scholarly journals Comparison of Model-Based Indices of Cerebral Autoregulation and Vasomotor Reactivity Using Transcranial Doppler versus Near-Infrared Spectroscopy in Patients with Amnestic Mild Cognitive Impairment

2017 ◽  
Vol 56 (1) ◽  
pp. 89-105 ◽  
Author(s):  
Vasilis Z. Marmarelis ◽  
Dae C. Shin ◽  
Takashi Tarumi ◽  
Rong Zhang
Keyword(s):  
Cognitive Impairment ◽  
Infrared Spectroscopy ◽  
Mild Cognitive Impairment ◽  
Near Infrared Spectroscopy ◽  
Transcranial Doppler ◽  
Cerebral Autoregulation ◽  
Near Infrared ◽  
Amnestic Mild Cognitive Impairment ◽  
Vasomotor Reactivity ◽  
Model Based

Increased Cerebral Vasomotor Reactivity in Migraine With Aura: An Autoregulation Disorder? A Transcranial Doppler and Near-Infrared Spectroscopy Study

Cephalalgia ◽  
2008 ◽  
Vol 28 (7) ◽  
pp. 689-695 ◽  
Author(s):  
F Vernieri ◽  
F Tibuzzi ◽  
P Pasqualetti ◽  
C Altamura ◽  
P Palazzo ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Migraine With Aura ◽  
Near Infrared Spectroscopy ◽  
Transcranial Doppler ◽  
Near Infrared ◽  
Cerebral Blood Volume ◽  
Cerebral Arteries ◽  
Invasive Approach ◽  
Vasomotor Reactivity ◽  
Haemoglobin Content

Migraine with aura (MA) is associated with changes in cerebral blood flow (CBF), whereas the role of cerebral autoregulation is uncertain. This study aimed to evaluate basal CBF, cerebral blood volume (CBV) and vasomotor reactivity (VMR) in MA patients. Twenty-one controls and 16 MA patients (eight with side predominance) underwent simultaneous examination of flow velocity in the middle cerebral arteries by transcranial Doppler (TCD) and of near-infrared spectroscopy (NIRS) parameters [oxygen haemoglobin saturation: oxygen%, and total haemoglobin content (THC)] at rest and after hypercapnia. Cerebral VMR, THC and oxygen% increases were significantly greater on the predominant compared with the non-predominant migraine side, with both sides of patients without side predominance and with controls. These findings suggest altered autoregulation in MA patients, possibly secondary to impaired cerebrovascular autonomic control. Simultaneous TCD and NIRS investigation could represent a non-invasive approach to evaluate cerebral haemodynamics at the cortical and subcortical level.

Reduced Frontal Activations at High Working Memory Load in Mild Cognitive Impairment: Near-Infrared Spectroscopy

2016 ◽  
Vol 42 (5-6) ◽  
pp. 278-296 ◽  
Author(s):  
Michael K. Yeung ◽  
Sophia L. Sze ◽  
Jean Woo ◽  
Timothy Kwok ◽  
David H.K. Shum ◽  
...  
Keyword(s):  
Older Adults ◽  
Working Memory ◽  
Cognitive Impairment ◽  
Infrared Spectroscopy ◽  
Mild Cognitive Impairment ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Memory Load ◽  
Load Condition ◽  
Working Memory Load

Background: Some functional magnetic resonance imaging studies have reported altered activations in the frontal cortex during working memory (WM) performance in individuals with mild cognitive impairment (MCI), but the findings have been mixed. The objective of the present study was to utilize near-infrared spectroscopy (NIRS), an alternative imaging technique, to examine neural processing during WM performance in individuals with MCI. Methods: Twenty-six older adults with MCI (7 males; mean age 69.15 years) were compared with 26 age-, gender-, handedness-, and education-matched older adults with normal cognition (NC; 7 males; mean age 68.87 years). All of the participants undertook an n-back task with a low (i.e., 0-back) and a high (i.e., 2-back) WM load condition while their prefrontal dynamics were recorded by a 16-channel NIRS system. Results: Although behavioral results showed that the two groups had comparable task performance, neuroimaging results showed that the MCI group, unlike the NC group, did not exhibit significantly increased frontal activations bilaterally when WM load increased. Compared to the NC group, the MCI group had similar frontal activations at low load (p > 0.05 on all channels) but reduced activations at high load (p < 0.05 on 4 channels), thus failing to demonstrate WM-related frontal activations (p < 0.05 on 9 channels). In addition, we found a positive correlation between the left WM-related frontal activations and WM ability primarily in the NC group (rs = 0.42, p = 0.035), suggesting a relationship between frontal hypoactivation and WM difficulties. Conclusion: The present findings suggest the presence of frontal dysfunction that is dependent on WM load in individuals with MCI.

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