Split Cord Malformations

Split cord malformations are one of rare and complex occult spinal dysraphism in which spinal cord divided into two symmetrical or non-symmetrical parts by medium septa which may be fibrous or bony (Meena RK, Doddamani RS, Sharma R. World Neurosurg 2019; Gezercan Y, Özsoy KM, Oktay K, Çetinalp NE, Erman T, Zeren M. Çukurova Üniversitesi 199:40, 2015). There are two types of SCMs. Type I SCM (diastematomyelia) is characterized by osseocartilaginous septum that divides spinal canal and spinal cord into two parts surrounded by separated thecal sacs. Type II SCM (diplomyelia) is characterized by medium fibrous septum that separate spinal cord into two parts within single thecal sac and spinal canal (Raskin JS, Litvack ZN, Selden NR. Split spinal cord, Youmans and Winn neurological surgery. Elsevier, Philadelphia, 2017; 3322–3330). The most commonly accepted theory is Unified theory by Pang in which the basic error occurred during gastrulation in which midline integration of notochord failed so that the ectoderm-endoderm adhesion persists by the unfused heminotochords that causes an accessory neurenteric canal (ANC) formation around which an endomesenchymal tract condensed and pass through the heminotochord leading to formation of hemineural plates. In general, clinical presentations categorized into: (1) skin lesions (2) back pain and (3) neurolagical deficits (due to spinal cord tethering) or patient may be asymptomatic. These lesions are best demonstrated by MRI, CT, sometimes CT myelography. When the diagnosis of split cord is confirmed in a child, prophylactic surgery is indicated because neurological deterioration is very common. The main aim of surgery is resection of median septum and any tethering bands.