Assessment of cerebrovascular reserve impairment using the breath-holding index in patients with leukoaraiosis

Abstract

Many studies have demonstrated that leukoaraiosis is associated with impaired cerebrovascular reserve function. However, the definitive hemodynamic changes that occur in leukoaraiosis are not clear, and there are many controversies. This study aimed to investigate hemodynamic changes in symptomatic leukoaraiosis using transcranial Doppler ultrasonography and the breath-holding test in a Chinese Han population, from northern China. A total of 203 patients who were diagnosed with ischemic stroke or clinical chronic progressive ischemic symptoms were enrolled in this study, including 97 males and 106 females, with an age range of 43-93 years. The severity of leukoaraiosis was evaluated according to the Fazekas grading scale, and patients were divided into four groups accordingly. Grade 0 was no leukoaraiosis, and grades I, II, and III were mild, moderate, and severe leukoaraiosis, respectively, with 44, 79, 44, and 36 cases in each group. Transcranial Doppler ultrasonography and the breath-holding test were performed. The mean blood flow velocity of the bilateral middle cerebral artery was measured and the breath-holding index was calculated. The breath holding index was correlated with leukoaraiosis severity and cognitive impairment. Patients with a low breath holding index presented poor performance in the Montreal Cognitive Assessment (MoCA) and executive function tests. That is, the lower the breath holding index, the lower the scores for the MoCA and the higher for the trail-making test Parts A and B. These results indicate that the breath-holding index is a useful parameter for the evaluation of cerebrovascular reserve impairment in patients with leukoaraiosis. In addition, the breath-holding index can reflect cognitive dysfunction, providing a new insight into the pathophysiology of leukoaraiosis. This study was approved by the Ethics Committee of the Fifth People's Hospital of Shenyang, China (approval No. 20160301) and registered in the Chinese Clinical Trial Registry (registration number: ChiCTR1800014421).

Keywords: blood flow velocity; breath-holding index; breath-holding test; cerebral hemodynamics; cerebral hypoperfusion; cerebral small vascular disease; cognitive function; middle cerebral artery; nerve regeneration; neural regeneration; white matter hyperintensities.

Figure 1

Comparison of breath-holding index (BHI) between each leukoaraiosis grade. **P < 0.01, vs. Grade I and II groups. Non-normally distributed data are expressed in lower quartile, median, and upper quartile. Quantitative data were compared using the Kruskal-Wallis test.