Amplitude of Low Frequency Fluctuation (ALFF) study of the spontaneous brain activities of patients with phantom limb pain.

OBJECTIVE

Our objective was to use Amplitude of Low-Frequency Fluctuation (ALFF) method to investigate the changes in spontaneous brain activity in HM patients and their relationships with clinical features.

PATIENTS AND

METHODS

This study was set out to observe, using Functional magnetic resonance imaging (fMRI), the changes in spontaneous brain activity in patients with phantom limb pain (PLP). Eleven amputees with PLP closely matched in age, sex, and education in a right side lower limb were scanned using fMRI to measure the amplitude of low-frequency fluctuation (ALFF) and functional connectivity (FC) in the resting state of the brain (GPLP) before use of prosthetic. They were then scanned again after recovering from PLP (GPLPr) after use of artificial limbs. Eleven healthy volunteers (GC) were also scanned.

RESULTS

When compared to GC, GPLP exhibited decreased ALFF in the left inferior parietal lobule, and GPLPr exhibited decreased ALFF in the left precuneus. When compared to GPLP, GC showed positive FC in the part regions of the limbic system structure. When compared to GC, the positive FC in GPLPr was significantly decreased in the midbrain. Finally, when compared to GPLPr, GPLP showed significantly decreased positive FC in the right precuneus and inferior parietal lobe. The central nervous system shows functional changes in the resting state of the brain in patients with PLP, which may indicate the presence of neurobiological changes. The recovery time of the changes may be longer than the pain symptoms of patients.

CONCLUSIONS

The technique of fMRI of the resting network of the brain in patients with PLP may be able to be used to monitor clinical therapeutic effects.