Neurology & Pain Management Coding Alert

When conducting electrodiagnostic (EDX) tests, neurologists must be cautious not to exceed the allowable number of procedures that an insurer will recognize to confirm a given diagnosis or differentiate between possible diagnoses. By following the American Association of Electrodiagnostic Medicine's (AAEM) recommendations and communicating with payers, neurology practices can minimize claim denials and accusations of abuse or overutilization.

Although each patient is unique, physician advocacy groups and insurers agree that there is a reasonable limit to the number of diagnostic studies (e.g., electromyography, nerve conduction studies, H-reflex) necessary to confirm or differentiate a given diagnosis(es). "You can't test and bill indiscriminately," warns Tiffany Schmidt, JD, policy director for the AAEM. "Overutilization and overbilling harms the patient and adversely affects reimbursement for all physicians."

To aid physicians and coders in preventing abuse and overutilization, the AAEM has developed a chart listing the "maximum number of tests necessary in 90 percent of cases" (see page 75), to which many insurers look when designing medical review policies. The number of tests varies according to the suspected condition(s) or diagnosis(es). "In simple, straightforward cases, fewer tests will be necessary. This is particularly true when results of the most critical tests are normal," Schmidt explains.

For instance, the AAEM Recommended Policy for Electrodiagnosic Testing states that a minimal evaluation for radiculopathy "includes one motor and one sensory NCS [nerve conduction study] and a needle EMG [electromyography] examination of the involved limb" but that testing can include "up to three motor NCSs (in cases of an abnormal motor NCS, the same nerve in the contralateral limb and another motor nerve in the ipsilateral limb can be studied) and two sensory NCSs." The AAEM policy further notes that H-reflexes and F-waves may provide complementary data to evaluate suspected radiculopathy.

Testing guidelines for mononeuropathy, for example, differ: To exclude radiculopathy, plexopathy or polyneuropathy, the policy notes, "It may be necessary to study three motor and three sensory nerves including the clinically affected nerve, the same nerve on the contralateral side and an unaffected ipsilateral nerve. F-wave studies provide additional diagnostic information. A needle EMG examination in the affected limb is indicated."

In a minority of cases (about 10 percent or fewer), the AAEM's recommended maximum number of tests for a given diagnosis may not provide sufficient information to properly evaluate the patient's condition. "In very complex cases, the maximum numbers in the table will be insufficient for the physician to arrive at a complete diagnosis," Schmidt says. "Also, in cases where there are borderline findings, additional tests may be required to determine if the findings are significant."

"One common circumstance is where the diagnosis found does not fully explain the patient's condition," says Neil Busis, MD, chief of the division of neurology and director of the neurodiagnostic laboratory at the University of Pittsburgh Medical Center at Shadyside, and clinical associate professor in the department of neurology, University of Pittsburgh School of Medicine.

"For example, a patient has a numb arm, and the only thing found after lots of tests is carpal tunnel syndrome [354.0] which doesn't explain all the patient's signs and symptoms. The number of tests allowed for CTS is far smaller than the number needed to diagnose that patient."

Schmidt agrees that there are numerous situations in which it may be necessary for an EDX consultant to perform tests not specifically ordered by the referring physician. "For example," she says, "when a patient is referred with a provisional diagnosis of carpal tunnel syndrome on the right, it is frequently necessary to perform electrodiagnostic studies on the patient's left side for comparison purposes."

"Another situation where the table falls down is when there are two diagnoses found," Busis continues. "The text explaining the AAEM recommendations explicitly states that the table does not apply in these cases."

Both Medicare and third-party insurers frequently state in their medical review policies for EDX testing that claims exceeding the AAEM recommendations "should be reviewed for medical necessity." The implication is that payers will apply additional scrutiny to such claims and therefore the neurologist must carefully document the need for additional testing. In the first example above, for instance, Busis explains that the examiner must submit two ICD-9 codes: one to describe the unexplained symptoms (e.g., numbness or weakness) and one for the CTS. "This signifies that CTS was not the whole story," he says.

Busis further notes that unlike CPT, ICD-9 has no modifier to describe a bilateral condition, which may require additional testing. "The numbers for unilateral and bilateral CTS in the [AAEM] table are different, but there is no way to flag the bilateral patients automatically." You will need to submit supplemental information, such as the patient note and the physician EMG report. "If you want to dictate a separate rationale for the study, that is OK, too," Busis says.

If payers balk at reimbursing for necessary procedures that nevertheless exceed the AAEM recommendations, remind them that diagnostic judgments based on inadequate information lower the quality of patient care and increase the risk of patient injury due to incorrect diagnosis, misdiagnosis or improper treatment.

"In addition," the AAEM's recommended policy stresses, "underutilization of needed diagnostic testing may cost payers money. If the physician does not get the full information needed for proper diagnosis from an initial consultation because the evaluation is inadequate, the consultation may need to be repeated in a more thorough manner with additional expense."

Neurologists must also be cautious not to bill EDX tests too frequently for the same patient. Aetna U.S. Healthcare's coverage policy bulletin for NCS (which is typical) states, "Utilization of nerve conduction studies at a frequency of two sessions per year would be considered appropriate for most conditions (e.g., unilateral or bilateral carpal tunnel syndrome, radicu-lopathy, mononeuropathy, polyneuropathy, myopathy and neuromuscular junction disorders). Nerve conduction velocity studies performed more frequently than twice a year should be reviewed for medical necessity."

As noted by the AAEM-recommended policy, there are clinical situations where a patient may require repeat testing (perhaps in as much as 20 percent of cases). Examples include the development of a new condition (i.e., a diagnosis is made on the first visit, but the patient subsequently develops a new set of symptoms); an inconclusive diagnosis such as when a serious diagnosis is suspected but the results of the needle EMG/NCS examination are insufficient when the patient has a rapidly developing disease (e.g., Guillain-Barr syndrome) or if the course of a disease changes unexpectedly; or if a patient is recovering from an injury (e.g., traumatic nerve injury) and requires repeat evaluations to monitor recovery, to help establish prognosis and/or to determine the need for and timing of surgical intervention.

If the physician determines that a patient's condition requires EDX testing in excess of a payer's frequency guidelines and he or she can document medical necessity the payer should recognize the claim. In such situations, the AAEM recommends that the reason for the repeat study be included in the body of the report or in the patient's chart and that the physician document a comparison with the previous test results.