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Neuroradiology Case of the Week

Case 240

Ashwani K. Sharma, MD and P-L Westesson, MD, PhD, DDS

Clinical Presentation: Patient is a follow-up case of relapsing multiple sclerosis. She presented with loss of balance and fell and has electric sensation in the feet. This was considered to be an MS exacerbation, and she was treated with high dosage intravenous methylprednisolone for 3 days. She had some improvement, although it was delayed and temporary. MR of the brain and spine were requested for evaluation of the disease.

Imaging Findings: Small intramedullary cystic lesion was seen posteriorly in the cervical spinal cord at the level of C4 vertebral body. No evidence of any bony abnormality was seen. Presumed diagnosis of neuroenteric cyst was made.

Diagnosis: Intramedullary neuroenteric cyst

Discussion: Neuroenteric cysts represent one form of the split notochord syndrome. This group of congenital disorders arises from abnormally persistent connection between embryonic endoderm and neuroectoderm. The presence of such midline ventral adhesions prevent normal induction and formation of the notochord, which typically splits around the area of endodermal/neuroectodermal connection. Lesions can be asymptomatic or the patients can present with pain, paresis, gait disturbances, etc. Usual age of detection is between second and fourth decade, with male to female ratio of 3:2 to 2:1.
    Imaging findings are midline cystic lesions which can vary in location from extra spinal to intraspinal and extradural to intradural and extramedullary or intramedullary. intramedullary lesions are usually ventral. Contents are usually cystic with no enhancement. Lesion can be associated with vertebral segmentation or fusion anomalies. Treatment is complete removal of the cyst.
     Differential diagnosis is arachnoid cyst, epidermoid/dermoid, syrinx, cystic tumor or meningocele.

References:

1. Lippman CR, Arginteanu M, Purohit D, Naidich TP, Camins MB. Intramedullary neurenteric cysts of the spine. Case report and review of the literature. J Neurosurg. 2001 Apr;94(2 Suppl):305-9. [Medline]
2. Brooks BS, Duvall ER, el Gammal T, Garcia JH, Gupta KL, Kapila A. Neuroimaging features of neurenteric cysts: analysis of nine cases and review of the literature. AJNR Am J Neuroradiol. 1993 May-Jun;14(3):735-46. [Medline]