility of acetazolamide-challenged perfusion computerized tomography (PCT) in patients suffering from aSAH to assess cerebrovascular reserve capacity (CVR) as a potential surrogate for DCI and neurological outcome.

Method: This prospective pilot study has been approved by the local ethics committee. Five patients (4 female, 1 male) with WFNS grades 2-4 and Fisher grade 3 or 4 were included for acetazolamide-challenged PCT on days 3 to 4 and 9 to11 after SAH ictus. PCT imaging was performed prior to and 20 min after intravenous administration of an acetazolamide bolus (1mg). Safety was monitored based on A) neurological status, B) intracerebral pressure (ICP), if already monitored, C) detection of DCI, D) angiographic vasospasm, and E) cerebral infarction on CT imaging to detect associated adverse or serious adverse events. These data were correlated with neurological outcome at discharge using the Glasgow outcome scale (GOS).

Results: None of the patients suffered serious adverse events related to acetazolamide-challenge. Additionally, no aSAH related neurological deterioration due to elevated ICP, evidence of DCI or angiographic vasospasm or aSAH related cerebral infarction occurred. All patients displayed a preserved CVR. However, analysis of perfusion parameters in the anatomical vicinity of the ruptured aneurysm demonstrated a tendency towards elevated Time to peak of the residue function (Tmax), in contrast to regions which were anatomically remote to the aneurysm, suggesting a putatively impaired regional CVR. All patients had a good (GOS 4 and 5) outcome 14 days and six weeks after SAH ictus.

Conclusions: The present study demonstrated for the first time the safety and feasibility of acetazolamide-challenged PCT scanning in aSAH patients. No serious adverse events related to the acetazolamide-challenge were detected. The primary results of the acetazolamide-challenge indicate that patients who do not experience DCI seem to have an intact CVR, and thus, good functional outcome. Additionally, regional analysis reveals a tendency towards impaired CVR. This effect might be more severe in patients with DCI. As result, a prospective single center study will be initiated to investigate the predictive value of CVR assessment to detect DCI in aSAH patients.