Closed spinal dysraphism: Clinical manifestations, diagnosis, and management

INTRODUCTION — Neural tube defects are congenital anomalies of neural development with a spectrum of clinical manifestations; they can affect the cranium or spine. They are the second most common congenital disability after congenital heart defects [1].

●Cranial defects include anencephaly, exencephaly, and encephalocele. (See "Primary (congenital) encephalocele" and "Anencephaly".)

●Open spinal dysraphism (spina bifida aperta) is characterized by a cleft in the spinal column, with herniation of the meninges (meningocele) or meninges and spinal cord (myelomeningocele) through the defect. (See "Myelomeningocele (spina bifida): Anatomy, clinical manifestations, and complications" and "Myelomeningocele (spina bifida): Management and outcome".)

●Closed spinal dysraphism (CSD) (also known as occult spinal dysraphism or spina bifida occulta) is characterized by failure of fusion of the vertebral bodies due to abnormal fusion of the posterior vertebral arches, with unexposed neural tissue; the skin overlying the defect is intact. The more common and least severe forms consist of isolated vertebral bony defects. However, the vertebral defects may occur in association with other more severe anomalies of the spinal cord and sacral structures, such as split spinal cord malformation or various cavitary defects of the spinal cord.

This topic will review the clinical manifestations, diagnosis, and management of closed spinal dysraphism. The etiology and different forms of closed spinal dysraphism are reviewed elsewhere. (See "Closed spinal dysraphism: Pathogenesis and types".)

TYPES OF CLOSED SPINAL DYSRAPHISM — The types of closed (occult) spinal dysraphic anomalies are discussed in detail separately. (See "Closed spinal dysraphism: Pathogenesis and types", section on 'Pathogenesis of closed spinal dysraphic anomalies'.)

Briefly, the spinal dysraphic anomalies can be classified into three groups, based on the developmental stage at which they are thought to arise:

●Anomalies of notochord development (see "Closed spinal dysraphism: Pathogenesis and types", section on 'Anomalies of notochord development'):

•Neurenteric cysts

•Split notochord syndrome

•Split spinal cord malformation

•Sacral meningeal cysts or sacral meningocele

•Dorsal dermal sinus tracts and cysts

●Abnormalities of primary neurulation (see "Closed spinal dysraphism: Pathogenesis and types", section on 'Abnormalities of primary neurulation'):

•Syringohydromyelia

•Spina bifida occulta

•Spinal lipomas and teratomas

●Anomalies of the caudal cell mass and secondary neurulation (see "Closed spinal dysraphism: Pathogenesis and types", section on 'Anomalies of the caudal cell mass and secondary neurulation'):

•Tight filum terminale

•Terminal diplomyelia

•Sacrococcygeal teratomas

•Caudal regression or sacral agenesis

Although described separately, more than one dysraphic state commonly coexists in the same patient.

CLINICAL MANIFESTATIONS — The clinical manifestations of closed (occult) spinal dysraphism (CSD) vary widely. The vast majority remains asymptomatic or very minimally symptomatic, such that patients never seek medical care. Others become symptomatic in adulthood. They may then present with spondylosis, degenerative disc disease, congenital and/or spinal stenosis, among others. However, some patients have severe presentations, including neurologic, genitourinary, gastrointestinal, or musculoskeletal anomalies [2-4].

In a retrospective series of 47 cases of symptomatic CSD collected at two university hospitals in the Netherlands, the age at diagnosis ranged from the postnatal period to 14 years (mean age 2 years). The early clinical signs and symptoms in these cases involved the following categories [5]:

●Tethered cord syndrome in 33 patients (70 percent) as manifested by:

•Neurologic abnormalities in the legs (ie, motor weakness, sensory loss, reflex changes, abnormal plantar responses)

•Urologic symptoms (ie, urinary incontinence/retention, urinary tract infections)

•Orthopedic problems (ie, foot deformities, scoliosis, leg length discrepancy, kyphosis)

●Dermatologic lesions in 28 patients (60 percent), as manifested by dimples, hypertrichosis, nevi, hyper/hypopigmentation, and hemangiomas

●Presence of a subcutaneous back mass in 19 patients (40 percent)

The clinical presentation varies to some degree by age. Younger children tend to present with cutaneous markers that lead to an evaluation for CSD [6]. They usually do not present with neurologic symptoms. However, on formal testing, most have mild signs of lower motor neuron dysfunction and abnormalities on urodynamic testing [7,8]. Older children and adolescents tend to present with either cutaneous stigmata or with progressive neurologic deficits. Some affected individuals remain asymptomatic into adulthood, at which time they may develop back pain with or without radiculopathy and perineal dysesthesias [8,9]. Other adults present with enuresis as the primary complaint due to adult primary tethered cord syndrome [10].

Cutaneous — A number of sacrococcygeal cutaneous lesions are associated with CSD (table 1), including fibroma pendulum (skin tag), dermal sinus tracts (picture 1), dimples or pits (picture 2), hypertrichosis, hyperkeratosis, areas of hyperpigmentation or hypopigmentation, hemangiomas (picture 3), pigmentary nevus, capillary malformations (port wine stains), subcutaneous lipomas and less commonly hamartomas, caudal appendages (true tail or pseudotail), and isolated deviation of the intergluteal cleft. One or more such cutaneous lesions are identified in 50 to 90 percent or more of patients with CSD in retrospective reports [5,11-15]. Prospective data are limited, but one prospective study that evaluated 48 children with hemangioma overlying the midline lumbar or sacral spine, most of whom were asymptomatic, found evidence of CSD (intraspinal lipoma or hemangioma, structural malformations of the cord, or tethered cord) by MRI or ultrasound in 21 (44 percent) [16].

Neurologic — The neurologic manifestations in patients with CSD are highly variable. Patients most often present with signs and symptoms related to lumbosacral spinal dysfunction, with autonomic and sphincteric dysfunction being more common and occurring earlier than sensorimotor deficits in the legs [7,17,18]. Less commonly, patients can present with meningitis (image 1) due to a ruptured dermal sinus or cyst [2,19]. Some affected individuals are completely asymptomatic [20].

The nature of the neurologic deficit may be static or progressive, with tethering and cord compression by extradural masses being common causes of progression. Lesions that are asymptomatic in infancy and early childhood may subsequently lead to neurologic deficits if untreated, which stresses the importance of thorough evaluation and early treatment in these patients [20,21].

Autonomic symptoms usually consist of urinary retention or incontinence [18,22], more subtle symptoms such as dysuria or recurrent urinary tract infections [18], or bowel obstruction in infancy or intractable constipation in childhood [2]. Sensorimotor symptoms may include leg weakness, decreased or increased muscle tone, or sensory deficits of the legs and perineal area [18,20,22]. In some cases, sensory loss can lead to atrophic ulceration of the skin.

Tethered cord syndrome — The tethered cord syndrome is caused by a stretch-induced dysfunction of the caudal spinal cord and conus. It can be a presentation of several forms of CSD, including spinal lipomas (image 2), tight filum terminale (image 3), split cord malformations, and the caudal regression syndrome [23]. The constellation of symptoms variably associated with the tethered cord syndrome includes back pain, bladder dysfunction, leg weakness, calf muscle atrophy, diminished or absent deep tendon reflexes, and dermatomal sensory loss [24]. Orthopedic signs include progressive scoliosis and various foot deformities. The pathogenesis of tethered cord syndrome is reviewed elsewhere. (See "Closed spinal dysraphism: Pathogenesis and types", section on 'Tethered cord syndrome'.)

In toddlers and children, tethered cord syndrome typically presents with progressive motor and sensory dysfunction, which may include gait abnormalities and loss of bladder control [25]. Older children and adolescents are more likely to complain of pain in the lumbosacral region, perineum, and legs. The tethered cord syndrome causes spinal dysfunction caudal to the T12/L1 spinal level and does not explain upper motor neuron signs. Therefore, patients should be evaluated for more proximal cord lesions if upper motor neuron signs (eg, spasticity or hyperreflexia) are present [17].

In the classic progression of symptoms with tethered cord syndrome, children begin to stumble after they have learned to walk normally [26]. Then they start dribbling urine after having achieved successful toilet training. Later, they develop musculoskeletal signs and symptoms; common findings include foot drop, painless sores, and scoliosis. Older children will often complain of back pain exacerbated by exercise, while younger children tend to have increased irritability and refuse to perform certain activities and movements, though without a frank complaint of pain.

Back pain, leg pain, and scoliosis are the primary symptoms of tethered cord syndrome in adults, and these may be difficult to distinguish from other more common causes of chronic back pain [27]. The earliest sign of motor dysfunction in the older child and adult with tethered cord syndrome is usually weakness of ankle dorsiflexion [28]. Sensory symptoms usually are patchy and vague, especially when related to tethered cord syndrome.

Urologic — In childhood, the most common cause of neurogenic bladder is spinal dysraphism [29]. However, the true prevalence of urologic involvement with CSD is unknown, and the diagnosis of bladder dysfunction is often delayed, particularly for pretoilet trained children. The problems are illustrated by the findings from a tertiary center that reported a series of 51 children with CSD, ages 6 months to 10 years (mean age 3 years) [30]. These patients were referred for a variety of reasons:

●Urinary tract problems, 25 patients:

•Incontinence, 17

•Recurrent urinary tract infections, 6

•Abnormal renal tract investigations at other hospitals, 2

●Neurologic deterioration, 12 patients

●Dermatologic abnormality overlying the lower spine, 8

●Videourodynamic assessment following spinal surgery, 5

●Fecal incontinence, 1

Of note, many of the children had normal or near-normal mobility, and in many cases bladder difficulty was not recognized before toilet training. The neurologic examination was normal or had only minor objective abnormalities in 33 patients. The spinal lesions predominantly involved lumbar or sacral levels and consisted of the following types of CSD [30]:

●Tethered cord (29 patients) secondary to:

•Intraspinal lipoma, 13 patients

•Diastematomyelia, 4

•Lipomeningocele, 4

•Syrinx, 2

•Other lesions, 6

●Meningocele, 7 patients

●Sacral agenesis, 5

●Tethered cord with no other intraspinal abnormality, 4

●Dysraphism and intraspinal lipoma, 2

●Syrinx, 2

●Dysraphism, 1

●Lipomeningocele, 1

Ultrasound of the renal tract was normal in 21 children; abnormal findings included dilated upper renal tracts, postmicturition residual volume, thickened bladder walls, unilateral small kidney, and renal scars [30]. Videourodynamic studies were abnormal in 49 of the 51 patients, with the following types of dysfunction:

●Detrusor hyperreflexia in 42 patients

●Incomplete bladder emptying in 35

●Detrusor sphincter dyssynergia in 22

●Decreased bladder compliance in 21

●Vesicoureteric reflux in 13

●Fixed (nonrelaxing) distal sphincter in 5

●A combination of two or more abnormalities in 31

These data suggest that children with CSD are at risk for neurogenic bladder dysfunction and kidney injury; neither the history of voiding habit nor the clinical neurologic examination is a reliable predictor of urologic problems [30].

Musculoskeletal — Orthopedic problems that may occur with CSD include scoliosis, kyphosis, lordosis, leg length discrepancy, and foot deformities [22,26,28,31,32].

The simplest form of CSD is posterior spina bifida (ie, a fusion defect of the posterior neural vertebral arch), which most commonly occurs at L5 or S1 [23]. This finding may be incidental and clinically asymptomatic or may be associated with signs of cord tethering, in which case it is suggestive of an additional CSD.

In patients with split spinal cord malformations (diplomyelia and diastematomyelia), complex abnormalities of the spinal column can occur, including hemivertebral agenesis or hypoplasia, vertebral body splitting in the sagittal plane, narrowing of the intervertebral space, and fusion of multiple spinal segments [3,33]. Distorted posterior spinal elements may be present, including bifid laminae or posterior fusion.

In patients with caudal regression syndrome, the distal sacrum and coccyx may be absent [34].

Other malformations — Some patients with CSD have associated anorectal malformations (eg, imperforate anus) or urogenital malformations [2,35,36].

Pain — Pain related to CSD usually is reported in the lower back, sacrococcygeal or gluteal areas, with or without a radicular pattern [18,20,37]. Pain may be exacerbated with Valsalva maneuver in the cases of lesions that are in communication with the subarachnoid space, such as Tarlov cysts [18,38].

EVALUATION AND DIAGNOSIS — The diagnosis of closed spinal dysraphism (CSD) is suggested by the typical associated clinical findings (see 'Clinical manifestations' above), particularly the presence of cutaneous stigmata, a subcutaneous mass in the back, or neurologic symptoms consistent with the tethered cord syndrome. The diagnosis is confirmed by radiologic demonstration of a spinal dysraphic lesion.

Given the evidence reviewed below, we recommend evaluation with MRI of the entire spine for infants and children who have two or more cutaneous lumbosacral spine lesions, a subcutaneous back mass, or neurologic symptoms suggestive of tethered cord syndrome. We suggest MRI of the spine for neurologically asymptomatic infants and children who have an isolated midline cutaneous lumbosacral spine lesion that is potentially high-risk for the development of CSD. These cutaneous lesions include atypical dimples (those >5 mm in size or located >2.5 cm from the anus), hemangiomas, cutis aplasia, and upraised lesions (ie, masses, tails, and hairy patches).

Examination — Evaluation for CSD starts with a thorough history and examination. This should include a rectal exam to evaluate for cloacal abnormalities and presacral masses [2].

In the presymptomatic or mildly symptomatic patient, it is important to detect the subtle clues that suggest an underlying spinal dysraphism [17,28,39]. This is difficult in younger patients who may not be able to express symptoms and who may not have achieved continence and ambulation. Such children may only show asymmetric postures or movements, or mere irritability. In addition, some will have fluctuating symptoms, which makes their diagnosis even more challenging [28]. Such cases highlight the importance of objective signs suggesting CSD, particularly midline cutaneous lesions over the lumbosacral spine (table 1) [18,20,22,28,40]. Since these cutaneous lesions are the most obvious marker of CSD, it is understandable that they are less prevalent or obvious in patients who present in adolescence or adulthood [20].

In most studies, which are largely retrospective, the presence of two or more congenital midline skin lesions implies a higher risk of associated CSD than an isolated cutaneous lesion [41-43]. As an example, in a large series of congenital lumbosacral lipomas, the frequency of dysraphic states in patients with an isolated cutaneous lesion was low (eg, none of 14 patients with an isolated cutaneous angioma) [20].

Whether all isolated cutaneous lesions require further evaluation for CSD in neurologically asymptomatic neonates and children is controversial. Nevertheless, certain isolated cutaneous lesions in asymptomatic neonates may be high-risk for CSD [43]. These include atypical dimples, particularly those that are large (>5 mm) or located >2.5 cm above the anus, hemangiomas, cutis aplasia, and upraised lesions (ie, masses, tails, and hairy patches) [42]. In the clinical experience of some experts, hemangiomas of infancy (vascular tumors) have a higher risk of CSD compared with midline capillary malformations [44,45].

The finding of a dimple associated with deviation of the intergluteal cleft should raise suspicion for a low-lying coccygeal lipoma not detected by palpation [20,46]. One prospective series obtained spinal MRI for children less than two years of age (mean age four months) with sacrococcygeal dimples [46]. Among 47 cases with dimples located at the upper edge of a deviated (ie, curved or deformed) gluteal crease, a spinal deformity of CSD was present on MRI in 45 percent. A high rate of CSD (50 percent) was found also among 16 children with dimples located above the gluteal crease, which were sometimes associated with skin pigmentation or a duplicated gluteal crease. Even among 65 children with dimples located within a straight gluteal crease, CSD was present in 17 percent.

Imaging — Imaging is an essential part of the evaluation for CSD.

●Imaging modalities – The optimal study for characterization of intraspinal and perispinal anomalies associated with CSD is MRI of the entire spine (image 2 and image 3), particularly since multiple abnormalities are often present in affected individuals [2,9,17,21,23,35,39,47].

During prenatal and early postnatal development, the conus medullaris (the most caudal end of the spinal cord) gradually shifts to a higher level, and reaches its final position at or above the L2/L3 intervertebral disc by approximately two months of age [48,49]. The finding of an anatomically low conus medullaris may be the only sign of occult tethered cord syndrome. While some reports indicate that the tethered cord syndrome can occur even in cases where the conus appears at a normal spinal cord level on MRI [50,51], there is no universally accepted definition or diagnostic criteria for tethered cord syndrome [24].

Plain radiographs are useful for detecting vertebral defects [3]. CT is also useful when the evaluation for bony abnormalities is important, especially thin-section, multi-planar CT with reformatted images [47].

In many cases, prenatal ultrasonography of the spine can identify spinal anomalies, especially if large enough [52,53]. However, some studies suggest the sensitivity of spinal ultrasound, even when performed before the age of four months (ie, prior to ossification of the posterior elements of the spine), is suboptimal for the detection of CSD [16].

●Imaging criteria – Prenatal ultrasound criteria proposed in 2021 included fetal conus medullaris position to improve the CSD detection rate. These also apply to prenatal MRI if one is done. Based on an 11-year experience, they classify closed spinal dysraphism into three classes [54]:

•Class 1 – Isolated low-lying conus (below L3)

•Class 2 – Low-lying conus with a lump on the dorsal side (echogenic or cystic lesions)

•Class 3 – Caudal regression syndrome or low-lying conus with additional major spinal defects (scoliosis, kyphosis)

Another group has proposed a sonographic algorithm to distinguish the spinal bones, even in the face of significant deformity, with the ongoing goal of developing a computer-assisted diagnosis system for CSD [55,56].

Urodynamics — Urodynamic testing can detect preclinical urologic dysfunction in children with CSD. Urodynamic testing is often used for preoperative evaluation of children who might benefit from neurosurgery for tethered cord release [57]. In a retrospective study of 123 children with cutaneous stigmata of CSD, abnormal urodynamic studies were present in 23 (19 percent). The determination of abnormal bladder function was based upon bladder capacity, bladder compliance, and level of detrusor activity (contractions) during filling. In the same study, spinal MRI was abnormal in 85 percent, suggesting its greater utility.

The method of urodynamic testing in children is reviewed separately. (See "Evaluation and diagnosis of bladder dysfunction in children", section on 'Urodynamic testing'.)

Ultrasound of abdomen and pelvis — Ultrasound of the abdomen and pelvis can assess the urinary system for pathologic changes such as a thickened bladder wall (suggesting detrusor hypertrophy), incomplete bladder emptying, upper tract dilatation, small kidney size, and renal scars [9]. However, these changes are nonspecific for the diagnosis of CSD.

TREATMENT — Surgery is considered the mainstay of treatment for closed spinal dysraphism (CSD) [8,20], although there are no data from randomized controlled trials to support or refute the efficacy of surgery. Patients with impairments due to neurologic deficits, bladder dysfunction, or chronic pain may benefit from physical and occupational therapy [26]. Surveillance and monitoring is needed to detect new or progressive deficits.

Surgery

●Interventions – Different types of surgical interventions are used to treat CSD [20,32]:

•Spinal neurosurgery aimed at altering the natural course of the disease, preventing further neurologic deterioration, and relieving, as much as possible, presurgical neurologic deficits.

•Surgeries to correct various comorbid conditions associated with CSD, such as urinary retention, incontinence, impotence, constipation, anorectal malformations, tumors, and dorsal cutaneous lesions. These interventions involve the fields of urologic, gastroenterologic, colorectal, oncologic, plastic, and general surgery. Urologic surgery for urinary incontinence includes implantation of an artificial urinary sphincter [58], and bladder augmentation surgery [59].

In CSD cases associated with cord tethering, surgery involves removal of any anatomic structure that is acting to tether the spinal cord and may include transection of the filum, resection of transitional lipoma, lysis of adhesions, and excision of dermal sinus tracts [32]. In addition, some data suggest that fashioning a large intradural compartment, with duraplasty if needed, is associated with a reduced risk of developing arachnoid adhesions and cord retethering [20].

●Indications – Although no clear consensus exists, the main indication for neurosurgery is new onset or progression of neurologic symptoms related to the CSD or tethered cord syndrome. Early neurosurgical intervention also is warranted for severe neonatal symptoms such as bowel obstruction. Additional indications for neurosurgical intervention include cases where the spinal cord is internally exposed, such as with intrasacral meningocele, to decrease the risk of infection and meningitis [20,39,40], and patients who need vertebral stabilization or pain relief [20,37,39,40]. In contrast, severely disabled patients with static deficits related to CSD are unlikely to benefit from surgery [8]. One series reported that such patients did not improve even when operated in infancy [17].

More controversial indications for surgical intervention include radiographic demonstration of a tethered cord (ie, conus medullaris lower than the L2/L3 intervertebral disc) in asymptomatic patients, or abnormal findings on urodynamic studies in a patient with CSD. The rationale for surgery in such cases is that even infants and children who are asymptomatic or mildly symptomatic may go on to develop progressive and irreversible neurologic deficits. Therefore, we suggest that all children with radiologically confirmed spinal dysraphism be referred for neurosurgical evaluation, especially if there is cord tethering, which untreated can lead to progressive neurologic deficit [2]. Conservative management with watchful monitoring is also an acceptable approach in patients who are asymptomatic or mildly symptomatic, given the highly variable natural history of CSD. (See 'Prognosis' below.)

Another controversial surgical aspect is whether untethering improves an associated syrinx. Limited evidence suggests that presence of a syrinx should not be taken into consideration when deciding on untethering surgery. A retrospective study identified 25 children over an 11-year span who had tethered cord and syrinx and had undergone detethering surgery [60]. Over an average follow-up of 8.4 years, radiologic reduction in syrinx size was inconsistent among the included patients, and change in syrinx size did not correlate with a change in clinical symptoms.

●Complications – Potential complications of surgery for CSD include cerebrospinal fluid leaks, wound infection, meningitis, bladder and bowel dysfunction, and neurologic injury [32]. The rate of neurologic injury is reported to be low (<1 percent) for some types of surgery such as filum terminale transection but can be much higher with surgery for other causes of cord tethering.

Monitoring — Asymptomatic patients with CSD who do not have surgery still require close monitoring to watch for the onset of neurologic, genitourinary, or gastrointestinal symptoms, especially with respect to incontinence or constipation. Patients who have surgery for CSD should remain under close monitoring because of the risk of future worsening, which can occur with spinal cord retethering or progression of a preexisting syrinx [20,21]. The earliest indication of retethering is usually urologic symptoms [28]. In addition, non-neurological symptoms may continue to progress postoperatively, as can be seen with preexisting scoliosis and pain [21,27].

For patients who do not require surgery, close monitoring of bladder and bowel function is needed to monitor for neurogenic bladder/bowel dysfunction. Extrapolating from patients with open spina bifida, spontaneous voiding is associated with a lower risk of urinary tract infection compared with continuous intermittent catheterization (CIC) [61]. However, despite an elevated risk of urinary tract infection (up to 80 percent), early CIC and conservative management (such as anticholinergic drugs for detrusor overactivity) preserves renal function in up to 90 percent of patient [29]. (See "Myelomeningocele (spina bifida): Urinary tract complications".)

Urodynamics are generally considered to be a good monitoring tool for both nonoperative patients and postoperative patients, and particularly for early detection of cord retethering. As an example, one series of 15 patients with split spinal cord syndrome were evaluated with urodynamic studies before and after surgery [7]. While nearly all of the patients lacked preoperative urological symptoms, most (11) had abnormal preoperative urodynamic findings. In addition, patients who deteriorated after surgery had worsening on urodynamic studies prior to progression of other symptoms.

Prevention — Managing risk factors in pregnancy should be instituted for all expecting mothers. (See "Closed spinal dysraphism: Pathogenesis and types", section on 'Risk factors'.)

In addition, preliminary data suggest that supplementation with myo-inositol may reduce the risk of recurrence in cases unresponsive to folic acid [62].

PROGNOSIS — The natural history of closed (occult) spinal dysraphism (CSD) is poorly studied. Reported outcomes are highly variable, and likely depend on the severity of the deficits at presentation as well as the nature and extent of the anomaly [2,20,63]. With watchful observation and conservative management, some patients remain stable for years [8], spontaneously improve [63], or have radiologic regression of spinal lipomas [64]. While some reports suggest that neurologic deterioration occurs in up to 75 percent of patients with tethered cord syndrome [65], others have found a much lower rate. As an example, one retrospective study reported 53 children with asymptomatic lipomas of the conus who were monitored during conservative management. Over a mean follow-up period of 4.4 years, neurologic deterioration was observed in 13 patients (25 percent) [66].

Estimates of long-term outcomes following neurosurgery for CSD are based mainly upon evidence from uncontrolled, retrospective, single-center case series. These data suggest that neurosurgery for CSD, most often release of a tethered cord, is associated with some degree of improvement in 33 to 90 percent of patients, and complete resolution of symptoms in occasional cases [9,20,35,67-70]. On the other hand, postoperative worsening has been reported in up to 13 percent of patients [9]. The inconsistency in reported outcomes is likely related to substantial differences among surgical studies with regard to types of patients (eg, children or adults with a range of spinal anomalies and symptoms), neurosurgical techniques, outcome assessments, and multiple other uncontrolled variables. Some studies suggest that patients with recent onset of symptoms tend to have a more complete resolution while those with long-standing symptoms tend to are less likely to exhibit meaningful improvement [8,26].

Patients who undergo surgery for tethered cord need continued follow-up (see 'Monitoring' above) because of the risk of postsurgical retethering [2,20,22]. This risk is related in part to the type of CSD associated with the initial tethering, and is considered to be higher with a split cord malformation or a transitional lipoma than with a thickened filum or lipomatous infiltration [32].

Finally, perception of disability in patients living with spina bifida has a direct bearing on their well-being. A qualitative study from South Africa looking at adolescents and their caregivers identified several positive promoters of well-being: family support, social support, special needs education, sports participation, independence, and "finding meaning in life" [71]. It also identified negative physical factors, including lack of resources, lack of access to medical care, and mobility challenges; and negative social factors, including bullying, harmful friendships, shame, secrecy, social isolation, and overall unhappiness.

SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Congenital malformations of the central nervous system".)

SUMMARY AND RECOMMENDATIONS

●The clinical manifestations of closed (occult) spinal dysraphism (CSD) vary widely and range from benign or asymptomatic to severe neurologic, genitourinary, gastrointestinal, or musculoskeletal anomalies. Common manifestations include tethered cord syndrome, cutaneous lesions, and presence of a subcutaneous back mass. (See 'Clinical manifestations' above.)

●A number of sacrococcygeal cutaneous lesions are associated with CSD (table 1), including dermal sinus tracts, dimples or pits, hypertrichosis, hyperkeratosis, areas of hyperpigmentation or hypopigmentation, hemangiomas, capillary malformations (port wine stains), subcutaneous lipomas, caudal appendages (true tail or pseudotail), and isolated deviation of the intergluteal cleft. (See 'Cutaneous' above.)

●The neurologic manifestations in patients with CSD are highly variable. The tethered cord syndrome can be a presentation of several forms of CSD. The constellation of symptoms variably associated with the tethered cord syndrome includes back pain, bladder dysfunction, leg weakness, calf muscle atrophy, diminished or absent deep tendon reflexes, and dermatomal sensory loss. Orthopedic signs include progressive scoliosis and various foot deformities. (See 'Neurologic' above and 'Tethered cord syndrome' above.)

●Closed spinal dysraphism is sometimes associated with neurogenic bladder dysfunction, with or without tethered cord syndrome. However, the true prevalence of urologic involvement with CSD is unknown, and the diagnosis of bladder dysfunction is often delayed, particularly for pretoilet trained children. (See 'Urologic' above.)

●The diagnosis of CSD is suggested by the typical associated clinical findings (see 'Clinical manifestations' above), particularly the presence of cutaneous stigmata, a subcutaneous mass in the back, or neurologic symptoms consistent with the tethered cord syndrome. The diagnosis is confirmed by radiologic demonstration of a spinal dysraphic lesion. (See 'Evaluation and diagnosis' above.)

●We recommend evaluation with MRI of the entire spine for infants and children who have two or more cutaneous lumbosacral spine lesions, a subcutaneous back mass, or neurologic symptoms suggestive of tethered cord syndrome. We suggest MRI of the spine for neurologically asymptomatic infants and children who have an isolated midline cutaneous lumbosacral spine lesion that is potentially high-risk for the development of CSD. These cutaneous lesions include atypical dimples (those >5 mm in size or located >2.5 cm from the anus), hemangiomas, cutis aplasia, and upraised lesions (ie, masses, tails, and hairy patches). (See 'Evaluation and diagnosis' above and 'Imaging' above.)

●Surgery is considered the mainstay of treatment for CSD, although there are no data from randomized controlled trials to support or refute the efficacy of surgery. We suggest referring all children with radiologically confirmed spinal dysraphism for neurosurgical evaluation, especially if there is cord tethering. Conservative management with watchful monitoring is also an acceptable approach in patients who are asymptomatic or mildly symptomatic, given the highly variable natural history of CSD. In CSD cases associated with cord tethering, surgery involves removal of any anatomic structure that is acting to tether the spinal cord. Surgical fashioning of a large intradural compartment, with duraplasty if needed, may reduce the risk of cord retethering. Potential complications of surgery for CSD include cerebrospinal fluid leaks, wound infection, meningitis, bladder and bowel dysfunction, and neurologic injury. (See 'Surgery' above.)

●The natural history of CSD is poorly studied. Reported outcomes are highly variable, and likely depend on the severity of the deficits at presentation as well as the nature and extent of the anomaly. Estimates of long-term outcomes following neurosurgery for CSD are based mainly upon evidence from uncontrolled, retrospective, single-center case series. (See 'Prognosis' above.)