Debate - Faradic or Galvanic for Bell's Palsy?
Original Editor - Gayatri Jadav Upadhyay
Lower motor neuron lesion of the facial nerve resulting in paralysis of the muscle that it supplies.
Choice of Current
For Muscles - Galvanic & For Nerve Trunk - Faradic
Why Galvanic for Muscles?
The only form of electrical current which could be used on face is interrupted direct current (I.D.C.). This is only to preserve the bulk of facial muscle and to prevent their atrophy until reinnervations or reconditioning completes. There is no room for the use of faradic current use on the face as it could lead to cause secondary contractures of the face.
How Faradic can cause secondary contractures?
Faradic currents have higher intensity than microcurrent stimulation. It is suitable for firming and toning body muscles. The current is a low-frequency alternating milli-amperage current delivered in a series of short pulses a few milliseconds in length. As the current passes through the conductive pads, it stimulates the motor points of the muscle triggering a visible muscle contraction.
Galvanic currents are used primarily for facial muscles. A galvanic current uses mild electric currents that consist of positive and negative ions to stimulate the local muscles. The outcome of a galvanic current is maintaining the muscle physiology.
The faradic current has a frequency of 50 Hz. It produces tetanic muscle contraction. By surging the faradic current, alternate contraction and relaxation of the muscles can be achieved. Also that faradic current having short pulse duration cannot be used to stimulate dennervated muscles as dennervated muscles require pulses of longer duration for having its effects. Galvanic current has long duration impulses selections that can be used to stimulate dennervated muscles.
Albeit until wallerian degeneration occurs by 14-21 days, response in the muscles can be obtained with faradic type of current depending upon the reaction of degeneration. Once walerian degeneration takes place, it is not possible to get the response from faradic type of current.
- Important - Facial muscles are very delicate and soft to tolerate the tetanic type of contraction produced by faradic current which could lead to the secondary contractures of the facial muscle. Hence the most suitable current in that case will be interrupted galvanic current, that produces a brisk twitches of the facial muscles. And there will no danger secondary contractures.
- For trunk stimulation - Faradic is a better option.
The contractures i.e. shortening occurs in the paralyzed muscle. It occurs more often in the antagonist muscles whose action is no longer opposed by paralyzed muscle.
1. A clinical treatise on the diseases of the nervous system, tr. by L. Putzel – Moriz Rosenthal.
2. Basanta Kumar Nanda Electrotherapy Simplified. Jaypee Brothers Publishers, 01-Dec-2008 Chapter 10, Low Frequency Current p.122
- Basanta Kumar Nanda Electrotherapy Simplified. Jaypee Brothers Publishers, 01-Dec-2008 Chapter 10, Low Frequency Current p.122