Spontaneous convexity subarachnoid haemorrhage: Clinical series of 3 patients with associated cerebral amyloid angiopathy.

BACKGROUND

Convexity subarachnoid haemorrhage (cSAH) is a rare type of spontaneous, non-traumatic, and nonaneurysmal SAH characterised by blood collections in one or more cortical sulci in the convexity of the brain; the aetiology varies. We report a clinical case series of 3 patients with cSAH associated with probable cerebral amyloid angiopathy (CAA) who presented with focal sensory seizures and responded well to corticosteroid treatment.

METHODS

Case 1 was a 67-year-old man reporting right-sided paroxysmal sensory episodes with Jacksonian progression, cheiro-oral symptoms, and motor dysphasia. Case 2 was a 79-year-old man reporting left-sided paroxysmal episodes with cheiro-oral signs and dysarthria. Case 3 was a 71-year-old woman also reporting recurrent left cheiro-oral signs and dysarthria. None of the patients had headache or clinical dementia. Aneurysms were ruled out using MR angiography.

RESULTS

Brain CT scan detected an isolated hyperintensity in a sulcus of the frontal convexity; brain gradient echo T2-weighted MRI sequences showed meningeal haemosiderosis and microbleeds. However, no atrophy was identified in medial temporal lobes including the hippocampal formation. All patients had low levels of beta-amyloid in CSF, low values on the Hulstaert index and high levels of phosphorylated tau protein. Patients were initially treated with prednisone and levetiracetam, but symptoms recurred in 2 patients after prednisone was discontinued.

CONCLUSIONS

We present a series of 3 patients with cSAH associated with CAA, characterised by a stereotypical syndrome responding well to corticoid treatment; there were no cases of headache or clinical dementia.