5 retrieved studies	No. 1	No. 2	No. 3	No. 4	No. 5
Author	Alakram & Puckree (2010)	Guzelant et al. (2014)	Kim & Choi (2015)	Tuncay et al. (2015)	Abdelatief (2020)
Type of study	CCT	CCT	RCT	RCT	RCT
Sample (n)	Experimental (n = 8) Age―38.6 17.7 Time from onset of Bell’s palsy until medication (days)―0.5; Time from onset of Bell’s palsy until physiotherapy (days)―14.1 Control (n = 8) Control group: Age―41.4 16.5. Time from onset of Bell’s palsy until medication (days)―0.9; Time from onset of Bell’s palsy until physiotherapy (days)―12.5.	rehabilitation program (n = 12) home exercise program (n = 6) no significant difference between ages.	GE: 30 patients (46.5 ± 16.3) were treated with prednisolone or/and acyclovir plus electrical stimulation within 7 days of the onset of symptoms. GC: 30 patients (49.17 ± 18.2) were treated with only prednisolone or/and acyclovir as a control group.	Experimental Group (n = 28) Control Group (n = 32) Experimental group, 16 (57.1%) patients had no axonal degeneration and 12 (42.9%) had axonal degeneration, compared Control group―17 (53.1%) had no axonal degeneration and 15 (46.9%) patients had axonal degeneration. Mean age, 44.8 T 17.6 Baseline House-Brackmann and Facial disability Index scores similar between groups.	196 participants (94 males and 102 females) with unilateral Bell’s palsy divided randomly into four groups with forty-nine patients.
Protocol	TENS pulsed setting and frequency of 10 Hz, a pulse width/duration of 10 microseconds Intensity used was to obtain a minimally visible contraction (orbicularis oculi, orbicularis oris, zygomaticus major) was stimulated separately for 10 minutes in a total of 30 minutes.	ES applied to motor points of eight muscles (m. frontalis, m. corrugator supercilii, m. orbicularis oculi, m. levator labii alaeque nasii, m. nasalis m. levator labii superioris, m. orbicularis oris, m. depressor labii inferioris) 100 milliseconds intermittent galvanic current for motor point treatment, 30 times as 3 rounds to each point, and at a current intensity as to obtain minimal contraction.	The stimulator frequency was 20 Hz with rectangular, monophasic spikes with a sub-threshold pulse (average 1/4 1.4 mA, 10 ms). electrode placed on the main branch of the facial nerve at the tragal pointer as a cathode, and on the intra-temporal area around the stylomastoid foramen as an anode. current increased to just below the sensory threshold.	Monophasic waveform having 100 msecs of pulse duration, 300 msecs of interpulse interval, and a pulse rate of 2.5 pulses/sec. A 3 cm² anode was placed over each muscle, and a 7 cm² cathode was placed over the proximal part of ipsilateral arm ES was applied to each of 11 facial muscles to evoke three sets of 30 minimal contractions.	TENS with Pulse rate: 100 Hz, stimulate time: 30 seconds, polarity: +, sweep: 1 Hz, sweep time: 1 second, ramp up: off, ramp down: off and time rest: off. intensity increased to produce a minimally visible contraction Two electrodes), one on the area between the upper part of the zygomatic bone and lateral aspect of the eyebrow while the other was placed on the area between the lower part of the zygomatic bone and mentalis muscle.
Criteria	Patients diagnosed with Bell’s palsy by a neurologist or otolaryngologist referred for physiotherapy with less than 30 days’ post onset.	Inclusion Criteria: no diagnosis of cerebrovascular disease in history; informed about PFP and protection methods recommended self-massage and educated about muscle function and mimic.	Inclusion criteria 1) within 1 week of onset of facial palsy, 2) less than grade 4 on the House-Brackmann facial nerve grading system (HB) and a score higher than 20 on the Sunnybrook facial nerve grading system (SB), 3) no other medical or psychological problems. Exclusion criteria: 1) participation in other therapies for facial nerve damage, 2) other causes such as tumor, infection, and infarction, 3) a greater than 90% degree of denervation on electroneuronography 4) pregnancy, 5) cardiac pacemaker, 6) excessive perspiration.	Criteria for inclusion were: 1) new onset of idiopathic facial paralysis within 48 hrs and; 2) either sex in the age group of 18 to 79 yrs. excluded if: had central nervous system disease, diabetes mellitus, varicella zoster virus infections, and recurrence of facial paralysis; were noncompliant and not presenting for follow-up visits.	Inclusive criteria for this study: patients with less than 30 days post-onset of Bell’s palsy lower motor neuron lesion Exclusive criteria patients with bilateral affection of Bell’s palsy or Any sensory impairment in the area of electrode placement, Pregnant women, upper motor neuron lesion and diabetic.
Program duration/ frequency	once a week, 5 minutes of heat, 10 minutes of massage, and 10 repetitions of exercises. Experimental group was then treated with an additional 30 minutes of electrical stimulation At home, all patients were instructed to do 10 repetitions of each exercise, three times daily.	Information not available.	One group (as a control) received drug treatment alone, and the other group (as an experimental group) received drug treatment plus SCLES.	Group 1 (n = 28): received physical therapy including hot pack, massage to the facial muscles, and facial expression exercises via a mirror, five times/week over 3 wks. Group 2 (n = 32) received ES daily in addition to the same physical therapy provided to group 1.	The session started by electrical stimulation followed by exercises and finished by infrared, massage and vibration to reduce lactic acid accumulation. Group A received conventional therapy, group B received TENS group C received faradic current stimulation. group D received TENS + faradic current.
Outcome measurement	The House-Brackmann Facial Nerve Grading Scale (HB) was used to assess the severity and monitor the changes.	Functional response to treatment was assessed by the House-Brackmann scale grading system. HBS evaluations were performed in pre-treatment and 6th week post-treatment and long-term 6th month visits of the patients.	House-Brackmann (HB) and Sunnybrook (SB) scales.	House-Brackmann scale and Facial Disability Index scores Latency and amplitude of compound muscle action potentials (electrophysiologic outcome measures).	House Brackmann (HB) Scale no.
Results	individual rates in the experimental group were higher than that of the control group, however, there was no statistically significant difference.	Significant improvement observed from the 6th week in the comparison between pre-treatment HBS, and 6th week (p = 0.01) and the 6th month (p = 0.05) HBSs of the patient group participated in rehabilitation program. A significant difference was also detected in between HBS obtained in 6 weeks after the end of the treatment and HBS obtained in the 6th month (p = 0.06) patients treated with home exercise program: showed a significant difference between the pre-treatment HBS and the 6th month HBS (p = 0.005).	The initial average score on the HB scale was not different between the two groups (3.46; experimental group, 3.47; control group). However, 2 weeks after the onset of palsy there was a significant difference in HB scores, which persisted for 6 months. However, these differences were not significant at 4, 10, and 12 weeks (independent-sample t-test: p > 0.05).	Posttreatment HB scores, indicating the clinical state, were better in group 2 than in group 1. FDI scores, representing functional status, improved significantly in both groups after the therapies, but posttreatment scores in group 2 were statistically higher than in group 1. Volitional movement of the facial muscles improved substantially in both groups, Motor latencies in the frontalis and orbicularis oris muscles were significantly shorter and the CMAP amplitudes of these muscles were significantly increased, in group 2.	In group B, there was a statistically significant improvement in grade IV, V, and VI compared to groups A, C, and D while there was no statistically significant difference among the four groups on grade II and III.
Effect-Sizes	ES = 0.33	Data presentation unable to calculate.	ES = 0.22.	Frontalis Amplitude → ES = 0.18 Latency → ES = 0.09 Orbicularis oris Amplitude → ES = 0.08 Latency → ES = 0.12.	Data presentation unable to calculate.
Conclusion	Predominant motor electrical stimulation did not add to nor deter progress. Electrical stimulation also proved to be a safe treatment intervention. Further work is required to establish the efficacy of this treatment in a larger group of patients in the acute stage of recovery from Bell’s palsy.	The recovery time is faster in the patients treated with the rehabilitation group that includes electrical stimulation. Therefore electrical stimulation therapy is an acceptable effective method for the treatment of facial paralysis.	SCLES appears to affect the early neural regenerative stages by preventing Wallerian degeneration in the area proximal to the injured site.	The addition of 3 wks of daily electrical stimulation shortly after facial palsy onset (4 wks), improved functional facial movements and electrophysiologic outcome measures at the 3-month follow-up in patients with Bell palsy.	TENS has a noticeable effect on grade IV, V, VI of HB scale from at least a month after the application, the application of TENS and faradic current appear to be safe methods in treating Bell’s palsy as they reduce the severity of its symptoms, especially in the early stages, with a preference for applying TENS over faradic current alone or with TENS.