Functional Magnetic Resonance Imaging of Working Memory among Multiple Sclerosis Patients

Sweet, Lawrence H.; Rao, Stephen M.; Primeau, Margaret; Mayer, Andrew R.; Cohen, Ronald A.

doi:10.1177/1051228403262695

Cited by 52 publications

(64 citation statements)

References 22 publications

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“…9 This pattern of activation differs from that seen in identity monitoring of verbal stimuli where activity in the ventrolateral prefrontal cortex, in particular, features more prominently. 30 A different picture emerges in subjects with MS. [6][7][8] Here, the findings can broadly be summarized as patterns of underactivity and overactivity in regions identified as functionally relevant in the healthy control data plus overactivity in ancillary regions, i.e., those not typically observed in the healthy control subjects. In addition, subjects with MS show increased activity relative to healthy controls as cognitive tasks become more complex.…”

Section: E14mentioning

confidence: 99%

“…31 To a degree, these compensatory efforts can boost psychometric performance giving rise to similar N-Back results between subjects with MS and healthy controls. 7,8 However, Figure 2 Between-group activation maps for the cannabis and noncannabis groups…”

Section: E14mentioning

confidence: 99%

“…Our choice of the latter as a marker of working memory was based on the fact that there is an available N-Back fMRI literature in subjects with MS, [6][7][8] albeit small, and a much larger one in healthy controls. 9 METHODS Sample selection.…”

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Effects of cannabis on cognition in patients with MS

et al. 2014

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Objective: To determine functional and structural neuroimaging correlates of cognitive dysfunction associated with cannabis use in multiple sclerosis (MS). Methods:In a cross-sectional study, 20 subjects with MS who smoked cannabis and 19 noncannabis users with MS, matched on demographic and neurologic variables, underwent fMRI while completing a test of working memory, the N-Back. Resting-state fMRI and structural MRI data (lesion and normal-appearing brain tissue volumes, diffusion tensor imaging metrics) were also collected. Neuropsychological data pertaining to verbal (Selective Reminding Test Revised) and visual (10/36 Spatial Recall Test) memory, information processing speed (Paced Auditory Serial Addition Test [2-and 3-second versions] and Symbol Digit Modalities Test), and attention (Word List Generation) were obtained. Results:The cannabis group performed more poorly on the more demanding of the Paced Auditory Serial Addition Test tasks (i.e., 2-second version) (p , 0.02) and the 10/36 Spatial Recall Test (p , 0.03). Cannabis users had more diffuse cerebral activation across all N-Back trials and made more errors on the 2-Back task (p , 0.006), during which they displayed increased activation relative to nonusers in parietal (p , 0.007) and anterior cingulate (p , 0.001) regions implicated in working memory. No group differences in resting-state networks or structural MRI variables were found. Conclusions:Patients with MS who smoke cannabis are more cognitively impaired than nonusers.Cannabis further compromises cerebral compensatory mechanisms, already faulty in MS. These imaging data boost the construct validity of the neuropsychological findings and act as a cautionary note to cannabis users and prescribers. Cognitive dysfunction affects 40% to 60% of patients with multiple sclerosis (MS).1 Data suggest that patients with MS who smoke cannabis have more extensive cognitive difficulties than those who do not. In particular, problems with working memory, 2 information processing speed, and executive dysfunction 3 appear to be exacerbated by the use of cannabis. Given that cognitive deficits in patients with MS are known to adversely affect the ability to sustain employment, maintain relationships, continue recreational pursuits, and attend to activities of daily living, 4 a better understanding of how smoking cannabis may impair brain function in MS is needed.To date, there have been no imaging-cognition studies of patients with MS who smoke cannabis. This contrasts with an extensive MRI literature of patients with MS in general in which cognitive deficits have been linked to numerous structural and functional brain metrics.

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Section: E14mentioning

confidence: 99%

Section: E14mentioning

confidence: 99%

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Effects of cannabis on cognition in patients with MS

et al. 2014

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“…It is known from previous neuroimaging studies that various versions of this task invoke activations in a large-scale network including prefrontal, premotor, supplementary motor, and parietal cortices (Cabeza and Nyberg, 2000;D'Esposito et al, 1998;Jonides, 1998, 1999). Since this task is one of the most frequently used high-level cognitive tasks in various clinical populations (e.g., Callicott et al, 2003;Kwon et al, 2001;Scheibel et al, 2003;Sweet et al, 2004;Valera et al, 2005), implementing it with a whole-brain multi-slice ASL approach would provide useful comparison CBF data for future clinical neuroimaging studies. It was predicted that we would replicate the results from prior normative studies using the 2-back task (for review, see Owen et al, 2005).…”

Section: Introductionmentioning

confidence: 99%

Continuous ASL perfusion fMRI investigation of higher cognition: Quantification of tonic CBF changes during sustained attention and working memory tasks

et al. 2006

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Arterial spin labeling (ASL) perfusion fMRI is an emerging method in clinical neuroimaging. Its non-invasiveness, absence of low frequency noise, and ability to quantify the absolute level of cerebral blood flow (CBF) make the method ideal for longitudinal designs or low frequency paradigms. Despite the usefulness in the study of cognitive dysfunctions in clinical populations, perfusion activation studies to date have been conducted for simple sensorimotor paradigms or with single-slice acquisition, mainly due to technical challenges. Using our recently developed amplitudemodulated continuous ASL (CASL) perfusion fMRI protocol, we assessed the feasibility of a higher level cognitive activation study in twelve healthy subjects. Taking advantage of the ASL noise properties, we were able to study tonic CBF changes during uninterrupted 6-min continuous performance of working memory and sustained attention tasks. For the visual sustained attention task, regional CBF increases (6-12 ml/100 g/min) were detected in the right middle frontal gyrus, the bilateral occipital gyri, and the anterior cingulate/medial frontal gyri. During the 2-back working memory task, significantly increased activations (7-11 ml/100 g/min) were found in the left inferior frontal/precentral gyri, the left inferior parietal lobule, the anterior cingulate/medial frontal gyri, and the left occipital gyrus. Locations of activated and deactivated areas largely concur with previous PET and BOLD fMRI studies utilizing similar paradigms. These results demonstrate that CASL perfusion fMRI can be successfully utilized for the investigation of the tonic CBF changes associated with high level cognitive operations. Increased applications of the method to the investigation of cognitively impaired populations are expected to follow.

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“…Alterations in the BOLD response to cognitive challenges have been shown in cognitively asymptomatic patients with MS, HIV infection, and genetic risk for AD. [22][23][24][25][26][27] BOLD fMRI performed during cognitive tasks, therefore, can help elucidate the complex relationship between metabolic and vascular health, cerebrovascular support for cognitive function, and behavioral performance. An accurate model of the relationship between cerebrovascular health and persistent metabolic dysfunction at midlife could prove instrumental in increasing the success of broader efforts to prevent and treat vascular cognitive impairment.…”

mentioning

confidence: 99%

Functional MR Imaging Evidence of Altered Functional Activation in Metabolic Syndrome

Hoth¹,

Gonzales²,

Tarumi³

et al. 2010

AJNR Am J Neuroradiol

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BACKGROUND AND PURPOSE:MetS is a cluster of risk factors associated with significant cardiovascular morbidity and mortality and diminished cognitive function. Given that little is known about the early signs of brain vulnerability related to persistent metabolic dysfunction, we set out to determine whether cognitively healthy middle-aged individuals with MetS exhibit an altered cerebrovascular response to a cognitive challenge relative to those without MetS. MATERIALS AND METHODS: Forty neurologically healthy adults aged 40 -60 years (19 with MetS and 21 healthy controls) performed a 2-back verbal working memory task during fMRI. We compared BOLD responses between the 2 groups in 8 a priori regions of interest previously shown to be associated with the 2-back in patients with cardiovascular disease.

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Functional Magnetic Resonance Imaging of Working Memory among Multiple Sclerosis Patients

Cited by 52 publications

References 22 publications

Effects of cannabis on cognition in patients with MS

Effects of cannabis on cognition in patients with MS

Continuous ASL perfusion fMRI investigation of higher cognition: Quantification of tonic CBF changes during sustained attention and working memory tasks

Functional MR Imaging Evidence of Altered Functional Activation in Metabolic Syndrome

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