Diastematomyelia is a condition occurring in the congenital stage where the upper lumbar part of the spinal cord splits. This is a subtype of spinal dysraphism. The spinal dysraphism is a group of congenital anomalies where it originated in the embryo specifically the dorsum part. This condition is also associated with diplomyelia but in dyplomyelia, cord has a duplicate rather than it being split.
In diastematomyelia, the splitting of the cord is in a sagittal or longitudinal direction. The “splitting” can either be partially or completely amongst the “hemicords”. What happens is that there is a split in the middle of the hemicord and then the two will reunite in the lower part of the cord.
The severity of the problem can vary so the signs and symptoms can also vary. The cords the split usually lie in the same covering like the dura and the arachnoid layer. But there are also cords that completely split even though they have different coverings or layers. According to studies, females are more affected and the cord that splits are usually occurs when there is a fibrous or cartilaginous septum in spinal cord.
The progression of the problem is of unknown origin thus it s called a “dysraphic state”. Most of the time, the diastematomyelia happens in the 9th thoracic area and the 1st sacral area of the spine. In the sacral area, the point of origin mostly happens in the lumbar vertebra in the upper portion. It is very seldom that the problem occurs in the cervical area.
The Spinal Cord
This is a part of the central nervous system or CNS along with the brain. This is a long and thin with bundles of nervous tissues and cells. It measures about 45 centimeters in men and 43 centimeters in women. More specifically, the thickness of the cord varies. The cervical and lumbar regions of the cord measures ½ inch. The thoracic area measures ¼ inch thickness. The cord is enclosed with the vertebral column.
There are 31 pairs of the spinal nerve and these are:
- 8 cervical pairs
- 12 thoracic pairs
- 5 lumbar pairs
- 5 sacral and
- 1 coccygeal pair
The cervical cord to the T1 or first thoracic pair supplies function to the upper extremity while the L1 to the S2 parts of the cord supplies the lower extremities. Thus, in cases of diastematomyelia the problem is mostly in the lower parts of the body.
Types of Diastematomyelia
- Type 1 or the dual dural sac. There is a spur in the middle of the sac and the problem is symptomatic. Some of the defining characteristics of this type include having a midline spur or osteorcartilaginous cord, some vertebral problems like spina bifida, butterfly vertebrae as well as hemivertebae. The patient may manifest symptoms like skin pigmentation and they are also present symptoms the same as having scoliosis.
- Type 2 or the single sac. This is the type that contains hemicords and the physical impairment is less noticed. In this case. The cord is either divided partially or completely and hydromyelia is also suspected but not all the time. Patients may also have spina bifida but it is not very common.
Diastematomyelia Signs and Symptoms
What is interesting in this problem is that the signs and symptoms may appear anytime however the diagnosis can be made during childhood years. Some of the signs and symptoms include:
- Stigmata or having cutaneous lesions. This include having subcutaneous mass, hemangioma, dimples, hairy patches, teratoma or lipoma
- Spinal deformities
- Weakness in the lower part of the body
- Lower back pain
- Scoliosis or signs and symptoms of scoliosis
- Urinary incontinence
- Loss of bladder and even bowel control
- Motor as well as sensory problems
- Tethered spinal growth symptoms which may be because of the improper or abnormal growth of the neural tube linked during
- the fetal development.
The problem is usually detected during prenatal ultrasound. That is why adult detection is rarely to happen but there are cases that it still happens. According to research 25% of the time, the diastematomyelia happens in the T7 and T12 while 50% of the time happens on L1 and L3. There are also other problems seen like spina bifida, hemivertebrae or the butterfly vertebrae detected.
Other diagnostic imaging test are done like MRI or Magnetic Resonance Imaging to help give proper view and analysis of the problem. CT scan can also be performed where it gives proper view of the bones, extra and intradural pathology of the problem.
During prenatal ultrasound, the diastematomyelia is detected during the third-trimester. The results show whether the problem is isolated or if there are neural tube defects involved.
For those patients diagnosed with diastematomyelia but is asymptomatic, there is no immediate surgical intervention needed. However, the patient is subjected to regular neurological assessment and routine check-ups to see if the condition deteriorates or not.
If the patient shows signs and symptoms of the problem, then immediate surgical intervention is needed. This should be done to avoid deterioration and worsening of the problem. The surgical treatment depends on the manifestation of the problems. The main goal of the surgery is to correct the problem for motor functions and other body functions to go back to normal.
Decompression surgery is one of the most common operations performed in cases of Diastematomyelia. This includes removal of the bony spur and sometimes the dural sac may or may not be repaired or resectioned. This procedure is mainly done to help alleviate the tension amongst the spinal cord which will create uncomfortable feeling to the patient.
It is also best for the family and patients to ask for second opinion and other recommendation for the problem. This is because the manifestations of the problems vary depending on the patient. This means that there are different treatment plans involved. There are cases where the manifestation is unique and it does not involve only 1 or 2 attending physicians. This is to ensure that the team looks for the welfare of the patient.