PT Classroom - A Review of Pain Management Interventions and Physical Therapy Implications ׀ by Nikhil Patel, MD & Chai Rasavong, MPT, MBA

Pain is described as “an unpleasant sensory and emotional experience associated with actual or potential tissue damage”. It is always subjective and its perception may vary from individual to individual. In 2006 the Center for Disease Control compiled a National Center for Health Statistics Report which revealed that 1 in 4 adults reported pain of 24hrs duration during last month, with 1 in 10 adults reporting chronic pain. The report also displayed findings that 25% of adults reported low back pain within the past 3 months.

Various health care providers can assist a patient with managing pain including: anesthesiologists, physiatrists, neurologists, oncologists, internists, orthopedic surgeons, neurosurgeons, psychiatrists, OB/GYN physicians, physical therapists, etc. When working with individuals who are suffering from pain the goals of pain management include: evaluating the patient, determining a proper diagnosis, controlling the pain, addressing any co-morbidities, improving function, facilitating return to work and avoiding unnecessary surgery.

Pain can be classified as acute or chronic. Acute pain serves a purpose and typically corresponds to the degree of injury, and commonly responds to conventional therapy. Chronic pain outlasts the initial injury, serves no beneficial purpose, may provide subjective ratings which exceeds the objective findings, has poor response to conventional therapy, and may be accompanied by major psycho-social co-morbidities.

Chronic pain can be classified as nociceptive or neuropathic. Nociceptive pain can occur when there is injury to tissue and can affect somatic or visceral tissues. Neuropathic pain can occur when there is injury to a nerve and can affect central, peripheral or sympathetic nerves. Neuropathic pain is secondary to biochemical and structural changes within the central and peripheral nervous system. Individuals experiencing neuropathic pain give the description of pain as “burning, electric, searing, tingling, migrating & traveling”. Examples of conditions which involve neuropathic pain includes: amputation, shingles, diabetic neuropathy & post-laminectomy syndrome.

To formulate an appropriate treatment plan for acute or chronic pain it is vital to have an accurate diagnosis. Obtaining a thorough history & physical should always be conducted. When obtaining a patient’s pain history various factors should be noted including site(s) of pain, severity of pain, onset, duration, what aggravates or relieves pain, impact on sleep, mood, activity and effectiveness of previous treatments. Red flags in pain assessment that should also be considered can include: poor function/motivation, pain always a 10 out of 10, altercations with staff, focus on particular medications, multiple admissions/frequent ER visits, alcohol, tobacco and illegal drug abuse.

In addition, imaging studies or tests such as MRI, CT, EMG & NCS can be utilized to assist in making a correct diagnosis. Other aids which can assist in making an accurate diagnosis can include diagnostic procedures such as facet blocks, discography or selective nerve blocks. These interventional procedures may be both diagnostic and therapeutic, when compared to imaging which is only diagnostic.

There are a variety of different treatment options to treat acute or chronic pain. They can include: medications - non-opioid analgesic medications & opioid medications, injection therapy, alternative therapies, psychological counseling, implantable devices and surgery. In the traditional “Ladder” approach to chronic pain management patients are carefully taken step by step through the treatment ladder. The first step is a trial of acetaminophen or nonsteroidal anti-inflammatory drugs (NSAIDs). However, you must always be aware of potential renal and hepatic damage. Physical therapy and similar treatments, as well as muscular relaxants, are recommended when NSAIDs fail to control a patient’s pain. If pain is still not under control, the physician may consider interventional procedures including epidural steroid, facet injections, nerve block, or radiofrequency ablation. If patient does not have significant pain relief with conservative management one may consider corrective surgery, long-term oral opioids, or implantable therapies – either neurostimulation or intrathecal pain therapy.

In this article we will further review the interventional procedures that are available for pain management. The minimally invasive techniques available include epidural steroid injections (ESI), sacroiliac joint injections (SIJ), and facet blocks. Implantable devices consisting of neurostimulation and intrathecal drug delivery can be utilized as well.

Epidural steroid injections (ESI) are performed under fluoroscopy where a spinal needle is placed in the epidural space and may have some spread over the spinal nerve as well. They are done with the aim of decreasing inflammation by: inhibition of PLA-2, inhibition of neural transmission in nociceptive C fibers, and reduction of capillary permeability which decreases edema & swelling. ESIs can be performed via translaminar, transforaminal or caudal approaches. All of these approaches should always be done with fluoroscopy. Physical therapy for the patient is recommended after the ESI for strengthening, stabilization, ROM, stretching, postural training, functional training, manual therapy, modalities and patient education. The patient is usually able to participate in physical therapy one or two days after the ESI and there should be no contraindications in regards to physical therapy treatment.

Facet blocks can be done by either putting corticosteroid directly into the joint or by blocking the medial branch nerve which innervates the facet join. An intra-articular block involves accurate placement of the needle in the joint cavity. It is not uncommon to see spillage outside the joint space (pericapsule) during the injection. Individuals that display degenerative joints will make access for this procedure difficult. A medial branch nerve block is technically easier and safer especially in the cervical spine. This procedure is diagnostic and involves anesthetizing two nerves per joint with lidocaine or marcaine. These are short acting anesthetics that typically will give pain relief for up to 4-6 hours. If the patient has two successful blocks with adequate pain relief for 4-6 hours, then the patient would be recommended for radiofrequency ablation, which denervates the medial branch nerves for up to one year.

Radiofrequency ablation involves insertion of an insulated probe and the generation of heat by electric current to create a lesion that destroys target tissue interrupting sensory conduction. It is performed through fluoroscopy under local anesthesia with minimal sedation. The radiofrequency lesion is set at 80 for 60-90 seconds on the targeted area. This procedure can provide significant prolonged relief and can be repeated. Effectiveness of pain management from this procedure can typically last 6-12 months before regeneration of the nerve. Physical therapy for the patient is also recommended after this procedure for strengthening, stabilization, ROM, stretching, postural training, functional training, manual therapy and patient education. The patient is usually able to participate in physical therapy a couple days after radiofrequency ablation and there should be no contraindications in regards to physical therapy treatment, aside from avoiding excessive ROM that exacerbates the patient’s pain.

Spinal Cord Stimulation (SCS) is a form of neurostimulation which was inspired by the “gate theory” involving the deliverance of low voltage electrical stimulation to the spinal cord to inhibit or block the sensation of pain through an implant. A trial procedure is performed first prior to a permanent implant being placed. The trial procedure involves a percutaneous lead being positioned in the epidural space. Electrical current from the lead generates parasthesia that can be adjusted in intensity and location to achieve the best pain coverage. Leads are attached to an external pulse generator. An external programmer can be used to adjust stimulation to meet pain management needs. Physical therapy for the patient is recommended after placement of the SCS for strengthening, stabilization, ROM, stretching, postural training, functional training, manual therapy and patient education. The patient is usually able to participate in physical therapy during the trail phase, however no excessive range of motion that may lead to the displacement of the leads during the trial phase. Contraindications in regards to physical therapy treatment include no modalities such as electrical stimulation or ultrasound to the area of the implant and leads. After a successful trial, the patient will be a candidate for implantation of the SCS. After implantation, the leads are much less likely to migrate and the patient can resume full active and passive ROM exercises.

Intrathecal pumps utilize an implanted pump for targeted drug delivery. Individuals that experience 50% or greater pain relief with a trial of intrathecal injections generally are good candidates for permanent implant. Physical therapy for the patient is recommended after placement of the pump for strengthening, stabilization, ROM, stretching, postural training, functional training, manual therapy and patient education. Contraindications to physical therapy treatment includes no modalities such as electrical stimulation or ultrasound to the area of the implant and no excessive painful range of motion. There is normally low risk of a lead migration when the intrathecal pump is implanted by a well trained surgeon.