Perimesencephalic and sulcal subarachnoid haemorrhage: an interesting presentation of posterior reversible encephalopathy syndrome

Abstract

DesCripTionA 38-year-old man with hypertension presented with sudden-onset headache and vomiting. He was irritable and had a blood pressure of 180/120 mm Hg. There were no meningeal signs or focal neurological deficits. His optic fundi were normal. Initial evaluation with CT of the brain showed subarachnoid haemorrhage (SAH) in the right parasagittal sulcal region ( figure 1A) and the left perimesencephalic cistern (figure 1B). A CT angiogram (CTA) followed by a digital subtraction angiogram (DSA) ruled out aneurysms ( figure 1C-F). The venous phase of DSA ( figure 1G) and magnetic resonance (MR) venogram (figure 1H,I) were normal. MRI of the brain (figure 2) showed hyperintense lesions in the bilateral parieto-occipital regions and the basal ganglia suggesting posterior reversible encephalopathy syndrome (PRES). He was managed with antihypertensives and made a gradual and complete recovery.Our patient presented with non-traumatic SAH on an emergent head CT scan. It showed simultaneous presence of blood in two interesting locations. The first is the perimesencephalic region, where the majority of cases are negative for aneurysms and is considered due to venous rupture.

Subarachnoid haemorrhage due to intracranial vertebral artery dissection presenting with atypical cauda equina syndrome features: case report

“…In various case series of cSAH, reported features have included focal and transient motor and/or sensory symptoms (42–73%), including facial nerve palsy and pronator drift [15, 16]; headache (18–65%); and confusion (9.8%) [17–20]. Although cSAH by definition spares the basal cistern and Sylvian fissures (which our case does not), descriptions of cSAH have been made even when these regions are not spared [21–23]. Alternative considerations for facial nerve palsy are compression by the aneurysm (which imaging did not suggest in our case) and vascular spasm disturbing the blood supply of the facial nucleus [24, 25].…”

Reversible Cerebral Vasoconstriction with Quadrigeminal Cistern Subarachnoid Hemorrhage

“…6 A case of PRES has been described in association with perimesencephalic SAH with no evidence of vasospasm. 7 The pathophysiologic mechanism of SAH in RCVS remains unknown, but abrupt stretching of vessel walls with or without small vessel rupture, or reperfusion injury have been proposed as possible mechanisms. 2 In the present case, the hemorrhage within the quadrageminal cistern was distant from the Circle of Willis or any other artery, further supporting the venous theory.…”