Anorectal anomaly: neuropathological changes in the sacral spinal cord

Area of Science:

• Neuroscience
• Developmental Biology
• Pediatric Surgery

Background:

• Anorectal anomalies in newborns are congenital conditions requiring surgical intervention.
• The underlying neuropathology, particularly within the sacral spinal cord, is not fully understood.
• Understanding sacral spinal cord development is crucial for addressing associated neurological deficits.

Purpose of the Study:

• To investigate the neuropathological features of the sacral spinal cord in newborns with anorectal anomalies.
• To identify alterations in motoneuron groups and the central canal structure.
• To explore the potential link between sacral myelodysplasia and anorectal malformations.

Main Methods:

• Histological examination of serial transverse sections of sacral spinal cords from five full-term newborns and ten newborns with anorectal anomalies.
• Nissl staining to visualize motoneurons.
• Microscopic analysis of the central canal and motoneuron populations (groups A and B).

Main Results:

• Two distinct motoneuron groups (posteriomedian - group A, anteriomedian - group B) were identified in the sacral spinal cord.
• Significant reductions in motoneuron numbers were observed in both groups in cases of anorectal anomalies compared to controls (Group B: 13.4-61.1%; Group A: 61.3-77.7%).
• Abnormalities in the S5 central canal morphology, including diamond shape, underdevelopment, sagittal septum division, and widening/flattening, were noted in affected newborns.

Conclusions:

• Sacral myelodysplasia, evidenced by altered motoneuron organization and central canal morphology, is a significant neuropathological feature associated with anorectal anomalies.
• These spinal cord changes may contribute to the peripheral nerve system pathologies observed in anorectal malformations.
• Further research into sacral myelodysplasia is warranted to improve understanding and management of anorectal anomalies.