Isolated Posterior Inferior Cerebellar Artery Dissection as a Cause of Ischemic Stroke: Clinical Features and Prognosis

Abstract

Background: The purpose of this study was to clarify the incidence, clinical and radiological features and outcomes of isolated posterior inferior cerebellar artery (PICA) dissection in isolated PICA territory infarctions. Methods: We retrospectively reviewed consecutive inpatients with ischemic stroke secondary to isolated PICA dissection from our stroke database between January 2004 and December 2013 and reviewed the literature with regard to those patients. Results: Of 167 consecutive patients with an isolated PICA territory infarction, a total of 10 patients (6.0%, 3 women, 48.1 ± 7.1 years) were diagnosed as having an isolated PICA dissection. Patients with PICA dissection were younger (p < 0.001), more commonly experienced headache at onset (p = 0.008), less commonly had hyperlipidemia (p = 0.044) and showed a lower modified Rankin Scale score at discharge (p = 0.002) when compared with patients without arterial dissection. In 6 of these 10 patients, PICA dissections had not been suspected on initial magnetic resonance angiography (MRA) and were confirmed by follow-up MRA or digital subtraction angiography. In the follow-up period (median 1.5 years, interquartile range 0.5-6.3 years), there were no recurrent ischemic or hemorrhagic stroke events. Conclusions: Isolated PICA dissection as an etiological mechanism in isolated PICA territory infarctions may be more common than was previously recognized to be. The diagnosis of PICA dissection is often difficult and requires close and repeated morphological evaluation. We should carefully identify PICA dissections as a possible cause of PICA territory infarctions.