Part B Insider (Multispecialty) Coding Alert

Start learning the difference between vasoreactivity and emboli detection

Neurologists will rejoice at three new codes that allow them to bill more accurately for transcranial Doppler studies.

Starting in January, you'll have to separate these studies into vasoreactivity studies and emboli detection. According to a preliminary list of codes, CPT 93890 will cover "transcranial Doppler study of the intracranial arteries; vasoreactivity study." Meanwhile, 93892-93893 will have emboli detection after the semicolon, either without (93892) or with (93893) intravenous microbubble injection.

Transcranial Doppler studies produce a sonographic scan of carotid arteries that physicians can use to predict strokes and diagnose other problems related to artery stenosis or vasospasm, says physician Gregory Barkley, head of the neuromagnetism laboratory at the Henry Ford Health System in Detroit. These studies require more equipment, laboratory time and know-how than standard Doppler study codes 93866 and 93868.

The American Association for Neurology surveyed its members on physician work values for these new codes in 2003, and provided examples of the different studies. In both cases, the physician obtains waveforms and velocity and pulsatility index values. For the vasoreactivity study, the physician also obtains capnometer values in the resting, hypercapnic and hypocapnic states. For emboli detection, the physician reviews each "high intensity transient signal" and classifies it as artifacts or genuine embolic signals. The doctor compares the number of embolic signals before and after IV injection and notes any "shower" of embolic signals, then reviews the waveforms to assess the adequacy of the Vasalva maneuver based on any transient reduction in cerebral flow velocities.

Separately, neurologists will have some new codes for central motor evoked potential studies for upper limbs (95928) and lower limbs (95929). These join previously listed EP procedures 92585/92586 (auditory EPs), 95925-95927 (somatosensory EPs) and 95930 (visual EP).

"These new codes allow us to code for interpretation of the motor pathway centrally from the cortex through the spine and on to the peripheral muscle," says Gloria Galloway, Associate Professor of Neurology at the Children's Hospital and OSU in Columbus, Ohio.

"In this sense motor EP differs from the sensory or SEP codes, which allow interpretation of the sensory tracts and sensory cortical responses," says Galloway, one of the authors of the codes' proposals. "We know that patients undergoing spinal surgeries are typically at risk for both motor and sensory deficits, so monitoring both pathways makes sense."

You should report a single unit of 95928/95929 for any and all sites that the neurologist tests during a single session. The codes are bilateral.

In the outpatient setting, neurologists may use 95928/95929 to identify upper motor neuron involvement in many disorders, including motor neuron diseases such as amyotrophic lateral sclerosis (ALS) and multiple sclerosis (MS). Additionally, neurologists may use central motor EP studies intraoperatively to monitor procedures involving scoliosis instrumentation, intramedullary spinal cord tumors, brain tumor resection, laminectomies or other surgical procedures to repair spondylosis and spinal stenosis, Galloway says.

CPT 2005 also adds two new time-based codes for electronic analysis of implanted complex deep brain neurostimulators, 95978 (...first hour) and 95979 (...each additional 30 minutes after first hour). The new codes reflect that brain stimulator reprogramming is more complex, risky, difficult and time consuming than reprogramming spinal and peripheral stimulators, comments one neurologist who is a member of the CPT advisory panel.

The AMA has revised 95971-95973 to eliminate references to brain neurostimulators and include simple spinal cord or peripheral neurostimulators only.