No abstract

BACKGROUND AND PURPOSE:Following mechanical recanalization of an acute intracranial vessel occlusion, hyperattenuated lesions are frequently found on postinterventional cranial CT. They represent either blood or-more frequently-enhancement of contrast agent. Here, we aimed to evaluate the prognostic value of these hyperattenuated intracerebral lesions.

Supratentorial superficial siderosis (SS) is a frequent imaging marker of cerebral amyloid angiopathy (CAA). It is most probably caused by focal subarachnoid hemorrhages (fSAHs). Based on single-case observations, it has been proposed that such fSAHs might be a predisposing factor for future intracranial hemorrhage. Here we tested the hypothesis if a SS as a residue of fSAHs must be regarded as a warning sign for future intracranial hemorrhage. Fifty-one consecutive patients with SS and no apparent cause other than possible or probable CAA were identified through a database search and followed-up for a median interval of 35.3 months (range 6-120 months). Main outcome measures were rate and location of new intracranial hemorrhages. Twenty-four patients (47.1 %) had experienced any new intracranial hemorrhage, 18 patients (35.3 %) had an intracerebral hemorrhage (ICH), and in 13 of them (25.5 %), the hemorrhage was located at the site of pre-existing siderosis. Six patients (11.7 %) had developed a new subarachnoid hemorrhage (SAH), four of them at the site of siderosis. Patients with SS are at substantial risk for subsequent intracranial hemorrhage. SS can be considered a warning sign of future ICH or SAH, which frequently occur adjacent to pre-existing SS. Prospective studies are needed to confirm these findings.

Cortical superficial siderosis (cSS) is an increasingly recognized MR-imaging marker most probably caused by focal convexity subarachnoid hemorrhage (SAH). There is accumulating evidence that cSS represents an important risk factor for subsequent intracranial hemorrhages. Here, we aimed to determine clinical symptoms, underlying etiologies, and radiological characteristics of cSS in a large patient cohort. We performed an electronic database search on all patients who presented between 2002 and 2013 to the university hospital Munich with non-traumatic and non-aneurysmal cSS. T2*-weighted gradient-echo sequences were analyzed regarding localization and extent of cSS as well as of acute SAH, intracerebral hemorrhages (ICH) and microbleeds. Besides, all available clinical, laboratory, imaging and histological data were analyzed. 113 subjects matched the inclusion criteria. The following etiologies for cSS were identified: definite (n = 6; 5 %), probable (n = 75; 66 %), and possible (n = 28; 25 %) cerebral amyloid angiopathy (CAA); reversible cerebral vasoconstriction syndrome: 2 (2 %); central nervous system vasculitis: 1; and hyperperfusion syndrome: 1. Acute ICH was evident in 55 (49 %) cases. Other clinical manifestations were: transient focal neurological episodes (TFNE): 38 (34 %); cognitive impairment: 14 (12 %); generalized seizure: 4 (4 %); and headache: 2 (2 %). Adjusting for age and gender, cognitive impairment was more frequent in disseminated cSS, while TFNE was more often found in focal cSS (p = 0.042). Our data indicate CAA to be the most common etiology of cSS. In absence of symptomatic ICH, patients with focal cSS frequently present with TFNE, while those with disseminated cSS commonly manifest with cognitive impairment.

Our results indicate that the detection of a central vein within a WML should not be considered a specific finding for MS; it is also found in WMLs of other etiologies.