Table 1.
Pathologies in which CVR was investigated.
| Pathology | Number of studies | Number of patients/controls | Mean age of patients/controls | Findings | References |
|---|---|---|---|---|---|
| Cerebral steno-occlusive diseases | 72 | 1786/541 | 51.4/44.9 | - Lower CVR than healthy controls (Hartkamp et al., 2017; Liu et al., 2017a; De Vis et al., 2018; Duffin et al., 2018; Venkatraghavan et al., 2018; Waddle et al., 2019) - Longer delays than healthy controls (Hartkamp et al., 2012; Duffin et al., 2015; Liu et al., 2017b; Waddle et al., 2019) - Increased CVR (Han et al., 2011a; Mandell et al., 2011; Watchmaker et al., 2019) and smaller delays (Watchmaker et al., 2019) after surgical intervention |
Piepgras et al., 1994; Guckel et al., 1995; Ohnishi et al., 1996; Schreiber et al., 1998; Hamzei et al., 2003; Shiino et al., 2003; Griffiths et al., 2005; Ziyeh et al., 2005; Ma et al., 2007; Haller et al., 2008; Mandell et al., 2008b, 2011; Chang et al., 2009, 2013; Donahue et al., 2009, 2013, 2016; Goode et al., 2009, 2016; Calviere et al., 2010; Bokkers et al., 2011; Conklin et al., 2011; Han et al., 2011a,b; Kim et al., 2011; Uchihashi et al., 2011; Hartkamp et al., 2012, 2017, 2018, 2019; Mutch et al., 2012; Poublanc et al., 2013, 2015; Spano et al., 2013; Thomas B. et al., 2013; Donahue et al., 2014; Sam et al., 2014, 2015; Sobczyk et al., 2014, 2015, 2016; Bouvier et al., 2015; De Vis et al., 2015b, 2018; Duffin et al., 2015, 2017, 2018; Faraco et al., 2015; Noguchi et al., 2015; Siero et al., 2015a; Herrera et al., 2016; Strother et al., 2016; van Niftrik et al., 2016; Dlamini et al., 2017, 2018; Federau et al., 2017; Fisher et al., 2017; Hu et al., 2017; Ladner et al., 2017; Liu et al., 2017a,b; Para et al., 2017; Wu et al., 2017; Fierstra et al., 2018b; Rosen et al., 2018; Sebok et al., 2018; Venkatraghavan et al., 2018; Hauser et al., 2019; Taneja et al., 2019; Waddle et al., 2019; Watchmaker et al., 2019; Papassin et al., 2020 |
| Dementia and cognitive impairment | 9 | 770/125 | 60.5/68.1 | - Lower CVR than healthy controls (Cantin et al., 2011; Yezhuvath et al., 2012) - Longer delays than healthy controls (Holmes et al., 2020) - Higher CVR deficit vs. healthy controls associated with higher leukoaraiosis (Yezhuvath et al., 2012) and hypertension (Haight et al., 2015) - Lower CVR in the bilateral frontal cortices of Alzheimer's patients compared to patients with vascular dementia (Gao et al., 2013) |
Cantin et al., 2011; Yezhuvath et al., 2012; Gao et al., 2013; Haight et al., 2015; Richiardi et al., 2015; Suri et al., 2015; Lajoie et al., 2017; McKetton et al., 2019; Holmes et al., 2020 |
| Normal ageing | 8 | NA/374 | Range: [20, 90] | - Lower CVR at older ages (Riecker et al., 2003; Liu et al., 2013; De Vis et al., 2015a; Bhogal et al., 2016; Leoni et al., 2017; Catchlove et al., 2018; Miller et al., 2019) - Greater WM CVR and shorter delay with increasing age (Thomas et al., 2014) |
Riecker et al., 2003; Liu et al., 2013; Thomas et al., 2014; De Vis et al., 2015a; Bhogal et al., 2016; Leoni et al., 2017; Catchlove et al., 2018; Miller et al., 2019 |
| Small vessel disease | 7 | 272/54 | 67.4/45.7 | - Lower CVR with increased WMH burden (Liem et al., 2009; Blair et al., 2020) and compared to healthy controls (Liem et al., 2009; Tchistiakova et al., 2015; Thrippleton et al., 2018; Atwi et al., 2019) - Longer delays than healthy controls (Sam et al., 2016a; Thrippleton et al., 2018; Atwi et al., 2019) - Reduced WM CVR associated with higher WMH volumes, basal ganglia PVS and higher venous pulsatility and lower foramen magnum CSF stroke volume (Blair et al., 2020) - Lower baseline CVR associated with progression of WMHs but not microbleeds or lacunar infarcts (Liem et al., 2009) - Lower CVR associated with increased number of vascular risk factors such as hypertension, diabetes, hypercholesterolemia (Tchistiakova et al., 2015), lower fractional anisotropy, lower CBF and CBV and higher mean diffusivity (Sam et al., 2016b) - Lower CVR and longer delays in NAWM that progressed into WMH (Sam et al., 2016a) |
Liem et al., 2009; Tchistiakova et al., 2015; Sam et al., 2016a,b; Thrippleton et al., 2018; Atwi et al., 2019; Blair et al., 2020 |
| Sport-related concussions | 7 | 113/128 | 18.6/21.2 | - Lower CVR in the default mode network at mid-season and 1 month post-season compared to pre-season baseline. Decrease in CBF occurred only 1 month after season (Champagne et al., 2019c) - Longitudinal reduction in CVR during season compared to pre-season baseline was associated with prolonged accumulation to high magnitude acceleration events (Svaldi et al., 2020) - Predominant increase in CVR compared to baseline during the recovery phase but remains mostly altered despite clinical recovery (Mutch et al., 2016b) - Higher CVR in clinically recovered patients with history of concussions than in athletes without (Mutch et al., 2018; Champagne et al., 2019b) |
Mutch et al., 2016b, 2018; Champagne et al., 2019b,c; Champagne et al., 2020a; Coverdale et al., 2020; Svaldi et al., 2020 |
| Obstructive sleep apnoea | 5 | 125/55 | 50.6/44.5 | - Greater CVR than in healthy controls measured using ASL with BH, BOLD with BH (Wu et al., 2020) and BOLD with EtCO2 targeting (Ryan et al., 2018). - ASL response to fixed CO2 enriched air reduced in patients with OSA compared to healthy controls, whereas BOLD response to fixed CO2 enriched air or BH did not show group differences (Ponsaing et al., 2018). |
Buterbaugh et al., 2015; Ponsaing et al., 2018; Ryan et al., 2018; Thiel et al., 2019; Wu et al., 2020 |
| Stroke | 5 | 135/102 | 58.7/51.0 | - Lower CVR in impaired tissue and compared to healthy controls (Krainik et al., 2005; Zhao et al., 2009; Geranmayeh et al., 2015) - Higher CVR with increasing distance from lesion (Taneja et al., 2019) - Reduced CVR associated with peri-infarct T2 hyperintensities, greater infarct volume and worse outcomes (Zhao et al., 2009) - Reduced CVR in the motor areas controlling the upper airway musculature compared to healthy controls (Buterbaugh et al., 2015). - No change in CVR upon CPAP withdrawal (Thiel et al., 2019) |
Krainik et al., 2005; Zhao et al., 2009; Geranmayeh et al., 2015; Raut et al., 2016 |
| Traumatic brain injury | 4 | 90/77 | 32.2/31.8 | - Lower CVR than healthy controls in one study (Amyot et al., 2018) - No difference in CVR between patients and healthy controls in one study (Champagne et al., 2020b) - Lower GM CVR with more concussion symptoms (da Costa et al., 2016) |
da Costa et al., 2016; Mutch et al., 2016a; Amyot et al., 2018; Champagne et al., 2020b |
| Gliomas | 4 | 50/12 | 43.9/not reported | - Lower CVR on ipsilateral side for low and high grade gliomas | Hsu et al., 2004; Pillai and Zaca, 2012; Zaca et al., 2014; Fierstra et al., 2018a |
| Diabetes | 3 | 103/32 | 67.5/61.8 | - Lower CVR in diabetic hypertensive patients than in only hypertensive patients (Kario et al., 2005; Tchistiakova et al., 2014) - Higher CVR in bilateral pre-frontal lobe in one study (Zhou X.-H. et al., 2015) - Increased CVR after candesartan therapy (Kario et al., 2005) |
Kario et al., 2005; Tchistiakova et al., 2014; Zhou X.-H. et al., 2015 |
| Pathologies investigated in two studies: | |||||
| - Cardia index and coronary artery disease (Anazodo et al., 2016; Jefferson et al., 2017) | |||||
| - Sickle cell disease (Leung et al., 2016a; Kosinski et al., 2017) | |||||
| - Multiple sclerosis (Metzger et al., 2018; Sivakolundu et al., 2019) | |||||
| - Obesity (Frosch et al., 2017; Tucker et al., 2020) | |||||
| - Brain arteriovenous malformation and cerebral proliferative angiopathy (Fierstra et al., 2011a,b) | |||||
| - Parkinson's disease (Al-Bachari et al., 2014; Pelizzari et al., 2019) | |||||
| Pathologies investigated in one study: | |||||
| - End-stage renal disease (Zheng et al., 2016) | |||||
| - Bipolar disorder (Urback et al., 2019) | |||||
| - Late-life depression (Abi Zeid Daou et al., 2017) | |||||
| - Late-onset epilepsy (Hanby et al., 2015) | |||||
| - HIV (Callen et al., 2020) | |||||
| - Aneurysmal subarachnoid haemorrhage (Da Costa et al., 2014) | |||||
| - MELAS (Rodan et al., 2015) | |||||
“Mean age” was computed by taking the average across studies of the reported mean/median age of the patients. GM, grey matter; WM, white matter; WMH, white matter hyperintensity; NAWM, normal-appearing white matter; CPAP, continuous positive airway pressure; MELAS, Mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes; HIV, Human immunodefiency viruses; CSF, cerebral spinal fluid; NA, not applicable; OSA, obstructive sleep apnoea; BH, breath-hold.