Acute bilateral cerebellar infarcts in the territory of posterior inferior cerebellar artery

Intraoperative visualization of bilateral thrombosis in the posterior inferior cerebellar artery apparent in the telovelomedullary segment

Unilateral posterior inferior cerebellar artery (PICA) thrombosis is frequent. However, bilateral PICA thrombosis is rare. Herein we report about an intraoperative visualization of a bilateral thrombosis of the telovelomedullary segment of the PICA. A 74-year-old woman was admitted to our department on day two of a bilateral PICA thrombosis with developing cerebellar infarction. Her Glasgow Coma Scale score dropped from 15 to 13, and cranial computed tomography revealed compression of the fourth ventricle with consecutive occlusive hydrocephalus. After the insertion of an external ventricular drainage, the patient underwent urgent suboccipital decompressive craniectomy with removal of infarcted cerebellar tonsils, which allowed the bilateral visualization of the thrombosed telovelomedullary segments. The surgical access may offer surgical therapeutic options in a hyperacute occlusion, such as thromb-/embolectomy or bypass procedures.

[Cerebellar infarction: prognosis and complications of vascular territories]

INTRODUCTION

Cerebellar infarction (CI) is uncommon, but may result in severe complications. The aim of our study was to determine the characteristics of patients with CI, as well as their outcomes as regards the territories affected.

PATIENTS AND METHODS

Data were collected from 124 patients admitted to our department during a five-year period, with a radiological diagnosis of CI, and with or without involvement of other brain territories.

RESULTS

The mean age in our series was 65.2 years, with most being male (68.5%). The posterior inferior cerebellar artery (PICA) was the most commonly affected territory at 49.2%, followed by superior cerebellar artery (SCA) at 17.7%, and anterior inferior cerebellar artery (AICA) at 10.5%. There was simultaneous supratentorial involvement in 13.7%, and two or three cerebellar arteries involved in 8.9%. The main aetiology in PICA was atherothrombosis (P=.02). On the other hand, cardio-embolism was the main origin in cases with more than one affected territory (P=.04). No particular aetiology could be found in SCA and AICA. There was haemorrhagic transformation in 29 patients (23.4%), particularly in the PICA and when other territories were involved. There was hydrocephalus in 15 patients (12.1%, 12 of them PICA; P=.02) in 2.9 ± 1.5 days from stroke onset. At discharge, the degree of disability was worse if more than one arterial territory was involved (Rankin ≥ 3, 64% versus 31-36%; P=.05). Four (3.2%) patients died.

CONCLUSIONS

CI is very heterogeneous. Nevertheless, it is noteworthy that PICA infarction is the most frequent type and its aetiology is usually atherothrombotic. Moreover, it is the territory most frequently associated with severe complications, which take place during the first week of the stroke.

Clinical outcome following surgical treatment for bilateral cerebellar infarction

OBJECTIVES

To analyze the initial clinical and radiological findings, the surgical treatment, and the clinical outcome following surgical decompression in patients with space-occupying bilateral cerebellar infarction.

MATERIALS AND METHODS

Ten patients with expansive bilateral cerebellar infarction and decreased level of consciousness were operated with suboccipital craniectomy, removal of the infarcted tissue, and placement of external ventricular drainage. Long-term outcome was assessed using the modified Rankin scale (mRS).

RESULTS

Mean Glasgow coma scale (GCS) score before surgery was 8.9 ± 3.3 and improved to 12.6 ± 3.6 at discharge. At the long-term follow-up (median 57.6 months), six patients had a favorable outcome (mRS 1.3 ± 0.8). Four patients, all with an associated brain stem infarct, had a poor outcome.

CONCLUSIONS

In the absence of brain stem infarcts, surgical treatment resulted in a favorable clinical outcome and should be considered a treatment option for patients with expansive bilateral cerebellar infarction.

Bilateral cerebellar infarction in the medial branches of posterior inferior cerebellar arterial territory—Using endoscopic third ventriculostomy to relieve acute hydrocephalus

Simultaneous bilateral cerebellar infarctions in posterior inferior cerebellar arterial (PICA) territory, without brain stem involvement are rare. We herein report a 51-year-old man developed sudden dizziness, nausea and vomiting. CT revealed hypodense bilateral lesions over the cerebellum corresponding to the medial PICA (mPICA) branch territory. His mental state deteriorated 2 days after onset; repeated CT showed severe third and lateral ventricular dilation. Endoscopic third ventriculostomy (ETV) was done to relieve the acute obstructive hydrocephalus. The patient was later discharged with only mild residual ataxia. Compared with conventional surgical treatments (external ventricular drainage, craniectomy and cerebellectomy), ETV has several advantages, including less risk and minimal invasiveness. However, further study is needed on its safety and efficacy under such circumstances.

Bilateral medial cerebellar infarction in a patient positive for lupus anticoagulant

Bilateral medial cerebellar infarction occurring simultaneously is rare. We describe a middle aged male with bilateral cerebellar infarction complicated by subsequent left superior cerebellar artery infarction. Lupus anticoagulant was positive. Though the prognosis is usually considered good, our patient made poor recovery.

Multiple Cerebellar Infarcts: Clinical and Pathophysiologic Features

We investigated the clinical features of 15 patients with multiple isolated ischemic lesions in the cerebellum. The main initial symptoms were vertigo and nausea/vomiting in 8 patients each, and headache in 6 patients. Dysarthria and cerebellar ataxia of the limbs and trunk were observed in 14 patients. The ischemic lesions were in the posterior inferior cerebellar artery (PICA) plus superior cerebellar artery (SCA) territories in 4 patients (27%), and PICA plus SCA plus anterior inferior cerebellar artery (AICA) territories in 3 patients (20%). Infarcts were in the AICA plus SCA territories in 2 patients (13%), PICA only in 2 patients (13%), and SCA only in 4 patients (27%). Hemorrhagic lesions were observed in the ischemic area in 2 patients (13%). Vascular lesions included occlusive lesions of the vertebral arteries in 9 patients (60%), but no abnormalities of the vertebrobasilar arterial system were observed in 6 patients (40%). The functional prognosis was good in most cases. The underlying mechanism was atherothrombotic, including arteriogenic embolism in 9 patients (60%) and cardiogenic embolism in 3 patients (20%). An embolic mechanism was considered in all cases, but in some cases an accurate pathogenesis of the cerebellar infarction was obscure.

Episodic vertigo: central nervous system causes

Episodic ataxia type 2 is a prototypical episodic vertigo and ataxia syndrome that is caused by mutations in the calcium channel gene CACNA1A. Recent discoveries regarding the molecular mechanisms that underlie this syndrome provide a model for understanding the more common familial episodic vertigo syndromes, particularly those associated with migraine. Vertigo due to cerebrovascular disease can be of peripheral or central origin, and can mimic more benign peripheral vestibular disorders. Small infarcts in the cerebellum and lateral medulla can present with vertigo without other localizing symptoms.

Bilateral cerebellar infarctions caused by a stenosis of a congenitally unpaired posterior inferior cerebellar artery

Bilateral symmetrical cerebellar infarcts in the territory supplied by the medial posterior inferior cerebellar artery (PICA) branches are extremely rare. In the few cases published, it has not been possible to clearly pinpoint the cause of this infarct pattern. The authors present the case history of a 58-year-old man who had acute headaches accompanied by pronounced rotatory vertigo with nausea and vomiting. The neurological examination revealed bilateral cerebellar signs. Cranial magnetic resonance imaging showed bilateral, nearly symmetrical infarcts in the territory of the medial branches of both PICAs. These bilateral PICA infarctions were caused by a stenosis of an unpaired PICA originating from the left vertebral artery supplying both cerebellar hemispheres.