Risk of occult spinal dysraphism based on lumbosacral cutaneous manifestations

Occult spinal dysraphism is a congenital failure of fusion of the posterior vertebral arches with intact skin overlying the defect. Lumbosacral cutaneous manifestations are associated with a variable risk of occult spinal dysraphism. Tethered cord syndrome is a type of occult spinal dysraphism that puts abnormal traction on the spinal cord. This study analyzed neonates and infants who were referred to our pediatric urology practice and had evidence of lumbosacral cutaneous manifestation on physical examination.

We reviewed the presence of lumbosacral cutaneous manifestations in neonates and infants evaluated in our pediatric urology clinic at our Institution over a 6-year period (1 March, 2015-28 February, 2021) with no prior diagnosis of lumbosacral cutaneous manifestation. All patients underwent a spinal ultrasound.

The most common lumbosacral cutaneous manifestations were bifurcated/duplicated gluteal folds (33%), gluteal asymmetry (19%), and sacral dimples (14%). A total of 34 (24%) patients had an abnormal spinal ultrasound; 15 (44%) of these infants underwent a lumbar magnetic resonance imaging. A coccygeal pit was statistically marginally higher in abnormal versus normal spinal ultrasound (p = 0.07). Patients with only one lumbosacral cutaneous manifestation (N = 121) were significantly more likely to have a normal spinal ultrasound compared to those with two or more lumbosacral cutaneous manifestation (N = 17) (79% vs 53%, p = 0.03).

Due to the varying risk of certain lumbosacral cutaneous manifestations with occult spinal dysraphism, all patients with a lumbosacral cutaneous manifestation should undergo spinal ultrasound. This study also highlights the importance of urodynamic studies when there are abnormal cutaneous findings. Routine physical examinations of the lumbar region for cutaneous manifestations of occult spinal dysraphism are vital to ensure prompt management of tethered cord syndrome and avoid potentially devastating consequences.