In each treatment session, the patients will receive EA treatment. The selected acupoints for needling will be BL2, GB1, GB14, ST2, SI18, ST6, ST4, ST7, SJ17, EX-HN16, EX-HN5, on affected side, and LI4, bilaterally. After the de-qi sensation is achieved, electrical stimulator will be connected to BL2-GB1, and ST4-ST6, and 2Hz continuous wave will be used for 20 min.

In each treatment session, the patientss will receive EA treatment. The selected acupoints for needling will be BL2, GB1, GB14, ST2, SI18, ST6, ST4, ST7, SJ17, EX-HN16, EX-HN5, on affected side, and LI4, bilaterally. After the de-qi sensation is achieved, electrical stimulator will be connected to BL2-GB1, and ST4-ST6, and 40Hz discontinuous wave will be used for 20 min.

In each treatment session, the patientss will receive EA treatment. The selected acupoints for needling will be BL2, GB1, GB14, ST2, SI18, ST6, ST4, ST7, SJ17, EX-HN16, EX-HN5, on affected side, and LI4, bilaterally. After the de-qi sensation is achieved, electrical stimulator will be connected to BL2-GB1, and ST4-ST6, and 2/100Hz dilatational wave will be used for 20 min.

In each treatment session, the subjects will receive EA treatment. The selected acupoints for needling will be BL2, GB1, GB14, ST2, SI18, ST6, ST4, ST7, SJ17, EX-HN16, EX-HN5, on affected side, and LI4, bilaterally. After the de-qi sensation is achieved, electrical stimulator will be connected to BL2-GB1, and ST4-ST6, and 2Hz continuous wave will be used for 20 min.

Evaluation of the facial nerve function using the Facial Nerve Grading System 2.0 (FNGS 2.0). In the FNGS 2.0, the minimal score is 4, which indicates normal function, and the maximal score is 24, which indicates the worst function.

The Sunnybrook grading scale includes 3 subscales, which are the resting symmetry subscale, the symmetry of voluntary movement subscale, and the synkinesis subscale. In the resting symmetry subscale, the minimal score is 0, which indicates normal resting symmetry, and the maximal score is 20, which indicates the most severe resting asymmetry. In the symmetry of voluntary movement subscale, the minimal score is 20, which indicates gross asymmetry of voluntary movement, and the maximal score is 100, which indicates normal symmetry of voluntary movement. And in the synkinesis subscale, the minimal score is 0, which indicates no involuntary muscle contraction associated with each expression, and the maximal score is 15, which indicates the most severe involuntary muscle contraction associated with each expression. The composite score equals to the symmetry of voluntary movement score minus the resting symmetry score and the synkinesis score.