95910
Nerve conduction studies; 7-8 studies
Nerve conduction studies (NCS) are essential diagnostic procedures used to assess the integrity and function of peripheral nerves. These studies are typically performed by a physician or a trained technician under medical supervision. During the test, electrodes are placed on the skin over specific nerves or muscles. A brief, controlled electrical stimulus is applied to one point on the nerve, and the resulting electrical response is recorded at another point. CPT 95910 specifically describes a session in which 7 to 8 distinct nerve conduction studies are performed and interpreted. These studies may encompass motor conduction, sensory conduction, or late responses such as H-reflexes or F-waves. For each nerve tested, the clinician measures several parameters: the distal latency, which indicates the time it takes for the impulse to travel; the amplitude of the compound muscle action potential (CMAP) or sensory nerve action potential (SNAP), which reflects the number of functioning nerve fibers; and the conduction velocity, which measures the speed of the impulse across a nerve segment. By analyzing these data points, clinicians can differentiate between various types of nerve damage, such as axonal loss, where amplitudes are reduced, or demyelination, where conduction velocities are slowed. The performance of 7 to 8 studies is common when evaluating patients with complex or systemic neurological complaints that involve multiple limbs or require a more extensive comparison across different nerve segments to reach an accurate diagnosis, such as in cases of suspected polyneuropathy or plexopathy.
Clinical Indications
- Peripheral neuropathy
- Radiculopathy
- Mononeuritis multiplex
- Brachial or lumbosacral plexopathy
- Guillain-Barre syndrome
- Chronic inflammatory demyelinating polyneuropathy (CIDP)
- Carpal tunnel syndrome or other entrapment neuropathies when multiple nerves are involved
- Neuromuscular junction disorders
- Traumatic nerve injury
- Evaluation of limb weakness or paresthesia
Procedure Steps
- Prepare the patient by explaining the procedure and ensuring skin is clean at electrode sites.
- Place recording electrodes (active and reference) over the belly of the target muscle for motor studies or along the nerve path for sensory studies.
- Position a ground electrode on the same limb to minimize electrical interference.
- Apply a stimulus using a handheld bipolar stimulator at a known anatomical site for the target nerve.
- Gradually increase stimulus intensity to achieve a supramaximal response where all available axons are depolarized.
- Measure and record the onset latency, peak amplitude, and duration of the resulting electrical waveform.
- Perform proximal stimulation on the same nerve to calculate the conduction velocity between the two points.
- Conduct F-wave or H-reflex studies as necessary to evaluate proximal nerve segments.
- Repeat the process for the remaining nerves until 7 to 8 distinct studies are completed.
- Compare recorded data with established age- and height-adjusted normal values.
Coding Guidelines
- CPT 95910 is reported once for the entire session involving 7 or 8 nerve studies.
- A single 'study' is defined as a motor conduction study (with or without F-wave), a sensory conduction study, or an H-reflex study per nerve.
- Stimulation of a single nerve at multiple locations (e.g., wrist and elbow for the ulnar nerve) still constitutes only one study for that nerve.
- Do not count F-waves as a separate study from the motor study of the same nerve.
- This code is frequently billed in conjunction with needle electromyography (EMG) codes 95860-95887.
- Technical and professional components are included; if only the interpretation is performed, use modifier -26.
- Comprehensive documentation must include the names of the nerves tested, the types of studies performed, and the specific results (latency, amplitude, etc.).