gms | German Medical Science

Objective: The term hemimyelomeningocele refers to a rare condition of spinal dysraphism in which open neural placode is localized in one hemicord of a split cord malformation of type I. This entity requieres attention due to lack of overt clinical evidence and neuroradiological investigation since the open neural tube defect of the newborn is generally repaired as an emergency.

Method: Between 1989 and 2013 800 newborns and infants with an open neural tube defect were operated on at the Division of Pediatric Neurosurgery at Marmara University Medical Center and Acıbadem University, Department of Neurosurgery. 168 patients (21%) presented an associated split cord malformation and within this group 32 cases (4%) were diagnosed as hemimyelomeningocele. The diagnosis of hemimyelomeningocele have been made either during preoperative physical examination or incidentally during operation. In 28 cases the placode had a paramedian localization, with hypertrichosis in 16 cases. Scoliosis was present in 11 cases with an additional foot deformity in 6 of them. In cases with neurological deficit, the deficit was typically asymmetrical. Five cases have been noted to have a normal neurological examination. Sensorimotor function was preserved on the side of the closed hemicord. In surgery, the neural tube is reconstructed, the septum removed, and a duraplasty was performed. There were no surgical morbidity and mortality. Detailed postoperative investigation with magnetic resonance imaging revealed the split cord malformation with two hemicords. Within the first month after surgery urine analysis & culture, urinary system U/S and voiding cystouretrogram were also performed.

Results: Only two patients presented with neurogenic bladder in the long-term follow-up period. The mean follow-up period was 5 years. Nine children needed a shunt during early infancy. Twelve children were classified as Gr. 2, whereas twenty as Gr. 3 according to the Oi and Matsumato’s Spina Bifida Neurological Scale (SBNS).

Conclusions: Hemimyelomeningocele is a rare subgroup of Spina bifida, which has significantly better prognosis compared to other types of Spina bifida. Preoperative diagnosis of both hemicords is crucial to preserve the intact hemicord during surgery.