Cardiorespiratory effects induced by vagus nerve stimulation in epileptic children

Pruvost, Mickael; Zaaimi, Boubker; Grebe, Reinhard; Wallois, Fabrice; Berquin, Patrick; Perlitz, Volker

doi:10.1007/s11517-006-0041-5

Cited by 19 publications

(10 citation statements)

References 26 publications

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“…VNS therapy effect on other physiological measures as blood pressure, respiratory sinus arrhythmia should be investigated. Concerning the RR variability, in a related study conducted in our laboratory for the same group of patients, we did not observe any decrease in heart rate variability; rather, we observed that VNS increases the principal frequency of the high frequency component (Pruvost et al, 2006).…”

Section: Discussionsupporting

confidence: 42%

Vagus Nerve Stimulation Therapy Induces Changes in Heart Rate of Children during Sleep

Zaaimi¹,

Grebe²,

Berquin³

et al. 2007

Epilepsia

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Summary:Purpose: This study analyzed changes in the heart rates of children receiving vagus nerve stimulation (VNS) therapy for pharmacoresistant epilepsy.Methods: Changes in the heart rates of ten children receiving VNS therapy for pharmacoresistant epilepsy were evaluated with polysomnographic recordings, including electrocardiogram (ECG), EEG, thoraco-abdominal distension, nasal airflow, and VNS artifacts. Measurements during stimulation were compared with those at baseline for each patient.Result: While the VNS therapy pulse generator was delivering stimulation, the heart rates of four children increased significantly (p < 0.01), decreased for one child, and increased at the end of the stimulation for one child. The heart rates of four children did not change. Changes in heart rate varied during VNS, within stimulation cycles for individual children and from one child to another. Changes in heart rate differed between rapid eye movement (REM) and non-REM (NREM) sleep states. Respiratory changes (increases in frequency and decreases in amplitude) were concomitant with the changes in heart rate.Conclusion: In this case series of children with pharmacoresistant epilepsy, cardiorespiratory variations occurred while the VNS therapy pulse generator was delivering stimulation. Understanding these variations may allow further optimization of VNS parameters. Key Words: Epilepsy-Vagus nerve stimulationHeart rate-Respiration.Vagus nerve stimulation (VNS) therapy has been used for treating pharmacoresistant epilepsy in Europe since 1994. Several studies have described the efficacy of this treatment (Handforth et al., 1998;DeGiorgio et al., 2000;Boon et al., 2001). The vagus nerve comprises large myelinated A fibers, small myelinated B fibers, and unmyelinated C fibers that transmit VNS signals. In animals, a decreased heart rate is an index for C fiber stimulation (Woodbury and Woodbury, 1990;McLachlan, 1993). Although intraoperative bradycardia and asystole associated with vagal activation has been reported (Asconapé et al., 1999;Tatum et al., 1999), many studies have reported the safety of VNS Therapy (Ben Menachem, 2001). However, changes in heart rate variability during VNS Therapy have been reported (Kamath, 1992;Setty et al., 1998;Frei and Osorio, 2001;Galli et al., 2003). The effects of VNS on heart rate have been investigated in an awake state (Kamath et al., 1992;Banzett et al., 1999;Binks et al., 2001) and in a mixed awake and sleep state (Frei and Osorio, 2001). Only one of these studies reported a change in heart rate in adults (Frei and Osorio, 2001), showing that VNS can induce a reduction in heart rate and a biphasic response of a reduction followed by an increase in heart rate. The key role of the vagus nerve in heart rate regulation led us to investigate the effect of VNS on heart rate during sleep in children receiving VNS Therapy. A previous study in our laboratory showed that VNS Therapy during sleep-induced respiratory changes. The time course of those respiratory variations was divided into three ...

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Section: Discussionsupporting

confidence: 42%

Vagus Nerve Stimulation Therapy Induces Changes in Heart Rate of Children during Sleep

Zaaimi¹,

Grebe²,

Berquin³

et al. 2007

Epilepsia

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“…It is, therefore, unlikely that the observed changes are due to changes in heart rate and increased respiratory rate. A previous study on the same patients (Pruvost et al, 2006) focused on measurement of vagal tone. The sympathovagal balance index was increased in all but one of these children, indicating a relative increase in sympathetic activity compared to the relative change in parasympathetic activity.…”

Section: Discussionmentioning

confidence: 99%

Vagus nerve stimulation induces changes in respiratory sinus arrhythmia of epileptic children during sleep

Zaaimi¹,

Grebe²,

Berquin³

et al. 2009

Epilepsia

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SUMMARYPurpose: This study analyzed the direct shortterm effect of vagus nerve stimulation (VNS) on respiratory sinus arrhythmia (RSA) in children with pharmacoresistant epilepsy. Methods: RSA magnitude is calculated as the ratio between maximum and minimum heart rate for each respiratory cycle-before, during, and after the actual VNS period. In 10 children, changes in RSA magnitude were evaluated on polysomnographic recordings, including electrocardiography (ECG), electroencephalography (EEG), thoracoabdominal distension, nasal airflow, and VNS artifacts. Measurements during stimulation were compared with those at baseline, immediately preceding the VNS periods and individually for each patient. Result: During VNS, respiratory frequency increased and respiratory amplitude decreased with a variable effect on cardiac activity. The coupling between heart rate and respiratory rate was disturbed and RSA magnitude decreased significantly in 6 of 10 children during VNS. These changes in RSA magnitude varied from one child to another. The observed changes for respiratory and cardiac activity were concomitant with changes in RSA but were not correlated. Conclusion: Together with disorders of respiration, cardiac activity, and oxygen saturation (SaO 2 ) described previously. VNS also modifies synchronization between cardiac and respiratory activity, resulting in poor optimization of oxygen delivery to tissues that can be regarded as an additive side effect, which should be considered in patients with already altered brain function. This interaction between the effects of VNS and potential autonomic nervous system (ANS) dysfunction already reported in epileptic patients should be considered to be potentially life-threatening. In addition, evaluation of changes in respiratory parameters can also provide reliable markers for further evaluation of the effectiveness of VNS.

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“…When studying interictal HRV before and after implantation, a number of studies reported findings indicating a shift back toward increased parasympathetic activity with VNS; with a similar shift noted in healthy subjects stimulated using transcutaneous VNS . However, multiple other studies failed to find a statistically significant difference before and after VNS treatment .…”

Section: Effects Of Treatment On Interictal Hrvmentioning

confidence: 97%

Heart rate variability measurement in epilepsy: How can we move from research to clinical practice?

2018

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Our objective was to critically evaluate the literature surrounding heart rate variability (HRV) in people with epilepsy and to make recommendations as to how future research could be directed to facilitate and accelerate integration into clinical practice. We reviewed relevant HRV publications including those involving human subjects with seizures. HRV has been studied in patients with epilepsy for more than 30 years and, overall, patients with epilepsy display altered interictal HRV, suggesting a shift in autonomic balance toward sympathetic dominance. This derangement appears more severe in those with temporal lobe epilepsy and drug-resistant epilepsy. Normal diurnal variation in HRV is also disturbed in at least some people with epilepsy, but this aspect has received less study. Some therapeutic interventions, including vagus nerve stimulation and antiepileptic medications, may partially normalize altered HRV, but studies in this area are sometimes contradictory. During seizures, the changes in HRV may be complex, but the general trend is toward a further increase in sympathetic overactivity. Research in HRV in people with epilepsy has been limited by inconsistent experimental protocols and studies that are often underpowered. HRV measurement has the potential to aid clinical epilepsy management in several possible ways. HRV may be useful in predicting which patients are likely to benefit from surgical interventions such as vagus nerve stimulation and focal cerebral resection. As well, HRV could eventually have utility as a biomarker of risk for sudden unexpected death in epilepsy (SUDEP). However, at present, the inconsistent measurement protocols used in research are hindering translation into clinical practice. A minimum protocol for HRV evaluation, to be used in all studies involving epilepsy patients, is necessary to eventually allow HRV to become a useful tool for clinicians. We propose a straightforward protocol, involving 5-minute measurements of root mean square of successive differences in wakefulness and light sleep.

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Cardiorespiratory effects induced by vagus nerve stimulation in epileptic children

Cited by 19 publications

References 26 publications

Vagus Nerve Stimulation Therapy Induces Changes in Heart Rate of Children during Sleep

Vagus Nerve Stimulation Therapy Induces Changes in Heart Rate of Children during Sleep

Vagus nerve stimulation induces changes in respiratory sinus arrhythmia of epileptic children during sleep

Heart rate variability measurement in epilepsy: How can we move from research to clinical practice?

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