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1.
Neurol Ther ; 12(1): 303-317, 2023 Feb.
Article in English | MEDLINE | ID: mdl-36534274

ABSTRACT

INTRODUCTION: Several studies have described prognostic value of serum neurofilament light chain (sNfL) at the group level in relapsing multiple sclerosis (RMS) patients. Here, we aimed to explore the temporal association between sNfL and development of subclinical disease activity as assessed by magnetic resonance imaging (MRI) at the group level and evaluate the potential of sNfL as a biomarker for capturing subclinical disease activity in individual RMS patients. METHODS: In the 12-week APLIOS study, patients (N = 284) received subcutaneous ofatumumab 20 mg. Frequent sNfL sampling (14 time points over 12 weeks) and monthly MRI scans enabled key analyses including assessment of the group-level temporal relationship of sNfL levels with on-study subclinical development of gadolinium-enhancing (Gd +)T1 lesions. Prognostic value of baseline sNfL ("high" vs. "low") level for subsequent on-study clinical relapse or Gd + T1 activity was assessed. Individual patient-level development of on-study Gd + T1 lesions was compared across three predictors: baseline Gd + T1 lesion number, baseline sNfL ("high" vs. "low"), and time-matched sNfL. RESULTS: In patients developing Gd + T1 lesions at week 4 (absent at baseline), sNfL levels increased during the month preceding the week-4 MRI scan and then gradually decreased back to baseline. High versus low baseline sNfL conferred increased risk of subsequent on-study clinical relapse or Gd + T1 activity (HR, 2.81; p < 0.0001) in the overall population and, notably, also in the patients without baseline Gd + T1 lesions (HR, 2.48; p = 0.0213). Individual patient trajectories revealed a marked difference in Gd + T1 lesions between patients with the ten highest vs. lowest baseline sNfL levels (119 vs. 19 lesions). Prognostic value of baseline or time-matched sNfL for on-study Gd + T1 lesions was comparable to that of the number of baseline MRI Gd + T1 lesions. CONCLUSIONS: sNfL measurement may have utility in capturing and monitoring subclinical disease activity in RMS patients. sNfL assessments could complement regular MRI scans and may provide an alternative when MRI assessment is not feasible. CLINICALTRIALS: GOV: NCT03560739. CLASSIFICATION OF EVIDENCE: This study provides class I evidence that serum neurofilament light may be used as a biomarker for monitoring subclinical disease activity in relapsing multiple sclerosis patients, as shown by its elevation in the weeks preceding the development of new gadolinium-enhancing T1 lesion activity.

2.
Mult Scler ; 28(6): 910-924, 2022 05.
Article in English | MEDLINE | ID: mdl-34605319

ABSTRACT

BACKGROUND: Ofatumumab, the first fully human anti-CD20 monoclonal antibody, is approved in several countries for relapsing multiple sclerosis (RMS). OBJECTIVE: To demonstrate the bioequivalence of ofatumumab administered by an autoinjector versus a pre-filled syringe (PFS) and to explore the effect of ofatumumab on B-cell depletion. METHODS: APLIOS (NCT03560739) is a 12-week, open-label, parallel-group, phase-2 study in patients with RMS receiving subcutaneous ofatumumab 20 mg every 4 weeks (q4w) (from Week 4, after initial doses on Days 1, 7, and 14). Patients were randomized 10:10:1:1 to autoinjector or PFS in the abdomen, or autoinjector or PFS in the thigh, respectively. Bioequivalence was determined by area under the curve (AUCτ) and maximum plasma concentration (Cmax) for Weeks 8-12. B-cell depletion and safety/tolerability were assessed. RESULTS: A total of 256 patients contributed to the bioequivalence analyses (autoinjector-abdomen, n = 128; PFS-abdomen, n = 128). Abdominal ofatumumab pharmacokinetic exposure was bioequivalent for autoinjector and PFS (geometric mean AUCτ, 487.7 vs 474.1 h × µg/mL (ratio 1.03); Cmax, 1.409 vs 1.409 µg/mL (ratio 1.00)). B-cell counts (median cells/µL) depleted rapidly in all groups from 214.0 (baseline) to 2.0 (Day 14). Ofatumumab was well tolerated. CONCLUSION: Ofatumumab 20 mg q4w self-administered subcutaneously via autoinjector is bioequivalent to PFS administration and provides rapid B-cell depletion.


Subject(s)
Multiple Sclerosis , Antibodies, Monoclonal , Antibodies, Monoclonal, Humanized/adverse effects , Humans , Injections, Subcutaneous , Multiple Sclerosis/chemically induced
3.
Mult Scler ; 28(8): 1229-1238, 2022 07.
Article in English | MEDLINE | ID: mdl-34787005

ABSTRACT

BACKGROUND: Ofatumumab, the first fully human anti-CD20 monoclonal antibody, has been developed as a treatment for relapsing multiple sclerosis (RMS) which can be self-administered at home. OBJECTIVE: To investigate the efficacy and safety of ofatumumab in RMS patients from Japan and Russia. METHODS: APOLITOS included a 24-week, double-blind, placebo-controlled core-part followed by an open-label extension-part. Patients were randomized (2:1) to subcutaneous ofatumumab 20 mg or placebo. Primary outcome was the number of gadolinium-enhancing (Gd+) T1 lesions per scan over 24 weeks. RESULTS: Sixty-four patients were randomized (ofatumumab, n = 43; placebo, n = 21). Primary endpoint was met; ofatumumab reduced Gd + T1 lesions versus placebo by 93.6% (p < 0.001) and the results were consistent across regions (Japan/Russia). Ofatumumab reduced annualized T2 lesion and relapse rate versus placebo by week 24. Both groups showed benefit from ofatumumab in the extension-part. Incidence of adverse events was lower with ofatumumab versus placebo (69.8% vs 81.0%); injection-related reactions were most common. No deaths, opportunistic infections, or malignancies were reported. CONCLUSION: Ofatumumab demonstrated superior efficacy versus placebo, with sustained effect through 48 weeks in RMS patients from Japan/Russia. Switching to ofatumumab after 24 weeks led to rapid radiological and clinical benefits. Safety findings were consistent with pivotal trials.


Subject(s)
Multiple Sclerosis, Relapsing-Remitting , Multiple Sclerosis , Antibodies, Monoclonal, Humanized/adverse effects , Double-Blind Method , Humans , Japan , Multiple Sclerosis/drug therapy , Multiple Sclerosis, Relapsing-Remitting/drug therapy , Multiple Sclerosis, Relapsing-Remitting/pathology , Recurrence , Treatment Outcome
4.
Alzheimers Dement (N Y) ; 5: 216-227, 2019.
Article in English | MEDLINE | ID: mdl-31211217

ABSTRACT

INTRODUCTION: Alzheimer's disease (AD) pathology, including the accumulation of amyloid beta (Aß) species and tau pathology, begins decades before the onset of cognitive impairment. This long preclinical period provides an opportunity for clinical trials designed to prevent or delay the onset of cognitive impairment due to AD. Under the umbrella of the Alzheimer's Prevention Initiative Generation Program, therapies targeting Aß, including CNP520 (umibecestat), a ß-site-amyloid precursor protein cleaving enzyme-1 (BACE-1) inhibitor, and CAD106, an active Aß immunotherapy, are in clinical development in preclinical AD. METHODS: The Alzheimer's Prevention Initiative Generation Program comprises two pivotal (phase 2/3) studies that assess the efficacy and safety of umibecestat and CAD106 in cognitively unimpaired individuals with high risk for developing symptoms of AD based on their age (60-75 years), APOE4 genotype, and, for heterozygotes (APOE ε2/ε4 or ε3/ε4), elevated brain amyloid. Approximately, 3500 individuals will be enrolled in either Generation Study 1 (randomized to cohort 1 [CAD106 injection or placebo, 5:3] or cohort 2 [oral umibecestat 50 mg or placebo, 3:2]) or Generation Study 2 (randomized to oral umibecestat 50 mg and 15 mg, or placebo [2:1:2]). Participants receive treatment for at least 60 months and up to a maximum of 96 months. Primary outcomes include time to event, with event defined as diagnosis of mild cognitive impairment due to AD and/or dementia due to AD, and the Alzheimer's Prevention Initiative preclinical composite cognitive test battery. Secondary endpoints include the Clinical Dementia Rating Sum of Boxes, Repeatable Battery for the Assessment of Neuropsychological Status total score, Everyday Cognition Scale, biomarkers, and brain imaging. DISCUSSION: The Generation Program is designed to assess the efficacy, safety, and biomarker effects of the two treatments in individuals at high risk for AD. It may also provide a plausible test of the amyloid hypothesis and further accelerate the evaluation of AD prevention therapies.

5.
Am J Manag Care ; 20(6): 461-72, 2014 Jun.
Article in English | MEDLINE | ID: mdl-25180434

ABSTRACT

OBJECTIVES: Novel specialty biopharmaceuticals hold promise for patients living with complex and chronic conditions. However, high research and development costs, special handling, and other necessary enhancements to patient support programs all contribute to frequently higher prices for these products. This study sought to assess the value of specialty pharmaceuticals through an examination of the clinical, functional, and economic benefits of these treatments for the top 3 disease areas by pharmaceutical spend: rheumatoid arthritis (RA), multiple sclerosis (MS), and breast cancer (BC). STUDY DESIGN: Systematic literature review. METHODS: A systematic review of market research and cost-effectiveness articles was conducted for each disease area to assess clinical, functional, and economic outcomes associated with specialty medicine treatments versus the previous standard of care. RESULTS: All RA clinical (American College of Rheumatology) and functional (Health Assessment Questionnaire) outcome articles were classified as positive. The median cost-effectiveness ratio was $38,900 per quality-adjusted life year (QALY). All MS clinical outcome (relapse rate) articles were positive. The MS functional outcome (Expanded Disability Status Scale) findings were less conclusive. The median cost-effectiveness ratio was $248,000 per QALY. The majority of BC articles yielded statistically inconclusive results for survival. All functional outcome (Quality of Life Questionnaire- Core 30) articles were positive. The median cost-effectiveness ratio was $51,900 per QALY. CONCLUSIONS: Novel specialty therapies hold promise for arresting disease progression and improving quality of life for the 3 conditions associated with the highest specialty pharmaceutical spend. These findings demonstrate a strong value proposition for specialty pharmaceuticals, and suggest even greater potential individual patient benefit with consideration of patient heterogeneity.


Subject(s)
Anti-Inflammatory Agents/therapeutic use , Antineoplastic Agents/therapeutic use , Antirheumatic Agents/therapeutic use , Arthritis, Rheumatoid/drug therapy , Breast Neoplasms/drug therapy , Multiple Sclerosis/drug therapy , Anti-Inflammatory Agents/economics , Antineoplastic Agents/economics , Antirheumatic Agents/economics , Arthritis, Rheumatoid/economics , Breast Neoplasms/economics , Cost-Benefit Analysis , Drug Costs , Female , Humans , Multiple Sclerosis/economics
6.
Circ Cardiovasc Qual Outcomes ; 6(5): 567-74, 2013 Sep 01.
Article in English | MEDLINE | ID: mdl-23922182

ABSTRACT

BACKGROUND: Oral anticoagulation therapy is the primary tool in reducing stroke risk in patients with nonvalvular atrial fibrillation but is underused. Patients nonpersistent with therapy contribute to this underuse. The objective of this study was to compare persistence rates in newly diagnosed nonvalvular atrial fibrillation patients treated with warfarin versus dabigatran as their oral anticoagulation. METHODS AND RESULTS: US Department of Defense administrative claims were used to identify patients receiving warfarin or dabigatran between October 28, 2010, and June 30, 2012. Patient records were examined for a minimum of 12 months before index date to restrict the analyses to those newly diagnosed with nonvalvular atrial fibrillation and naive-to-treatment, identifying 1775 on warfarin and 3370 on dabigatran. Propensity score matching was used to identify 1745 matched pairs. Persistence was defined as time on therapy to discontinuation. Kaplan-Meier curves were used to depict persistence over time. Cox proportional hazards model was used to determine the factors significantly associated with persistence. Using a 60-day permissible medication gap, the persistence rates were higher for dabigatran than for warfarin at both 6 months (72% versus 53%) and 1 year (63% versus 39%). Patients on dabigatran with a low-to-moderate risk of stroke (CHADS2<2) or with a higher bleed risk (HEMORR2HAGES>3) had a higher likelihood of nonpersistence (hazard ratios, 1.37; 95% confidence interval, 1.17-1.60; P<0.001; and hazard ratios, 1.24; 95% confidence interval, 1.04-1.47; P=0.016). CONCLUSIONS: Patients who initiated dabigatran treatment were more persistent than patients who began warfarin treatment. Within each cohort, patients with lower stroke risk were more likely to discontinue therapy.


Subject(s)
Anticoagulants/therapeutic use , Antithrombins/therapeutic use , Atrial Fibrillation/drug therapy , Benzimidazoles/therapeutic use , Medication Adherence , Stroke/prevention & control , Warfarin/therapeutic use , beta-Alanine/analogs & derivatives , Aged , Aged, 80 and over , Anticoagulants/adverse effects , Antithrombins/adverse effects , Atrial Fibrillation/complications , Atrial Fibrillation/diagnosis , Benzimidazoles/adverse effects , Chi-Square Distribution , Dabigatran , Female , Hemorrhage/chemically induced , Humans , Kaplan-Meier Estimate , Logistic Models , Male , Middle Aged , Multivariate Analysis , Odds Ratio , Propensity Score , Proportional Hazards Models , Retrospective Studies , Risk Factors , Stroke/etiology , Time Factors , Treatment Outcome , Warfarin/adverse effects , beta-Alanine/adverse effects , beta-Alanine/therapeutic use
7.
PLoS One ; 8(5): e63959, 2013.
Article in English | MEDLINE | ID: mdl-23704962

ABSTRACT

Chronic hepatitis C virus (HCV) infection can lead to advanced liver disease (AdvLD), including cirrhosis, decompensated cirrhosis, and liver cancer. The aim of this study was to determine recent historical rates of HCV patient progression to AdvLD and to project AdvLD prevalence through 2015. We first determined total 2008 US chronic HCV prevalence from the National Health and Nutrition Evaluation Surveys. Next, we examined disease progression and associated non-pharmacological costs of diagnosed chronic HCV-infected patients between 2007-2009 in the IMS LifeLink and CMS Medicare claims databases. A projection model was developed to estimate AdvLD population growth through 2015 in patients diagnosed and undiagnosed as of 2008, using the 2007-2009 progression rates to generate a "worst case" projection of the HCV-related AdvLD population (i.e., scenario where HCV treatment is the same in the forecasted period as it was before 2009). We found that the total diagnosed chronic HCV population grew from 983,000 to 1.19 million in 2007-2009, with patients born from 1945-1964 accounting for 75.0% of all patients, 83.7% of AdvLD patients, and 79.2% of costs in 2009, indicating that HCV is primarily a disease of the "baby boomer" population. Non-pharmacological costs grew from $7.22 billion to $8.63 billion, with the majority of growth derived from the 60,000 new patients that developed AdvLD in 2007-2009, 91.5% of whom were born between 1945 and 1964. The projection model estimated the total AdvLD population would grow from 195,000 in 2008 to 601,000 in 2015, with 73.5% of new AdvLD cases from patients undiagnosed as of 2008. AdvLD prevalence in patients diagnosed as of 2008 was projected to grow 6.5% annually to 303,000 patients in 2015. These findings suggest that strategies to diagnose and treat HCV-infected patients are urgently needed to increase the likelihood that progression is interrupted, particularly for patients born from 1945-1964.


Subject(s)
Disease Progression , Hepatitis C, Chronic/epidemiology , Hepatitis C, Chronic/pathology , Aged , Cohort Studies , Costs and Cost Analysis , Hepatitis C, Chronic/economics , Hepatitis C, Chronic/mortality , Humans , Middle Aged , Models, Biological , United States/epidemiology
8.
Psychiatry Res ; 172(1): 24-30, 2009 Apr 30.
Article in English | MEDLINE | ID: mdl-19216061

ABSTRACT

Transitive inference (TI) is the ability to infer the relationship between items (e.g., A>C) after having learned a set of premise pairs (e.g., A>B and B>C). Previous studies in humans have identified a distributed neural network, including cortex, hippocampus, and thalamus, during TI judgments. We studied two aspects of TI using functional magnetic resonance imaging of subjects who had acquired the six-item sequence (A>B>C>D>E>F) of visual stimuli. First, the identification of novel pairs not containing end items (i.e., B>D, C>E, B>E) was associated with greater left hippocampal activation compared with the identification of novel pairs containing end items A and F. This demonstrates that the identification of stimulus pairs requiring the flexible representation of a sequence is associated with hippocampal activation. Second, for the three novel pairs devoid of end items we found greater right hippocampal activation for pairs B>D and C>E compared with pair B>E. This indicates that TI decisions on pairs derived from more adjacent items in the sequence are associated with greater hippocampal activation. Hippocampal activation thus scales with the degree of relational processing necessary for TI judgments. Both findings confirm a role of the hippocampus in transitive inference in humans.


Subject(s)
Hippocampus/physiology , Memory/physiology , Adult , Brain/physiology , Brain Mapping , Cognition/physiology , Female , Humans , Judgment/physiology , Magnetic Resonance Imaging , Male , Neural Pathways/physiology , Neuropsychological Tests , Recognition, Psychology , Visual Perception/physiology
9.
Arch Gen Psychiatry ; 63(4): 356-65, 2006 Apr.
Article in English | MEDLINE | ID: mdl-16585464

ABSTRACT

CONTEXT: Memory deficits are common in schizophrenia. Recent studies have demonstrated that relational memory is particularly impaired. OBJECTIVE: To study the neural correlates of relational memory in schizophrenia using functional magnetic resonance imaging. DESIGN: Cross-sectional case-control study. SETTING: Academic medical center. Subjects Twenty patients with schizophrenia and 17 control subjects. MAIN OUTCOME MEASURES: Behavioral performance and brain activity were assessed during the discrimination of previously seen and novel pairs of visual stimuli, which varied in the degree of relational memory load. We performed whole-brain and region-of-interest (hippocampus) analyses. RESULTS: Schizophrenic subjects displayed normal activation of the presupplementary motor area and ventral prefrontal cortex, but significantly decreased recruitment of the right parietal cortex and anterior cingulate cortex when discriminating novel pairs derived from a sequence of stimuli. Discrimination accuracy was decreased in schizophrenia only when the flexible representation of a sequence was required. This selective deficit was associated with decreased activation of the right parietal cortex and left hippocampus. CONCLUSIONS: Schizophrenia is characterized by a specific deficit of relational memory, which is associated with impaired function of the parietal cortex and hippocampus. Abnormal relational memory may be at the core of 2 prominent features of schizophrenia, ie, cognitive deficits and psychosis.


Subject(s)
Cerebral Cortex/physiopathology , Memory Disorders/physiopathology , Models, Neurological , Schizophrenia/physiopathology , Schizophrenic Psychology , Adult , Brain Mapping , Case-Control Studies , Cognition Disorders/physiopathology , Cross-Sectional Studies , Female , Functional Laterality/physiology , Hippocampus/physiopathology , Humans , Magnetic Resonance Imaging/methods , Male , Neuropsychological Tests , Oxygen/blood , Parietal Lobe/physiopathology , Psychomotor Performance/physiology , Temporal Lobe/physiopathology
10.
Schizophr Bull ; 32(2): 332-40, 2006 Apr.
Article in English | MEDLINE | ID: mdl-16319377

ABSTRACT

Smaller medial temporal lobe volume is a frequent finding in studies of patients with schizophrenia, but the relative contributions of the hippocampus and three surrounding cortical regions (entorhinal cortex, perirhinal cortex, and parahippocampal cortex) are poorly understood. We tested the hypothesis that the volumes of medial temporal lobe regions are selectively changed in schizophrenia. We studied 19 male patients with schizophrenia and 19 age-matched male control subjects. Hippocampal and cortical volumes were estimated using a three-dimensional morphometric protocol for the analysis of high-resolution structural magnetic resonance images, and repeated measures ANOVA was used to test for region-specific differences. Patients had smaller overall medial temporal lobe volumes compared to controls. The volume difference was not specific for either region or hemisphere. The finding of smaller medial temporal lobe volumes in the absence of regional specificity has important implications for studying the functional role of the hippocampus and surrounding cortical regions in schizophrenia.


Subject(s)
Hippocampus/anatomy & histology , Hippocampus/physiopathology , Magnetic Resonance Imaging , Parahippocampal Gyrus/anatomy & histology , Parahippocampal Gyrus/physiopathology , Schizophrenia/physiopathology , Adult , Cerebral Cortex/anatomy & histology , Diagnostic and Statistical Manual of Mental Disorders , Female , Humans , Male , Temporal Lobe/anatomy & histology
11.
Psychiatry Res ; 139(3): 191-8, 2005 Aug 30.
Article in English | MEDLINE | ID: mdl-16055310

ABSTRACT

Activity in the hippocampus is modulated by novelty detection, and by the processing of conjunctions between two stimuli. We investigated whether the hippocampus is activated by discrimination of stimulus-stimulus relationships in novel versus familiar pairs of visual stimuli in 15 healthy subjects using functional magnetic resonance imaging. Subjects were asked to recognize the previously rewarded stimulus in each case. We found significantly greater activation of the right hippocampus when discriminating previously seen compared with novel pairs of visual stimuli. This activation was evident in individual subjects and was not related to stimulus novelty, reward contingency, or task instruction. Right hippocampal activation during discrimination of previously seen pairs of objects was correlated with activity in the anteromedial thalamus, cingulate cortex, and contralateral hippocampus.


Subject(s)
Hippocampus/metabolism , Visual Perception , Adult , Female , Humans , Magnetic Resonance Imaging , Male , Recognition, Psychology
12.
Biol Psychiatry ; 57(9): 1011-9, 2005 May 01.
Article in English | MEDLINE | ID: mdl-15860342

ABSTRACT

BACKGROUND: In healthy individuals, the activity of the medial temporal lobe habituates rapidly with the repeated presentation of a stimulus. Using functional magnetic resonance imaging (fMRI), we tested the hypothesis that habituation of the medial temporal lobe is reduced in schizophrenia. METHODS: During fMRI scanning, fearful and happy faces were presented repeatedly to healthy control subjects (n =16) and patients with schizophrenia (n =18). Habituation of medial temporal lobe structures was measured by comparing the hemodynamic response occurring during the early and late portions of the presentation of each face. RESULTS: Control subjects demonstrated significant medial temporal lobe habituation to fearful but not to happy faces. In contrast, patients with schizophrenia did not demonstrate medial temporal lobe habituation in response to fearful or happy faces. In a direct, between-group comparison, right hippocampal habituation to fearful faces was significantly greater in control subjects than in the schizophrenia patients. Also, there were no significant differences between the patients and control subjects in the early medial temporal lobe response to fearful faces, suggesting that attenuated hippocampal habituation in schizophrenia is not associated with a reduction in initial activation. CONCLUSIONS: These findings suggest that there is abnormal modulation of hippocampal responses to fearful faces in schizophrenia.


Subject(s)
Facial Expression , Fear , Hippocampus/pathology , Hippocampus/physiopathology , Schizophrenia/pathology , Schizophrenia/physiopathology , Adult , Brain Mapping , Habituation, Psychophysiologic/physiology , Hippocampus/blood supply , Humans , Image Processing, Computer-Assisted/methods , Magnetic Resonance Imaging/methods , Male , Middle Aged , Oxygen/blood , Photic Stimulation/methods , Psychiatric Status Rating Scales , Temporal Lobe/blood supply , Temporal Lobe/pathology , Temporal Lobe/physiopathology , Time Factors
13.
Hippocampus ; 14(2): 153-62, 2004.
Article in English | MEDLINE | ID: mdl-15098721

ABSTRACT

Studies in rodents have demonstrated that the integration and flexible expression of memories, necessary for transitive inference, depend on an intact hippocampus. To test this hypothesis in humans, we studied brain activation during the discrimination of a series of overlapping and non-overlapping arbitrary visual stimulus pairs. We report that transitive inference about overlapping pairs is associated with right anterior hippocampal activation, whereas recognition of non-overlapping stimulus pairs is associated with bilateral medial temporal lobe activation centered in the anterior parahippocampal gyrus. We conclude that immediate access to simple stimulus-stimulus relationships is mediated via the parahippocampal gyrus, whereas the flexible representation of memory requires the recruitment of the hippocampus.


Subject(s)
Hippocampus/physiology , Memory/physiology , Adult , Association Learning/physiology , Behavior/physiology , Cognition/physiology , Discrimination, Psychological/physiology , Female , Humans , Magnetic Resonance Imaging , Male , Mental Recall/physiology , Motor Cortex/physiology , Nerve Net/physiology , Parahippocampal Gyrus/physiology , Photic Stimulation , Psychomotor Performance/physiology , Reaction Time/physiology , Recruitment, Neurophysiological/physiology
14.
Biol Psychiatry ; 55(7): 668-75, 2004 Apr 01.
Article in English | MEDLINE | ID: mdl-15038994

ABSTRACT

BACKGROUND: Patients with schizophrenia have smaller hippocampal volumes and perform abnormally on most declarative memory tasks. Although these findings are likely related, the impact of hippocampal pathology on cognitive performance in schizophrenia remains unclear. This study examined this relationship by measuring the volume of the hippocampus and its activation during memory task performance. METHODS: Participants included 15 patients with schizophrenia and 16 age-matched control subjects. Hippocampal volume was determined via three-dimensional volumetric analysis of high-resolution magnetic resonance images. Hippocampal activity was assessed by measuring changes in blood oxygen level-dependent signal during a recognition memory task. RESULTS: Patients with schizophrenia had smaller hippocampal volumes bilaterally and demonstrated poorer performance on the recognition memory task, largely because of a heightened rate of false alarms to novel stimuli. Both groups showed robust hippocampal activity to old and new items when compared with a low-level baseline task; however, direct comparison of hippocampal activity during recognition task performance revealed that healthy control, but not the schizophrenia, subjects showed significant right anterior hippocampal activation during the evaluation of novel items. CONCLUSIONS: The impaired ability to classify new items as previously not experienced is associated with decreased recruitment and smaller volume of the hippocampus in schizophrenia.


Subject(s)
Hippocampus/physiopathology , Image Enhancement , Image Processing, Computer-Assisted , Magnetic Resonance Imaging , Memory, Short-Term/physiology , Schizophrenia/physiopathology , Schizophrenic Psychology , Verbal Learning/physiology , Adult , Atrophy , Attention/physiology , Chronic Disease , Cognition Disorders/diagnosis , Cognition Disorders/physiopathology , Cognition Disorders/psychology , Dominance, Cerebral/physiology , Hippocampus/pathology , Humans , Male , Mathematical Computing , Middle Aged , Oxygen Consumption/physiology , Recruitment, Neurophysiological/physiology , Reference Values , Schizophrenia/diagnosis
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