Determination of the normal conus medullaris level in term infants: the role of MRI in early infancy

Tethered Cord Syndrome: Role of Imaging Findings in Surgical Decision-Making

For infants presenting with urinary problems or lower extremity weakness, imaging is ordered to investigate spinal pathology. Tethered cord syndrome (TCS) often manifests without conclusive anatomic evidence. In our case, a premature infant presented with urosepsis and was found to have an asymmetric gluteal crease and a sacral dimple. Renal ultrasound showed mild hydronephrosis, and a cystourethrogram revealed bilateral high-grade vesicoureteral reflux. Ultrasound and magnetic resonance imaging demonstrated a borderline low-lying spinal cord at the mid-L3 vertebral level. Urodynamic testing to confirm neurogenic bladder could not be completed on the first attempt due to urinary tract infection and on the second attempt due to instrument intolerance. Despite the lack of conclusive imaging evidence of a tethered cord, enough supportive clinical data was present to proceed with surgical intervention with the goal of preventing the progression of neurological dysfunction. Because TCS is ultimately a clinical diagnosis, appropriate management should not be discouraged by inconclusive or borderline imaging findings.

Comparison of Ultrasonographic Findings between Patients with Tethered Cord Syndrome and Healthy Children

Background

Tethered cord syndrome (TCS) is a type of occult spinal dysraphism, which necessitates early detection as an essential component of patient management in reducing complications. This study aimed to compare the findings of spinal cord ultrasonography between TCS patients and healthy individuals.

Methods

The current study is a case-control study of patients who were admitted to the Akbar and Ghaem Hospitals (Mashhad, Iran) in 2019. The study population comprised 30 children with TCS aged under two years old, and the control group included 34 healthy peers of the same age. The maximum distance of the spinal cord from the posterior canal wall was measured in millimeters using ultrasonography. Demographic and sonographic findings of each participant were recorded in checklists, which were then entered into SPSS software. P values less than 0.05 were considered statistically significant.

Results

The study included 30 children with TCS and 34 healthy individuals with a mean age of 7.67±6.39 months. TCS patients had a significantly shorter maximum distance of the spinal cord from the posterior wall of the spinal canal than the control group (1.75±0.62 mm vs. 2.79±0.76, P<0.001). After performing corrective surgery, the TCS patients indicated significant improvement in this interval (1.57±0.54 mm to 2.95±0.49 mm, respectively, P=0.001).

Conclusion

In comparison to children without TCS, the spinal cord was substantially closer to the posterior canal wall in TCS patients. However, these outcomes were improved significantly in patients after surgery.

Morphometric Analysis of Spinal Cord and Its Termination Within the Vertebral Canal: An Observational Study in the Fetuses of Third Trimester Gestational Age

Background & aim The spinal cord is the continuation of the brain from the lower point of the medulla and the terminal portion of the developing neural tube. The spinal cord develops within the bony canal, called the vertebral canal, formed by the union of individual vertebrae in the vertebral column. Initially, the development of the length of the vertebral column and spinal cord are the same but later on undergo alterations. The growth of the vertebral column is faster than that of the spinal cord because the spinal cord appears to terminate early within the vertebral canal. To measure the length of the spinal cord and lowermost point of conus medullaris in the third trimester gestational age fetuses. Material and methods The present cross-section observational study was carried out on 30 fetuses collected from the museum of the Anatomy Department and Obstetrics and Gynecology Department. Before starting the study, permission and approval from the university's ethical committee were received. The dissection of fetuses includes the incision of the skin, removal of superficial and deep muscles, and a laminectomy. The meninges were cut and removed to note the vertebra level of the termination of the spinal cord. The spinal cord was taken out, and the total length of the spinal cord was measured. The fetuses were categorized into three groups determined by their gestational age (the first group was 28-31 weeks, the second group was 32-35 weeks, and the third group was 36-40 weeks). Observation In the present study, 81.8% of male fetuses were in the 36-40 weeks gestational age group, and 52.6 % of female fetuses were in the 32-35 weeks, gestational age group. The mean length of the spinal cords was 14.74±1.45cm, with a range of 10.95 cm to a maximum of 16.60 cm. In the full-term gestational age group, male fetuses had a greater length of spinal cord than female fetuses. Sixteen fetuses had a spinal cord termination at level L2, followed by eight fetuses at the L3 level and six fetuses at the L4 level. Out of 11 male fetuses, eight fetuses had spinal cord termination at the L2 vertebra level, two at the L3 level, and one fetus at the L4 level. In female fetuses, eight had a spinal cord termination at the L2 level, six at the L3 level, and five at the L4 level. Conclusion The spinal cord length and level of conus medullaris depend on the age of the fetuses. In prenatal diagnosis for different spinal cord pathology, these values can be used as reference values in future studies.