Autonomic Nervous System Modifications During Wakefulness and Sleep in a Cohort of Patients with Acute Ischemic Stroke.

GOAL

The aims of our study were to investigate autonomic modifications in wakefulness and sleep in a cohort of patients with acute ischemic stroke and to evaluate whereas these modifications were dependent by sleep stage and stroke lateralization.

MATERIALS AND METHODS

We prospectively enrolled 42 patients (22 men and 20 women, mean age: 69.8 ± 11.3; range: 32-92 years) with acute ischemic stroke. All participants underwent a full-night polysomnography. As index of autonomic nervous system we used Heart Rate Variability (HRV), analyzed in wakefulness and during different sleep stages. First, we compared our cohort with a control group of 42 healthy subjects, matched for age and sex. Subsequently, we divided our cohort in 2 subgroups according stroke lateralization (21 right, 21 left) and compared with control population.

FINDINGS

We observed significant modifications of HRV parameters mainly for the right lesions. In particular, we observed a prevalent parasympathetic tone during the wake (low frequency/high frequency [LF/HF]: right: 2.99 ± 8.91; controls: 3.88 ± 3.42; P < .01) and during REM (LF/HF right: 0.03 ± 1.58; controls: 2.92 ± 3.97; P < .01) accompanied by a significant reduction of sympathetic tone during REM (LF right: 23.85 ± 44.42 n.u.; controls: 51.13 ± 32.25 n.u.; P < .01), and by a reduction of parasympathetic tone during N3 (HF right: 28.09 ± 37.67 n.u.; controls: 43.08 ± 68.39 n.u.; P < .01).

CONCLUSIONS

Our study indicates that autonomic dysfunctions in acute ischemic stroke are prevalent in right-side lesions and strictly dependent by sleep-wake stage.