Electromyography (EMG) may be indicated for the following types of conditions:
- Nerve compression syndromes, including carpal tunnel syndrome and other focal compressions.
- Radiculopathy – cervical, lumbosacral.
- Mono/polyneuropathy – metabolic, degenerative, hereditary.
- Myopathy – including poly- and dermatomyositis, myotonic, and congenital myopathies.
- Plexopathy – idiopathic, trauma, infiltration.
- Neuromuscular junction disorders – myasthenia gravis. Single fiber EMG (95872) is of special value here.
- At times, before botulinum toxin type A (BOTOX® ) injection, for localization (95873, 95874).
- At times, prior to injection of phenol or other substances for nerve blocking or chemodenervation (95873, 95874).
Electromyography is an eligible procedure when performed for any of the indications listed in the Text Attachment below.
A “surface” EMG (S3900) is not the same as a conventional EMG (95860-95864). It involves the use of a probe that is passed over the surface of the skin in order to measure electrical muscle activity. This method of EMG testing is considered experimental/investigational. It is not eligible for payment. Scientific evidence does not demonstrate the efficacy of the surface EMG. A participating, preferred, or network provider can bill the member for the denied service.
An H-reflex test (95934, 95936) can be paid separately from any EMG studies and NCV studies listed under procedure codes 95900-95904. Payment should be limited to one unilateral or bilateral study per session per code.
Neuromuscular junction testing (repetitive stimulation) should be processed separately under procedure code 95937. Payment should be limited to two repetitive stimulations per session.
- NOTE:
- Refer to Medical Policy Bulletin M-51 for information on Nerve Conduction Velocity (NCV) Studies.
Description
Electromyography is the study and recording of intrinsic electrical properties of skeletal muscles. A conventional EMG is invasive in that it involves the percutaneous placement of a needle electrode into muscle for the purpose of recording electrical activity and evaluating muscle disorders. Needle electrodes are of two types: monopolar or concentric, and are often (but not always) disposable. EMG testing relies on both auditory and visual feedback to the electromyographer. The electromyographer depends on ongoing real-time clinical diagnostic evaluation in making the determination to continue, modify, or conclude a test. This requires a knowledge base of anatomy, physiology, and neuromuscular diseases.
EMG results reflect not only on the integrity of the functioning connection between a nerve and its innervated muscle, but also on the integrity of a muscle itself. The axon innervating a muscle is primarily responsible for the voluntary contraction, survival and nourishment of the muscle. Interruption of the axon, therefore, will alter the EMG.
Neurogenic disorders are able to be distinguished from myopathic disorders by a carefully performed EMG. For example, both polymyositis and amyotrophic lateral sclerosis (ALS) produce apparent weakness. Polymyositis, however, has a very different prognosis than ALS. An EMG is very valuable in making this distinction. An EMG can help to differentiate whether nerve pathology is classified as axonal (having to do with the nerve cell) or demyelinating (having to do with destruction or deterioration of the myelin sheath of the nerve). EMGs are commonly performed to confirm a suspected diagnosis. |
