Occult spinal dysraphisms in newborns with skin markers: role of ultrasonography and magnetic resonance imaging

Abstract

LUS in newborns with specific skin markers is a valid method to select patients in which MRI can be performed to detect OSD. The presence of a simple sacral dimple alone is a negligible marker for occult neural pathology while the presence of isolated dermal sinus or more than one cutaneous marker could be considered indicative of higher risk of spinal dysraphism.

Cutaneous markers of occult spinal dysraphism

“…MRI is the gold standard for diagnosing OSD, but ultrasound screening can be acceptable in young infants with low-risk lesions. 1,2 In this case, the caudal appendage and the combined cutaneous markers conferred a high risk for OSD. 1,2 Spinal dermal sinuses are often associated with a tethered spinal cord and/or inclusion tumors and predispose to an increased risk for cerebrospinal fluid infection and Figure 1 Pseudotail, deviated gluteal cleft, and paraspinal hypopigmented macula.…”

Determining the optimal timing of screening spinal cord ultrasonography to detect filum terminale lipoma in infants

“…It is well-recognized that spinal cord US can be used as an easy screening tool for the detection of filum terminale lipoma by measuring the thickness of the filum terminale in young children. There is an increasing demand for screening spinal cord US to detect intraspinal abnormalities [9,10,25]. Although US cannot replace MRI for a definite diagnosis, it can be used to screen infants with skin stigmata, VACTERL syndrome, and urological or gait abnormalities, and to select infants who need lumbosacral MRI [9,25].…”

“…Explanations about the optimal timing of spinal cord US have been proposed in several previous studies. One group explained that spinal cord US is most useful in infants up to 6 months of age before the spine ossifies; this group performed US in infants up to 1 month of age [25]. Another study involved spinal cord US in infants up to the ninth week of age [9].…”

Do all newborns with an isolated sacrococcygeal dimple require investigation for spinal dysraphism?

“…Sacral cutaneous abnormalities are found in 2.2%–7.2% of all neonates 2. These can be associated with occult spinal dysraphism, which encompasses a variety of skin-covered neural tube defects such as dorsal dermal sinus or lipomyelomeningocele.…”

“…They are isolated if they are not associated with other sacral cutaneous abnormalities. This critical appraisal of the scientific literature shows that there is a substantial body of evidence to suggest that isolated simple sacrococcygeal dimples are rarely associated with spinal dysraphisms, if at all, and therefore they should not warrant routine imaging 1 2 5 6. Conversely, the presence of a combination of two or more lesions (eg, dimple and haemangioma) has been associated with a higher risk of spinal dysraphism, and should therefore be investigated 7.…”