1
|
Guo H, Grajauskas L, Habash B, D'Arcy RCN, Song X. Functional MRI technologies in the study of medication treatment effect on Alzheimer's disease. Aging Med (Milton) 2018; 1:75-95. [PMID: 31942484 PMCID: PMC6880690 DOI: 10.1002/agm2.12017] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 04/02/2018] [Indexed: 12/14/2022] Open
Abstract
Alzheimer's disease (AD) is the most common cause of late-life dementia. Characterized by progressive neurodegeneration, the disease is expressed as gradual memory loss together with decline in cognitive abilities and other brain functions. Despite extensive research over the past decade, the cause and cure of AD both remain largely unknown. Several AD-associated deficits have been targeted for interventions, including those based on amyloid-beta, tau, and inflammation hypotheses. Only 2 types of medications-cholinesterase inhibitors and memantine-have been approved, to control the cognitive symptoms of AD such as the loss of memory, language, and executive function. Noninvasive in vivo functional magnetic resonance imaging (MRI) technologies, including the blood oxygen level-dependent functional MRI, arterial spin labeling-based perfusion MRI, and the proton magnetic resonance spectroscopy have been used to study the effect of ChEIs and memantine in the brain. Most of these studies have demonstrated increased functional activation and connectivity, increased regional brain blood flow and volume post-treatment, and positive responses of critical brain metabolites reflecting neuronal status and functionality in patients with AD and mild cognitive impairment. The findings have contributed to the understanding of the mechanisms underlying the medication treatments and support the crucial role of functional MRI technologies in the development and refinement of AD medication therapies.
Collapse
Affiliation(s)
- Hui Guo
- SFU ImageTech LaboratorySurrey Memorial HospitalSurreyBCCanada
- Health Sciences and InnovationSurrey Memorial HospitalFraser HealthSurreyBCCanada
- Department of Diagnostic ImagingTianjin Medical University General HospitalTianjinChina
| | - Lukas Grajauskas
- SFU ImageTech LaboratorySurrey Memorial HospitalSurreyBCCanada
- Health Sciences and InnovationSurrey Memorial HospitalFraser HealthSurreyBCCanada
| | - Baraa Habash
- SFU ImageTech LaboratorySurrey Memorial HospitalSurreyBCCanada
- Department of Engineering ScienceSimon Fraser UniversityBurnabyBCCanada
| | - Ryan CN D'Arcy
- SFU ImageTech LaboratorySurrey Memorial HospitalSurreyBCCanada
- Health Sciences and InnovationSurrey Memorial HospitalFraser HealthSurreyBCCanada
- Department of Engineering ScienceSimon Fraser UniversityBurnabyBCCanada
- Department of Computing ScienceSimon Fraser UniversityBurnabyBCCanada
| | - Xiaowei Song
- SFU ImageTech LaboratorySurrey Memorial HospitalSurreyBCCanada
- Health Sciences and InnovationSurrey Memorial HospitalFraser HealthSurreyBCCanada
- Department of Engineering ScienceSimon Fraser UniversityBurnabyBCCanada
- Department of Computing ScienceSimon Fraser UniversityBurnabyBCCanada
| |
Collapse
|
2
|
Canu E, Sarasso E, Filippi M, Agosta F. Effects of pharmacological and nonpharmacological treatments on brain functional magnetic resonance imaging in Alzheimer's disease and mild cognitive impairment: a critical review. ALZHEIMERS RESEARCH & THERAPY 2018; 10:21. [PMID: 29458420 PMCID: PMC5819240 DOI: 10.1186/s13195-018-0347-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 01/22/2018] [Indexed: 12/23/2022]
Abstract
BACKGROUND A growing number of pharmacological and nonpharmacological trials have been performed to test the efficacy of approved or experimental treatments in Alzheimer disease (AD) and mild cognitive impairment (MCI). In this context, functional magnetic resonance imaging (fMRI) may be a good candidate to detect brain changes after a short period of treatment. MAIN BODY This critical review aimed to identify and discuss the available studies that have tested the efficacy of pharmacological and nonpharmacological treatments in AD and MCI cases using task-based or resting-state fMRI measures as primary outcomes. A PubMed-based literature search was performed with the use of the three macro-areas: 'disease', 'type of MRI', and 'type of treatment'. Each contribution was individually reviewed according to the Cochrane Collaboration's tool for assessing risk of bias. Study limitations were systematically detected and critically discussed. We selected 34 pharmacological and 13 nonpharmacological articles. According to the Cochrane Collaboration's tool for assessing risk of bias, 40% of these studies were randomized but only a few described clearly the randomization procedure, 36% declared the blindness of participants and personnel, and only 21% reported the blindness of outcome assessment. In addition, 28% of the studies presented more than 20% drop-outs at short- and/or long-term assessments. Additional common shortcomings of the reviewed works were related to study design, patient selection, sample size, choice of outcome measures, management of drop-out cases, and fMRI methods. CONCLUSION There is an urgent need to obtain efficient treatments for AD and MCI. fMRI is powerful enough to detect even subtle changes over a short period of treatment; however, the soundness of methods should be improved to enable meaningful data interpretation.
Collapse
Affiliation(s)
- Elisa Canu
- Neuroimaging Research Unit, Institute of Experimental Neurology, Division of Neuroscience, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Via Olgettina, 60, 20132, Milan, Italy
| | - Elisabetta Sarasso
- Neuroimaging Research Unit, Institute of Experimental Neurology, Division of Neuroscience, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Via Olgettina, 60, 20132, Milan, Italy.,Laboratory of Movement Analysis, Division of Neuroscience, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy
| | - Massimo Filippi
- Neuroimaging Research Unit, Institute of Experimental Neurology, Division of Neuroscience, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Via Olgettina, 60, 20132, Milan, Italy.,Department of Neurology, Institute of Experimental Neurology, Division of Neuroscience, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy
| | - Federica Agosta
- Neuroimaging Research Unit, Institute of Experimental Neurology, Division of Neuroscience, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Via Olgettina, 60, 20132, Milan, Italy.
| |
Collapse
|
3
|
Metzger FG, Ehlis AC, Haeussinger FB, Fallgatter AJ, Hagen K. Effects of cholinesterase inhibitor on brain activation in Alzheimer's patients measured with functional near-infrared spectroscopy. Psychopharmacology (Berl) 2015; 232:4383-91. [PMID: 26359227 DOI: 10.1007/s00213-015-4066-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Accepted: 08/26/2015] [Indexed: 11/25/2022]
Abstract
RATIONALE Neurobiological effects of neuropsychiatric medication can contribute to the understanding of mechanisms of action and to the evaluation of target medication effects. Cholinesterase inhibitors (ChEI) have been used in patients with Alzheimer's disease (AD) for years with only small knowledge about the underlying neurobiological effects. The measurement of brain activation links neurobiological and functional aspects but is challenging in the group of demented patients; here, an alternative method, functional near-infrared spectroscopy (fNIRS), is introduced to measure those medication effects. OBJECTIVES The current study investigated the influence of ChEI on cortical activation of patients with AD measured using fNIRS during a verbal fluency task (VFT). METHODS In this study, 24 probable AD patients were investigated three times using fNIRS: before medication with rivastigmine was given (t0), when the medication was at the target dose after 4 weeks (t1), and after the target dose was kept constant for a further 8 weeks (t2). RESULTS The results show a concentration increase of oxygenated hemoglobin as measured with fNIRS from t0 to t2 in speech relevant areas and a general decrease in prefrontal areas. Behaviorally, an improvement was found for the VFT used to measure cortical activation during fNIRS. In the neuropsychological test battery, no significant changes were found, yet high effect sizes for the mini mental status examination, immediate and delayed word list recall were found. CONCLUSIONS The results indicate a positive effect of ChEI on cognitive function. The underlying cortical changes can be imaged using fNIRS.
Collapse
Affiliation(s)
- Florian G Metzger
- Psychophysiology and Optical Imaging; Department of Psychiatry and Psychotherapy, University Hospital of Tuebingen, Calwerstrasse 14, 72076, Tuebingen, Germany.
- Geriatric Center, University Hospital of Tuebingen, Calwerstrasse 14, Tuebingen, 72076, Germany.
| | - Ann-Christine Ehlis
- Psychophysiology and Optical Imaging; Department of Psychiatry and Psychotherapy, University Hospital of Tuebingen, Calwerstrasse 14, 72076, Tuebingen, Germany
| | - Florian B Haeussinger
- Psychophysiology and Optical Imaging; Department of Psychiatry and Psychotherapy, University Hospital of Tuebingen, Calwerstrasse 14, 72076, Tuebingen, Germany
- Graduate School of Neural Information Processing, University of Tuebingen, Oesterbergstr. 3, Tuebingen, 72074, Germany
| | - Andreas J Fallgatter
- Psychophysiology and Optical Imaging; Department of Psychiatry and Psychotherapy, University Hospital of Tuebingen, Calwerstrasse 14, 72076, Tuebingen, Germany
- Center of Integrative Neuroscience (CIN), Cluster of Excellence, University of Tuebingen, Otfried-Müller-Str. 25, Tuebingen, 72076, Germany
| | - Katja Hagen
- Psychophysiology and Optical Imaging; Department of Psychiatry and Psychotherapy, University Hospital of Tuebingen, Calwerstrasse 14, 72076, Tuebingen, Germany
| |
Collapse
|
4
|
Li HJ, Hou XH, Liu HH, Yue CL, He Y, Zuo XN. Toward systems neuroscience in mild cognitive impairment and Alzheimer's disease: a meta-analysis of 75 fMRI studies. Hum Brain Mapp 2014; 36:1217-32. [PMID: 25411150 DOI: 10.1002/hbm.22689] [Citation(s) in RCA: 136] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Revised: 10/03/2014] [Accepted: 11/03/2014] [Indexed: 11/11/2022] Open
Abstract
Most of the previous task functional magnetic resonance imaging (fMRI) studies found abnormalities in distributed brain regions in mild cognitive impairment (MCI) and Alzheimer's disease (AD), and few studies investigated the brain network dysfunction from the system level. In this meta-analysis, we aimed to examine brain network dysfunction in MCI and AD. We systematically searched task-based fMRI studies in MCI and AD published between January 1990 and January 2014. Activation likelihood estimation meta-analyses were conducted to compare the significant group differences in brain activation, the significant voxels were overlaid onto seven referenced neuronal cortical networks derived from the resting-state fMRI data of 1,000 healthy participants. Thirty-nine task-based fMRI studies (697 MCI patients and 628 healthy controls) were included in MCI-related meta-analysis while 36 task-based fMRI studies (421 AD patients and 512 healthy controls) were included in AD-related meta-analysis. The meta-analytic results revealed that MCI and AD showed abnormal regional brain activation as well as large-scale brain networks. MCI patients showed hypoactivation in default, frontoparietal, and visual networks relative to healthy controls, whereas AD-related hypoactivation mainly located in visual, default, and ventral attention networks relative to healthy controls. Both MCI-related and AD-related hyperactivation fell in frontoparietal, ventral attention, default, and somatomotor networks relative to healthy controls. MCI and AD presented different pathological while shared similar compensatory large-scale networks in fulfilling the cognitive tasks. These system-level findings are helpful to link the fundamental declines of cognitive tasks to brain networks in MCI and AD.
Collapse
Affiliation(s)
- Hui-Jie Li
- Key Laboratory of Behavioral Science, Institute of Psychology, Chinese Academy of Sciences, Beijing, 100101, China
| | | | | | | | | | | |
Collapse
|
5
|
Risacher SL, Wang Y, Wishart HA, Rabin LA, Flashman LA, McDonald BC, West JD, Santulli RB, Saykin AJ. Cholinergic Enhancement of Brain Activation in Mild Cognitive Impairment during Episodic Memory Encoding. Front Psychiatry 2013; 4:105. [PMID: 24062699 PMCID: PMC3775540 DOI: 10.3389/fpsyt.2013.00105] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Accepted: 08/30/2013] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVE To determine the physiological impact of treatment with donepezil (Aricept) on neural circuitry supporting episodic memory encoding in patients with amnestic mild cognitive impairment (MCI) using functional magnetic resonance imaging (fMRI). METHODS Eighteen patients with MCI and 20 age-matched healthy controls (HC) were scanned twice while performing an event-related verbal episodic encoding task. MCI participants were scanned before treatment and after approximately 3 months on donepezil; HC were untreated but rescanned at the same interval. Voxel-level analyses assessed treatment effects on activation profiles in MCI patients relative to retest changes in non-treated HC. Changes in task-related connectivity in medial temporal circuitry were also evaluated, as were associations between brain activation, task-related functional connectivity, task performance, and clinical measures of cognition. RESULTS At baseline, the MCI group showed reduced activation during encoding relative to HC in the right medial temporal lobe (MTL; hippocampal/parahippocampal) and additional regions, as well as attenuated task-related deactivation, relative to rest, in a medial parietal lobe cluster. After treatment, the MCI group showed normalized MTL activation and improved parietal deactivation. These changes were associated with cognitive performance. After treatment, the MCI group also demonstrated increased task-related functional connectivity from the right MTL cluster seed region to a network of other sites including the basal nucleus/caudate and bilateral frontal lobes. Increased functional connectivity was associated with improved task performance. CONCLUSION Pharmacologic enhancement of cholinergic function in amnestic MCI is associated with changes in brain activation and functional connectivity during episodic memory processing which are in turn related to increased cognitive performance. fMRI is a promising biomarker for assessing treatment related changes in brain function.
Collapse
Affiliation(s)
- Shannon L Risacher
- Department of Radiology and Imaging Sciences, Center for Neuroimaging, Indiana University School of Medicine , Indianapolis, IN , USA ; Indiana Alzheimer Disease Center, Indiana University School of Medicine , Indianapolis, IN , USA
| | | | | | | | | | | | | | | | | |
Collapse
|
6
|
Goveas JS, Xie C, Ward BD, Wu Z, Li W, Franczak M, Jones JL, Antuono PG, Li SJ. Recovery of hippocampal network connectivity correlates with cognitive improvement in mild Alzheimer's disease patients treated with donepezil assessed by resting-state fMRI. J Magn Reson Imaging 2011; 34:764-73. [PMID: 21769962 DOI: 10.1002/jmri.22662] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2010] [Accepted: 04/29/2011] [Indexed: 11/06/2022] Open
Abstract
PURPOSE To identify the neural correlates of cognitive improvement in mild Alzheimer's disease (AD) subjects following 12 weeks of donepezil treatment. MATERIALS AND METHODS Resting-state functional connectivity magnetic resonance imaging (R-fMRI) was used to measure the hippocampal functional connectivity (HFC) in 14 mild AD and 18 age-matched normal (CN) subjects. AD subjects were scanned at baseline and after donepezil treatment. CN subjects were scanned only at baseline as a reference to identify regions correlated or anticorrelated to the hippocampus. Before each scan, participants underwent cognitive, behavioral, and functional assessments. RESULTS After donepezil treatment, neural correlates of cognitive improvement measured by Mini-Mental State Examination scores were identified in the left parahippocampus, dorsolateral prefrontal cortex (DLPFC), and inferior frontal gyrus. Improvement in AD Assessment Scale-cognitive subscale scores correlated with the HFC changes in the left DLPFC and middle frontal gyrus. Stronger recovery in the network connectivity was associated with cognitive improvement. CONCLUSION R-fMRI may provide novel insights into the brain's responses to AD treatment in clinical pharmacological trials, and also may predict clinical response.
Collapse
Affiliation(s)
- Joseph S Goveas
- Department of Psychiatry and Behavioral Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA
| | | | | | | | | | | | | | | | | |
Collapse
|