Cerebral Vasomotor Reactivity and Apnea Test in Symptomatic and Asymptomatic High-Grade Carotid Stenosis.

INTRODUCTION: Cerebral vasomotor reactivity (VMR) represents an autoregulatory response of the arterial trunks on the specific vasoactive stimuli, most commonly CO2. OBJECTIVE: The aim of this retrospective study was to compare VMR in high-grade symptomatic (SCAS) and asymptomatic carotid stenosis (ACAS), using the apnea test to evaluate the hemodynamic status. METHODS: The study included 50 patients who were hospitalized at the neurology and vascular surgery departments as part of preparation for carotid endarterectomy. We evaluated VMR by calculating the breath holding index (BHI) in 34 patients with SCAS and 16 patients with ACAS, with isolated high-grade carotid stenosis. We evaluated the impact of risk factors and collateral circulation on BHI, as well as the correlation between the degree of carotid stenosis and BHI. RESULTS: A pathological BHI was more frequent in the SCAS group (p<0.01). There was no difference in the range of BHI values between the groups, both ipsilaterally and contralaterally. Only male gender was associated with pathological BHI in both groups (p<0.05). Collateral circulation did not exist in over 60% of all subjects. We confirmed a negative correlation between the degree of carotid stenosis and BHI. CONCLUSION: SCAS and ACAS patients present with different hemodynamics. While ACAS patients have stable hemodynamics, combination of hemodynamic and thromboembolic effects is characteristic of SCAS patients.

A case series of 22 patients with internal carotid artery dissection.

The aim of this study was to analyze the spectrum of clinical presentations of internal carotid artery dissection. Twenty-two patients with internal carotid artery dissection, mean age 39.02, were evaluated over the past ten years. Magnetic resonance imaging and magnetic resonance angiography were used to establish the diagnosis. Facial and neck pain and Horner's syndrome were the only presenting symptoms in 4 patients (without brain infarction); facial pain, Horner's syndrome and contralateral sensorimotor deficit in 6; headache and contralateral sensorimotor deficit in 2; contralateral sensorimotor deficit with or without speech impairment in 10. Internal carotid artery dissection was triggered by a trauma in 7, whereas it was spontaneous in 15. Magnetic resonance imaging revealed infarction in 18 patients. A good outcome (modified Rankin score 0-2) was seen in 20 patients. The spectrum of clinical presentations of internal carotid artery dissection is variable. Internal carotid artery dissection is not necessarily accompanied by infarction on magnetic resonance imaging.