Aetiopathogenesis and long-term outcome of isolated pontine infarcts

Abstract

Background and purpose: Isolated pontine strokes cause characteristic neurological syndromes and have a good short-term prognosis. The aim of this study was to examine the long-term survival, cumulative recurrence rate and clinical handicap of patients with isolated pontine infarcts of different aetiology.

Methods: One hundred consecutive patients with an isolated pontine infarction were identified by imaging studies and evaluated prospectively. After extensive study, cases were classified according to the aetiopathogenetic mechanisms: stroke due to basilar artery branch disease (BABD), small-artery disease (SAD) and large-artery-occlusive disease (LAOD). During a mean follow-up period of 46 months, stroke presentation and initial course, early and long-term mortality, disability and recurrence were evaluated.

Results: BABD was the most frequent cause of isolated pontine ischaemia (43%), followed by SAD (34%) and LAOD (21%). Hypertension was the most prominent risk factor, especially among patients with SAD (94.1%). Neurological impairment on admission was more severe in the LAOD group, followed by BABD. After 1 month patients with LAOD had the highest cumulative mortality (14.3%, p = 0.026) and more severe disability (61.1%, p = 0.001). Five-year mortality rate was 20.6%, 14% and 23.8% in the SAD-, BABD- and in LAOD-group respectively (p = 0.776). Cumulative 5-year recurrence rate was 2.3 % for BABD, 14.3 % for LAOD, and 29.4 % for SAD (p = 0.011).

Conclusions: Overall long-term survival of patients with isolated pontine infarcts is good. Initial differences regarding short-term outcome in infarctions of different aetiology resolve with time. Effective secondary prevention among SAD patients may limit stroke recurrence and positively influence long-term prognosis.