A team at the University of Texas selected the thalamus of the brain as the benchmark for its research published in the latest edition of 'The Journal of Neuroscience'.
'The thalamus is a central area that relates to the rest of the brain and acts as the 'post office'. It also is an area that has the least amount of damage from lesions in the brain but we see volume loss, so it appears other brain damage related to the disease is also occurring,' Khader Hasan, who led the team, said.
Researchers have known that the thalamus loses volume in size with typical aging, which accelerates after age 70. The team's purpose was to assess if there was more volume loss in patients with multiple sclerosis, which could explain the dementia-related decline associated with the disease.
'Multiple sclerosis patients have cognitive deficits and the thalamus plays an important role in cognitive function. The lesions we can see but there is subclinical activity in multiple sclerosis where you can't see the changes.
'There are neurodegenerative changes even when the brain looks normal and we saw this damage early in the disease process,' the scientists said.
For their research, the scientists used precise imaging by the powerful 3 Tessla MRI scanner to compare the brains of 109 patients with the disease to 255 healthy subjects.
Adjusting for age-related changes in the thalamus, the patients with multiple sclerosis had less thalamic volume than the controls. The amount of thalamic loss also appeared to be related to the severity of disability.
'This is looking at multiple sclerosis in a different way. The thalami are losing cellular content and we can use this as a marker of what's going on. If we can find a way to detect the disease earlier in a more vulnerable population, we could begin treatment sooner,' Hasan said.