NCV/EMG

NCV/EMG

Electromyography 

Electromyography (EMG) is a diagnostic procedure to assess the health of muscles and the nerve cells that control them (motor neurons). EMG results can reveal nerve dysfunction, muscle dysfunction or problems with nerve-to-muscle communication. Motor neurons transmit electrical signals that cause muscles to contract. An EMG uses tiny devices called electrodes to translate these signals into graphs, sounds or numerical values. During a needle EMG, a needle electrode is inserted directly into a muscle and records the electrical activity in that muscle.

Nerve Conduction Velocity (NCV) measures the speed at which an electrical impulse travels along a nerve. During an NCV, patch-like electrodes are applied to your skin in several places over the nerve to be tested. Low-level electricity is dispensed through the electrodes to stimulate the nerve. The amount of electricity is similar to a shock from static electricity. The velocity, or speed, at which the electrical signal flows through the nerve is measured and displayed on a screen. The information from these studies is combined and interpreted by a specialist.

EMG/NCV is commonly used with diagnosis of:
• Spinal nerve root impairments
• Focal peripheral nerve entrapments (mononeuropathies)
• Polyneuropathy, plexopathies
• Muscle disease disorders
• Neuromuscular junction disorders
• Lower motoneuron disease.

EMG/NCV may be helpful with the following:
• Numbness/tingling in arms, legs, hands, feet, and/or face
• Unexplained muscle weakness
• Neck pain with radiation into shoulder or arm
• Lumbar pain with radiation into leg or foot
• Muscle pain or cramping
• Limb pain