Magnetic stimulation of the sacral roots

Area of Science:

• Neuroscience
• Urology
• Biomedical Engineering

Background:

• Spinal cord injury (SCI) often impairs bladder function, affecting detrusor activity and sphincter control.
• Assessing the integrity of sacral nerve pathways is crucial for managing neurogenic bladder.
• Conventional methods like sacral evoked potentials have limitations in distinguishing between afferent and efferent pathways.

Purpose of the Study:

• To evaluate the safety and efficacy of magnetic stimulation in assessing detrusor and striated sphincter motor pathways in SCI patients.
• To compare magnetic stimulation results with urodynamic studies and conventional sacral evoked potentials.

Main Methods:

• Magnetic stimulation using an 83 mm surface coil was applied to 11 SCI patients.
• Detrusor activity and evoked potentials of the striated urinary sphincter motor pathways were recorded.
• Urodynamic studies and sacral evoked potentials were performed prior to magnetic stimulation.

Main Results:

• Magnetic stimulation was easy to perform and reproducible in all patients.
• Mean sacral motor pathway latency was 27.9 ms.
• Detrusor response was observed in 7 patients at bladder volumes > 200 ml.
• No complications were reported.

Conclusions:

• Magnetic stimulation is a safe and effective tool for evaluating the detrusor and striated sphincter motor pathways.
• Combined with sacral evoked potentials, it allows for indirect evaluation of sensory pathways.
• This technique offers a valuable method for assessing bladder function in SCI patients.