Diastematomyelia - split-notochord-syndroms - two seperate chorda cords in MRI sequence скачать в хорошем качестве

Diastematomyelia - split-notochord-syndroms - two seperate chorda cords in MRI sequence

This video is about diastematomyelia Diastematomyelia belongs to the spectrum of split-notochord-syndroms. The pathogenesis is an incomplete separation oft he embryonic ecto- and entoderm so that two separate chorda cords lateral of the adhesion are formed. This leads to the formation of two separate spinal hemicords as well as vertebral anomalies like block or butterfly vertebra. The migration of embryonic mesenchyme in the adhesion results in the development of a fibrous, cartilagenious or bony septum. The location is mostly in the region of the deep thorakal or lumbal spinal cord. There are two different types of diastematomyelia The first typ consists out of a cartelagenious or bony spur with two separate dural tubes. This type is in almost 100% associated with a tethered cord, which means that the spinal conus lies below the 2. Lumbar vertebra. This type has more severe symptoms than the Second type which consists out of a fibrous septum and a common dural tupe for both hemicords. With the second type you find a tethered cord in about 50% of cases. In most cases both hemicords have their own central canal and one ventral and dorsal horn as well as nerve root. Mostly the hemicords unite above and below the cleft. The best imaging method is MRI where you can identify both hemicords well. The separating septum has low signal on T2. If it is ossified as in a typ 2 diastomatomyelia it has a bright signal on T1 and it can also be well visualised on CT. A fibrous or cartilagenious septum would have a low signal on T1 as well. The T1 is also the best sequence to look for associated lesions of the filum terminale like a fibrolipoma as well as vertebral anomalies. In T2 you can best evaluated the numbers of dural tubes and the existence of a possible associated syringohydromyelia. The symptoms can be pain due to vertebral scoliosis. In 50% of cases there will be cutaneous stigmatas like hyperpigmentation or hairy patches. In case of tethered cord there can be neurological symptoms of the lower limbs and urologic dysfunction. Apart from the tethered cord there are other anomalies like a lipoma of the filum terminale, a syringohydromyelia, Chiari-2-malformation, dermal sinus, epidermoid or spinal dysraphism. The associated anomalies determine the spectrum of symptoms.