Introduction: The aim of this study is to analyze the clinical presentation, radiological findings, surgical treatment and outcome of nonterminal myelocystoceles (NTM)treated by this author.

Methods: Between 1998 and 2010, 20 patients with NTMs were treated by this author. All children underwent neurological evaluation and MRI evaluation. Surgical findings were recorded. The aim of surgery was to detether the cord and achieve watertight dural closure after sectioning the fibrvascular stalk in type I lesions ; detethering, syrinx drainage and watertight dural closure in type II lesions. Follow up ranged from 3 months – 2 years.

Results: Age: ranged from newborn to 3 years. Female: male ratio was 9:1. Lesion locations were as follows: Cervical :6, Thoracic 6, Lumbar 8. All children except one were normal neurologically. Radiologically, 2 children had Rossi Type II NTMs and the remaining 18 had Rossi Type I NTMs. No patient with lumbar NTM had Type II lesion. All children with lumbar NTMs had lowlying cords. Radiologically, type I lesions were characterized by posterior tenting of the cord at the site of the lesion. One patient had associated hydrocephalus. Six of the eight lumbar NTMs had radiological evidence of tonsillar herniation. No patient had postoperative CSF leak and there was no retethering during an average follow up of 9 months.

Conclusions: NTMs are not rare lesions. They are often misdiagnosed as meningoceles. Improper diagnosis may lead to suboptimal treatment without adequately untethering the cord. Failure to recognize the pathology of NTMs leads to delayed deterioration because of tethering. Proper recognition and appropriate surgical technique leads to good outcome. NTMs are under diagnosed lesions. Awareness of the radiological presentation is the key to diagnosis.

Patient Care: Commonly, non terminal myelocystoceles are misdiagnosed as meningoceles. As the surgical management is different for both these lesions, ability of the participants to differentiate these two lesions will improve patient outcomes

Learning Objectives: By the conclusion of this session, participants should be able to :1) diagnose non terminal myelocystoceles, 2) differentiate the two types of non terminal myelocystoceles, 3)Understand the differences in the surgical management of non terminal myelocystoceles, 4) understand the difference between non terminal myelocystoceles and meningoceles with whom they are commonly confused.

References: 1. Muthukumar N: Terminal and non terminal Myelocystoceles. J Neurosurg. 2007 Aug;107(2 Suppl):87-97. 2.Pang D, Dias MS.:Cervical myelomeningoceles.Neurosurgery. 1993 Sep;33(3):363-72; 3.Etus V, Sarisoy HT, Ceylan S.:Surgical technique and outcome in cervical and thoracic myelomeningocoele surgery.J Clin Neurosci. 2006 Jul;13(6):643-7.