Cortical stimulation for voiding dysfunction in multiple sclerosis
Reviewed by Jay Khastgir

Voiding dysfunction (VD) increases morbidity in patients with multiple sclerosis (MS), and may be associated with urinary tract infections, stones and renal failure. Catheterisation is required when impaired hand function precludes self-catheterisation, which is associated with further morbidity. In this pilot study 10 females with MS and voiding dysfunction (identified from symptom scores and ≥40% post-void residual (PVR) / bladder capacity) underwent concurrent functional MRI imaging and urodynamic study. Changes in brain activation in regions of interest were identified which were targeted by a non-invasive transcranial magnetic stimulation (TMS) device employing magnetic coils placed over the scalp. Devised by the Neurophysiology and Neuromodulation Laboratory at the Houston Methodist Hospital, this apparatus consists of up to six magnets rotated by battery-operated motors known as microstimulators attached onto a neoprene cap. Specific stimulation parameters were used to elicit excitation or inhibition via an oscillating magnetic field that can penetrate a depth of approximately 2cm from the scalp. Repetitive application of TMS to the motor cortex reduced PVR and increased voiding detrusor pressures, and notably, brain activity patterns of MS patients after treatment began to resemble those in previously reported healthy controls. The improvement was short-lasting but remained apparent at four months post treatment. This is an interesting study because of the potential for a novel treatment modality for VD. However, there are obvious shortcomings: it is a pilot study of only 10 patients with MS, all women, with short-term follow-up data reported. MS is a heterogeneous disease which may have multiple lesions in the brain and spinal cord and consequently this treatment may be applicable to those with lesions accessible to transcutaneous stimulation. I hope this heralds a bright future for neuromodulatory therapies.

Non-invasive, individualized, cortical modulation using transcranial rotating permanent magnet stimulator for voiding dysfunction in women with multiple sclerosis: a pilot trial.
Khavari R, Tran K, Helekar SA, et al.
JOURNAL OF UROLOGY
2022;207:657-68.