Neuromodulation for Overactive Bladders
What is Neuromodulation?
Neuromodulation is a form of overactive bladder treatment that alters or modulates nerve activity via electrical impulses or pharmaceutical agents to modify neural activity in a target area. This changes its function or relieves symptoms. Neuromodulation can be used to treat a wide range of conditions from chronic pain relief to overactive bladders and can even restore hearing in a deaf patient through aids such as cochlear implants.
In this case, we will talk about how neuromodulation can be used to treat overactive bladders (OAB) via Percutaneous Tibial Nerve Stimulation (PTNS) and Sacral Nerve Stimulation (SNS).
What is an Overactive Bladder (OAB)?
An overactive bladder (OAB) refers to a group of urinary symptoms, with the most common symptom being the sudden and uncontrolled need to urinate. These urinary symptoms are:
- Urinary urgency — The sudden need to urinate and trouble holding the bladder before reaching the toilet. It may or may not be associated with incontinence.
- Urge incontinence — Leakage or the involuntary loss of urine when one feels the urge.
- Frequent urination — The need to urinate more often than what you would usually experience. In general, most will pee 5-6 times/day.
- Nocturia — The need to wake up at night to urinate. If one pees more than once per night, it is considered nocturia.
Generally, we are aware of when our bladder fills up to about half full. Most people will feel the strong urge to empty when the bladder is 90% full. To empty the bladder, our pelvic floor is relaxed, and the brain sends a signal to the bladder to start squeezing the urine out.
When we experience OAB, some people may even leak urine when they feel this urge to pee (incontinence). Since OAB is the uncontrolled urge to pee, it is suggested that involuntary contractions of the muscles in the bladder wall may be the cause of the issue.
How does Neuromodulation treat overactive bladders?
Neuromodulation for OAB is reversible and a minimally invasive procedure. Electrical impulses are sent along nerves which control the muscles in the bladder wall. Since muscle contraction and relaxation are controlled by the body’s own bioelectrical impulses through nerves, the electrical impulse from the neuromodulation generator can interfere with those impulses and cause a change in the muscle action.
The change in frequency of voiding is decided by the frequency and current used in the electrical impulse. The frequency and current used vary from patient to patient as every bladder size and muscle structure differs slightly.
Examples of overactive bladder treatment with neuromodulation include Sacral Nerve Stimulation (SNS) and Percutaneous Tibial Nerve Stimulation (PTNS).
In this case, we will talk about how neuromodulation can be used to treat overactive bladders (OAB) via Percutaneous Tibial Nerve Stimulation (PTNS), Sacral Nerve Stimulation (SNS) and Transcutaneous Electrical Nerve Stimulation (TENS).
What is Percutaneous Tibial Nerve Stimulation?
Your doctor/nurse will place a thin needle that is connected to an electric current near your ankle. The needle passes through the skin and stimulates the tibial nerve. This nerve runs from the inner part of the ankle, along the leg, up to the sacral nerves in the lower back.
This procedure requires no anaesthesia and has no downtime. You will be fully clothed and relaxed in a sitting position throughout the procedure.
A treatment course for tibial nerve stimulation generally includes 12 sessions. These sessions are done once a week at the clinic and usually last 20-30 minutes. The effect may wear off over time and you will likely need more treatment/maintenance courses after the initial 12 sessions. The urologist will discuss with you about the maintenance plan if this overactive bladder treatment works well.
In general, there will be 50-70% improvement in the symptoms and this varies for each patient.
Are there any risks to PTNS?
PTNS is a well-tolerated procedure and has few side effects. You may feel some mild pain when the needle is being placed but this will stop once the needle is removed. During the procedure, you may feel some aching sensations down the leg and foot when the current runs through.
Are there any alternatives to PTNS?
Alternatives to percutaneous tibial nerve stimulation include more conservative forms of overactive bladder treatment such as pelvic floor muscle exercises, medications or neurotoxin injections to the bladder muscle.
Neuromodulation can also be achieved via Sacral Nerve Stimulation (SNS). This is a comparatively more invasive technique that aims to modify the same nerves to help manage overactive bladder symptoms.
What is Sacral Nerve Stimulation (SNS) or Sacral Neuromodulation (SNM)?
The sacral nerve is part of a network of nerves found in the last part of the spine area at the gluteus maximus (buttocks). These nerves control and receive sensory information for the posterior thigh, most of the lower leg, the entire foot and part of the pelvis, including the bladder.
Unlike PTNS, sacral neuromodulation involves the surgical implantation of a permanent electrode through the lower back to reach the sacral nerve. A thin piece of lead connects the electrode to a neurostimulator, a device that is about the size of a standard SIM card. The neurostimulator will generate electrical impulses which are transmitted to the sacral nerves. This will help the bladder muscles stay relaxed for a longer period of time, reducing the urge to pee.
The neurostimulator is battery operated. Depending on the model and frequency of use, it has a battery life of about 2-5 years. After the battery is used up, the neurostimulator needs to be surgically replaced in a quick procedure. The electrode will not be touched in the replacement procedure.
The urologist will insert a test lead in the first part of the treatment (usually under local anesthesia) and patients will be expected to assess if there are any improvements before the second part of the treatment. A permanent lead is then inserted if the patient reports at least 50% improvement in the symptoms.
Are there any side effects to Sacral Nerve Stimulation?
Sacral Nerve Stimulation may have possible side effects such as pain, skin irritation, issues with the device (malfunction), lead migration and site infection. It is important to handle the lead and battery carefully to prevent complications such as loss of sensation or pain.
What is Transcutaneous Electrical Nerve Stimulation (TENS)?
TENS is a treatment module that transmits electrical impulses through electrodes. A device is attached to the ankle, subsequently transmitting electrical impulses to the posterior tibial nerve, which is close to the nerve fibres controlling the bladder.
The fundamental aim is to improve neurological urinary control by facilitating messages between the brain and the bladder. It has been proven clinically efficient in many studies, improving symptoms affiliated with an overactive bladder.
How is Transcutaneous Electrical Nerve Stimulation (TENS) administered?
In this specific case, a device called TENSI+ is prescribed to be used at home for approximately 20 minutes a day. Generally, improvement in symptoms is observed with 12 weeks of consistent usage. Patients may then sustain the results by maintaining the use of Tensi+. Tensi+ is favoured by many as it is self-administrable, non-invasive and non-medicinal. It also avoids multiple weekly visits to the clinic or hospital for PTNS.
How do I know if Neuromodulation is right for me?
Neuromodulation is an ideal third-line option if more conservative methods like bladder retraining and drug treatment do not suffice. Based on medical literature, 50-60% of patients have experienced symptom improvement.
However, there are certain contraindications for this form of overactive bladder treatment. For example, patients with permanent pacemakers are advised against neuromodulation as a precautionary measure to prevent interference with their implanted device. Your urologist will advise you on your options based on your medical history.
An overactive bladder can greatly affect one’s day to day activities and hence, their quality of life. However, there are numerous ways to effectively manage these symptoms with the right overactive bladder treatment methods. Nerve stimulation, or neuromodulation, is a viable second-line treatment option with promising results. Always remember to communicate both your needs and concerns with your urologist so that they can work with you in crafting a treatment plan that best suits you.