Reliability and validity of neuropsychological screening and assessment strategies in MS

Journal of Neurology - Neuropsychological impairment is common in MS but routine evaluation is cumbersome. Many proposed avenues to more cost effective evaluation of cognition in MS have appeared...     

Risk factors for and management of cognitive dysfunction in multiple sclerosis

Cognitive impairment is common in multiple sclerosis (MS), especially when assessed by neuropsychological tests that emphasize mental processing speed, episodic memory, and some aspects of executive function. In this Review, we question why some MS patients develop severe impairment in cognitive abilities, while cognitive ability remains intact in others. We find that the heterogeneity in neuropsychological presentation among patients with MS reflects the influence of many factors, including genetics, sex, intelligence, disease course, comorbid neuropsychiatric illness, and health behaviors. Neuropsychological deficits are also robustly correlated with brain MRI metrics. Male patients with early evidence of cerebral gray matter atrophy are most prone to impairment, whereas high premorbid intelligence improves the neuropsychological prognosis. Routine evaluation of cognition is useful for helping patients to navigate problems related to activities of daily living and work disability and, if reliable methods are employed, cognitive decline can be detected and included among the many clinical signs of disease progression or treatment failure. Pharmacological treatments for neuropsychological impairment are on the horizon, although presently no firm medical indications exist for the condition.     

Regional magnetic resonance imaging lesion burden and cognitive function in multiple sclerosis: a longitudinal study

OBJECTIVE: To investigate the relationship between magnetic resonance imaging regional lesion burden and cognitive performance in multiple sclerosis (MS) over a 4-year follow-up period. DESIGN: Twenty-eight patients with MS underwent magnetic resonance imaging and took the Brief, Repeatable Battery of Neuropsychological Tests in Multiple Sclerosis at baseline, 1-year, and 4-year follow-up. An automated 3-dimensional lesion detection method was used to identify MS lesions within anatomical regions on proton density T2-weighted images. The relationship between magnetic resonance imaging regional lesion volumes and the Brief, Repeatable Battery of Neuropsychological Tests in Multiple Sclerosis results was examined using regression analyses. RESULTS: At all time points, frontal lesion volume represented the greatest proportion of total lesion volume, and the percentage of white matter classified as lesion was also highest in frontal and parietal regions. On neuropsychological testing, when compared with age- and educational level-matched control subjects, patients with MS showed significant impairment on tests of sustained attention, processing speed, and verbal memory (P<.001). Performance on these measures was negatively correlated with MS lesion volume in frontal and parietal regions at baseline, 1-year, and 4-year follow-up (R = -0.55 to -0.73, P<.001). CONCLUSIONS: Multiple sclerosis lesions show a propensity for frontal and parietal white matter. Lesion burden in these areas was strongly associated with performance on tasks requiring sustained complex attention and working verbal memory. This relationship was consistent over a 4-year period, suggesting that disruption of frontoparietal subcortical networks may underlie the pattern of neuropsychological impairment seen in many patients with MS.     

Cognitive impairment in multiple sclerosis

In this article we present a review of problems associated with cognitive dysfunctions in multiple sclerosis (MS). Neuropsychological investigations demonstrated that cognitive dysfunctions are common in MS patients and affect 40-65% of them. Cognitive deficits were found mainly on measures of memory, attention, information-processing speed, executive functions and abstract reasoning. The differences and degree of cognitive dysfunctions in MS are highlighted and usually related to different clinical appearance (clinical course, duration, disability level, treatment type). Furthermore, we have reviewed published correlations between psychopathological dysfunctions and neuroimaging results (mainly MRI techniques and functional imaging). The results of these correlations showed that an important role in cognitive impairment is related to the total lesion area, the severity of the pathological damage of the normal-appearing brain tissue (NABT), and brain atrophy.     

Multiple sclerosis

Multiple sclerosis (MS) is a demyelinating disease of the central nervous system that commonly leads to inflammatory and atrophic brain pathology, often causing cognitive impairment. MS-associated cognitive impairment was first described over a century ago. However, with the advent of standardized neuropsychological testing and quantitative brain imaging, the frequency, quality, and correlates of cognitive impairment are better understood. Dementia is rare in MS, although it is known to occur in 10 to 25% of patients. Our data suggest a frequency of 22% among clinic attendees. In addition to the cognitive impairments evident in MS dementia, changes in personality and social behavior also occur. For example, some patients develop euphoria sclerotica and marked deficiency in social empathy, conditions that in combination with executive dysfunction cause considerable hardship for patients and caregivers. These neuropsychiatric manifestations of MS dementia are correlated with magnetic resonance imaging indicators of brain atrophy, including ventricle enlargement, neocortical volume, and normalized whole brain volume. Recent developments in pharmacological treatment for disease progression and management of cognitive symptoms hold promise for patients suffering from the degenerative aspects of MS.     

Central nervous system involvement in the eosinophilia-myalgia syndrome.

A patient with eosinophilia-myalgia syndrome developed progressive central nervosa system involvement that did not improve despite discontinuation of L-tryptophan therapy. Neurologic impairment was manifested initially by spastic monoparesis, which was improved by treatment with methyl-prednisolone and hydroxyurea. Recurrence of weakness was accompanied by gait ataxia, dysphagia, and complaints of a gradual decline in memory and concentration. Neuropsychological testing identified a broad pattern of cognitive deficits suggestive of a subcortical dementia, and magnetic resonance imaging demonstrated multiple high-signal lesions in the white matter. Cognitive deficits appear to be underrecognized in patients with the eosinophilia-myalgia syndrome. The response of our patient's initial symptoms to corticosteroid therapy suggests a possible role for autoimmune mechanisms in the pathogenesis of central nervous system involvement in the eosinophilia-myalgia syndrome. Neuropsychological evaluation should be performed in patients with cognitive complaints to delineate the full spectrum of central nervous system impairment associated with the eosinophilia-myalgia syndrome.     

Cortical lesions and cognitive impairment in multiple sclerosis

Multiple sclerosis (MS) is a chronic inflammatory and degenerative disease of the central nervous system. In the last decade, pathological and magnetic resonance imaging (MRI) studies have shown that a significant portion of inflammatory lesions are located in the grey matter, especially in the cerebral cortex, of MS patients. Cortical inflammatory lesions (CL) can be demonstrated in vivo in MS patients by double inversion recovery (DIR) MRI sequence. Neuropsychological deficits constitute a major clinical aspect of MS, being demonstrated in a percentage ranging from 40 to 65% of patients, and have been shown to be associated with cortical demyelination and atrophy. Recent DIR studies in MS patients having different clinical forms of the disease have disclosed that CL burden not only correlates with the severity of physical disability, but is also one of the major structural changes associated with disease-related cognitive impairment.     

Treatment options of cognitive impairment in multiple sclerosis

Multiple sclerosis (MS) is a progressive disease of the CNS, characterized by the production of widespread lesions in the brain and spinal cord. Inflammatory demyelination has traditionally been seen as the main disease process in MS; however, axonal damage or loss is increasingly being documented to occur early in the disease. Cognitive deficits can occur independently of physical disability, which complicates their identification and recognition. More recently, cortical demyelination has been identified among possible causes of cognitive impairment in MS. Neuropsychological studies have consistently demonstrated that 40–65% of patients with MS experience cognitive dysfunction, particularly in recent memory, information processing speed, and sustained attention. Early detection of cognitive impairment is essential to enable therapeutic intervention to alleviate symptoms or prevent further cognitive decline, although how best to manage MS-related cognitive impairment is currently unclear. Treatment strategies for cognitive impairment in MS are still in their infancy. This article will summarize several pharmacological attempts to enhance cognitive performances in people with MS.     

Screening for multiple sclerosis cognitive impairment using a self-administered 15-item questionnaire

Since there is a need for cost-effective screening techniques to identify neuropsychological impairment in multiple sclerosis (MS) patients, and because existing methods require cognitive testing with subsequent interpretation by a neuropsychologist, a brief self-report procedure was developed to screen for neuropsychological impairment in MS. In the first phase of the study, a pool of 80 items was generated based on a literature review and consultation with healthcare professionals. The set was reduced to 15 via Rasch analysis. Using these items, a brief (five minute) MS Neuropsychological Screening Questionnaire (MSNQ), including patient- and informant-report forms, was composed. In phase II, 50 MS patients and their caregivers completed the MSNQ. A comprehensive neuropsychological test battery was also administered. Analyses covered the reliability of the MSNQ and correlations between both patient- and informant-report scores and objective neuropsychological testing. Cronbach's alpha coefficients were 0.93 and 0.94 for the patient- and informant-report forms, respectively, and both forms of the test were strongly correlated with a more general cognitive complaints questionnaire. The patient MSNQ form correlated significantly with measures of depression but not with objective tests of cognitive function. In contrast, the informant form was correlated with patient cognitive performance but not depression. A cut-off score of 27 on the informant form of the MSNQ optimally separated patients based on a neuropsychological summary score encompassing measures of processing speed and memory. There were two false-negatives and one false-positive, giving the test a sensitivity of 0.83 and a specificity of 0.97. It is concluded, therefore, that this self-administered neuropsychological screening test is reliable and predicts neuropsychological impairment in MS patients with a reasonable degree of accuracy.     

Diffusion-weighted imaging predicts cognitive impairment in multiple sclerosis

Following a previous study with diffusion tensor imaging, we investigated the correlation between diffusion-weighted imaging (DWI) and cognitive dysfunction in multiple sclerosis (MS). We studied 60 MS patients (mean age 45.8+/-9.0 years) using 1.5-T MRI. Disease course was RR=40 and SP = 20. Mean disease duration was 12.8+/-8.7 years. Mean EDSS was 3.4+/-1.7. Whole brain, gray and white matter normalized volumes were calculated on 3D SPGR T1-WI using a fully automated Hybrid SIENAX method. Parenchymal mean diffusivity (PMD) maps were created after automated segmentation of the brain parenchyma and cerebrospinal fluid using T2-WI and DW images. Histogram analysis was performed and DWI indices of peak position (PP), peak height (PH), mean parenchymal diffusivity (MPD) and entropy were obtained. Neuropsychological (NP) evaluation emphasized auditory/verbal and visual/spatial memory, as well as processing speed and executive function. We found significant correlations between DWI and performance in all cognitive domains. Overall, stronger correlations emerged for MPD and entropy than other DWI measures, although all correlations were in the expected direction. The strongest association was between DWI entropy and performance on the Symbol Digit Modalities Test, which assesses processing speed and working memory (r = -0.54). Fisher r to z transformations revealed that DWI, gray matter (GMF) and whole brain (BPF) atrophy, T1-lesion volume (LV) and T2-LV all accounted for similar amounts of variance in NP testing. Stepwise regression models determined whether multiple MRI measures predicted unique additive variance in test performance. GMF (R2 = 0.35, F =30.82, P <0.01) and entropy (DeltaR2 =0.06, DeltaF=5.47, P <0.05) both accounted for unique variance in processing speed. Our data make a stronger case for the clinical validity of DWI in MS than heretofore reported. DWI has very short acquisition times, and the segmentation method applied in the present study is reliable and fully automated. Given its overall simplicity and moderate correlation with cognition, DWI may offer several logistic advantages over more traditional MRI measures when predicting the presence of NP impairment.     

Cerebral metabolism, anatomy, and cognition in monozygotic twins discordant for dementia of the Alzheimer type.

One pair of monozygotic twins discordant for dementia of the Alzheimer type (DAT) was studied using neuropsychological testing, quantitative x-ray computed tomography (QCT) and magnetic resonance imaging (MRI) of the brain. Cerebral glucose metabolism was measured using positron emission tomography (PET) and 2-[18-F]fluoro-2-deoxy-D-glucose (FDG). The affected twin had a seven year history of progressive cognitive impairment and was severely demented. Neuropsychological testing of the affected twin demonstrated marked deficits in all areas of cognitive function. The asymptomatic twin showed some impairment on tests of perceptual organisation and delayed recall. The affected twin had loss of gray matter and ventricular enlargement on QCT and MRI compared with healthy controls (p less than 0.05). He also had frontal and parietal lobe hypometabolism and increased asymmetry of metabolism on PET compared to both his twin and healthy age-matched controls (p less than 0.05). PET, QCT, and MRI distinguished changes in the twin with DAT compared with his brother and healthy controls. Although the subtle neuropsychological abnormalities of the asymptomatic twin may be signs of early DAT, they were not accompanied by any changes in regional cerebral metabolism or brain structure.     

Cognitive impairment in multiple sclerosis

BACKGROUNd: Cognitive impairment is increasingly being recognized as a common and disabling symptom of multiple sclerosis (MS) that contributes to poor quality of life in affected patients. Despite the high prevalence of cognitive impairment in MS, cognitive function is not assessed routinely in clinical practice or in clinical trials. The perception that cognitive assessments are costly, time-consuming, complicated, and difficult to administer and interpret has contributed, at least in part, to the failure to incorporate cognitive testing into standard clinical evaluation of patients with MS. Detailed studies of cognitive impairment in MS are rare and guidelines for the assessment of cognitive function in MS are lacking.TREATMENT: How to manage cognitive decline in MS also requires further study. Licensed disease-modifying drug (DMD) treatments for MS reduce brain lesion development, and associations between brain lesions and cognitive performance have been reported, providing a rationale for DMD treatment of MS-associated cognitive impairment. There is some evidence for cognitive benefits of DMDs, but as few pivotal DMD trials included cognitive assessments, the effects of these agents on cognition are not fully understood and more studies are needed.CONCLUSIONS: It is only through further studies that it will be possible to identify patients with, or at risk of, cognitive impairment and to provide appropriate therapy to limit the effects of this potentially devastating symptom.     

Brain atrophy and cognitive impairment in multiple sclerosis: a review

Multiple sclerosis (MS) is a common neurological disease in the Western hemisphere that leads to neurological dysfunctions and frequently from its onset to cognitive impairment, which together predict quality of life. Recent pathological and imaging studies have focused on brain atrophy representing axonal injury and loss as being crucial for developing disability and neuropsychological impairment. Brain atrophy has therefore been proposed to be a tool for monitoring disease progress. Here, we review the possible origins of brain atrophy and its correlation with cognitive impairment in MS.     

Structural MRI correlates of cognitive impairment in patients with multiple sclerosis

In a multicenter setting, we applied voxel‐based methods to different structural MR imaging modalities to define the relative contributions of focal lesions, normal‐appearing white matter (NAWM), and gray matter (GM) damage and their regional distribution to cognitive deficits as well as impairment of specific cognitive domains in multiple sclerosis (MS) patients. Approval of the institutional review boards was obtained, together with written informed consent from all participants. Standardized neuropsychological assessment and conventional, diffusion tensor and volumetric brain MRI sequences were collected from 61 relapsing‐remitting MS patients and 61 healthy controls (HC) from seven centers. Patients with ≥2 abnormal tests were considered cognitively impaired (CI). The distribution of focal lesions, GM and WM atrophy, and microstructural WM damage were assessed using voxel‐wise approaches. A random forest analysis identified the best imaging predictors of global cognitive impairment and deficits of specific cognitive domains. Twenty‐three (38%) MS patients were CI. Compared with cognitively preserved (CP), CI MS patients had GM atrophy of the left thalamus, right hippocampus and parietal regions. They also showed atrophy of several WM tracts, mainly located in posterior brain regions and widespread WM diffusivity abnormalities. WM diffusivity abnormalities in cognitive‐relevant WM tracts followed by atrophy of cognitive‐relevant GM regions explained global cognitive impairment. Variable patterns of NAWM and GM damage were associated with deficits in selected cognitive domains. Structural, multiparametric, voxel‐wise MRI approaches are feasible in a multicenter setting. The combination of different imaging modalities is needed to assess and monitor cognitive impairment in MS. Hum Brain Mapp 37:1627‐1644, 2016. © 2016 Wiley Periodicals, Inc.     

Repeated assessment of neuropsychological deficits in multiple sclerosis using the Symbol Digit Modalities Test and the MS Neuropsychological Screening Questionnaire

BACKGROUND: Brief cognitive performance tests and self-report measures of neuropsychological symptoms have been proposed for screening purposes in multiple sclerosis (MS) clinics. To better understand the reliability of screening methods, two tests, the Symbol Digit Modalities Test (SDMT) and the MS Neuropsychological Screening Questionnaire (MSNQ), were administered to 76 patients with MS and 25 healthy controls, matched on demographic characteristics. METHODS: Tests were administered at monthly intervals, over 6 months. In addition, the Beck Depression Inventory Fast Screen for medical patients (BDIFS) was administered to monitor for changes in depression. Our objectives were to determine the reliability of these measures and the relative contribution of cognitive impairment and depression in predicting self-report MSNQ scores. RESULTS: Results showed that both the SDMT and MSNQ have good to excellent reproducibility over repeated testing. In MS, there are minimal practice effects over successive tests, in the order of 0.2 SD for SDMT and minimal change in the MSNQ. Regression analyses modeled to predict MSNQ based on SDMT and BDIFS showed significant contribution for both, but with the majority of variance being accounted for depression. CONCLUSIONS: We conclude that these brief screening tests provide some independent information about the mental status of patients with MS and are reliable, even when used in monthly, successive examinations.     

Combined semantic dementia and apraxia in a patient with frontotemporal lobar degeneration

In this study we report neuropsychological and brain-imaging findings in a patient with frontotemporal lobar degeneration. Brain imaging using registration of (18)fluorodeoxyglucose (FDG)-PET data to three-dimensional (3-D) magnetic resonance imaging showed atrophy and highly significant hypometabolism of the left temporal lobe and both frontal lobes. Volumetric measurements of the hippocampi/amygdala showed a reduction in volume of 25% on the left compared to right within cortical areas. Neuropsychological testing revealed semantic dementia with severe anomia as well as apraxia with impairment of both recognition and production of motor acts. The implications of this case of early manifestation of frontotemporal lobar degeneration for our knowledge of dementia are discussed.     

Brain Single Photon Emission Computed Tomography Imaging in Landau-Kleffner Syndrome

Summary: Five right–handed children with Landau-Kleffner syndrome (LKS) who had disease onset between the ages of 3 and 9 years were studied with EEG and single-photon emission computed tomography (SPECT) before and, in four cases, after 6 months of corticosteroid treatment. EEG findings included both focal and generalized spikes as well as spike-wave discharges with bilateral temporal predominance. These increased markedly during sleep in 1 child, and continuous spike-and-wave complexes appeared during slow-wave sleep in another patient. Neuropsychological testing demonstrated verbal auditory agnosia. Magnetic resonance imaging (MRI) was performed in 4 children and was normal. Brain SPECT imaging demonstrated abnormal perfusion in the left temporal lobe in all patients. The response to corticosteroid therapy was mixed. Our findings reinforce the concept that LKS is a functional disease affecting the language-dominant brain areas. We conclude that SPECT imaging may be of diagnostic assistance in the evaluation of this syndrome of unknown etiology.     

Cerebral activation patterns during working memory performance in multiple sclerosis using FMRI

Working memory deficits are common in Multi Sclerosis (MS) and have been identified behaviourally in numerous studies. Despite recent advance in functional magnetic resonance imaging (fMRI), few published studies have examined cerebral activations associated with working memory dysfunction in MS. The present study examines brain activation patterns during performance of a working memory task in individual with clinically definite MS, compared to healthy controls (HC). fMRI was performed using a 1.5 Tesla GE scanner during a modified Paced Auditory Serial Addition Test (mPA-SAT). Participants were 6 individuals with MS with working memory impairment as evidenced on neuropsychological testing, 5 individuals with MS without working memory impairment, and 5 HC. Groups were demographically equivalent. Data were analyzed using Statistical Parametric Mapping (SPM99) software, with a stringent significance level (alpha < .005, voxel extent > or =8). Both MS groups and the HC group were able to perform the task, with comparable performance in terms of numbers of correct responses. Activation patterns within the HC and MS not-impaired groups were noted in similar brain regions, consistent with published observations in healthy samples That is, activations were lateralized to the left hemisphere, involving predominantly frontal regions. In contrast, the MS impaired group showed greater right frontal and right parietal lobe activation, when compared with the HC group. Thus, it appears that working memory dysfunction in MS is associated with altered patterns of cerebral activation that are related to the presence of cognitive impairement, and not solely a function of MS.     

Cognitive and brain magnetic resonance imaging findings in adrenomyeloneuropathy

Neuropsychological functioning and brain magnetic resonance imaging (MRI) were evaluated in 84 men with adrenomyeloneuropathy (AMN). MRI was normal in 61%, the “pure AMN” group, while 39%, the “cerebral AMN” group, showed brain white matter abnormalities. Except for mild deficits in psychomotor speed and visual memory, neuropsychological function was normal in pure AMN. Most patients with cerebral AMN had normal IQ and language but evidenced impaired psychomotor speed, spatial cognition, memory, and executive functions. Patients with MRI evidence of very severe cerebral disease had global and language impairment as well, and deficits in all patients were highly correlated with degree of brain MRI involvement.     

Basal ganglia, thalamus and neocortical atrophy predicting slowed cognitive processing in multiple sclerosis

Information-processing speed (IPS) slowing is a primary cognitive deficit in multiple sclerosis (MS). Basal ganglia, thalamus and neocortex are thought to have a key role for efficient information-processing, yet the specific relative contribution of these structures for MS-related IPS impairment is poorly understood. To determine if basal ganglia and thalamus atrophy independently contribute to visual and auditory IPS impairment in MS, after controlling for the influence of neocortical volume, we enrolled 86 consecutive MS patients and 25 normal controls undergoing 3T brain MRI and neuropsychological testing. Using Sienax and FIRST software, neocortical and deep gray matter (DGM) volumes were calculated. Neuropsychological testing contributed measures of auditory and visual IPS using the Paced Auditory Serial Addition Test (PASAT) and the Symbol Digit Modalities Test (SDMT), respectively. MS patients exhibited significantly slower IPS relative to controls and showed reduction in neocortex, caudate, putamen, globus pallidus, thalamus and nucleus accumbens volume. SDMT and PASAT were significantly correlated with all DGM regions. These effects were mitigated by controlling for the effects of neocortical volume, but all DGM volumes remained significantly correlated with SDMT, putamen (r = 0.409, p < 0.001) and thalamus (r = 0.362, p < 0.001) having the strongest effects, whereas for PASAT, the correlation was significant for putamen (r = 0.313, p < 0.01) but not for thalamus. We confirm the significant role of thalamus atrophy in MS-related IPS slowing and find that putamen atrophy is also a significant contributor to this disorder. These DGM structures have independent, significant roles, after controlling for the influence of neocortex atrophy.