Abstract
Objective: Cerebral vasomotor reactivity (VMR) and coherence of resting state electroencephalographic (EEG) rhythms are impaired in Alzheimer's disease (AD) patients. Here we tested the hypothesis that these two variables could be related. Methods: We investigated VMR and coherence of resting state EEG rhythms in nine normal elderly (Nold) and in 10 amnesic mild cognitive impairment (MCI) subjects. Resting state eyes-closed EEG data were recorded at baseline pre-CO2 (ambient air, 2min), during 7% CO2/air mixture inhalation (hypercapnia, 90s) and post-CO2 (ambient air, 2min) conditions. Simultaneous frontal bilateral near-infrared spectroscopy (NIRS) was performed to assess VMR by cortical oxy- and deoxy-haemoglobin concentration changes. EEG coherence across all electrodes was computed at delta (2-4Hz), theta (4-8Hz), alpha 1 (8-10.5Hz), alpha 2 (10.5-13Hz), beta 1 (13-20Hz), beta 2 (20-30Hz) and gamma (30-40Hz) bands. Results: In Nold subjects, 'total coherence' of EEG across all frequency bands and electrode pairs decreased during hypercapnia, with full recovery during post-CO2. Total coherence resulted lower in pre-CO2 and post-CO2 and presented poor reactivity during CO2 inhalation in MCI patients compared with Nold subjects. Hypercapnia increased oxy-haemoglobin and decreased deoxy-haemoglobin concentrations in both groups. Furthermore, the extent of changes in these variables during CO2 challenge was correlated with the EEG coherence, as a reflection of neurovascular coupling. Conclusions: Hypercapnia induced normal frontal VMR that was detected by NIRS in both Nold and amnesic MCI groups, while it produced a reactivity of global functional coupling of resting state EEG rhythms only in the Nold group. Significance: In amnesic MCI patients, global EEG functional coupling is basically low in amplitude and does not react to hypercapnia.
| Original language | English |
|---|---|
| Pages (from-to) | 685-693 |
| Number of pages | 9 |
| Journal | Clinical Neurophysiology |
| Volume | 125 |
| Issue number | 4 |
| DOIs | |
| Publication status | Published - Apr 2014 |
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Keywords
- Amnesic mild cognitive impairment (MCI)
- Electroencephalography (EEG)
- Hypercapnia (CO)
- Near-infrared spectroscopy (NIRS)
- Resting state
ASJC Scopus subject areas
- Clinical Neurology
- Neurology
- Physiology (medical)
- Sensory Systems
- Medicine(all)
Cite this
Hypercapnia affects the functional coupling of resting state electroencephalographic rhythms and cerebral haemodynamics in healthy elderly subjects and in patients with amnestic mild cognitive impairment. / Babiloni, Claudio; Vecchio, Fabrizio; Altavilla, Riccardo; Tibuzzi, Francesco; Lizio, Roberta; Altamura, Claudia; Palazzo, Paola; Maggio, Paola; Ursini, Francesca; Ercolani, Matilde; Soricelli, Andrea; Noce, Giuseppe; Rossini, Paolo Maria; Vernieri, Fabrizio.
In: Clinical Neurophysiology, Vol. 125, No. 4, 04.2014, p. 685-693.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Hypercapnia affects the functional coupling of resting state electroencephalographic rhythms and cerebral haemodynamics in healthy elderly subjects and in patients with amnestic mild cognitive impairment
AU - Babiloni, Claudio
AU - Vecchio, Fabrizio
AU - Altavilla, Riccardo
AU - Tibuzzi, Francesco
AU - Lizio, Roberta
AU - Altamura, Claudia
AU - Palazzo, Paola
AU - Maggio, Paola
AU - Ursini, Francesca
AU - Ercolani, Matilde
AU - Soricelli, Andrea
AU - Noce, Giuseppe
AU - Rossini, Paolo Maria
AU - Vernieri, Fabrizio
PY - 2014/4
Y1 - 2014/4
N2 - Objective: Cerebral vasomotor reactivity (VMR) and coherence of resting state electroencephalographic (EEG) rhythms are impaired in Alzheimer's disease (AD) patients. Here we tested the hypothesis that these two variables could be related. Methods: We investigated VMR and coherence of resting state EEG rhythms in nine normal elderly (Nold) and in 10 amnesic mild cognitive impairment (MCI) subjects. Resting state eyes-closed EEG data were recorded at baseline pre-CO2 (ambient air, 2min), during 7% CO2/air mixture inhalation (hypercapnia, 90s) and post-CO2 (ambient air, 2min) conditions. Simultaneous frontal bilateral near-infrared spectroscopy (NIRS) was performed to assess VMR by cortical oxy- and deoxy-haemoglobin concentration changes. EEG coherence across all electrodes was computed at delta (2-4Hz), theta (4-8Hz), alpha 1 (8-10.5Hz), alpha 2 (10.5-13Hz), beta 1 (13-20Hz), beta 2 (20-30Hz) and gamma (30-40Hz) bands. Results: In Nold subjects, 'total coherence' of EEG across all frequency bands and electrode pairs decreased during hypercapnia, with full recovery during post-CO2. Total coherence resulted lower in pre-CO2 and post-CO2 and presented poor reactivity during CO2 inhalation in MCI patients compared with Nold subjects. Hypercapnia increased oxy-haemoglobin and decreased deoxy-haemoglobin concentrations in both groups. Furthermore, the extent of changes in these variables during CO2 challenge was correlated with the EEG coherence, as a reflection of neurovascular coupling. Conclusions: Hypercapnia induced normal frontal VMR that was detected by NIRS in both Nold and amnesic MCI groups, while it produced a reactivity of global functional coupling of resting state EEG rhythms only in the Nold group. Significance: In amnesic MCI patients, global EEG functional coupling is basically low in amplitude and does not react to hypercapnia.
AB - Objective: Cerebral vasomotor reactivity (VMR) and coherence of resting state electroencephalographic (EEG) rhythms are impaired in Alzheimer's disease (AD) patients. Here we tested the hypothesis that these two variables could be related. Methods: We investigated VMR and coherence of resting state EEG rhythms in nine normal elderly (Nold) and in 10 amnesic mild cognitive impairment (MCI) subjects. Resting state eyes-closed EEG data were recorded at baseline pre-CO2 (ambient air, 2min), during 7% CO2/air mixture inhalation (hypercapnia, 90s) and post-CO2 (ambient air, 2min) conditions. Simultaneous frontal bilateral near-infrared spectroscopy (NIRS) was performed to assess VMR by cortical oxy- and deoxy-haemoglobin concentration changes. EEG coherence across all electrodes was computed at delta (2-4Hz), theta (4-8Hz), alpha 1 (8-10.5Hz), alpha 2 (10.5-13Hz), beta 1 (13-20Hz), beta 2 (20-30Hz) and gamma (30-40Hz) bands. Results: In Nold subjects, 'total coherence' of EEG across all frequency bands and electrode pairs decreased during hypercapnia, with full recovery during post-CO2. Total coherence resulted lower in pre-CO2 and post-CO2 and presented poor reactivity during CO2 inhalation in MCI patients compared with Nold subjects. Hypercapnia increased oxy-haemoglobin and decreased deoxy-haemoglobin concentrations in both groups. Furthermore, the extent of changes in these variables during CO2 challenge was correlated with the EEG coherence, as a reflection of neurovascular coupling. Conclusions: Hypercapnia induced normal frontal VMR that was detected by NIRS in both Nold and amnesic MCI groups, while it produced a reactivity of global functional coupling of resting state EEG rhythms only in the Nold group. Significance: In amnesic MCI patients, global EEG functional coupling is basically low in amplitude and does not react to hypercapnia.
KW - Amnesic mild cognitive impairment (MCI)
KW - Electroencephalography (EEG)
KW - Hypercapnia (CO)
KW - Near-infrared spectroscopy (NIRS)
KW - Resting state
UR - http://www.scopus.com/inward/record.url?scp=84896709714&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84896709714&partnerID=8YFLogxK
U2 - 10.1016/j.clinph.2013.10.002
DO - 10.1016/j.clinph.2013.10.002
M3 - Article
C2 - 24238990
AN - SCOPUS:84896709714
VL - 125
SP - 685
EP - 693
JO - Clinical Neurophysiology
JF - Clinical Neurophysiology
SN - 1388-2457
IS - 4
ER -