Article

OBJECTIVE: To investigate metabolic changes within the spinal cord using proton
magnetic resonance spectroscopy ((1)H-MRS) and determine their relationship with
clinical function in patients with complete brachial plexus avulsion who
underwent reimplantation of the ventral roots. METHODS: Single-voxel (1)H-MRS of
the cord between C1 and C3 was performed in 10 patients with normal spinal cord
on MRI, who underwent reimplantation of C5 to T1 ventral roots on average 5.5
years earlier, and 19 healthy controls. The ratios of the concentrations of the
following main metabolites, with respect to total creatine levels, were obtained:
total N-acetyl-aspartate, choline-containing compounds, creatine and
phosphocreatine (Cr), and myo-inositol (m-Ins). Patient disability was assessed
using upper limb scales. Differences in metabolite concentration ratios and their
correlations with disability were investigated. RESULTS: Patients showed
increased m-Ins/Cr ratio compared with controls, which was associated with the
level of function of the affected arm and time from injury. CONCLUSIONS: The
finding of increased m-Ins/Cr in patients suggests that reactive gliosis, perhaps
in response to the degeneration of avulsed fibers, may occur in the spinal cord
above the site of injury and be relevant to motor dysfunction. However, this
pathological process appears to diminish with time. These insights underline the
need to integrate metabolic imaging with structural and functional magnetic
resonance imaging to obtain a complete view of spinal cord plasticity. Last, this
study provides the first steps toward identifying markers to serve as outcome
measures for trials comparing strategies of plexus repair following avulsion
injury.

Langue : ANGLAIS