Tethered spinal cord syndrome (TSCS) refers to a pathological condition where the spinal cord is abnormally anchored due to congenital or acquired causes (e.g., spina bifida, spinal lipoma, trauma), leading to impaired retraction of the conus medullaris and traction-induced hypoplasia. This condition often results in neurogenic lower urinary tract dysfunction (NLUTD) and defecatory disorders, severely impacting patients' physical and mental health. Symptoms include voiding/storage dysfunction, lower limb sensorimotor deficits, skeletal deformities, and pain. Due to multisystem involvement, it may lead to severe sequelae and high disability rates. However, video urodynamic (VUD) characteristics in TSCS-associated NLUTD remain underreported. This study explores VUD features in TSCS patients with NLUTD.

Six patients with TSCS secondary to sacral spina bifida occult or sacrococcygeal tumors, presenting with storage/voiding dysfunction and constipation, were enrolled. All underwent MRI, revealing tethered cords (n=6), including 2 cases with lipomas, 1 with myelomeningocele, and 3 with lumbosacral spina bifida. VUD was performed per International Continence Society (ICS) standards. Patients were positioned upright, with transurethral catheters recording bladder filling pressure, pressure-flow parameters, and urethral pressure, while rectal catheters measured abdominal pressure. Parameters included: first sensation of bladder filling, detrusor overactivity during storage, maximum cystometric capacity, bladder compliance, maximum flow rate, maximum detrusor pressure, post-void residual urine volume, maximum urethral closure pressure, bladder morphology, and vesicoureteral reflux.

All patients exhibited low bladder compliance. Two showed phasic detrusor overactivity during storage, and two had partial bladder neck opening during storage. Mean first sensation volume was 205 mL, and maximum cystometric capacity was 340 mL.

During voiding, 4 patients demonstrated areflexic detrusor with complete abdominal straining, while 2 had weakened detrusor contraction with partial straining. Maximum flow rate averaged 5.5 mL/s, maximum detrusor pressure was 59.64 cmH2O, and mean residual urine volume was 310 mL. Three patients had reduced maximum urethral closure pressure, and three were at the lower normal limit. Four had bilateral hydronephrosis, two exhibited vesicoureteral reflux, and all six displayed abnormal bladder morphology with irregular walls.

TSCS-associated NLUTD predominantly manifests as reduced bladder compliance, impaired or absent detrusor contractility, low flow rates, and elevated residual urine, often accompanied by detrusor overactivity, decreased urethral closure pressure, and upper urinary tract damage (e.g., hydronephrosis, chronic renal insufficiency). Video urodynamics plays an indispensable role in diagnosing, classifying, and evaluating therapeutic outcomes in these patients