Thalamic connectivity in patients with sleep-disordered breathing (SDB) after stroke

Background : Thalamus-cortical connections are essential for normal sleep1. Stroke can alter this circuit affecting also breathing during sleep2. Aim: To compare the functional connectivity of ventral-postero-lateral thalamic nucleous (VPL-TN) in stroke patients affected by SDB (S-SDB) as respect to stroke cases not affected (S) and to healthy controls (HC). Methods: stroke patients were submitted to clinical, neuroradiological and full nocturnal polysomnography (PSG) monitoring. Conventional and functional MR exams during resting state (rs-fMRI) were performed in a single session (3 Tesla Siemens-Verio) in 12 stroke patients and in 11 HCs. Statistical analysis of rs-fMRI connectivity was performed using the FMRIB software package. A seed analysis approach was performed using VPL-TN as region of interest. Significant difference in rs-fMRI connectivity among the groups (S-SDB, S, HC) was set at p < 0.05. Results: six stroke patients out of 12 had a SDB. No differences were found between S and S-SDB groups as to risk profile and PSG data (Tab.1). rs-fMRI connectivity analysis indicated that precuneus (PreCu) and brainstem (BS) were significantly more connected with VPL-TN in S-SDB as respect to HC. When comparing S-SDB to S patients, a further significantly higher connectivity with anterior cingulate cortex (ACC) was revealed (Fig. 1-2). Conclusions: A higher connectivity between VPL-TN and regions involved also in modulating chemosensitivity (ACC and BS)3, 4 or alertness (PreCu)5 was observed during wake in S-SDB as respect to S patients. These preliminary data support the hypothesis that stroke may cause an SDB as the consequence of an altered sleep-wake circuit