Inspiratory pre‐motor potentials during quiet breathing in ageing and chronic obstructive pulmonary disease

Abstract

A cortical contribution to breathing is determined by the presence of a Bereitschaftspotential, a low amplitude negativity in the averaged electroencephalographic (EEG) signal, which begins ∼1 s before inspiration. It occurs in healthy individuals when external inspiratory loads to breathing are applied. In chronic obstructive pulmonary disease (COPD), changes in the lung, chest wall and respiratory muscles produce an internal inspiratory load. We hypothesized that there would be a cortical contribution to quiet breathing in COPD and that a cortical contribution to breathing with an inspiratory load would be linked to dyspnoea, a major symptom of COPD. EEG activity was analysed in 14 participants with COPD (aged 57-84 years), 16 healthy age-matched (57-87 years) and 15 young (18-26 years) controls during quiet breathing and inspiratory loading. The presence of Bereitschaftspotentials, from ensemble averages of EEG epochs at Cz and FCz, were assessed by blinded assessors. Dyspnoea was rated using the Borg scale. The incidence of a cortical contribution to quiet breathing was significantly greater in participants with COPD (6/14) compared to the young (0/15) (P = 0.004) but not the age-matched controls (6/16) (P = 0.765). A cortical contribution to inspiratory loading was associated with higher Borg ratings (P = 0.007), with no effect of group (P = 0.242). The data show that increased age, rather than COPD, is associated with a cortical contribution to quiet breathing. A cortical contribution to inspiratory loading is associated with more severe dyspnoea. We propose that cortical mechanisms may be engaged to defend ventilation with dyspnoea as a consequence.

Inhibition of central activation of the diaphragm: a mechanism of weaning failure

“…2 ). The second consists in the activation of the premotor cortex by the increased mechanical load imposed on the respiratory muscles ( 40 , 75 ).…”

Decreased respiratory-related postural perturbations at the cervical level under cognitive load

“…This result indicates the central modulation of the PV interaction and suggests that postural control partly depends on central interactions between the cortical control of breathing and cognition in healthy humans. Therefore, as dual tasks are common in real-life settings, our results lead us to hypothesize that postural control may be less efficient in situations associated with a pathological adaptive increase in awake cortical respiratory drive, such as in healthy individuals during experimental dyspnoea (Raux et al 2007) or in some patients with obstructive sleep apnoea syndrome (OSAS) (Launois et al 2015), chronic obstructive pulmonary disease (COPD) (Nguyen et al 2018) or hyperventilation syndrome (Dubois et al 2016). In these settings, the pre-inspiratory potential observed in the motor cortex and the supplementary motor area during resting ventilation (Raux et al 2007) has been associated with a perturbation of attentional resources (Sharman et al 2014), which suggests that the balance between cognition, postural control and the control of breathing under cognitive load is impaired.…”

Discharge properties of human diaphragm motor units with ageing

“…eupnoea) in healthy older adults in their 8th decade (Nguyen et al . ). Studies of electromyographic activity (EMG) also suggest there are age‐related changes in neural control of respiratory muscles.…”

“…We recently demonstrated, using electroencephalography, the presence of an 'abnormal' cortical drive during quiet breathing (i.e. eupnoea) in healthy older adults in their 8th decade (Nguyen et al 2018b). Studies of electromyographic activity (EMG) also suggest there are age-related changes in neural control of respiratory muscles.…”