MRI and polysomnographic findings of patients affected by post-stroke sleep apnea

Aim: The aim of our study was to compare characteristics of stroke patients who presented Obstructive Sleep Apnea/Hypopnea (OSAH) to those of cases that presented Central Sleep Apnea/Hypopnea (CSAH) events at PSG, and to investigate relationships between the type of breathing disturb during sleep and the location of brain damage. Methods: Thirty four patients were submitted to clinical, neuroradiological and polisomnographyc study (PSG) after 4 months of stroke. A Sleep Disordered Breathing (SDB) was diagnosed in all cases with an AHI > 5. Patients were classified as affected by predominantly OSAH (pOSAH), or predominantly CSAH (pCSAH). Comparisons were made among the groups and correlation analyses were done in each group. Significance was set at p < 0.005. Results: Twenty six patients with ischemic strokes had a SDB during sleep (56% embolic, 31% lacunar, 8% large artery, 8% with undetermined cause). The 61% of them showed pOSAH. Except for age, no statistical differences were found between the two groups as to clinical findings, risk factors for stroke, PSG data, or location of brain lesion. Correlation analysis outlined that in pOSAH cases the time interval from stroke to PSG (Δt) was inversely related to both TST (p = 0.017) and TSP (p = 0.039);in pCSAHs it was inversely related to SE Index (p = 0.021) and directly related to both ODI (p = 0.016) and with the n. of arrhythmias/h sleep (p = 0.033). In pCSAH, AHI did not correlate with ODI. Conclusions: Our data suggest that among cases with post stroke SDB is included 3 different subgroups of cases: OSAHs who terminate the obstruction by arousal, OSAHs who do not arise and alternate obstructive to central events, and CSAHs due to the direct effect of stroke on the breathing network;in a forth subgroup of cases, the microstructure of sleep might be altered, with the consequent occurrence of sleep-related events. Further studies are needed to clarify these hypotheses as well as the role of poststroke depression on the nature and occurrence of SDB after stroke.

Are you suffering from a large arterial occlusion?Please raise your arm!

Background and purpose Triage tools to identify candidates for thrombectomy are of utmost importance in acute stroke.No prognostic tool has yet gained any widespread use.We compared the predictive value of various models based on National Institutes of Health Stroke Scale(NIHSS)subitems,ranging from simple to more complex models,for predicting large artery occlusion(LAO)in anterior circulation stroke.Methods Patients registered in the SITS international Stroke Register with available NIHSS and radiological arterial occlusion data were analysed.We compared 2042 patients harbouring an LAO with 2881 patients having no/distal occlusions.Using binary logistic regression,we developed models ranging from simple 1 NIHSS-subitem to full NIHSS-subitems models.Sensitivities and specificities of the models for predicting LAO were examined.results The model with highest predictive value included all NIHSS subitems for predicting LAO(area under the curve(AUC)0.77),yielding a sensitivity and specificity of 69%and 76%,respectively.The second most predictive model(AUC 0.76)included 4-NIHSS-subitems(level of consciousness commands,gaze,facial and arm motor function)yielding a sensitivity and specificity of 67%and 75%,respectively.The simplest model included only deficits in arm motor-function(AUC 0.72)for predicting LAO,yielding a sensitivity and specificity of 67%and 72%,respectively.Conclusions Although increasingly more complex models yield a higher discriminative performance for predicting LAO,differences between models are not large.Assessing grade of arm dysfunction along with an established stroke-diagnosis model may serve as a surrogate measure of arterial occlusion-status,thereby assisting in triage decisions.