Prominent brain axonal damage and functional reorganization in "pure" adrenomyeloneuropathy.

[adrenomyeloneuropathy]

Cerebral involvement is usually absent in pure adrenomyeloneuropathy (AMN ). Recently , nonconventional MR studies have reported brain abnormalities in patients with pure AMN , providing evidence that occult cerebral involvement may occur in this disease . It remains unclear , however , whether these brain abnormalities reflect centripetal extension of spinal cord long -tract axonopathy or can be the expression of a pathologic process largely involving the brain .Conventional MRI and proton MR spectroscopic imaging (1 H-MRSI ) data of four patients with pure AMN were compared to those of four men with spinal cord injury (SCI ) and 10 age-matched healthy men (HM ). Resonance intensity areas of N-acetylaspartate (NAA ) and choline were calculated as ratios to creatine (Cr ) in voxels located in white matter (WM ) regions . Functional MRI (fMRI ) data during simple motor task were obtained in a separate session in three patients with AMN and three age-matched HM .Conventional MRI examinations were normal in all patients . On 1 H-MRSI , NAA /Cr values were lower in all WM regions of patients with AMN than in those of patients with SCI (p < 0 .05 ) and HM (p < 0 .01 ). In contrast , patients with SCI showed NAA /Cr values lower than HM only in the periventricular WM (p = 0 .04 ). At fMRI , patients with AMN showed a more pronounced activation than HM in all movement-associated cortical regions contralateral to the hand moved and an exclusive voxel activation of the primary motor , somatosensory , and posterior parietal cortices ipsilateral to the hand moved .CNS damage in pure adrenomyeloneuropathy is not confined exclusively to spinal cord and seems to primarily involve the brain .