Functional connectivity tied to balance in MS patients

A team of Italian researchers used resting-state fMRI to examine functional connectivity abnormalities in the brain in patients with multiple sclerosis (MS). They wanted to see how abnormalities in cerebellar dentate nuclei (DNs) affect an individual’s balance, posture and muscle tone.

The study was published Dec. 22, 2017, in Radiology.

“[T}he pathophysiologic mechanisms underlying balance dysfunction in patients with MS have not yet been fully understood, even though altered cerebellar connections have been suggested to play a key role,” wrote lead author Francesca Tona, MD, with Sapienza University of Rome, and colleagues.

The study included 25 patients with relapsing-remittance MS (10 women and 15 men with a mean age of 35.1) and 20 healthy individuals in a control group (eight women and 12 men with a mean age of 30). All 45 participants underwent clinical evaluation, static posturography assessment and MR imaging.

The MRI of all participants led to conclusion such as:

• Displacement of the center of pressure (COP) path was wider in the control group, while total gray and white matter volumes were significantly lower in MS patients.
• Functional connectivity (FCs) was similar in both groups, though MS patients displayed lower FC in both thalami and caudate nuclei.
• Posturography measures and FC maps were correlated in MS patients where FC was lower.

The decreased connectivity in the left caudate nucleus correlated with diminished balance, regardless of age and lesion volume.

“The main findings that emerge from this study are that FC between the cerebellar DN and some supratentorial brain structures is altered in MS patients and that this alteration is related to balance, regardless of lesion burden and global clinical disability,” wrote Tona et al. “In particular, poor balance is associated with a reduction in connectivity between the DN and the left caudate nucleus.”