The significance of cutaneous spinal lesions is related to there association with spinal dysraphism. This is defined as an absent or incomplete fusion of the bony spinal column. Spina bifida aperta are posterior protrusions of neural tissue such as meningomyeloceles. Occult spinal dysraphism including meningoceles and tethered cords may not be recognized on physical examination and diagnostic imaging may be necessary to detect them. Cutaneous lesions may be predictors of these occult malformations and progressive neurologic deficits may be preventable by early diagnosis and neurosurgical correction. An important part of the neworn examination is the inspection of the lumosacral region and buttocks.
Midline lumbosacral skin lesions
1. Tufts of hair
2. Lipomas. These are soft subcutaneous masses
3. Dimples. Dimples below the intergluteal crease end blindly and are not connected to the spinal cord. Some above the crease have tracts leading to the spinal cord and may lead to the development of meningitis with unusual organisms, neurologic deficits, and tethering of the cord. All patients with meningitis should have a thorough inspection of their backs.
6. Skin hypertrophy or atrophy
7. Hyperpigmentation and hypopigmention of the skin
8. Skin tags
Greater than 50% of patients with tethered cords have an isolated cutaneous lower back lesion. Tethered cords are often asymptomatic until the child is ambulatory or presents with neurologic deficits. At birth, the conus is at the L-3 level and reaches the adult level ( L1-L2) at about 3 month of age. If the cord is tehtered, it is unable to ascend normally and blood supplies to the cord are compromised and ischemic changes result . Children may present with pain in the lower extremities, a limp, atrophy of an extremity, sensory abnormalities, urinary incontinence, and bowel difficulties. The bilateral nature of the symptoms and multiple levels of involvement, may be clues to the diagnosis. Prompt neurosurgical referral is suggested.
Diagnosis of Spinal Dysraphism
1. Careful examination of midline back of all newborns
2. Palpation of the lower spine and feel for incomplete fusion of the bony spine
3. Bladder abnormalities such as failure to urinate and empty the bladder completely
4. Unexplained constipation
5. Disparity of growth of the legs or neurological findings in the lower extremities including sensory abnormalities
6. Ultrasound of the the lower back is an effective noninvasive screening tool. May follow up with a CT scan or MRI.
7. Neurosurgical referral
1. It is recommened that women of reproductive age take 0.4 mg of folic acid daily to decrease the risk of defects.