Caudal regression syndrome

Overview

Caudal regression syndrome (CRS), also known as sacral agenesis, is a rare congenital disorder that affects the development of the lower (caudal) end of the spine. The condition results in partial or complete absence of the sacrum and, in more severe cases, the lumbar spine. CRS can also affect the spinal cord, lower limbs, genitourinary tract, and gastrointestinal system. The severity of the condition varies widely, ranging from mild abnormalities to profound structural and functional impairments.

Causes

The exact cause of caudal regression syndrome is not fully understood, but several contributing factors have been identified:

• Maternal diabetes: One of the most strongly associated risk factors; CRS is more common in infants born to mothers with poorly controlled pregestational diabetes

• Genetic and environmental factors: Though no single gene has been definitively linked, a combination of genetic susceptibility and environmental triggers is suspected

• Vascular disruption theory: Some researchers suggest that an interruption in blood supply to the lower developing embryo contributes to the syndrome

CRS typically arises sporadically, but rare familial cases have also been reported.

Symptoms

The symptoms and severity of CRS can vary greatly depending on the extent of spinal and organ involvement. Common features include:

• Partial or complete absence of the sacrum and lower spine

• Lower limb deformities: Including clubfoot, shortened legs, hip dislocation, or joint contractures

• Abnormal gait or inability to walk

• Neurological deficits: Weakness, paralysis, or absent reflexes in the lower limbs

• Bladder and bowel dysfunction: Incontinence or retention due to nerve involvement

• Anal atresia or imperforate anus

• Renal and genitourinary anomalies: Including horseshoe kidney, vesicoureteral reflux, or genital malformations

• Spinal cord tethering or abnormalities seen on imaging

Diagnosis

Caudal regression syndrome can be diagnosed prenatally or postnatally. Diagnostic tools include:

• Prenatal ultrasound: May detect abnormal spinal development, limb deformities, or genitourinary anomalies

• Fetal MRI: Provides detailed images of spinal and pelvic structures

• Postnatal imaging: X-rays, MRI, or CT scan to assess the extent of vertebral, spinal cord, and organ involvement

• Neurological evaluation: To determine motor and sensory deficits

• Urologic and gastrointestinal studies: Such as renal ultrasound, voiding cystourethrogram (VCUG), or barium enema to evaluate organ function

Treatment

Treatment for caudal regression syndrome is multidisciplinary and tailored to the individual’s needs. It focuses on managing physical deformities, preserving function, and addressing complications. Management strategies include:

• Orthopedic interventions: Bracing, physical therapy, or surgery to correct limb deformities and improve mobility

• Urologic management: Clean intermittent catheterization (CIC), medications, or surgery to manage bladder dysfunction

• Gastrointestinal care: Bowel management programs or surgical correction of anorectal anomalies

• Neurosurgical monitoring: For tethered cord or other spinal cord issues

• Assistive devices: Such as wheelchairs, walkers, or orthoses to support mobility

• Psychosocial support: Counseling and educational support for developmental challenges

Prognosis

The prognosis for individuals with caudal regression syndrome depends on the severity of spinal involvement and associated organ anomalies. Many individuals with mild forms of the condition can walk independently and lead productive lives. Those with more severe forms may require lifelong support and use of assistive devices. Early diagnosis, a comprehensive care plan, and regular follow-up with a multidisciplinary medical team can significantly improve functional outcomes and quality of life.