Interventional Pain Medicine

What is Neuromodulation?

Neuromodulation is the procedure that involves direct stimulation of the nervous system with electrical signals or direct administration of medicines into the nervous system for therapeutic purposes. It modulates the activity of target cells in the brain or the nervous system at specific locations in the body, delivering mild electrical stimulation or drugs in order to relieve pain or restore function. The technique is primarily used for the treatment of unmanageable chronic pain and/or movement disorders.

The most common neuromodulation therapies depending on the type of disorder include:

    1. Spinal cord stimulation to treat chronic neuropathic pain;

    2. Deep brain stimulation for movement disorders.

    3. Sacral nerve stimulation for pelvic pain, bladder and motion problems disorders (incontinence / retention) 

    4. Spinal cord stimulation for ischemic disorders such as angina and peripheral vascular disease.

Persistent nerve pain or functional problems of bladder are better regulated than lifelong medications which usually have various side-effects. A gentle dose of electric current delivered to the precisely identified appropriate nerves helps to regulate abnormal nerve function.

Two major factors that contribute significantly in patient selection for the stimulation therapy are:

    1. Patient’s should be willing to undergo the trial therapy before committing to permanent battery implantation – A trial lead is precisely placed at an appropriate nerve providing an opportunity to try the effect of treatment before committing to permanent implantation of pulse generator battery.

    2. Reversibility without permanent damage – Neurostimulation is a non-ablative (no deliberate nerve destruction) and completely reversible therapy. 

Sacral Nerve Stimulation 

What is sacral nerve stimulation?

Sacral nerve stimulation also known as Pelvic Neuromodulation has proven to be quite a useful treatment option for chronic dysfunction of the urinary, bowel and pelvic floor. In pelvic neuromodulation, the sacral nerve that controls the bladder, bowel and pelvic floor and the muscles related to their function, is stimulated with mild electrical pulses. The stimulation enables the person to perceive the sensation of bladder fullness and the desire to empty the bladder, spontaneously and completely.

How does sacral nerve stimulation work?

The muscles in the pelvic area, such as the pelvic floor, urethral sphincters, bladder and anal sphincter are all controlled by the brain through nerves that run from the sacral area. Our sensations, such as fullness in the bladder or rectum, are also relayed to the brain via these nerve routes.

SNM works by activating or inhibiting the urinary tract reflexes, by delivering mild electrical impulses to the sacral nerve that serves the lower urinary tract. Besides the local stimulation, neuromodulation also influences the higher centers of bladder control in the brain (known as pontine micturition center).

When is sacral nerve stimulation indicated?

SNM is indicated in patients with chronic urinary retention, voiding dysfunction, bowel dysfunction and chronic pain syndromes. In patients with chronic urinary retention, the only known forms of treatment are clean intermittent self-catheterization (CISC) or indwelling supra-pubic/transurethral catheters. At times CISC can be a painful and traumatic process, and SNM offers an effective therapeutic alternative.

Spinal Cord Stimulation

This common form of neuromodulation involves using a device to deliver electrical current in therapeutic doses to the spinal cord to disrupt pain signals from the spinal cord to the brain, converting them to a more pleasant tingling sensation. This has been proven a safe and effective therapeutic approach for managing chronic pain of the arms and legs, neck and back often after spine surgery, or for other neuropathic conditions. This is indicated in persistent nerve pain conditions like:

    1. Post-Spine surgery nerve pain
    2. Diabetic Neuropathy
    3. Complex Regional pain syndrome
    4. Post herpetic neuralgia
    5. Post Amputation Phantom pain
    6. Peripheral Vascular (Circulation) disease
    7. Severe Angina in spite of CABG / Stenting

What does neuromodulation involve?

Neuromodulation involves the surgical implantation of three components just like a pacemaker implant in the heart:

    1. A lead – special insulated wires with an electrode at the tip that delivers mild electrical pulses to the affected area
    2. Extension wires – connect the electrodes to the neurostimulator
    3. A Pulse Generator – which is a small electronic device implanted under the skin, leaving no device hanging out of the body. This can be programmed to deliver the right current using a sophisticated remote. The stimulator sends mild electrical pulses via insulated leads to targeted areas of the spinal cord, the nerves or brain to block the transmission of signals that either cause pain or bladder control problems.

Implantation of a neuromodulating stimulator is a procedure which takes around 3 to 6 hours (in one or two stages) and is usually done under a local anesthesia by a skilled and experienced interventional pain physician.

What are the benefits for neuromodulation?

Neuromodulation therapies improve peoples’ lives by providing an alternative line of treatment to long-term drug therapy and giving symptomatic relief from persistent or chronic conditions. Such treatment options are significant especially when existing drugs are not proving to be effective or are resulting in problems like tolerance development, addiction, adverse side-effects or toxicity. 

What are the side effects of these treatments?

Similar to any other procedure, neuromodulation also has some minor easily manageable complications which are specific to the technique, therapy and disease. The majority of issues are easily dealt with adjustments in the implanted hardware. Fortunately, serious complications are extremely rare, making it a procedure with a very high safety profile.

Dr. Hirachand S Mutagi
Senior Consultant - Pain Management
MD, FRCA, FFPMRCA
Pain Management

Sacral Neuromodulation for Incontinence

Incontinenece – Bowel and Bladder Control Problems

Incontinence problems are emotive issues and can never be considered as a normal part of life at any age. Even though these problems are very common among people of both genders and have a significant impact on the quality of life, most of the case go unreported often due to the following reasons:

    1. Patients feels embarrassed to seek treatment

       Sometimes people consider their symptoms to be normal side effects of aging and/or child birth

      Often patients and a large pool of treating doctors are also unaware of the successful treatment options available, apart from medications
      Personal hygiene issues arising due to incontinence also lead to profound psychological problems like social isolation and emotional distress.

What is Sacral Neuromudulation (SNM)?

Sacral Neuromodulation (using gentle electric impulses) is an established treatment option gaining popularity for people with bladder and bowel issues.

Sacral Neuromudulation is a technique in which the sacral nerve that controls the bladder, bowel and pelvic floor and the muscles related to their function, is stimulated with mild electrical impulses using a device known as Neurostimulator (like an heart pacemaker). The electrical stimulation modulates nerves that supply the bladder, bowels, urinary & anal sphincters, and the pelvic floor muscles. This enables the person to perceive the sensation of bladder fullness and the desire to empty the bladder, spontaneously and completely. The intensity and frequency of the impulses generated by the neurostimulator can be modified by both the physician and the patient through an external programmer.

How does sacral nerve stimulation work?

The muscles in the pelvic area, such as the pelvic floor, urethral sphincters, bladder and anal sphincter are all controlled by the brain through nerves that run from the sacral area. Sensations such as fullness in the bladder or rectum, are also relayed to the brain via these nerve routes. SNM works by activating or inhibiting these reflexes. This implantable system sends electrical impulses to an area near the sacral nerve to modulate the neural activity that influences the behavior of the pelvic floor, lower urinary track, urinary and anal sphincters, and colon. Unlike oral medications that target the muscular component of bladder control, Sacral Neuromodulation offers control of symptoms through direct modulation of the nerve activity. Besides the local stimulation, neuromodulation also influences the higher centers of bladder control in the brain (known as pontine micturition center).

When is sacral nerve stimulation indicated?

SNM has been a proven treatment modality for bladder control, bowel control problems and persistent pelvic / perineal pain syndromes. Some of the common indications for sacral neuromodulation are:
Urinary urge incontinence and frequency (not stress incontinence):

    1. Bowel (motion) Incontinence
    2. Persistent Perineal / Pelvic pain

It is also worth trying for:

    1. Chronic non-Obstructive Urine retention
    2. Chronic constipation

It is also indicated in patients with chronic urinary retention, voiding dysfunction, bowel dysfunction and chronic pain syndrome. In patients with chronic urinary retention, the only known forms of treatment are Clean Intermittent Self-Catheterization (CISC) or Indwelling Supra-pubic /Transurethral Catheters. Often patients find CISC to be a painful and traumatic process, in such cases SNM offers to be an effective therapeutic alternative. 
Sacral Neuromodulation for Bladder Control
SNM is an innovative and successful therapy for patients with overactive bladder and urinary retention problems for whom conservative treatments have failed. The neuromodulation therapy provides efficient bladder control by addressing the nerve component. In appropriately selected patients, SNM can considerably reduce or even eliminate the symptoms of overactive bladder and urinary retention. Although it must be noted that the therapy is not recommended for patients with mechanical obstruction like – benign prostatic hypertrophy, cancer or urethral stricture.

The therapy is more appropriate for patients who:

    1. Suffer from quality of life issues
    2. Experience urge incontinence or urgency/frequency issues
    3. Experience urinary retention without an obstruction
    4. Desire an alternative to medication due to side-effects or lack of efficacy 

Sacral Neuromodulation for Bowel Control

SNM therapy for bowel control is indicated in patients with chronic fecal incontinence for whom the conservative treatments have not worked well. The therapy is more appropriate for patients who:

    1. Suffer from quality of life issues
    2. Experience chronic fecal incontinence

For both Bowel control and Bladder control therapies, it is very essential to choose the patients properly, such that they fulfill the following criteria:

    1. They must be appropriate candidates for surgery

       They should be able to properly operate the system by themselves
       They should have received satisfactory results from test stimulation

When is sacral nerve stimulation contraindicated?

SNM is generally contraindicated in the following cases:

    1. Mechanical outlet obstruction or Complete disruption of bladder and bowel sphincter)
    2. Diathermy use (shortwave, microwave, ultrasound)
    3. Inadequate response to test stimulation or inability to operate the device

Safety and efficacy of SNM has still not be established for the following:

    1. Age younger than 16 years
    2. Patients with neurologic conditions such as multiple sclerosis

Your doctor is the best person to discuss, if it is still worth undertaking a trial of sacral nerve stimulation to improve symptoms.

When can a Sacral Stimulator be implanted?

Sacral stimulation implant is a non-ablative (not destroying nerves) treatment option that is only completed if the trial stimulation over few days is successful in reducing / resolving the patient’s problems. It is one of the few treatment options where one can try the therapy before committing to a full implantation of the stimulator system.

At Sakra World Hospital we have an experienced Neuromodulation team that can guide patients in achieving good outcomes in reducing their embarrassing bladder and bowel issues.

Trigeminal neuralgia- Yes! Excruciating pain but not a suicide disease

Trigeminal neuralgia (TGN), a severe unilateral paroxysmal facial pain, often severe enough to be frequently described the most painful condition, even reported to induce suicidal thoughts. Its nickname of Suicide Disease (Myth), is misplaced and carried across generations without substantiating evidence. While the severity of pain may bring in suicidal thoughts, but there is no conclusive evidence of a significant suicide rate.

Incidence:

TGN is a rare condition with differing incidence / prevalence data varying between 4-13 per 100,000 population each year, with higher prevalence over 50 year olds and females. However, data from Indian subcontinent is at odds to other published literature with a male preponderance noted in Indian literature published between 1960-1980. The possible cultural differences in Indian subcontinent (data reporting and collecting) may have contributed to this significant variance in prevalence.

Cause of TGN:

TGN is mostly idiopathic (no identifiable cause) and a small proportion (<10%) is secondary to multiple sclerosis (1-5% of MS patients), tumor or cyst in cerebellopontine angle.
Sophisticated imaging techniques (MRI) in recent past have frequently identified compression of trigeminal nerve exit point from the brain by a small artery (less commonly vein) in over 80% of idiopathic TGN. The sustained arterial compression of nerve exit site accumulated with aging results in damage to the nerve wrapping layer (demyelination).
The exact consequence of demyelination and resulting TGN is unclear, with the most promising hypothesis being nerve fiber damage from compression by an adjacent artery.

Diagnosis of TGN

TGN remains entirely a clinical diagnosis, not requiring a MRI scan (Myth 2). Imaging is usually undertaken to rule out organic pathology if clinical examination (numbness, bilateral disease, younger patient) suggests possible secondary cause. The increasing recognition of nerve wrapping damage at the nerve exit site from the brain by small arteries as a cause for idiopathic TGN and the availability of high resolution contrast enhanced imaging techniques are commonly undertaken before contemplating surgical treatments.

Diagnostic Criteria

    1. Paroxysm of unilateral pain lasts under 2min in a 1-3 divisions of trigeminal nerve
    2. Pain characteristics (at least one):
    3. Intense , sharp, stabbing
        i) Precipitated by trigger zones
        ii) Each attack is similar in character, location, trigger
    4. Normal neurological examination
    5. No other disease / cause identified to explain the pain

Background pain between paroxysms and mild sensory loss are features of atypical TGN (refractory form of disease).

Your doctor well versed with managing facial nerve pains may be in a position to distinguish TGN from other potentially confusion conditions like trigeminal neuropathy, Cluster headache, SUNCT ( the worst headache ever), other neuralgias and neck related headaches.

Imaging in TGN

Trigeminal neuralgia is a clinical diagnosis, meaning there is no need for expensive scans / tests. Since 5-10% of TGN have a secondary cause identified, investigations are dependent on clinical examination identifying atypical features (e.g. Dental x-rays, sinus x-ray / CT scan).

Investigations are done to:

    1. Clarify the differential diagnosis; for example, by taking dental x rays
    2. Magnetic Resonance Imaging to detect secondary TGN, particularly with a view to surgical cure
    3. Identify artery compressing nerve exit site from the brain before contemplating surgical treatment. Interestingly, 3-12% incidence of compressing artery in asymptomatic individuals, imaging studies for artery compression are only considered in clinically diagnosed patients, rather than to make a diagnosis.

Conventional MRI is good at ruling out sinus, CP angle tumors / cysts and multiple sclerosis. Artery compression needs a more complex specialized MRI scanning sequence.

Treatment of TGN

Carbamazepine remains the drug of choice for TGN.  Its use has been traditional and based on old small studies of debatable quality. Based on the best available evidence including Cochrane reviews, guidelines continue to recommend Carbamazepine as the first line of treatment .Nearly 70% gain reasonable good benefit from it. Oxy-carbamazepine has a better side-effect profile and is likely to be better tolerated. Cognitive side-effects are common and hematological side-effects warrant regular monitoring of blood counts.

In spite of unproven benefit for other anti-epileptic, alternative antiepileptic mediations are tried (with acceptable reasoning / logic) in patients intolerant of Carbamazepine. These include lamotrigine, phenytoin and gabapentin among others.

Surgical procedures for Trigeminal Neuralgia

TGN surgical treatment can broadly be classified in two categories Microvascular decompression (major brain operation) and palliative destructive procedures of trigeminal ganglion / nerve (Non-surgical needle procedures).

    1. Microvascular decompression (MVD) aims at relieving nerve roots arterial compression and hence provides pain relief. The palliative destructive procedures involves heat (Radiofrequency burn), chemical (glycerol), physical (Balloon Compression) or radiation induced (stereotactic radiosurgery Gamma knife) nerve exit site partial destructive lesions. Apart from the Gamma knife technique, the ablative procedures involve accessing the trigeminal neural path through the foramen ovale.
    
    2. Palliative destructive procedures: RF thermal ablation has the better results with higher incidence of numbness, while balloon compression causes jaw weakness. The Radiofrequency ablation procedure provides good pain relief for well over 3 years. The cost and risk of major brain surgery especially in elderly people are prohibitive in considering major brain surgery (Microvascular decompression -MVD) which does provide better result without numbness 80-90% pain relief with a 10% recurrence rate over 10 years-20 years.

Your Pain Specialist is well placed to discuss your treatment options and assist you with a helping hand in you fight against pain. They can help you in managing your pain killers based on their vast experience and guide / provide a suitable procedure to control your pain.

Dr. Hirachand Shripad Mutagi
Senior Consultant - Pain Management
MD, FRCA, FFPMRCA
Pain Management

Your Challenges in Managing Pain -Dr Hirachand Shripad Mutagi

Pain is inevitable problem in everybody’s life, fulfilling an important function of warning us of illness / injury. However, when it persists even after body healing (Chronic Pain), it present significant challenges for the sufferer. Apart from personal physical, emotional, social and financial suffering; the journey to find the pain source and treatment takes him/her from pillar to post. Modern medicine’s trend for super specialization is good at addressing short term problems easily diagnosed by sophisticated investigations. However, problem in function (non-structural problems) tend to get missed.

Modern healthcare medicine focuses on specialization and your doctors looks for pain sources in internal organs, bones and joints. The muscular, ligaments and nerve problems tend to get missed. Pain is defined as an emotional experience, and precisely emotional impact of pain and suffering need to be identified, assessed and addressed. In summary, your pain specialist can be viewed as your helping hand who understands hidden causes for pain, its emotional and social impact on your life. If you have had blood tests and scans, not demonstrating the cause of your pain (medically Unexplained pain), the pain specialist may be able to help you.

Our body is complex, further complicated by the mind that interacts in shaping your pain experience. Your pain specialist will use his experience, knowledge and individualized examination to guide you in managing your pain. He may have to resort to precise needle techniques to identify your pain source, a big step towards addressing the problem. His goal remains in helping you deal with challenges in managing your pain.

In chronic pain, it is often the inability to do simple day-to-day things that hurt more than the pain itself. Your pain specialist’s main focus remains in reducing your dependence on your family and participate in the family’s wellbeing. The physiotherapy form an important spoke in the treatment pain. Your pain physician will work with his team of physiotherapist, psychologist and occupational therapist to find the best combination of treatments for you.

The pain physician has the following tools to assist you:

1. Identifying the source of the pain by thorough examination and on occasions on precise placement of numbing agent near anticipated pain source.
2. Interrupting the pain pathway – by using chemical or precisely delivered heat treatment.
3. Resetting the pain nerve circuitry –eg. Spinal cord stimulation or sacral stimulation.
4. Stabilizing dynamic problems in spine / joints – eg. Internal fixation of fractured vertebrae (vertebroplasty) due to injury / cancer.

Dr. Hirachand Shripad Mutagi
Senior Consultant - Pain Management
MD, FRCA, FFPMRCA
Pain Management

Pain A disease in its own right!! -Dr. Hirachand Mutagi

The world is waking up to an epidemic of persistent pain. We grow up being told and understand that pain is a symptom of disease. To start with, it is absolutely the right thing to do. Pain serves as a warning signal, that we investigate and find underlying causes to treat them. Nobody can argue against this ideology.

But, what about the tests and scans not finding anything of significant, a very common scenario. Great! I don’t have cancer, TB, Infection, etc. But, I still have the pain! A google scholarly article search on “medically unexplained symptoms” confirms a rapidly expanding literature on this aspect. A survey of symptoms that went on to have an identifiable cause in western world general practice unearths sobering patterns.

Let’s look at the “glass half full scenario” – Only a small proportion of patients with symptoms have an identifiable cause and the others have normal investigations (blood tests and scans). That sounds good.

Now the “Glass Half empty scenario” - A large proportion of people don’t have an identifiable / and hence curable cause for their symptoms. Here begins a journey of seeing multiple specialists spread across a wide geographical area, each providing nuggets on information to create a concoction of confused understanding about causation, treatment options and prognosis. Each of these nuggets of information / treatment are absolutely right in a specific context, but considering the overall individual it adds to the confusion. Into this scenario, add the contribution of quacks and divine healers and you have a path to disaster for that confused individual (don’t forget the plight of near and dear ones). A multitude of health care providers (doctors and non-doctors) with specialization focus on symptoms specific to their specialization and provide a diagnosis / treatment. Varied explanations from each is counterproductive in the long run, As is rightly said “ Too many cooks spoil the both”.

Factors in development of medically unexplained symptoms

• Expectation of instant curet
• Appearance of uncertainty and inability to provide an explanation
• Expressed concern about disease explanations
• Failure to convince patient that the complaint is accepted as genuine
• Reassurance without a positive explanation being given
• Ambiguous and contradictory advice
• Excessive investigation and treatment

Patients' understandable attempts to alleviate their symptoms may paradoxically exacerbate them. For example, excessive rest to reduce pain or fatigue may contribute to disability in the longer term. Doctors may also contribute to this by failing to address patients' concern or unwittingly increasing fear of disease (such as by excessive investigation). Patients views about treatment being focused on medicines, immediate cure, curative surgery, reluctance to engage in physiotherapy and aversion to address frustration / low mood all contribute to a treatment failure. Here we go , ready for the next specialist consultation.....

The World is Waking Up

The medical fraternity is slowly waking up to the fact that “Persistent pain is a medical condition by itself.” So much so that conferences are organized to raise awareness of the issue, as in - “Chronic Pain – A disease in its own right” Second Lilly Pain Masterclass Meeting held at the Royal College of Physicians in London 2012.

The EFIC (European Federation of IASP Chapters) current declaration on pain is that “Pain is as a major health problem, a disease in its own right”.

An organization called the International Association for the Study of Pain has defined pain as an “unpleasant sensory and emotional experience associated with actual or potential tissue damage or described of in terms of such damage”. Even then there are 500 types of chronic pain and no two patients suffer in a similar fashion. The words emotional experience have great significant in defining pain. The fact that we can’t explain it does not mean it does not exist for that patient.

Current Thinking and Lines of Research

Chronic pain often outlives its original causes, worsens over time, and takes on a puzzling life of its own. There is emerging evidence that over time, untreated pain eventually rewrites the central nervous system, causing pathological changes to the brain and spinal cord, and that these in turn cause greater pain. Sometimes the original problem creates new ones as the patient distorts posture and avoids exercise in an attempt to reduce the pain.  In chronic pain, the protective mechanism of avoidance becomes maladaptive and counterproductive.

Achieving a happy, informed and relaxed patient, as treatment goes along is just as important as any medicine or medical procedure to ease pain / suffering.

The Western world have recognized this and “Pain management Centre/ clinic” form a busy part of the clinic / hospital. They focus of an overall detailed assessment of this persistent pain to formulate an individualized treatment regime with a combination of medicines, physiotherapy, non-surgical treatments and training on improving ability to lead an independent life. Hence reducing reliance on help from near and dear ones. The initial challenge in these setting is in unravelling the different counterproductive beliefs of a desperate patient while specific treatments are provided to achieve a happy patient at the end of the journey.

If the above article resonates with your past experience, its time you recognize it, take charge and build your road to recovery. A helping hand is always available……

Blog By

Dr. Hirachand Mutagi. (MD, FRCA, FFPMRCA)
Senior Consultant Pain Management.
SakraPain Centre.