Occipital neurostimulation-induced muscle spasms: implications for lead placement.

BACKGROUND: For many headache types, occipital peripheral nerve stimulation (ONS) provides significant relief of chronic, frequent, and severe headaches. Though rarely reported, ONS may cause painful muscle spasms that make stimulator use impractical. The classic description of the technique advocates placement of the leads transversely at the level of the arch of C1 or at C1-2. At that level, the greater occipital nerve (GON) infrequently pierces the superficial fascia of the neck muscles to become superficial. However, important anatomic variability exists. OBJECTIVE: To report placement of leads higher at the nuchal line rather than the classically recommended C1 level to avoid ONS-induced muscle spasm. METHODS: Four interventional pain physicians independently revised ONS leads due to painful muscle stimulation. Five case reports of surgical ONS lead revision for management of ONS-induced muscle spasms are described and discussed. RESULTS: Placement of peripheral neurostimulator leads at or above the nuchal line in these 5 cases provided good paresthesiae without causing neck muscle spasm. CONCLUSION: Lead placement at the level of C1 or C1-2 may cause some patients to have intolerable neck/occipital spasm during neurostimulation. This is the first known published report of technical variation in the location of lead placement, at the nuchal line in a transverse fashion, for ONS. Placing ONS leads at the level of the occipital protuberance appears to eliminate ONS-induced muscle spasm while allowing good paresthesia coverage. LIMITATIONS: Stimulation parameters vary, thus posting parameters may be misleading as muscle spasms occurred despite multiple reprogramming attempts and were a function of lead position, not program settings.

Radiofrequency cannula with active tip radio-opaque marker: image analysis for facet, gray ramus, and dorsal root ganglion techniques.

BACKGROUND: Radiofrequency neurolysis is a common technique used in the treatment of chronic pain, particularly facet (zygapophyseal joint) arthralgia. A needle-like cannula is insulated except for the exposed active tip, which is positioned as parallel and adjacent as possible to the targeted nerve branch. Via an inserted probe connected to a radiofrequency generator, energy flowing from the tip of the cannula creates a heat lesion in the 80 - 85 degree Celsius range mostly about the length of the exposed active tip and in proportion to the diameter of the probe. The common active tip lengths used for neurolysis are 5mm or 10mm. The cannulae are FDA approved. The manufacturer advises physicians not to bend or otherwise modify a cannula prior to use. The cannulae are available straight or bent, sharp and blunt. The technique is guided under C-arm fluoroscopy. X-rays passing through the patient demonstrate in 2 dimensions the projected relative radio-opaque bony landmarks and the metallic cannula. Most currently available cannulae are uniform in their radio-opacity from tip to hub. The physician must make an educated guess as to the portion of the cannula that will be making the lesion in relationship to the bony landmark. OBJECTIVE: A new radiofrequency cannula with a radio-opaque marker (ROC) delineates the proximal end of the active tip. The cannula was used in a phantom model. Images were reproduced with explanation of the potential advantage of the new device. RESULT: The marker on the new cannula was visible and did help delineate the active tip as well as its orientation. It was also helpful in making sequential lesions at the same nerve using a "tip to tail" repositioning technique. CONCLUSION: The ROC did represent an improvement over standard cannulae to optimize visualization of cannula and thus lesion placement using a phantom model. The applications described were only for conventional or "hot" RF.

Implanted occipital nerve stimulators.

BACKGROUND: Chronic headache represents a very significant public health and economic issue. One treatment modality for chronic refractory headache involves the use of subcutaneous implanted neurostimulator leads in the occipital region. Varied types of headache etiologies including migraine, transformed migraine, chronic daily headache, cluster headache, hemicrania continua, occipital neuralgia, and cervicogenic headache have been studied with peripheral nerve field stimulation and found responsive to stimulation of the suboccipital region, known commonly as occipital nerve stimulation (ONS). OBJECTIVE: To evaluate the strength of evidence that occipital nerve stimulation is an effective treatment of benign headache. STUDY DESIGN: A systematic review of occipital nerve stimulation for the treatment of chronic headache. METHODS: A systematic review of the literature through EMBASE and PubMed/Medline for clinical studies was performed. The Agency for Healthcare Research and Quality (AHRQ) criteria was utilized to assess the evidence regarding occipital nerve stimulators and arrives at conclusions as to their efficacy in the treatment of headache. Studies were also graded using AHRQ criteria. The overall body of evidence was then graded on a 5 level scale from Level I (conclusive), Level II (strong), Level III (moderate), Level IV (limited) to Level V (indeterminate). RESULTS: Ten observational studies, of which 4 were prospective, and a number of case series, case reports, and reviews were identified. No randomized controlled trials (RCT) were identified. All of the articles reported positive outcomes including improved pain relief, reduced frequency, intensity, and duration of headaches with reduced medication consumption. ONS was reportedly successful for 70 - 100% of patients. Reduction of pain in patients with occipital headaches and transformed migraine is significant and rapid; for cluster patients the improvement may be less dramatic and it may take several months of occipital stimulation to achieve relief. No long-term adverse events occurred. Several short-term incidents occurred including infection, lead displacement, and battery depletion. The body of evidence as a whole is a level of strength of IV, limited. CONCLUSION: ONS is a useful tool in the treatment of chronic severe headaches with at least Level IV (limited) evidence based on multiple positive studies.

Lumbar retrodiscal transforaminal injection.

BACKGROUND: Spinal injections are commonly used to treat lumbar radiculitis and back pain. Delivery of medication to specific targeted pathology is considered important for a successful therapeutic outcome. A variety of routes of injection have been devised for epidural injection of corticosteroid. OBJECTIVES: The author demonstrates a variation of the transforaminal injection technique. The radiographic spread of contrast is described using a more oblique and ventral caudad approach in the epidural space "retrodiscal." It is suggested that the radiographic findings of this technique for discogenic causes of induced radiculitis and/or back pain may yield more precise targeting of putative pathologic sources of radiculopathy and back pain in selected patients. METHODS: In patients with disc pathology and radiculitis, the anatomy of the lumbar epidural space is reviewed for its potential effect on the flow of injectate. Contrast spread was documented for lumbar transforaminal injection using a needle placement more oblique and behind the disc rather than in the cranial portion. Comparison is made to a typical contrast spread of an infra-pedicular placed transforaminal injection. RESULTS: Retrodiscal contrast injection results in reliable coverage of the retrodiscal region, the exiting nerve at that foraminal level and the proximal portion of the transiting segmental neural sleeve. CONCLUSIONS: The radiographic findings demonstrate a difference between classic infra-pedicular versus retrodiscal transforaminal epidural contrast injection patterns, particularly at relatively low volumes. The clinical advantage of one technique versus the other should be established in randomized prospective studies.

Interventional techniques: evidence-based practice guidelines in the management of chronic spinal pain.

BACKGROUND: The evidence-based practice guidelines for the management of chronic spinal pain with interventional techniques were developed to provide recommendations to clinicians in the United States. OBJECTIVE: To develop evidence-based clinical practice guidelines for interventional techniques in the diagnosis and treatment of chronic spinal pain, utilizing all types of evidence and to apply an evidence-based approach, with broad representation by specialists from academic and clinical practices. DESIGN: Study design consisted of formulation of essentials of guidelines and a series of potential evidence linkages representing conclusions and statements about relationships between clinical interventions and outcomes. METHODS: The elements of the guideline preparation process included literature searches, literature synthesis, systematic review, consensus evaluation, open forum presentation, and blinded peer review. Methodologic quality evaluation criteria utilized included the Agency for Healthcare Research and Quality (AHRQ) criteria, Quality Assessment of Diagnostic Accuracy Studies (QUADAS) criteria, and Cochrane review criteria. The designation of levels of evidence was from Level I (conclusive), Level II (strong), Level III (moderate), Level IV (limited), to Level V (indeterminate). RESULTS: Among the diagnostic interventions, the accuracy of facet joint nerve blocks is strong in the diagnosis of lumbar and cervical facet joint pain, whereas, it is moderate in the diagnosis of thoracic facet joint pain. The evidence is strong for lumbar discography, whereas, the evidence is limited for cervical and thoracic discography. The evidence for transforaminal epidural injections or selective nerve root blocks in the preoperative evaluation of patients with negative or inconclusive imaging studies is moderate. The evidence for diagnostic sacroiliac joint injections is moderate. The evidence for therapeutic lumbar intraarticular facet injections is moderate for short-term and long-term improvement, whereas, it is limited for cervical facet joint injections. The evidence for lumbar and cervical medial branch blocks is moderate. The evidence for medial branch neurotomy is moderate. The evidence for caudal epidural steroid injections is strong for short-term relief and moderate for long-term relief in managing chronic low back and radicular pain, and limited in managing pain of postlumbar laminectomy syndrome. The evidence for interlaminar epidural steroid injections is strong for short-term relief and limited for long-term relief in managing lumbar radiculopathy, whereas, for cervical radiculopathy the evidence is moderate. The evidence for transforaminal epidural steroid injections is strong for short-term and moderate for long-term improvement in managing lumbar nerve root pain, whereas, it is moderate for cervical nerve root pain and limited in managing pain secondary to lumbar post laminectomy syndrome and spinal stenosis. The evidence for percutaneous epidural adhesiolysis is strong. For spinal endoscopic adhesiolysis, the evidence is strong for short-term relief and moderate for long-term relief. For sacroiliac intraarticular injections, the evidence is moderate for short-term relief and limited for long-term relief. The evidence for radiofrequency neurotomy for sacroiliac joint pain is limited. The evidence for intradiscal electrothermal therapy is moderate in managing chronic discogenic low back pain, whereas for annuloplasty the evidence is limited. Among the various techniques utilized for percutaneous disc decompression, the evidence is moderate for short-term and limited for long-term relief for automated percutaneous lumbar discectomy, and percutaneous laser discectomy, whereas it is limited for nucleoplasty and for DeKompressor technology. For vertebral augmentation procedures, the evidence is moderate for both vertebroplasty and kyphoplasty. The evidence for spinal cord stimulation in failed back surgery syndrome and complex regional pain syndrome is strong for short-term relief and moderate for long-term relief. The evidence for implantable intrathecal infusion systems is strong for short-term relief and moderate for long-term relief. CONCLUSION: These guidelines include the evaluation of evidence for diagnostic and therapeutic procedures in managing chronic spinal pain and recommendations for managing spinal pain. However, these guidelines do not constitute inflexible treatment recommendations. These guidelines also do not represent a "standard of care."

Opioid guidelines in the management of chronic non-cancer pain.

BACKGROUND: Opioid abuse has increased at an alarming rate. However, available evidence suggests a wide variance in the use of opioids, as documented by different medical specialties, medical boards, advocacy groups, and the Drug Enforcement Administration (DEA). OBJECTIVES: The objective of these opioid guidelines by the American Society of Interventional Pain Physicians (ASIPP) is to provide guidance for the use of opioids for the treatment of chronic non-cancer pain, to bring consistency in opioid philosophy among the many diverse groups involved, to improve the treatment of chronic non-cancer pain, and to reduce the incidence of drug diversion. DESIGN: A policy committee evaluated a systematic review of the available literature regarding opioid use in managing chronic non-cancer pain. This resulted in the formulation of the essentials of guidelines, a series of potential evidence linkages representing conclusions, followed by statements regarding relationships between clinical interventions and outcomes. METHODS: Consistent with the Agency for Healthcare Research and Quality (AHRQ) hierarchical and comprehensive standards, the elements of the guideline preparation process included literature searches, literature synthesis, systematic review, consensus evaluation, open forum presentations, formal endorsement by the Board of Directors of the American Society of Interventional Pain Physicians (ASIPP), and blinded peer review. Evidence was designated based on scientific merit as Level I (conclusive), Level II (strong), Level III (moderate), Level IV (limited), or Level V (indeterminate). RESULTS: After an extensive review and analysis of the literature, the authors utilized two systematic reviews, two narrative reviews, 32 studies included in prior systematic reviews, and 10 additional studies in the synthesis of evidence. The evidence was limited. CONCLUSION: These guidelines evaluated the evidence for the use of opioids in the management of chronic non-cancer pain and recommendations for management. These guidelines are based on the best available scientific evidence and do not constitute inflexible treatment recommendations. Because of the changing body of evidence, this document is not intended to be a "standard of care."

Evidence-based practice guidelines for interventional techniques in the management of chronic spinal pain.

Evidence-based practice guidelines for interventional techniques in the management of chronic spinal pain are systematically developed and professionally derived statements and recommendations that assist both physicians and patients in making decisions about appropriate health care in the diagnosis and treatment of chronic or persistent pain. The guidelines were developed utilizing an evidence-based approach to increase patient access to treatment, to improve outcomes and appropriateness of care, and to optimize cost-effectiveness. All types of relevant and published evidence and consensus were utilized. The guidelines include a discussion of their purpose, rationale, and importance, including descriptions of the patient population served, the methodology, and the pathophysiologic basis for intervention. Multiple diagnostic and therapeutic interventional techniques are included in this document. Strong evidence was shown for diagnostic facet joint blocks for the diagnosis of facet joint pain, and lumbar provocative discography for discogenic pain. Moderate evidence was shown for sacroiliac joint blocks in the diagnosis of sacroiliac joint pain, and for transforaminal epidural injections in the preoperative evaluation of patients with negative or inconclusive imaging studies, but with clinical findings of nerve root irritation. Moderate to strong evidence was shown for multiple therapeutic interventional techniques including medial branch blocks and medial branch neurotomy; caudal epidural steroid injections and transforaminal epidural steroid injections; lumbar percutaneous adhesiolysis; and implantable therapies. These guidelines do not constitute inflexible treatment recommendations. It is expected that a provider will establish a plan of care on a case-by-case basis, taking into account an individual patient's medical condition, personal needs, and preferences, and the physician's experience. Based on an individual patient's needs, treatment different from that outlined here could be warranted. These guidelines do not represent "standard of care."

Role of digital subtraction fluoroscopic imaging in detecting intravascular injections.

Complications of unintended intravascular penetration and subsequent injection of local anesthetics and/or other drugs occasionally are devastating. Multiple reports have related to unrecognized intravascular placement of the needle. The generally accepted technique during interventional techniques is intermittent fluoroscopy. In fact, this may miss vascular uptake due to rapid washout. Thus, digital subtraction, the commonly accepted standard for documenting angiography and venography, may be a useful tool for documentation of and/or avoidance of intravascular placement of the needle and subsequent injections with interventional techniques. This case report involves description of digital subtraction to enhance visualization of contrast distribution during injection. Three series of images are included from atlanto-occipital joint, caudal epidural catheterization, and a cervical transforaminal injection. The case reports demonstrate that digital subtraction fluoroscopic imaging is superior to intermittent or live fluoroscopy in detecting intravascular injections with interventional techniques.

Is digital subtraction flouroscopy a useful tool for the interventional pain physician?

Most interventional pain physicians are experts in the use of fluoroscopy and understand its importance in improving the safety, accuracy and efficacy of diagnostic and therapeutic procedures. The addition of digital subtraction may enhance the utility of radiography and improve the accuracy of our interpretations. This article illustrates the use of the technique in several patients. The utility of this enhanced technique in clinical versus research application remains to be determined.