When it is needed?1. A patient is complaining of numbness.2. A patient is complaining of tingling (paresthesias).3. A patient has pain.4. A patient has weakness.5. A patient has a limp.6. A patient has muscle atrophy.7. A patient has depressed deep tendon reflexes.8. A patient has fatigue.
REACTION OF REGENERATION TEST F-G TEST Faradic response-innervated muscles Galvanic response- innervated /denervated Wallarian degeneration and degeneration
CHRONOXIE & RHEOBASE 1. The root word “rheo” means current and “base” means foundation: thus the rheobase is the foundation, or minimum, current (stimulus strength) that will produce a response. 2. The root word “chrona” means time and “axie” means axis: chronaxie, then, is measured along the time axis and, thus, is a Duration that gives a response when the nerve is stimulated at twice the rheobase strength.
GALVANIC TWITCH-TETANUS RATIOTEST Continuous DC used1 : 3.5to 6.5 In denervation unity occurs, both happens with same intensity
NERVE EXCITABILITY TEST MONOPHONIC PULSED CURRENT IS USED Between normal and affected side stimulation amplitude difference chronoxie amplitude 0.3 ms 3.5mA 1.0 ms 2mA
EMG-MUAP A motor unit is defined as one motor neuron and all of the muscle fibers it innervates. When a motor unit fires, the impulse (called an action potential) is carried down the motor neuron to the muscle. The area where the nerve contacts the muscle is called the neuromuscular junction, or the motor end plate. After the action potential is transmitted across the neuromuscular junction, an action potential is elicited in all of the innervated muscle fibers of that particular motor unit. The sum of all this electrical activity is known as a motor unit action potential (MUAP)
CMRR-common mode rejectionratioS1+n - S2+n OUTPUT If output is less the CMRR is high and the machine is more reliable
INDICATIONS Diseases of muscle, Neuropathy nerve and NMJ Myopathy Radiculopathy Myelopathy
FINDINGS OF EMG fibrillation+ PSW-acute High frequency unresolved nerve injury dicharge- many causes Fasciculation – problem Large MUAP-chronic in nerve cell body or axonal injury due to new spinal cord terminal branches >5to7mV Small MUAP-myopathy < 1mV