Anterior cervical myelomeningocele: a rare malformation of the spinal cord.

Cervical myelomeningocele (MMC) is an uncommon congenital malformation of the spinal cord and accounts for a small proportion of neural tube defects. These lesions mostly occur in the dorsal part of the body. Only a single case of an anterior cervical MMC has been previously reported. The authors report a second case of anterior cervical MMC diagnosed when the patient began to experience symptoms of bilateral hand weakness in adulthood. In this patient, MR imaging of the cervical spine showed an anterior cervical MMC at the C6-7 level with hydrocephalus, thinning of the genu and trunk of the corpus callosum, maldevelopment of the cerebellar tonsils, and expansion of the fourth ventricle, posterior cranial fossa, and subarachnoid space. A CT scan and a 3D CT reconstruction of the cervical spine clearly demonstrated contiguous fusions of multiple lower-cervical vertebrae and neural arches, which was consistent with Type III Klippel-Feil syndrome. The patient was advised to undergo operative treatment to prevent the progression of her neurological deficit. However, after being notified of the potential neurological risks, the patient declined surgery and opted for conservative treatment with a hard neck collar. At 4 months' follow-up, the patient's neurological deficit remains stable with the MMC left untreated. The authors presume that the possible pathogenesis of anterior cervical MMC may greatly differ from that of posterior lesions. This lesion could also be associated with multiple other spinal abnormalities, which highlights the importance of comprehensive preoperative radiological examinations.