Christopher T. Plastaras

Symptom provocation of fluoroscopically guided cervical nerve root stimulation. Are dynatomal maps identical to dermatomal maps

Study Design. This prospective study consisted of mechanical stimulation of cervical nerve roots C4 to C8 in patients with cervical radicular symptoms undergoing diagnostic selective nerve root block. Objectives. To document the distribution of pain and paresthesias that result from stimulation of specific cervical nerve roots and compare that distribution to documented sensory dermatomal maps. Summary of Background Data. Cervical dermatomes were first studied in the late 19th century. The results of those studies underpin current clinical decision making for patients with neck and arm pain. However, it has been observed that patients with radicular symptoms may have cervical pathology by radiographic imaging that is not corroborative, or have imaging studies that suggest a lesion at a level other than the one suggested by the patients dermatomal symptoms. These observations may suggest that cervical dermatomal mapping is inaccurate or the distribution of referred symptoms (dynatome) from cervical root irritation is different than the sensory deficit outlined by dermatomal maps. Methods. Inclusion criteria consisted of consecutive patients undergoing fluoroscopically guided diagnostic cervical selective nerve root blocks from C4 to C8. Immediately preceding contrast injection, mechanical stimulation of the root was performed. An independent observer interviewed and recorded the location of provoked symptoms on a pain diagram. Visual data was subsequently compiled using a 793 body sector bit map. Forty‐three clinically relevant body regions were defined on this bit map. Frequencies of symptom provocation and likelihood of symptom location from C4 to C8 stimulation of each nerve root were generated. Results. One hundred thirty‐four cervical nerve root stimulations were performed on 87 subjects. There were 4 nerve root stimulations at C4, 14 at C5, 43 at C6, 52 at C7, and 21 at C8. Analyzing the frequency of involvement of the predetermined clinically relevant body regions either individually or in various combinations yielded more than 1,000 bits of data. Although the distribution of symptom provocation resembled the classic dermatomal maps for cervical nerve roots, symptoms were frequently provoked outside of the distribution of classic dermatomal maps. Conclusion. The current study demonstrates a distinct difference between dynatomal and dermatomal maps.

Fluoroscopically guided therapeutic sacroiliac joint injections for sacroiliac joint syndrome.

Slipman CW, Lipetz JS, Plastaras CT, Jackson HB, Vresilovic EJ, Lenrow DA, Debra L. Braverman DL: Fluoroscopically guided therapeutic sacroiliac joint injections for sacroiliac joint syndrome. Am J Phys Med Rehabil 2001;80:425–432. ObjectiveTo investigate the outcomes resulting from the use of fluoroscopically guided therapeutic sacroiliac joint injections in patients with sacroiliac joint syndrome. DesignA retrospective study design with independent clinical review was utilized. Thirty-one patients were included; each patient met specific physical examination criteria and failed to improve clinically after at least 4 wk of physical therapy. Each patient demonstrated a positive response to a fluoroscopically guided diagnostic sacroiliac joint injection. Therapeutic sacroiliac joint injections were administered in conjunction with physical therapy. Outcome measures included Oswestry scores, Visual Analog Scale pain scores, work status, and medication usage. ResultsPatients’ symptom duration before diagnostic injection averaged 20.6 mo. An average of 2.1 therapeutic injections was administered. Follow-up data collection was obtained at an average of 94.4 wk. A significant reduction (P = 0.0014) in Oswestry disability score was observed at the time of follow-up. Visual Analog Scale pain scores were reduced (P < 0.0001) at the time of discharge and at follow-up. Work status was also significantly improved at the time of discharge (P = 0.0313) and at follow-up (P = 0.0010). A trend (P = 0.0645) toward less drug usage was observed. ConclusionsThese initial findings suggest that fluoroscopically guided therapeutic sacroiliac joint injections are a clinically effective intervention in the treatment of patients with sacroiliac joint syndrome. Controlled, prospective studies are necessary to further clarify the role of therapeutic injections in this patient population.

Comparative Effectiveness of Lumbar Transforaminal Epidural Steroid Injections with Particulate Versus Nonparticulate Corticosteroids for Lumbar Radicular Pain due to Intervertebral Disc Herniation: A Prospective, Randomized, Double-Blind Trial

BACKGROUND Lumbar transforaminal epidural injections are commonly utilized to treat radicular pain due to intervertebral disc herniation. OBJECTIVE This study aims to determine if there was a major difference in effectiveness between particulate and nonparticulate corticosteroids for acute radicular pain due to lumbar disc herniation. DESIGN A multicenter, double blind, prospective, randomized trial on 78 consecutive subjects with acute uni-level disc herniation resulting in unilateral radicular pain. All subjects received a single level transforaminal epidural steroid injection with either dexamethasone or triamcinolone. Repeat injections were allowed as determined by the blinded physician and subjects. Primary outcomes included: number of injections received, surgical rates, and categorical pain scores at 2 weeks, 3 months, and 6 months. Secondary outcomes included mean Oswestry Disability Index. RESULTS Both triamcinolone and dexamethasone resulted in statically significant improvements in pain and function at 2 weeks, 3 months, and 6 months, without clear differences between groups. The surgical rates were comparable with 14.6% of the dexamethasone group and 18.9% of the triamcinolone group receiving surgery. There was a statistically significant difference in the number of injections received, with 17.1% of the dexamethasone group receiving three injections vs only 2.7% of the triamcinolone group. CONCLUSIONS Transforaminal epidural corticosteroid injections are an effective treatment for acute radicular pain due to disc herniation, and frequently only require 1 or 2 injections for symptomatic relief. Dexamethasone appears to possess reasonably similar effectiveness when compared with triamcinolone. However, the dexamethasone group received slightly more injections than the triamcinolone group to achieve the same outcomes.

The Rate of Detection of Intravascular Injection in Cervical Transforaminal Epidural Steroid Injections With and Without Digital Subtraction Angiography

To determine whether digital subtraction angiography (DSA) combined with real‐time fluoroscopic imaging improves the detection rate of intravascular injection during cervical transforaminal epidural steroid injections (CTFESIs).

The Effect of Long-Distance Bicycling on Ulnar and Median Nerves An Electrophysiologic Evaluation of Cyclist Palsy

Background Distal ulnar neuropathies have been identified in cyclists because of prolonged grip pressures on handlebars. The so-called cyclist palsy has been postulated to be an entrapment neuropathy of the ulnar nerve in the Guyon canal of the wrist. Previous studies utilizing nerve conduction studies have typically been either case reports or small case series. Hypothesis Electrophysiologic changes will be present in the ulnar and median nerves after a long-distance multiday cycling event. Study Design Cohort study; Level of evidence, 2. Methods A total of 28 adult hands from 14 subjects underwent median and ulnar motor and sensory nerve conductions, which were performed on both hands before and after a 6-day, 420-mile bike tour. A ride questionnaire was also administered after the ride, evaluating the experience level of the cyclist, equipment issues, hand position, and symptoms during the ride. Results Distal motor latencies of the deep branch of the ulnar nerve to the first dorsal interosseous were significantly prolonged after the long-distance cycling event. The median motor and sensory studies as well as the ulnar sensory and motor studies of the abductor digiti minimi did not change significantly. Electrophysiologic and symptomatic worsening of carpal tunnel syndrome was observed in 3 hands, with the onset of carpal tunnel syndrome in 1 hand after the ride. Conclusion Long-distance cycling may promote physiologic changes in the deep branch of the ulnar nerve and exacerbate symptoms of carpal tunnel syndrome.

The practical management of Achilles tendinopathy.

The Achilles tendon, named after the legendary warrior and hero of Homer’s Iliad, is the strongest and thickest tendon in the human body. Despite this fact, Achilles tendinopathy is a common overuse injury, particularly in runners and other athletes. Kujala et al showed a 10-fold increase in Achilles injuries in runners compared with age-matched controls. Another study reported the incidence of Achilles tendinopathy in top-level runners as 7% to 9%. The specific factors linking this injury with running include excessive mileage, sudden increase in training intensity, decrease in recovery time, change of running surface, and poor footwear. This injury also is common in athletes who compete in racquet sports, track and field, volleyball, and soccer. Other factors that have been associated with Achilles tendinopathy include various biomechanical deficits, older age, male gender, increased body weight and height, and fluoroquinolone exposure.

Therapeutic zygapophyseal joint injections for headaches emanating from the C2-3 joint.

Slipman CW, Lipetz JS, Plastaras CT, Jackson HB, Yang ST, Meyer AM: Therapeutic zygapophyseal joint injections for headaches emanating from the C2-3 joint. Am J Phys Med Rehabil 2001;80:182–188. ObjectiveTo report our experience using fluoroscopically guided therapeutic intra-articular C2-3 zygapophyseal joint injections in patients with chronic headaches after a whiplash event. DesignRestrospective study (n = 18 patients) with independent clinical review. Each patient experienced persistent daily headache symptoms which failed to improve after at least 3 mo of physical therapy, activity restriction, and the use of oral analgesics. Each patient demonstrated initially a positive response to a diagnostic intra-articular C2-3 joint injection. Data collection and analysis were performed by an independent clinical reviewer. Outcome measures included headache frequency, medication usage, symptom response to medication, and employment status. ResultsPatients’ symptom duration before diagnostic injection averaged 34 mo. Follow-up data collection transpired at an average of 19 mo after the final therapeutic injection. In 61% of patients, fewer than three headaches were experienced each week; these headaches were relieved with the use of oral analgesics. ConclusionsAlthough the inherent limitations of this study preclude a definitive statement regarding the efficacy of C2-3 injections, these initial findings suggest that therapeutic intra-articular zygapophyseal joint injections are effective in the treatment of headaches emanating from the C2-3 joint after a whiplash event. Future controlled, prospective studies are necessary to clarify the role of such injections in this challenging patient population.

Utility of the anesthetic test dose to avoid catastrophic injury during cervical transforaminal epidural injections

BACKGROUND CONTEXT Reports of serious complications from cervical transforaminal epidural corticosteroid injections often consider accidental intra-arterial injection the most likely mechanism of injury. As a result, many physicians have instituted methods to prevent intravascular injections. Routine use of the anesthetic test dose is one such method. The utility of the anesthetic test dose in this function has not been characterized in the current literature. PURPOSE The aim of this study was to determine the utility of injecting an anesthetic test dose before cervical transforaminal epidural corticosteroid injection and estimate the rate of false-negative intravascular contrast injection using live fluoroscopy and digital subtraction angiography (DSA). STUDY DESIGN Two-center retrospective study. PATIENT SAMPLE A consecutive cohort of men and women, ages of 23 to 83, who underwent cervical transforaminal epidural injection and received the anesthetic test dose after contrast injection was negative for vascular uptake, observed using live fluoroscopy or DSA. OUTCOME MEASURES Response to the anesthetic test dose was documented in each procedure note and recorded as either positive or negative. METHODS Records of three physiatrists at two academic spine centers (Center A and Center B) were reviewed to identify all patients who received a cervical transforaminal epidural injection during the preceding 5 years, resulting in a cohort of consecutively treated patients at each center. Each patient record was reviewed for demographics, indication for injection, procedure level and side, needle gauge, use of DSA, volume and type of anesthetic test dose used, and result of test dose injection. The test dose was considered positive if the following occurred: agitation or other sudden central nervous system change; gross motor deficits and/or paresthesias in the trunk, legs, or contralateral arm; systemic symptoms of anesthetic toxicity including cardiac arrhythmia, perioral numbness, metallic taste, dizziness, and/or ringing in the ear. For analysis, injections were separated into groups to compare results at Center A to Center B and to compare injections that used DSA to those that did not. The incidence of a positive response was calculated as a percentage from the total number of injections in the group. Differences between groups were analyzed for statistical significance using the Fisher exact test. RESULTS Six hundred seventy-eight injections were included. Of these, 349 were performed at Center A with test doses given after contrast injection under live fluoroscopy. The remaining 329 were performed at Center B, 183 also using live fluoroscopy, and 146 using DSA. The overall incidence of a positive anesthetic test dose was 0.59% (4/678). There was no significant difference between the incidence at each of the two centers (0.86% [3/349] vs. 0.30% [1/329]; p=.63). The overall incidence after live fluoroscopy was 0.75% (4/532) and after DSA was 0% (0/146), but this difference was not statistically significant (p=.58). Positive symptoms elicited by test dose administration included midneck and contralateral arm pain, metallic taste, dizziness, tachycardia, full body paresthesias, auditory changes, slurred speech, and motor ataxia. In all four cases with a positive response, the procedure was immediately terminated, symptoms resolved, and no lasting complications were observed. CONCLUSIONS The routine use of an anesthetic test dose appears to be safe and capable of detecting potentially dangerous intravascular injections undetected by conventional techniques. Positive responses occur in a small portion of those who receive the test dose injection. Further studies are required to determine the optimal dose and concentration of anesthetic to be used and the time required for observation after test dose administration.

Electrodiagnostic challenges in the evaluation of lumbar spinal stenosis

Taken together, the most common electromyographic finding in lumbar spinal stenosis is bilateral multilevel radiculopathy. The sensitivity of electrodiagnostic testing for radiculopathy is difficult to quantify because there is no criterion standard. Differentiating peripheral neuropathy and lumbar spinal stenosis on electromyography and routine nerve-conduction studies can be clinically challenging, especially when the two entities may be present simultaneously in older patients.

Inadvertent intradiscal contrast flow during lumbar transforaminal epidural steroid injections: a case series examining the prevalence of intradiscal injection as well as potential associated factors and adverse events.

OBJECTIVES The primary aim was to evaluate the prevalence of inadvertent intradiscal injection during fluoroscopically guided contrast-enhanced lumbar transforaminal epidural steroid injections. The secondary aim was to determine if there are any risk factors for or adverse events as a result of inadvertent intradiscal contrast injection. DESIGN The study was a retrospective case series. SETTING The study was set in three outpatient spine care centers. PATIENTS A search was conducted in a database of spinal injection procedures from July 2000-May 2008. Fifteen cases of inadvertent intradiscal contrast flow were identified. These cases were matched with one control case with the same age, gender, level, and side of injection. INTERVENTIONS The prevalence of intradiscal contrast flow with lumbar transforaminal epidural steroid injection was calculated. Chart review of the cases and controls was performed. An independent, blinded examiner evaluated needle tip placement. OUTCOME MEASURES Frequency of intradiscal contrast flow during lumbar transforaminal epidural steroid injections and the relationship between the occurrence of intradiscal contrast flow with potential risk factors. RESULTS The prevalence of inadvertent intradiscal injection during lumbar transforaminal epidural steroid injections was 0.17%. All of the patients received prophylactic antibiotics after inadvertent disk injection, and there were no infectious or other complications identified. CONCLUSIONS Intradiscal contrast injection is an infrequently reported event during lumbar transforaminal epidural steroid injections. Our data support that the prevalence is very low and there might be an association with ipsilateral foraminal stenosis. Although there is potential for significant adverse complications with intradiscal injection, our data set did not show serious sequelae.