Article

Limb amputation and chronic phantom limb pain (PLP) are both associated with
neural alterations at all levels of the neuraxis. We investigated gray matter
volume of 21 upper limb amputees and 14 healthy control subjects. Results
demonstrate that amputation is associated with reduced gray matter in areas in
the motor cortex representing the amputated limb. Additionally, patients show an
increase in gray matter in brain regions that belong to the dorsal and ventral
visual stream. We subdivided the patient group into patients with medium to high
PLP (HPLP; N = 11) and those with slight PLP (SPLP; N = 10). HPLP patients showed
reduced gray matter in brain areas involved in pain processing. SPLP patients
showed a significant gray matter increase in regions of the visual stream.
Results indicate that all patients may have an enhanced need for visual control
to compensate the lack of sensory feedback of the missing limb. As we found these
alterations primarily in the SPLP patient group, successful compensation may have
an impact on PLP development. Therefore, we hypothesize that visual adaptation
mechanisms may compensate for the lack of sensorimotor feedback and may therefore
function as a protection mechanism against high PLP development.

Langue : ANGLAIS