Related Experiment Video
Updated: Apr 29, 2026
09:33
Diffusion Tensor Magnetic Resonance Imaging in the Analysis of Neurodegenerative Diseases
Published on: July 28, 2013
27.9K
Extensive white matter dysfunction in cognitively impaired patients with secondary-progressive multiple sclerosis
P L Francis1, T L Chia2, R Jakubovic2
1Medical Imaging (P.L.F., T.L.C., R.J., R.I.A.), Sunnybrook Health Sciences Centre philip.francis@utoronto.ca.
AJNR. American Journal of Neuroradiology
|May 17, 2014
Summary
Cognitive impairment in multiple sclerosis is linked to widespread white matter (WM) damage. White matter fractional anisotropy, a measure of WM integrity, is a key predictor of cognitive status in patients.
Area of Science:
- Neuroscience
- Radiology
- Neurology
Background:
- Cognitive impairment is a significant disabling symptom in multiple sclerosis (MS).
- White matter (WM) dysfunction is implicated in cognitive decline in MS.
- Diffusion Tensor Imaging (DTI) allows for the investigation of WM integrity.
Purpose of the Study:
- To investigate the association between cognitive impairment and WM dysfunction in secondary-progressive multiple sclerosis (SPMS).
- To identify specific WM tracts affected in cognitively impaired SPMS patients using DTI.
Main Methods:
- Cognitive performance was assessed using the Minimal Assessment of Cognitive Function in Multiple Sclerosis (MACFIMS).
- Cognitive impairment was defined as scoring >1.5 standard deviations below healthy controls on ≥2 subtests.
- Tract-based spatial statistics with threshold-free cluster enhancement was used to compare fractional anisotropy maps against cognitive status.
Main Results:
- Cognitively impaired SPMS patients (25/45) showed reduced global gray matter (GM) and WM volumes, increased WM lesion volumes, and lower WM skeleton fractional anisotropy compared to non-impaired patients.
- Impaired patients exhibited significantly lower fractional anisotropy in over 50% of voxels within all major WM tracts, notably the corpus callosum.
- Multivariate logistic regression indicated that only WM skeleton fractional anisotropy remained a significant predictor of cognitive status after accounting for confounders.
Conclusions:
- Patients with SPMS and cognitive impairment demonstrate extensive WM dysfunction.
- Specific WM tracts crucial for cognition, such as the corpus callosum, are preferentially affected.
- WM skeleton fractional anisotropy is a significant predictor of cognitive status in SPMS.
Related Concept Videos
01:19Multiple Sclerosis l: Introduction
20
Multiple sclerosis is a chronic autoimmune disease of the central nervous system (CNS) that affects the brain, spinal cord, and optic nerves. It is an inflammatory demyelinating disorder and a leading cause of neurological disability in young adults.EpidemiologyMS commonly begins between 20 and 40 years of age and is twice as common in women. Its exact cause remains unclear, but genetic susceptibility contributes, with higher risk in first-degree relatives and identical twins. A greater...
20
01:22Dementia l: Introduction
33
Dementia is an acquired, progressive syndrome characterized by a decline in multiple cognitive domains severe enough to impair daily functioning and reduce independence. Although memory loss is a central feature, the diagnosis requires additional deficits involving language, executive function, visuospatial skills, judgment, calculation, or abstract reasoning. These cognitive impairments reflect underlying neurodegenerative or vascular processes that gradually disrupt neuronal networks...
33
01:25Secondary Spinal Cord Injury llI: Pathophysiology
51
Early Ischemia and Ionic ImbalanceWithin minutes of spinal cord injury, a secondary cascade begins, progressing over hours to weeks. Vascular damage reduces blood flow, causing ischemia and mitochondrial dysfunction. ATP depletion leads to ion pump failure, membrane depolarization, sodium influx, potassium efflux, and water accumulation, resulting in cellular swelling. Increased intracellular calcium further disrupts mitochondria and accelerates cellular injury.Excitotoxicity and Neuronal...
51
01:23Alzheimer Disease ll: Pathophysiology
34
Alzheimer disease involves structural changes in the brain that begin long before symptoms appear. The most distinctive features are extracellular neuritic plaques and intracellular neurofibrillary tangles.Neuritic plaques form in the cerebral cortex and around blood vessels. These plaques contain a dense core of beta-amyloid (Aβ)—a toxic protein fragment that clumps outside neurons. The core is surrounded by damaged neuronal extensions, as well as reactive astrocytes and...
34
01:29Alzheimer Disease l: Introduction
21
Alzheimer disease is a chronic, progressive, and irreversible neurodegenerative disorder and the most common cause of dementia in older adults. It leads to gradual neuronal loss, causing cognitive decline, behavioral changes, and loss of functional independence.Risk Factors and EtiologyThe disease is multifactorial. Age is the strongest risk factor, with prevalence doubling every 5 years after age 65. Genetic factors include mutations in genes such as APP, PSEN1, and PSEN2, which are associated...
21