Aerobic exercise increases hippocampal volume and improves memory in multiple sclerosis: preliminary findings

Area of Science:

• Neuroscience
• Exercise Physiology
• Rehabilitation Medicine

Background:

• Multiple sclerosis (MS) commonly causes hippocampal atrophy, leading to significant memory impairment in 50% of patients.
• Current pharmacological and behavioral treatments for MS-related memory deficits are ineffective.
• Aerobic exercise is known to enhance memory and hippocampal neurogenesis in animal models.

Purpose of the Study:

• To investigate the effects of aerobic exercise on memory and hippocampal structure/function in ambulatory individuals with MS.
• To compare the efficacy of aerobic exercise versus non-aerobic stretching for improving memory in MS patients.

Main Methods:

• Pilot study involving two ambulatory, memory-impaired MS participants randomized to aerobic (stationary cycling) or non-aerobic (stretching) exercise.
• Intervention: 30-minute sessions, 3 times/week for 3 months.
• Assessments: High-resolution MRI (hippocampal volume), fMRI (hippocampal connectivity), and memory tests.

Main Results:

• Aerobic exercise led to a 16.5% increase in hippocampal volume and a 53.7% improvement in memory.
• Aerobic exercise also increased hippocampal resting-state functional connectivity.
• Non-aerobic exercise showed minimal changes in hippocampal volume (2.8%) and no memory improvement (0.0%).
• Cognitive improvements were specific to memory, with no significant changes in overall gray matter or other cognitive functions.

Conclusions:

• Aerobic exercise is the first demonstrated effective treatment to increase hippocampal volume, connectivity, and memory in MS patients.
• This natural, self-administered intervention is cost-effective and has no adverse side effects.
• Aerobic exercise represents a potential breakthrough in managing memory deficits associated with multiple sclerosis.