Neurosurgery Coding Alert

Coding a case of carpal tunnel syndrome seems easy since ICD-9 only includes one diagnosis: 354.0 (Carpal tunnel syndrome). Carrier policies can complicate matters, however, so follow these guidelines to ensure proper reimbursement, even if testing doesn't establish a definitive diagnosis up front.

Even if your neurosurgeon suspects a patient has carpal tunnel syndrome (CTS), reporting diagnosis 354.0 before he completes all testing might limit your options down the road. While you're waiting for test results, report the patient's symptoms to justify any services your physician provides. Typical signs and symptoms of CTS can include:

• numbness and tingling (782.0)

• aching pain in the thumb, index, and middle fingers

that might move up the arm (729.5)

• hand and grip muscle weakness (728.87)

• feeling of swollen hand (729.81).

Diagnosis tip: Use caution before automatically assigning 354.0. Inflammation caused by arthritis, pregnancy, obesity, hypothyroidism, repetitive motion disorder (RMD), or diabetes can mimic symptoms of CTS.

But, "CTS is not the only disease process that can cause the symptoms generally associated with CTS," explains Rena Hall, CPC, billing/insurance coordinator at Kansas City Neurosurgery Group in Missouri.

If you do have a conclusive diagnosis, however, you should use it instead of signs and symptoms.

Example: Your neurosurgeon completes a nerve conduction study (95900, Nerve conduction, amplitude and latency/velocity study, each nerve; motor, without Fwave study) and electromyography (95860, Needle  electromyography; one extremity with or without related paraspinal areas) and confirms a carpal tunnel syndrome diagnosis. Now that you have conclusive test results, you can report 354.0 as the primary diagnosis.

ICD-9 guidelines state, "Signs and symptoms that are integral to a disease process should not be assigned as additional codes."

Translation: You report signs and symptoms only if your physician doesn't confirm CTS or if the patient has additional signs and symptoms not integral to CTS. If your physician diagnoses CTS after procedures, such as 95900 or 95904 (Nerve conduction, amplitude and latency/ velocity study, each nerve; sensory), you do not report signs and symptoms as secondary diagnoses. The reasoning is that these diagnoses are integral to arriving at the primary diagnosis, so don't need separate reporting.

When you're coding the gamut of tests the patient might go through, don't mix up guidelines for reporting an electromyogram (EMG) versus nerve conduction study (also called a nerve conduction velocity study, or NCV). "EMGs are usually done for more proximal lesions," says William J. Mallon, MD, medical director of Triangle Orthopaedic Associates in Durham, N.C. "NCVs are mostly done for CTS diagnosis. The EMG rules out other problems, such as cervical radiculopathy," Mallon says.

When you're coding an EMG, be sure to choose the code that properly reflects the number of limbs your physician stimulates.

Example 1: Your provider performs a complete EMG study on an extremity or both extremities. If the patient  has carpal tunnel syndrome in only one hand, submit 95860; if the patient has CTS in both hands, report 95861 (... 2 extremities with or without related paraspinal areas) instead.

NCV difference: Nerve conduction velocity studies (such as 95900) differ because you bill according to the number of individual nerves tested. Many carriers limit the number of NCSs during a single session and/or during a certain period of time.

Example 2: Some carriers will reject claims for more than eight NCSs performed on a patient over a six- or eight-month period. Your neurosurgeon could reach that limit in a single session, so contact your individual payers to verify its limits.

"In more classic, severe cases, NCVs are not necessary to make the diagnosis," Mallon says. "The American Academy of Orthopaedic Surgeons (AAOS) current treatment algorithm requires that they be obtained only if the physician is not certain of the diagnosis."

CPT help: Check the "Type of Study/Maximum Number of Studies" table at the end of CPT's Appendix J for more information on study frequency. This table helps you substantiate the number of test units for multiple needle EMGs, NCSs, or other EMG studies that you can have for various diagnoses.

Physicians often use a range of noninvasive, conservative treatments for patients in the early stages of CTS -- which is what carriers expect. "Each insurance carrier, including workers' compensation, has its own set of guidelines pertaining to treatment of CTS," Hall says. "Contact your carrier for specifics before moving to the next treatment step," Hall advises.

A patient often begins treatment by taking over-thecounter pain medications and wearing what Mallon terms an "off-the-shelf" wrist brace or splint, although a therapist can make the patient a custom brace.

Injection option: If NSAIDs, splints, and physical therapy have either failed to help the patient's condition or are not otherwise indicated, your neurosurgeon might reexploadminister injections into the carpal tunnel to relieve discomfort. You'll report this service with 20526 (Injection, therapeutic [e.g., local anesthetic, corticosteroid]; carpal tunnel).

Bilateral checkpoint: If your physician injects both of the patient's wrists during CTS treatment, bill it as a bilateral service with either modifier 50 (Bilateral procedure) or modifiers LT (Left side) and RT (Right side). Check which option the carrier prefers for bilateral procedures before filing your claim.

When your neurosurgeon has reached a positive diagnosis, the patient's symptoms have lasted for three or more months, and conservative therapies have not helped, he might recommend surgery to reduce pressure on the median nerve.

"Surgery could also be indicated for more severe CTS with thenar motor involvement, which is usually noted on the exam," says Mallon.

When the patient reaches that point, CPT includes two codes related to surgical treatment of CTS. You'll report the procedure based on whether the surgeon follows an open or endoscopic approach:

• 29848 -- Endoscopy, wrist, surgical, with release of transverse carpal ligament (for an endoscopic approach)

• 64721 -- Neuroplasty and/or transposition; median nerve at carpal tunnel (for an open approach).

Myth buster: Patients might assume their easiest option is the endoscopic procedure. While that might sometimes be true, it's not necessarily the case. "Current open techniques use such a small incision that there is no longer a significant benefit to endoscopic release," Mallon states. "The complications of endoscopic release are rare in experienced hands, but they are very, very rare in open surgery, and can be very troublesome ��" notably laceration of a digital nerve or a branch of the median nerve, or a partial laceration of the median nerve itself."

Pre-work check: Because surgery is a last-resort treatment for CTS, consider obtaining preauthorization to determine the carrier's coverage limits before your neurologist performs the procedure.