Diffusion tensor imaging and magnetic resonance spectroscopy of transient cerebral white matter lesions in X-linked Charcot-Marie-Tooth disease

Background: X-linked Charcot-Marie-Tooth disease (CMTX) is a common inherited axonal or mixed axonal-demyelinating neuropathy. The disease is caused by mutations in the GJB1 gene encoding the gap junction protein connexin32, which is expressed in both Schwann cells in the peripheral nervous system and oligodendrocytes in the central nervous system. Several reports have described CMTX patients presenting with transient and recurrent central nervous system (CNS) symptoms with transient white matter lesions in the brain. Patients: We describe a man with CMTX who presented with transient CNS symptoms and abnormal cerebral white matter lesions in MRI. He was subjected to a detailed MRI examination using two specialized techniques, diffusion tensor imaging (DTI) and magnetic resonance spectroscopy (MRS). Results: In the early stage of his CNS symptoms, MRS studies revealed reduced N-acetyl-aspartate (NAA) levels in deep white matter, and DTI revealed reduced fractional anisotropy within lesions. Interestingly, these reductions began to recover from day 19 after admission, and follow-up DTI and MRS studies on day 101 revealed a reversal of the abnormalities. Conclusion: The findings of reversible reductions in fractional anisotropy and NAA levels in our patient suggest reversible axonal damage associated with deficient oligodendrocyte gap junctions.