LAC 40:I.2019
C. Magnetic resonance imaging (MRI), myelography, or computed axial tomography (CT) scanning following myelography, and other imaging procedures and testing may provide useful information for many spinal disorders. When a diagnostic procedure, in conjunction with clinical information, can provide sufficient information to establish an accurate diagnosis, the second diagnostic procedure will become a redundant procedure. At the same time, a subsequent diagnostic procedure can be a complementary diagnostic procedure if the first or preceding procedures, in conjunction with clinical information, cannot provide an accurate diagnosis. Usually, preference of a procedure over others depends upon availability, a patient’s tolerance, and/or the treating practitioner’s familiarity with the procedure. Subsequent MRI may be indicated with a change in neurological exam, change in symptoms or a contemplated surgical intervention.
1. Imaging studies are generally accepted, well-established and widely used diagnostic procedures. In the absence of myelopathy, or neurological changes, or history of cancer, imaging usually is not appropriate until conservative therapy has been tried and failed. Six to eight weeks of treatment are usually an adequate period of time before an imaging procedure is in order, but the clinician should use judgment in this regard. When indicated, imaging studies can be utilized for further evaluation of the low back, based upon the mechanism of injury, symptoms, and patient history. Prudent choice of a single diagnostic procedure, a complementary combination of procedures, or a proper sequential order of complementary procedures will help ensure maximum diagnostic accuracy and minimize adverse effect to the patient. When the findings of the diagnostic imaging and testing procedures are not consistent with the clinical examination, the clinical findings should have preference. There is good evidence that in the asymptomatic population, disc bulges, annular tears, or high intensity zone areas, and disc height loss are prevalent 40 to 60 percent of the time depending on the condition, study, and age of the patient. Therefore, the existence of these anatomic findings should not be considered relevant without physiologic and clinical correlation in an individual patient. The studies below are listed in frequency of use, not importance:
a. Magnetic Resonance Imaging (MRI) is rarely indicated in patients with non-traumatic acute low back pain with no neuropathic signs or symptoms. It is generally the first follow-up imaging study in individuals who respond poorly to proper initial conservative care. MRI is useful in suspected nerve root compression, myelopathy, masses, infections, metastatic disease, disc herniation, annular tear, and cord contusion or severe incapacitating pain. MRI is contraindicated in patients with certain implants.
ii. Specialized MRI Scans
2. Other Tests. The following diagnostic procedures in this subsection are listed in alphabetical order, not by importance:
a. Electrodiagnostic Testing
i. Electromyography (EMG), Nerve Conduction Studies (NCS) These are generally accepted, well-established and widely used diagnostic procedures. EMG and NCS, when performed and interpreted by a trained physician/electrophysiologist, may be useful for patients with suspected neural involvement whose symptoms are persistent or unresponsive to initial conservative treatments. They are used to differentiate peripheral neural deficits from radicular and spinal cord neural deficits and to rule out concomitant myopathy. However, F-Wave Latencies are not diagnostic for radiculopathy.
b. Injections—Diagnostic
iv. In general, relief should last for at least the duration of the local anesthetic used and should significantly result in functional improvement and relief of pain. Refer to Injections-Spinal Therapeutic for information on other specific therapeutic injections.
(c). The interpretation of the test results are primarily based on functional change, symptom report, and pain response (via a recognized pain scale), before and at an appropriate time period after the injection. The diagnostic significance of the test result should be evaluated in conjunction with clinical information and the results of other diagnostic procedures. Injections with local anesthetics of differing duration may be used to support a diagnosis. In some cases, injections at multiple levels may be required to accurately diagnose low back pain.
(f). Contraindications
(g). Specific Diagnostic Injections. In general, relief should last for at least the duration of the local anesthetic used and should significantly relieve pain and result in functional improvement. Refer to “Injections – Therapeutic” for information on specific therapeutic injections.
c. Personality/ Psychological/ Psychiatric/ Psychosocial Evaluation. These are generally accepted and well-established diagnostic procedures with selective use in the low back population, but have more widespread use in subacute and chronic low back populations. Diagnostic testing procedures may be useful for patients with symptoms of depression, delayed recovery, chronic pain, recurrent painful conditions, disability problems, and for preoperative evaluation. Psychological/psychiatric /psychosocial and measures have been shown to have predictive value for postoperative response, and therefore should be strongly considered for use pre-operatively when the surgeon has concerns about the relationship between symptoms and findings, or when the surgeon is aware of indications of psychological complication or risk factors for psychological complication (e.g. childhood psychological trauma). Psychological testing should provide differentiation between pre-existing conditions versus injury caused psychological conditions, including depression and posttraumatic stress disorder. Psychological testing should incorporate measures that have been shown, empirically, to identify comorbidities or risk factors that are linked to poor outcome or delayed recovery.
i. Formal psychological or psychosocial evaluation should be performed on patients not making expected progress within 6 to 12 weeks following injury and whose subjective symptoms do not correlate with objective signs and test results. In addition to the customary initial exam, the evaluation of the injured worker should specifically address the following areas:
ii. Personality/ psychological/ psychiatric / psychosocial evaluations consist of two components, clinical interview and psychological testing. Results should help clinicians with a better understanding of the patient in a number of ways. Thus, the evaluation result will determine the need for further psychosocial interventions; and in those cases, Diagnostic and Statistical Manual of Mental Disorders (DSM) diagnosis should be determined and documented. The evaluation should also include examination of both psychological comorbidities and psychological risk factors that are empirically associated with poor outcome and/or delayed recovery. An individual with a Ph.D., Psy.D, or psychiatric M.D./D.O. credentials should perform initial evaluations, which are generally completed within one to two hours. A professional fluent in the primary language of the patient is preferred. When such a provider is not available, services of a professional language interpreter should be provided.
(b). Clinical Evaluation. At the discretion of the evaluating physician, clinical evaluation may address the following areas:
(c). Tests of Psychological Functioning. Psychometric testing is a valuable component of a consultation to assist the physician in making a more effective treatment plan. Psychometric testing is useful in the assessment of mental conditions, pain conditions, cognitive functioning, treatment planning, vocational planning, and evaluation of treatment effectiveness. There is no general agreement as to which standardized psychometric tests should be specifically recommended for psychological evaluations of pain conditions. It is appropriate for the mental health provider to use their discretion and administer selective psychometric tests within their expertise and within standards of care in the community. Some of these tests are available in Spanish and other languages, and many are written at a sixth grade reading level. Examples of frequently used psychometric tests performed include, but not limited to, the following.
(d). Comprehensive Psychological Inventories. These tests are designed for detecting various psychiatric syndromes, but in general are more prone to false positive findings when administered to medical patients.
(e). Brief Multidimensional Screens for Medical Patients. Treating providers, to assess a variety of psychological and medical conditions, including depression, pain, disability and others, may use brief instruments. These instruments may also be employed as repeated measures to track progress in treatment, or as one test in a more comprehensive evaluation. Brief instruments are valuable in that the test may be administered in the office setting and hand scored by the physician. Results of these tests should help providers distinguish which patients should be referred for a specific type of comprehensive evaluation.
(f). Brief Multidimensional Screens for Psychiatric Patients. These tests are designed for detecting various psychiatric syndromes, but in general are more prone to false positive findings when administered to medical patients.
(g). Brief Specialized Psychiatric Screening Measures
d. Provocation Discography
ii. Indications. Discography may be indicated when a patient has a history of functionally limiting, unremitting low back pain of greater than four months duration, with or without leg pain, which has been unresponsive to all conservative interventions. A patient who does not desire operative therapeutic intervention is not a candidate for an invasive non-therapeutic intervention, such as provocation discography.
iii. Pre-conditions for provocation discography include all of the following.
v. Contraindications-include:
vi. Special Considerations
vii. Reporting of Discography. In addition to a narrative report, the discography report should contain a standardized classification of disc morphology the pain response, and the pressure at which pain is produced. All results should be clearly separated in the report from the narrative portion. Asymptomatic annular tears are common and the concordant pain response is an essential finding for a positive discogram.
(b). Caution should be used when interpreting results from discography. Several studies indicate that a false positive discogram for pain is likely above a pressure reading of 50 psi above opening pressure. The false positive rate appears to drop to approximately 25 percent using a pressure of 20 psi above opening pressure in a population with low back pain.
(i). Reporting disc morphology as visualized by the post-injection CT scan (when available) should follow the Modified Dallas Discogram Scale where:
[a]. Grade 0 = Normal Nucleus
[b]. Grade 1 = Annular tear confined to inner one-third of annulus fibrosis.
[c]. Grade 2 = Annular tear extending to the middle third of the annulus fibrosis.
[d]. Grade 3 = Annular tear extending to the outer one-third of the annulus fibrosis.
[e]. Grade 4 = A grade 3 tear plus dissection within the outer annulus to involve more than 30 degrees of the disc circumference.
[f]. Grade 5 = Full thickness tear with extra-annular leakage of contrast, either focal or diffuse.
(ii). Reporting of pain response should be consistent with the operational criteria of the International Spine Intervention Society (ISIS) Guidelines or American Society of Interventional Pain Physicians (ASIPP) Guidelines. The report must include the level of concordance for back pain and /or leg pain using a 10-point VAS, or similar quantitative assessment. It should be noted that change in the VAS scale before and after provocation is more important than the number reported.
[a]. Unequivocal Discogenic Pain
[i]. stimulation of the target disc reproduces concordant pain
[ii]. the pain should be registered at least 7 on a 10-point VAS.
[iii]. the pain is reproduced at a pressure of less than 15 psi above opening pressure; and
[iv]. stimulation of two adjacent discs does not produce pain at all
[b]. Definite Discogenic Pain
[i]. stimulation of the target disc reproduces concordant pain
[ii]. the pain should be registered as at least 7 on a 10-point VAS.
[iii]. the pain is reproduced at a pressure of less than 15 psi above opening pressure; and
[iv]. stimulation of at least one adjacent disc does not produce pain at all
[c]. Highly Probable Discogenic Pain
[i]. stimulation of the target disc reproduces concordant pain
[ii]. that pain should be registered as at least 7 on a 10-point VAS.
[iii]. that the pain is reproduced at a pressure of less than 50 psi above opening pressure; and,
[iv]. stimulation of two adjacent discs does not produce pain at all
[d]. Probable Discogenic Pain
[i]. stimulation of the target disc reproduces concordant pain;
[ii]. that pain should be registered as at least 7 on a 10-point VAS;
[iii]. the pain is reproduced at a pressure of less than 50 psi above opening pressure; and
[iv]. stimulation of one adjacent disc does not produce pain at all, and stimulation of another adjacent disc at greater than 50 psi, produces pain, but the pain is not concordant.
[e]. Multiple combinations of factors are possible. However, if the patient does not qualify for at least a ‘Probable Discogenic Pain’ level, then the discogram should be considered negative. The VAS score prior to the discogram should be taken into account when interpreting the VAS score reported by the patient during the discogram.
[i]. Time Parameters for Provocation Discography are as follows:
aa. Frequency: One time only
bb. Maximum: Repeat Discography is rarely indicated
3. Special tests are generally well-accepted tests and are performed as part of a skilled assessment of the patients’ capacity to return to work, his/her strength capacities, and physical work demand classifications and tolerance. The procedures in this subsection are listed in alphabetical order, not by importance.
a. Computer-Enhanced Evaluations: may include isotonic, isometric, isokinetic and/or isoinertial measurement of movement, range of motion, endurance, or strength. Values obtained can include degrees of motion, torque forces, pressures, or resistance. Indications include determining validity of effort, effectiveness of treatment and demonstrated motivation. These evaluations should not be used alone to determine return to work restrictions.
b. Functional capacity evaluation (FCE) is a comprehensive or modified evaluation of the various aspects of function as they relate to the worker’s ability to return to work. FCEs should not be used as the sole criteria to diagnose malingering. Areas such as endurance, lifting (dynamic and static), postural tolerance, specific range of motion (ROM), coordination and strength, worker habits, employability as well as psychosocial, cognitive, and sensory perceptual aspects of competitive employment may be evaluated. Reliability of patient reports and overall effort during testing is also reported. Components of this evaluation may include: musculoskeletal screen; cardiovascular profile/aerobic capacity; coordination; lift/carrying analysis; job-specific activity tolerance; maximum voluntary effort; pain assessment/psychological screening; and non-material and material handling activities. Standardized national guidelines (such as National Institute for Occupational Safety and Health (NIOSH)) should be used as the basis for FCE recommendations.
i. When an FCE is being used to determine return to a specific jobsite, the provider is responsible for fully understanding the physical demands and the duties of the job that the worker is attempting to perform. A jobsite evaluation is frequently necessary. A job description should be reviewed by the provider and FCE evaluator prior to this evaluation. FCEs cannot be used in isolation to determine work restrictions. It is expected that the FCE may differ from both self-report of abilities and pure clinical exam findings. The length of a return to work evaluation should be based on the judgment of the referring physician and the provider performing the evaluation. Since return to work is a complicated multidimensional issue, multiple factors beyond functional ability and work demands should be considered and measured when attempting determination of readiness or fitness to return to work. The authorized treating physician must interpret the FCE in light of the individual patient's presentation and medical and personal perceptions. FCEs should not be used as the sole criteria to diagnose malingering.
c. Jobsite Evaluation—a comprehensive analysis of the physical, mental, and sensory components of a specific job. The goal of the Jobsite evaluation is to identify any job modification needed to ensure the safety of the employee upon return to work. These components may include, but are not limited to: postural tolerance (static and dynamic); aerobic requirements; range of motion (ROM); torque/force; lifting/carrying; cognitive demands; social interactions; visual perceptual; sensation; coordination; environmental requirements of a job; repetitiveness; essential job functions; and ergonomic set up. Job descriptions provided by the employer are helpful but should not be used as a substitute for direct observation.
ii. Requests for a jobsite evaluation should describe the expected goals for the evaluation. Goals may include, but are not limited to the following:
(e). to give detailed work/activity restrictions.
d. Vocational Assessment. The vocational assessment should provide valuable guidance in the determination of future rehabilitation program goals. It should clarify rehabilitation goals, which optimize both patient motivation and utilization of rehabilitation resources. If prognosis for return to former occupation is determined to be poor, except in the most extenuating circumstances, vocational assessment should be implemented within 3 to 12 months post-injury. Declaration of Maximum Medical Improvement (MMI) should not be delayed solely due to lack of attainment of a vocational assessment.
e. Work Tolerance Screening (Fitness for Duty) - a determination of an individual's tolerance for performing a specific job as based on a job activity or task and may be used when a full Functional Capacity Evaluation is not indicated. It may include a test or procedure to specifically identify and quantify work-relevant cardiovascular, physical fitness and postural tolerance. It may also address ergonomic issues affecting the patient’s return-to-work potential.
AUTHORITY NOTE: Promulgated in accordance with R.S. 23:1203.1.
HISTORICAL NOTE: Promulgated by the Louisiana Workforce Commission, Office of Workers Compensation Administration, LR 37:1658 (June 2011), amended by the Louisiana Workforce Commission, Office of Workers Compensation, LR 40:1137 (June 2014), LR 46:1246 (September 2020), LR 49:519 (March 2023).