Electromyography (EMG)

Electromyography is the recording of electrical activity from muscle tissue. Muscles cells generate action potentials when electrically stimulated or under pathological conditions. An electromyograph detects these changes in electrical activity and represents an important diagnostic tool to monitor nerve root function and muscle cell activity.

Electromyography recording

EMG activity can be recorded using different types of electrodes, including monopolar needles, concentric needles, bipolar needles, and single-fiber needles. Without the use of high and low frequency filters, EMG signals would be very noisy and difficult to interpret. The low frequency filter should be set to 10-30 Hz and the high frequency filter to 10-20 kHz, for example.

1. Spontaneous EMG. After recording electrodes are inserted into muscle tissue, the background EMG activity is stable and quiet under normal conditions. For IONM, spontaneous EMG activity is monitored continuously
2. Stimulated EMG
3. Single Fiber EMG

Cranial Nerves

1. Facial Nerve
2. Cranial Nerve III IV and VI
3. Other Cranial Nerves

Intraoperative Monitoring

1. Pedicle screws
2. Peripheral Nerves
3. Brachial Plexus
4. Dorsal Rhizotomy
5. Skull Base Tumor
6. Others

Anesthesia and Other Factors

1. Anesthesia Methods
2. Muscle Relaxants
3. Temperature
4. Tourniquet
5. Others