Spontaneous Non-aneurysmal subarachnoid hemorrhage

Recent data showed increasing numbers of cases of spontaneous nonaneurysmal subarachnoid hemorrhage.

Spontaneous Subarachnoid Hemorrhage with Negative Angiography can be determined in 14-22 %.

Intracranial arteriovenous malformation (AVM): 45% of cases (AVMs more commonly cause ICH & IVH than SAH)

Certain vasculitides that involve the CNS

Rarely due to tumor

Cerebral artery dissection (may also be posttraumatic)

Rupture of a small superficial artery

Rupture of an infundibulum

Coagulation disorders:

Iatrogenic or bleeding dyscrasias:

Thrombocytopenia

Dural sinus thrombosis

Spinal AVM: usually cervical or upper thoracic

Pretruncal nonaneurysmal SAH

Perimesencephalic nonaneurysmal subarachnoid hemorrhage

Rarely reported with some drugs: e.g. cocaine

Sickle cell anemia

Pituitary apoplexy

The studies show a low complication rate for subarachnoid hemorrhage (SAH) patients with a normal angiography, especially in the perimesencephalic subarachnoid hemorrhage group. The prognosis appears to be less favorable in terms of a more frequent need for external ventricular drainage (EVD), so a more cautious approach is recommended in this subgroup ¹⁾.

Between 1999 and 2013, 214 patients suffered from nonaneurysmal subarachnoid hemorrhage (NASAH), 14% of all patients with SAH. Outcome was assessed according to the modified Rankin Scale (mRS) at 6 months. Risk factors were identified based on the outcome.

The number of patients with NASAH increased significantly in the last 15 years of the study period. There was a statistically significant increase in the rate of nonperimesencephalic (NPM)-SAH occurrence and antiplatelet agents use, while the proportion of elderly patients remained stable.

Favorable outcome (mRS 0-2) was achieved in 85% of cases, but patients treated with antiplatelet agents had a significantly higher risk for an unfavorable outcome. Further analysis showed that elderly patients, and especially the subgroup with a Fisher Scale 3 bleeding pattern, had a high risk for an unfavorable outcome, whereas the subgroup of NPM-SAH without a Fisher Grade 3 bleeding pattern had a favorable outcome, similar to perimesencephalic subarachnoid hemorrhage (PM)-SAH.

Over the years, a significant increase in the number of patients with NASAH has been observed. Also, the rate of aCP use has increased significantly. Risk factors for an unfavorable outcome were age > 65 years, Fisher Grade 3 bleeding pattern, and aCP use. Both “PM-SAH” and “NPM-SAH without a Fisher Grade 3 bleeding pattern” had excellent outcomes. Patients with NASAH and a Fisher Grade 3 bleeding pattern had a significantly higher risk for an unfavorable outcome and death. Therefore, for further investigations, NPM-SAH should be stratified into patients with or without a Fisher Grade 3 bleeding pattern. Also, cases of spontaneous SAH should be stratified into NASAH and aneurysmal SAH ²⁾.

From 1999 to 2009, data of 125 patients with non-aneurysmal SAH were prospectively entered into a database. All patients underwent repetitive cerebral angiography. Outcome was assessed according to the modified Rankin Scale (mRS) (mRS 0-2 favorable vs. 3-6 unfavorable). Also, patients were divided in two groups according to the distribution of blood in the CT scan (perimesencephalic and non-perimesencephalic SAH).

106 of the 125 patients were in good WFNS grade (I-III) at admission (85%). Overall, favorable outcome was achieved in 104 of 125 patients (83%). Favorable outcome was associated with younger age (P < 0.001), good admission status (P < 0.0001), and absence of hydrocephalus (P = 0.001).73 of the 125 patients suffered from perimesencephalic SAH, most patients (90%) were in good grade at admission, and 64 achieved favorable outcome.52 of the 125 patients suffered from non-perimesencephalic SAH and 40 were in good grade at admission. Also 40 patients achieved favorable outcome.

Patients suffering from non-aneurysmal SAH have better prognosis compared to aneurysm related SAH and poor admission status was the only independent predictor of unfavorable outcome in the multivariate analysis. Patients with a non-perimesencephalic SAH have an increased risk of a worse neurological outcome. These patients should be monitored attentively ³⁾.

Non perimesencephalic subarachnoid hemorrhage.

Non-aneurysmal perimesencephalic subarachnoid hemorrhage.

Traumatic subarachnoid hemorrhage, the most common cause of SAH.

see Non aneurysmal subarachnoid hemorrhage outcome.

From 2006 to 2017, 154 patients suffering from non-aneurysmal SAH were admitted to the Department of Neurosurgery, Rheinische Friedrich-Wilhelms-University Bonn, Germany.

Patients were stratified according to the distribution of cisternal blood into patients with perimesencephalic subarachnoid hemorrhage (pSAH) versus non-perimesencephalic SAH (npSAH). C reactive protein (CRP) and white blood cells (WBC) assessments were performed within 24 h of admission as part of routine laboratory workup. Outcome was assessed according to the modified Rankin Scale (mRS) after 6 months and stratified into favorable (mRS 0-2) vs. unfavorable (mRS 3-6).

The multivariate regression analysis revealed “CRP > 5 mg/l” (p = 0.004, OR 143.7), “WBC count > 12.1 G/l” (p = 0.006, OR 47.8), “presence of IVH” (p = 0.02, OR 13.5), “poor-grade SAH” (p = 0.01, OR 45.2) and “presence of CVS” (p = 0.003, OR 149.9) as independently associated with unfavorable outcome in patients with non-aneurysmal SAH.

Elevated C-reactive protein and WBC count at admission were associated with unfavorable outcome after non-aneurysmal SAH ⁴⁾.