What are the clinical features of spina bifida occulta?

Clinical Features of Spina Bifida Occulta

Spina bifida occulta presents with a wide spectrum of clinical features ranging from asymptomatic findings to significant neurological and urological dysfunction, with symptoms often appearing in late childhood or adulthood. 1

Neurological Manifestations

• Patients with spina bifida occulta typically present with dominant upper motor neuron signs, in contrast to the cystic form which shows predominantly lower motor neuron signs 1
• Chronic low back pain that may radiate to the legs is a common presenting symptom, which can be misdiagnosed as routine back pain for years before proper diagnosis 2
• Tethered cord syndrome is a significant concern requiring continued surveillance in all patients with occult spina bifida 3
• Some patients may present with unpredictable neurological deficits that can progress over time if left untreated 2
• Symptoms may be subtle or absent until adulthood, making diagnosis challenging 4

Urological Manifestations

• Urinary symptoms may be the sole initial complaint in up to 33% of patients with occult spina bifida, with no other obvious neurological abnormalities 1
• Common urodynamic abnormalities include:
  • Detrusor hyperreflexia during bladder filling (42% of cases) 1
  • Low compliance detrusor (67% of cases) 1
  • Detrusor-sphincter dyssynergia (27% of cases) 1
  • Impaired bladder sensation (8% of cases) 1
• Regular urodynamic testing is recommended to detect bladder dysfunction before upper tract changes develop 3
• Urinary incontinence and enuresis are common manifestations that can persist into adulthood 1

Bowel Dysfunction

• Fecal incontinence can have an even greater impact on quality of life than urinary incontinence due to more noticeable odor 5
• Approximately 50% of patients can achieve bowel control with dietary modifications, laxatives, suppositories, and/or manual evacuation 5
• More severe cases may require retrograde enemas (75% success rate) or surgical interventions like the Antegrade Continence Enema (MACE) procedure (77% success rate for complete or near-complete fecal continence) 5

Radiological Features

• Spina bifida occulta is characterized by incomplete fusion of the posterior elements of the vertebrae, most commonly in the lumbosacral region 6
• The condition can rarely occur in other regions such as the cervicothoracic spine 7
• MRI examination is essential for characterization of intraspinal and perispinal abnormalities, especially in cases of chronic lower back pain that fail to improve with standard management 2

Important Clinical Considerations

• There is significant controversy regarding the causal relationship between radiological findings of spina bifida occulta and lower urinary tract dysfunction 6
• Some studies suggest spina bifida occulta may be a coincidental finding in children with lower urinary tract and bowel dysfunction 6
• Chronic kidney disease due to poor bladder dynamics represents a serious long-term complication requiring proactive management 3
• Transition of care from pediatric to adult services is extremely important for patients with spina bifida occulta to ensure continuity of management 3
• Surgical intervention is indicated for those at risk for renal deterioration or who fail to achieve satisfactory continence with medical management 3

Treatment Considerations

• Early and regular urodynamic testing with clean intermittent catheterization (CIC) and/or pharmacotherapy should be initiated before development of upper tract changes 3
• Intraoperative neurophysiological monitoring can assist in identifying the appropriate level for decompression in patients requiring surgical intervention 2
• Major reconstructive urological surgeries may be necessary to protect the upper urinary tract and achieve continence 3
• Comprehensive management should focus on promoting independence early in childhood to improve outcomes in adulthood 8