[Focal convexal subarachnoid hemorrhage: clinical presentation, imaging patterns and etiologic findings in 23 patients].

INTRODUCTION

Clinical presentation and etiology of localized nontraumatic convexal subarachnoid hemorrhage (cSAH) have been described in a few patients. They differ from those of aneurysmal subarachnoid bleeding which is diffuse. The purpose of this study was to describe the clinical presentation, the radiologic findings and causes of cSAH.

METHODS

We selected patients admitted to the neurology department of CHU of Nîmes or Montpellier, from May 2008 to May 2011, who presented with cSAH, observed in a single cortical sulcus unrelated to trauma and identified on brain MRI T2* weighted images as a hyposignal in one sulcus of the convexity. Data collection was retrospective.

RESULTS

Twenty-three patients (14 men and nine women) were included. Mean age was 69.5years (range 29-86). Patients had mostly sensory or sensorimotor deficits which was regressive in less than 30minutes, recurrent, and seldom accompanied by headache. Brain MRI allowed the identification of patients with old brain hematomas (n=2), lobar microbleeds (n=7) and superficial cortical hemosiderosis (n=6). The etiologic diagnosis was determined in 43% (n=10/23): cerebral amyloid angiopathy (n=3), reversible cerebral vasoconstriction syndrome (n=2), primary cerebral angiitis (n=1), posterior reversible encephalopathy syndrome (n=1), cortical vein thrombosis (n=3, two of them associated with dural sinus thrombosis). Cerebral angiography was performed in 11 patients and gave the etiologic diagnosis (angiitis, cortical vein thrombosis) in two. Follow-up was available for 16 patients (mean 12months, range 3months to 5years). Etiology was established during follow-up in two patients, both had cerebral amyloid angiopathy diagnosed after recurrent lobar hematomas.

CONCLUSIONS

cSAH has various causes, but clinical presentations appear to be relatively stereotyped with recurrent and brief episodes of sensorimotor deficits. A comprehensive assessment and monitoring would lead to an etiologic diagnosis in some patients.