Clinical characteristics and outcome of the capsular warning syndrome: a multicenter study

The capsular warning syndrome is defined as recurrent transient lacunar syndromes that usually precede a capsular infarction. Several aspects regarding the clinical management are controversial. We report the clinical and radiological characteristics of a multicenter series of patients with capsular warning syndrome, as well as their functional outcome during the follow-up.

We sought to describe the clinico-radiological spectrum of the capsular warning syndrome and to report the functional outcomes and recurrences of these patients during the follow-up.

We conducted a multicenter study that collected clinical and radiological data from patients with capsular warning syndrome during 2003-2013. Capsular warning syndrome was defined as the succession of three or more motor or sensory-motor lacunar syndromes within a period of 72 h, with complete recovery between them. We recorded the functional outcome (favorable when Rankin scale score ≤2) and recurrences during follow-up.

Our study included 42 patients whose mean age was 66.4 ± 10 years; 71.4% of them were men. The mean number of episodes before a permanent neurological impairment occurred or before a complete recovery of symptoms was 5.1 ± 2.3. Up to 30 patients (71.2%) had an acute infarct visible on the neuroimaging (computed tomography/magnetic resonance imaging). The internal capsule was the most frequent infarct location (50%), but other locations were noted. Twelve patients (28.6%) received thrombolysis in the acute phase. A favorable outcome was observed in 39 patients (92.9%). After a mean follow-up of 35 ± 29 months, only one patient suffered a recurrent ischemic stroke.

Capsular warning syndrome preceded an ischemic infarction in 71.2% of patients. In addition to the internal capsule, other locations were noted. The most effective treatment remains unclear. The functional prognosis is favorable in most patients and recurrences are rare.