Occipital neuralgia is a type of neuralgia that is caused by the stimulation of the occipital nerve. The occipital nerve branches from the second and third cervical nerves to the greater occipital nerve, lesser occipital nerve, and third occipital nerve, while pain occurs along the stimulated nerve branches [1]. Moreover, pain can occur in the forehead, ears, and temporal area, while symptoms such as skin hypersensitivity and numbness may occur [2,3]. The main pain is a stabbing feeling, but patients may also experience a persistent throbbing, tightening sensations, or an electric shock-like feeling [4]. The causes of occipital nerve stimulation include muscle tension, degenerative changes in the cervical spine, viral infection of the occipital nerve, inflammation, and nerve damage due to trauma [2].

In Western medicine, noninvasive treatments for occipital neuralgia include nonsteroidal anti-inflammatory drugs, muscle relaxants, anticonvulsants, and antidepressants as well as physical and manual therapies. If no response to these noninvasive treatments is observed, invasive treatments, such as occipital nerve block, botulinum toxin injection, radiofrequency coagulation, nerve decompression, and neurectomy, are performed to improve the pressure on the soft tissue around the occipital nerve [4]. However, drug treatments only temporarily relieve symptoms and are often ineffective in the long term [5]. Although nerve block and Botox injections have been proven to be effective, their relief period is often limited. Furthermore, side effects, such as skin changes, pigmentation, and hair loss, have been reported with steroid-based nerve blocks [5,6]. There is a lack of research on the independent effects of non-pharmacological treatments such as physical therapy and cryotherapy [7]. To date, nerve root resection and radiofrequency thermal coagulation are rarely used because they tend to cause neuromas or exhibit a high treatment failure rate. Although pain relief due to nerve resection and neurolysis is possible, abnormal sensations, such as dullness in the nerve area, may occur [5,8].

In traditional Korean medicine, treatments such as autotomy, moxibustion, Chuna, acupuncture, thread embedding, and pharmacopuncture are commonly used to manage occipital neuralgia [9]. Among them, autotomy is a combination of traditional Korean acupuncture and modern Western surgical techniques. It treats chronic painful conditions that are caused by soft tissue damage through adhesion peeling, incision, and cutting of the damaged tissue area. Moreover, acupotomy has the advantage of minimizing both infection and damage to the procedure area through a minimally invasive approach, while also reducing time and cost [10,11].

Occipital neuralgia is also commonly caused by tension and adhesions in the soft tissues, and autotomy is considered effective in dissociating fibrosis and adhesions in the affected area [12]. Although autotomy has been widely used for treating occipital neuralgia, an analysis of the latest studies has not been conducted [12]. Therefore, this study aims to evaluate recent research trends and assess effectiveness and safety of autotomy treatment for occipital neuralgia.

1. Data search

This study searched for articles published between October 2008 and January 2021, with no restrictions on country, language, sex, or age. The search was conducted from October 2023 to May 2024 and included the following databases: PubMed, the Cochrane Library, China National Knowledge Infrastructure (CNKI), and Wanfang Data as international databases, and the Oriental Medicine Advanced Searching Integrated System (OASIS), Research Information Sharing Service (RISS), and Korean Studies Information Service System (KISS) as domestic databases.

In PubMed and the Cochrane Library, the search included various combinations of the following terms for occipital neuralgia: occipital neuralgia, neuralgia, occipital, occipital headache, C2 neuralgia, Arnold’s neuralgia, nervus occipitalis neuralgia, occipital nerve compression syndrome, and occipital nerve entrapment syndrome. For autotomy, the following terms were combined: autotomy, autotomy, acupotomology, apotome, stiletto needle, small needle-knife, needle knife, needle scalpel, miniscalpel, miniscalpel acupuncture, miniscalpel needle, stiletto needle, sword-like needle, acupuncture knife, knife-shaped acupuncture, and ceramic acupuncture therapy. In CNKI and Wanfang Data, these words were used in combination with additional terms, such as zhěnbù tóutòng (in Chinese), zhěnshénjīng tòng (in Chinese), zhěn shénjīng kǎyāxìng tóutòng (in Chinese), and zhěndà shénjīng kǎyā zōnghézhēng (in Chinese), which refer to occipital neuralgia as well as zhēndāo (in Chinese) and dāozhēn (in Chinese), both of which refer to autotomy. In OASIS, RISS, and KISS, additional terms, such as Hudusingyeongtong (in Korean), Dochim (in Korean), and Chimdo (in Korean), were searched (Tables 1–3).

Table 1 . Database search details.

Database	Search terms (occipital neuralgia)	Search terms (acupotomy)	Search language
PubMed	Occipital neuralgia, neuralgia, occipital, occipital headache, C2 neuralgia, Arnold’s neuralgia, nervus occipitalis neuralgia, occipital nerve compression syndrome, occipital nerve entrapment syndrome	Acupotomy, acupotomies, acupotomology, acupotome, stiletto needle, small needle-knife, needle knife, needle scalpel, miniscalpel, miniscalpel acupuncture, miniscalpel needle, stiletto needle, sword-like needle, acupuncture knife, knife-shaped acupuncture, ceramic acupuncture therapy	English
Cochrane Library	Same as PubMed	Same as PubMed	English
CNKI	Includes PubMed search terms (occipital neuralgia, neuralgia, etc.) and Chinese terms (zhěnbù tóutòng, zhěnshénjīng tòng, zhěn shénjīng kǎyāxìng tóutòng, zhěndà shénjīng kǎyā zōnghézhēng)	Includes PubMed search terms (autotomy, needle knife, etc.) and Chinese terms (zhēndāo, dāozhēn)	English, Chinese
Wanfang Data	Same as CNKI	Same as CNKI	Chinese
OASIS	Includes PubMed search terms (occipital neuralgia, neuralgia, etc.) and Korean terms (Hudusingyeongtong)	Includes PubMed search terms (occipital neuralgia, neuralgia, etc.) and Korean terms (Dochim, Chimdo)	English, Korean
RISS	Same as the OASIS	Same as the OASIS	English, Korean
KISS	Same as the OASIS	Same as the OASIS	English, Korean

CNKI, China National Knowledge Infrastructure; OASIS, Oriental Medicine Advanced Searching Integrated System; RISS, Research Information Sharing Service; KISS, Korean Studies Information Service System..

Table 2 . Methods of searching for PubMed.

No.	Search term
#1	Occipital neuralgia [all fields]
#2	Neuralgia [all fields]
#3	Occipital [all fields]
#4	Occipital headache [all fields]
#5	C2 neuralgia [all fields]
#6	Arnold’s neuralgia [all fields]
#7	Nervus occipitalis neuralgia [all fields]
#8	Occipital nerve compression syndrome [all fields]
#9	Occipital nerve entrapment syndrome [all fields]
#10	#1 OR #2 OR #3 OR #4 OR #5 OR #6 OR #7 OR #8 OR #9
#11	Acupotomy [all fields]
#12	Acupotomies [all fields]
#13	Acupotomology [all fields]
#14	Acupotome [all fields]
#15	Stiletto needle [all fields]
#16	Small needle-knife [all fields]
#17	Needle knife [all fields]
#18	Needle scalpel [all fields]
#19	Miniscalpel [all fields]
#20	Miniscalpel acupuncture [all fields]
#21	Miniscalpel needle [all fields]
#22	Sword-like needle [all fields]
#23	Acupuncture knife [all fields]
#24	Knife-shaped acupuncture [all fields]
#25	Ceramic acupuncture therapy [all fields]
#26	#11 OR #12 OR #13 OR #14 OR #15 OR #16 OR #17 OR #18 OR #19 OR #20 OR #21 OR #22 OR #23 OR #24 OR #25
#27	#10 AND #26

Table 3 . Methods of searching for the Cochrane Library.

No.	Search terms
#1	“occipital neuralgia” OR “neuralgia” OR “occipital” OR “occipital headache” OR “C2 neuralgia” OR “Arnold’s neuralgia”
	OR “nervus occipitalis neuralgia” OR “occipital nerve compression syndrome” OR “occipital nerve entrapment syndrome”
#2	“acupotomy” OR “acupotomies” OR “acupotomology” OR “acupotome” OR “stiletto needle” OR “small needle-knife”
	OR “needle knife” OR “needle scalpel” OR “miniscalpel” OR “miniscalpel acupuncture” OR “miniscalpel needle”
	OR “stiletto needle” OR “sword-like needle” OR “acupuncture knife” OR “knife-shaped acupuncture” OR “ceramic acupuncture therapy”
#3	#1 AND #2

2. Data selection and exclusion criteria

1) Selection criteria

Among the studies on occipital neuralgia, randomized controlled trials (RCTs) were selected. In the intervention group, autotomy alone and concurrent treatments that could confirm the effect of autotomy treatment were selected. In the control group, no restrictions were placed as long as the effects of autotomy treatment could be compared.

2) Exclusion criteria

We excluded studies that were not related to occipital neuralgia, those that did not involve living human participants (such as anatomical studies and cell tests), those that were not RCTs, those that did not involve autotomy treatment, and studies where autotomy was used in both the intervention and control groups (making comparison impossible). We also excluded studies with insufficient evaluation measures other than clinical efficacy or those for which the full text was not available.

3. Data extraction

After reviewing the full texts of the studies that were finally selected, the information on the publication year and country, number of participants, illness duration, treatment method, type of treatment tool, stimulation site, stimulation method and depth, treatment frequency, evaluation tool, treatment results, adverse events, follow-up, and the risk of bias assessment was obtained by two independent reviewers.

4. Risk of bias assessment

The studies that were finally selected were assessed for bias using Cochrane’s Risk of Bias 2 (RoB2) tool. The evaluation process was conducted independently by two reviewers to ensure accuracy and minimize bias. Any disagreements between the reviewers were resolved through discussion or consultation with a third reviewer if necessary. The evaluation items included specific signaling questions as per the RoB2 guidelines, such as “randomization process, deviations from the intended interventions, missing outcome data, measurement of the outcome, selection of the reported result, and other biases.” The risk of bias was assessed as “high, some concerns, or low,” in accordance with the recommended approach indicated in the RoB2 guidelines [13].

1. Study selection

We searched seven domestic and international databases and found a total of 305 studies: 2 in PubMed, 1 in the Cochrane Library, 188 in CNKI, 114 in Wanfang, and none in OASIS, RISS, or KISS. After excluding 69 overlapping studies, 236 studies were selected based on their titles and abstracts. Of the 236 studies, we excluded 118 studies: 111 were unrelated to occipital neuralgia, and 7 did not involve living human participants, such as anatomical studies and cell tests. The remaining 118 studies underwent secondary screening through full-text review, leading to the exclusion of 107 studies: 76 were not RCTs; 19 studies were unrelated to autotomy treatment; 4 used autotomy in both the intervention and control groups, making it impossible to compare the effects; 7 had insufficient evaluation criteria, with some focusing only on clinical efficacy; and 1 study had no full text available. Finally, 11 RCT studies were selected for this trend analysis (Fig. 1).

Figure 1. Preferred Reporing Items for Systematic Reviews and Meta- Analyses flow diagram of the literature screening and selection processes. CNKI, China National Knowledge Infrastructure; OASIS, Oriental Medicine Advanced Searching Integrated System; RISS, Research Information Sharing Service; KISS, Korean Studies Information Service System; RCT, randomized controlled trial.

2. Study analysis

1) Publication year and country

Of the selected 11 RCTs, 4 were published in 2008, 2014, 2020, and 2021 [3,14-16], 2 in 2016 [2,17], 2 in 2019 [1,9], and 3 in 2018 [18-20]. All the studies were published in China (Table 4).

Table 4 . A summary of the studies of the intervention and control groups.

Study	Sample size (n)	Duration of illness (mean)	Treatment	Treatment information (diameter × length)	Treatment sites/number	Stimulation method/depth	Frequency
Xie and Feng [1]	IG 35	7.14 ± 6.12 (months)	Acupotomy	Hanzhang brand No.4 (0.6 mm × 50 mm)	External occipital protuberance, both 2.5- and 5-cm points from the external occipital protuberance on the nuchal line, posterior tubercle of the atlas, and spinous process (7 points)	Insert the needle knife vertically into the skin at a fixed point (the knife edge line is consistent with the longitudinal axis of the human body), loosen it layer by layer to the bone surface, and peel two to three knives up, down, left, and right (0.5 cm)	1/week (3 times)
	CG 35	6.61 ± 7.15 (months)	EA	Global brand, Xinsheng brand	External occipital protuberance, both 2.5- and 5-cm points from the external occipital protuberance on the nuchal line, posterior tubercle of the atlas, and spinous process (7 points)	Perform tonic and purging techniques for 1 minute	1 (30 minutes)/week (3 times)
Tan [14]	IG 30	10.80 ± 2.55 (months)	Acupotomy + electromagnetic spectrum therapy	Hanzhang brand (0.4 mm × 40 mm)	The middle and inner 1/3 of the line connecting the external occipital protuberance, bilateral external occipital protuberances, mastoid process of the temporal bone, lesser occipital nerve subcutaneous superficial exit point, and 2nd cervical spinous process (> 6 points)	Make the needle insertion direction perpendicular to the occipital bone surface, apply pressure to separate the needle insertion, and cooperate with the technique of vertical and horizontal stripping Cut layer by layer to the bone surface, lift the needle under the skin, and turn the incision line up (90/0.5 cm)	1/week (3 times)
	CG 30	10.20 ± 3.38 (months)	AT + electromagnetic spectrum therapy	Tianxie brand (0.30 mm × 40 mm, 0.30 mm × 25 mm)	GB20, GB12, GV16, GV19, GV20, SI3, BL62, LI4, ST44, GB43, TE5, EX-HN1, LR3	A leveling tonic and flattening technique is performed	2 (30 minutes)/week (3 times)
Chen [9]	IG 36	13.10 ± 8.87 (months)	Acupotomy + functional exercise	Huayou brand No.4 (0.6 mm × 40 mm)	2.5 or 5 cm away from the external occipital protuberance, posterior tubercle of the atlas, and spinous process of the second axis	Touch the bone surface lightly, withdraw the needle for longitudinal cutting, and turn the knife for transverse cutting/NR	2/week (1 time), 2/day (for 1 week)
	CG 35	13.30 ± 8.90 (months)	Celcoxib 0.2 g + functional exercise	NR	NR	NR	1C BID (for 1 week), 2/day (for 1 week)
Zhao and Luo [3]	IG 120	2.30 ± 1.37 (years)	Acupotomy	Hanzhang brand No.4 (0.6 mm × 50 mm)	External occipital protuberance, above and below the occipital bone Between the lines, look for them approximately 2.5 and 5 cm apart from the posterior midline Tender points	Cut through tightness, contractures, adhesions, thickened fascia, and leg fibers (2–4 knives); the cutting depth of the needle knife is based on the bone surface. The amplitude does not exceed 0.3 cm. Cut it lengthwise and dredge it (0.3–0.5 cm)	1/week (1 time)
	CG 120	2.20 ± 1.39 (years)	Nerve block	1% lidocaine or analgesic solution 5–6 mL	The midpoint of the line connecting the posterior edge of the mastoid process and cervical bispinous process 1 cm upward	NR	1/week (1 time)
Wang [2]	IG 30	14.77 ± 14.01 (months)	Acupotomy	Hanzhang brand No.4 (0.6 mm × 50 mm)	GV17, GB19, GB12	The knife penetrates the skin and passes through the superficial fascia, ligaments, tendons, and other tissues to the bone surface of the skull The knife edge line is turned to 90° to the longitudinal axis (to the bone surface)	1/week (3 times)
	CG 30	14.43 ± 12.54 (months)	AT	Disposable sterile AT needle (0.35 mm × 40 mm)	GV16, BL10, GB20, GB12	The needle tip of the Fengchi point should be toward the tip of the nose, the Tianzhu point should be pointed straight, the Wangu point should be pointed downward, and the Fengfu point should be pointed downward (20–25 mm)	1 (30 minutes)/day (for 2 weeks)
Zhang et al. [17]	IG 38	4.00 (months)–12.00 (years)	Acupotomy + Ozone injection	Hanzhang brand No.4 (0.6 mm × 50 mm)	The greater occipital nerve passes through the subcutaneous part, starting point of the upper nuchal line of the trapezius muscle, starting point of the suboccipital muscle, and inferior nuchal line	The knife edge line is consistent with the longitudinal axis of the human body. After the needle knife reaches the bone surface, turn the knife edge. The line should be 90°, the blade should be peeled with three to five knives, and the range should not exceed 0.5 cm (within 0.5 cm)	1/week (1–3 times)
	CG 34	3.00 (months)–8.00 (years)	EA	Huatuo brand (0.35 mm × 50 mm)	GB20, BL10, GB8, EX-HN5, EX-B2	NR	1 (20 minutes)/day (for 3 weeks)
Chen et al. [18]	IG 32	32.34 ± 27.95 (days)	Acupotomy	Beryllium needle, Le Moxibustion Brand (0.4 mm × 50 mm)	The midpoint of the bilateral bony external auditory doors and the posterior midline (17–20 mm)	Press the fingertip of your left thumb on the painful area, and insert the needle 0.5 cm vertically to the body surface The incision line should be parallel to the posterior midline (0.5 cm)	2/week (4 times)
	CG 29	30.07 ± 31.90 (days)	AT + neck moisten compress therapy	Huatuo brand (0.35 mm × 25 mm)	GB20, BL10, GB8, EX-HN5, EX-B2	NR	1 (20 minutes)/2 days (14 times)
Li and Fu [19]	IG 25	3.80 ± 1.00 (years)	Acupotomy + carbamazepine 0.1 g	Microprismatic needle knife	Tender points	Penetrate the skull vertically, stab continuously, block, cut the tendon arch, release the nerve, and combine to release the occiput/NR	1/5 days (3 times), 1-T TID (for 2 weeks)
	CG 25	4.10 ± 1.20 (years)	Carbamazepine 0.1 g	NR	NR	NR	1-T TID (for 2 weeks)
Chen et al. [15]	IG 39	1.60 ± 0.50 (years)	Acupotomy + target bipolar electrocoagulation	Ma’anshan Le Moxibustion Brand No.4	Tender point at the midpoint of the line connecting the external occipital protuberance	After the needle knife reaches the bone surface of the occipital bone, turn the knife edge line 90° and perform local release using three to six scalpels (0.5 cm)	1 time
	CG 39	1.55 ± 0.40 (years)	Target bipolar electrocoagulation	NR	NR	NR	1 time
Wang [16]	IG 46	2.28 ± 1.54 (months)	Acupotomy	NR	The inner 1/3 of the line connecting the external occipital protuberance and the mastoid process The midpoint of the line connecting the spinous process and the mastoid process The tender point	Insert the needle into a depth that passes through the deep fascia, and perform three to five multipoint releases/until the deep fascia	1/5 days (2 times)
	CG 46	2.22 ± 1.41 (months)	Carbamazepine 0.1 g	NR	NR	NR	1-T TID (for 10 days)
Wang and Cai [20]	IG 43	2.10 ± 0.60 (months)	Acupotomy	NR	The midpoint of the line connecting the mastoid process and the spinous process of the second cervical vertebra	Insert the needle into the bone surface and along the longitudinal direction. Make three to five incisions with the axial knife, and the range should not exceed 0.5 cm	1/week (3 times)
	CG 43	2.20 ± 0.40 (months)	Nerve block	2% lidocaine 3 mL + prednisolone acetate 5 mL + sterile water 5 mL injection	The midpoint of the line connecting the spinous process of the second cervical vertebra, tenderness, and the point where the radiating pain is induced in the top of the head or forehead	NR	1/week (3 times)

IG, intervention group; CG, control group; EA, electroacupuncture; AT, acupuncture; GB, gallbladder; GV, governor vessel; SI, small intestine; BL, bladder; LI, large intestine; ST, stomach; TE, triple energizer; EX-HN, extra point head and neck; LR, liver; NR, non-recorded; C, capsule; BID, bis in did; EX-B, extra point back; TID, ter in die..

3. Study subject analysis

1) Number of participants

The total number of participants across the studies was 950, with the lowest number being 50 and the highest number being 240. One study (9.09%) had < 60 participants [19], nine studies (81.81%) had 60–120 participants [1,2,9,14-18,20], and one study (9.09%) had 120 participants [3], with an average of 86.36 participants (Table 4).

2) Duration of illness

The duration of occipital neuralgia in the participants ranged from 3 months to 12 years. Three studies (27.27%) presented only the average duration of illness [9,15,18] (Table 4).

3) Treatment method of the intervention group

Of the 11 studies, 5 studies (45.45%) used autotomy as a single intervention [1-3,16,20], and 6 studies (54.54%) used autotomy in combination with other treatments [9,14,15,17-19]. One study (9.09%) used oral medication [19], exercise therapy [9], osteopathy [18], ozone injection [17], electromagnetic field therapy [14], and bipolar electrocautery [15] as concurrent treatments, respectively (Table 4).

4) Type of autotomy

Of the seven studies (63.63%) that mentioned the thickness and length of the autotomy needles, four studies (36.36%) used 0.6 mm × 50 mm needles [1-3,17], one study (9.09%) used 0.6 mm × 40 mm needles [9], one study (9.09%) used 0.4 mm × 40 mm needles [14], one study (9.09%) used 0.4 mm × 50 mm needles [18]. One study described only the brand of the needle such as Le moxibustion brand [15] (Table 4).

5) Stimulation site of the intervention group

Only one study described the exact acupuncture points of GV17, GB19, and GB12 [2]. The other 10 studies (90.90%) described the autotomy insertion points based on the anatomical locations rather than the acupuncture points, such as the area connecting the occipital process and the mastoid process [14-16], the area horizontally located near the occipital process [1,3,9], the area connecting the mastoid process and the spinous process of the second cervical vertebra [16,17,20], the posterior processes of the first and second cervical vertebrae [1,9,14], and the horizontal area connecting the ears on both sides [18,19] (Table 4, Fig. 2).

Figure 2. Acupotomy stimulation sites.

6) Stimulation method and depth of the intervention group

Of the seven studies (63.63%) that inserted the needle vertically [1,2,6,9,17,18,20], three (27.27%) rotated the needle 90° to make a horizontal incision [2,9,17], one (9.09%) made an incision parallel to the direction of the insertion, and three (27.27%) made an incision in an unspecified direction [1,6,20]. Furthermore, one study (9.09%) inserted the needle in the vertical and horizontal directions of the body and then rotated it 90° to make an incision [14], one study (9.09%) did not provide the direction of insertion but made an incision by rotating it 90° after insertion [15], and three studies (27.27%) did not describe the stimulation method in detail [16,17,19]. The depth of the needle insertion was specified to be stimulated within 0.5 cm in seven studies (63.63%) [1,3,14,15,17,18,20], while four studies (36.36%) either did not specify the depth or stated that the needle was inserted up to the bone surface or deep fascia [2,9,16,19] (Table 4).

7) Treatment frequency of the intervention group

The treatment frequency was once a week in seven studies (63.63%) [1-3,14,15,17,20], twice a week in two studies (18.18%) [9,18], and once every 5 days in two studies (18.18%) [16,19]. Five studies (45.45%) had a treatment period of 3 weeks [1,2,14,17,20], two studies (18.18%) lasted 1 week [3,9], and four studies (36.36%) had varying treatment duration of 1 day, 10 days, 2 weeks, or 4 weeks [15,16,18,19] (Table 4).

8) Treatment methods of the control group

The control group used a total of seven treatment methods. The most common treatment was Western medicine, used in three studies (27.27%) [9,16,19]. Other treatment included celecoxib (0.2 g) in one study (9.09%), carbamazepine (0.1 g) in two studies (18.18%), electroacupuncture and nerve block in two studies (18.18%) [1,3,17,20], and bipolar electrocautery, general acupuncture, wet compression therapy, and electromagnetic field therapy in one study (9.09%) each [2,14,15,18] (Table 4).

9) Treatment frequency of the control group

Treatment frequency was once a week in three studies (27.27%) [1,3,20]. In two studies (18.18%), treatment was administered three times a day [16,19], twice a day [9,18], once a day [2,17], or twice a week [14,20], while one study (9.09%) implemented a single-time treatment [15]. The treatment period of 3 weeks was the most common in five studies (45.45%) [1,2,14,17,20], followed by 1 week in two studies (18.18%) [3,9] and 1 day, 10 days, 2 weeks, or 4 weeks in one study (9.09%) [15,16,18,19]. The minimum number of treatments was 1 time [3,15], while the maximum number was 42 times [15] (Table 4).

10) Evaluation tools

A total of 11 assessment tools were used in 11 studies. The most frequently used assessment tools were the clinical efficacy evaluation scale [1-3,14-17,19,20] and the visual analog scale (VAS) [1,14-20], which were used in 10 studies (90.90%). Two studies used the Headache Impact Test (HIT-6) [1,14] and 6-point Behavioral Rating Scale (BRS6) [2,9] (18.18%), and one study (9.09%) used the symptom score [9], cervical range of motion (ROM) score [2], cervical spondylosis efficacy score [17], pressure meter [18], infrared thermal imaging [15], pain relief time score [3], and analgesic effect score [3] (Table 5).

Table 5 . Summary of the results of the studies.

Study	Sample size (n)	Outcome	Result	Adverse event	Follow-up
Xie and Feng [1]	IG 35 CG 35	1. VAS 2. HIT-6 3. Clinical efficacy 4. Clinical efficacy (after 3 months)	1. IG (35): 6.80 ± 1.30 → 2.71 ± 2.05 (p < 0.01)CG (35): 6.80 ± 1.28 → 3.97 ± 2.88 (p < 0.01)IG < CG (p < 0.05) 2. IG (35): 11.83 ± 7.07 → 1.51 ± 1.02 (p < 0.05)CG (35): 11.83 ± 6.47 → 6.29 ± 3.92 (p < 0.05)IG < CG (p < 0.05) 3. IG (35): 94.29CG (35): 74.29IG > CG (p < 0.05) 4. IG (35): 85.71CG (35): 60.00IG > CG (p < 0.05)	NR NR	3 months
Tan [14]	IG 30 CG 30	1. VAS 2. HIT-6 3. Clinical efficacy	1. IG (30): 6.93 ± 1.36 → 2.03 ± 1.33 (p < 0.05)CG (30): 7.07 ± 1.31 → 3.87 ± 1.85 (p < 0.05)IG < CG (p < 0.05) 2. IG (30): 59.73 ± 3.79 → 39.87 ± 2.73 (p < 0.05)CG (30): 60.03 ± 3.12 → 47.73 ± 5.84 (p < 0.05)IG < CG (p < 0.05) 3. IG (30): 96.67CG (30): 83.33IG > CG (p = 0.007)	Blood oozing (3) Blood oozing (2)	NR
Chen [9]	IG 36 CG 35	1. VAS 2. BRS6 3. Symptom score 4. Clinical efficacy	1. IG (36): 5.56 ± 1.31 → 3.41 ± 0.84 (after 1 week) → 0.61 ± 0.64 (after 3 weeks; p < 0.05)CG (35): 5.51 ± 0.95 → 3.14 ± 0.81 (after 1 week) → 1.28 ± 1.01 (after 3 weeks; p < 0.05)IG < CG (after 1 week; p > 0.05)IG < CG (after 3 weeks; p < 0.05) 2. IG (36): 5.22 ± 0.72 → 3.33 ± 0.83 (after 1 week) → 0.67 ± 0.53 (after 3 weeks; p < 0.05)CG (35): 5.23 ± 0.69 → 3.40 ± 0.81 (after 1 week) → 1.68 ± 0.72 (after 3 weeks; p < 0.05)IG < CG (after 1week; p > 0.05)IG < CG (after 3 weeks; p < 0.05) 3. IG (36): 6.08 ± 1.38 → 3.03 ± 0.77 (after 1 week) → 0.53 ± 0.61 (after 3 weeks; p < 0.05)CG (35): 6.00 ± 1.24 → 3.17 ± 1.04 (after 1 week) → 1.88 ± 0.98 (after 3 weeks; p < 0.05)IG < CG (after 1 week; p > 0.05)IG < CG (after 3 weeks; p < 0.05) 4. IG (30): 94.44CG (30): 74.29IG > CG (p < 0.05)	NR NR	NR
Zhao and Luo [3]	IG 120 CG 120	1. Pain relief time 2. Analgesic effect (SF-MPQ + VAS + PRI) 3. Clinical efficacy (after 3 months)	1. IG (120): initial pain relief time (1.00 ± 3.70) and complete pain relief time (9.00 ± 3.50)CG (120): initial pain relief time (1.00 ± 2.90) and complete pain relief time (12.00 ± 6.90)IG > CG (initial pain relief time; p > 0.05)IG < CG (complete pain relief time; p < 0.05) 2. IG (120): 41.50 ± 2.30 → 0.79 ± 0.37 (p < 0.0001)CG (120): 42.10 ± 3.20 → 2.50 ± 1.33 (p < 0.0001)IG < CG (p < 0.05) 3. IG (120): 100CG (120): 93.33IG > CG (p < 0.05)	NR NR	3 months
Wang [2]	IG 30 CG 30	1. VAS 2. BRS6 3. ROM score 4. Clinical efficacy	1. IG (30): 6.97 ± 1.79 → 1.43 ± 1.14 (p < 0.05)CG (30): 7.07 ± 1.62 → 2.83 ± 1.56 (p < 0.05)IG < CG (p < 0.05) 2. IG (30): 3.47 ± 0.94 → 1.20 ± 1.01 (p < 0.05)CG (30): 3.50 ± 0.86 → 1.80 ± 1.06 (p < 0.05)IG < CG (p < 0.05) 3. IG (30): 2.50 ± 0.68 → 1.13 ± 0.43 (p < 0.05)CG (30): 2.40 ± 0.62 → 1.50 ± 0.68 (p < 0.05)IG < CG (p < 0.05) 4. IG (30): 93.3CG (30): 90.0IG > CG (p < 0.05)	NR NR	NR
Zhang et al. [17]	IG 38 CG 34	1. VAS 2. Cervical spondylosis efficacy scores 3. Clinical efficacy	1. IG (38): 7.03 ± 1.02 → 1.12 ± 0.91 (p < 0.05)CG (34): 7.11 ± 1.04 → 2.63 ± 1.12 (p < 0.05)IG < CG (p < 0.05) 2. IG (38): 15.23 ± 1.80 → 24.60 ± 2.99 (p < 0.01)CG(34): 14.55 ± 1.91 → 22.17 ± 2.34 (p < 0.01)IG > CG (p < 0.01) 3. IG (38): 97.40CG (34): 85.30IG > CG (p < 0.05)	NR NR	NR
Chen et al. [18]	IG 32 CG 29	1. VAS 2. Pressure meter 3. Infrared thermal imaging	1. IG (32): 5.69 ± 1.09 → 1.69 ± 0.86 (p < 0.01)CG (29): 5.79 ± 1.18 → 2.45 ± 0.96 (p < 0.01)IG < CG (p < 0.05) 2. IG (32): 3.23 ± 0.44 → 5.06 ± 0.51 (p < 0.01)CG(29): 3.23 ± 0.44 → 4.58 ± 0.77 (p < 0.01)IG > CG (p < 0.05) 3. IG (32): 0.77 ± 0.60 → 0.30 ± 0.17 (p < 0.01)CG (29): 0.74 ± 0.65 → 0.43 ± 0.21 (p < 0.01)IG < CG (p < 0.05)	NR NR	NR
Li and Fu [19]	IG 25 CG 25	1. VAS 2. Clinical efficacy	1. IG (25): 5.34 ± 0.10 → 1.52 ± 0.32 (p < 0.05)CG (25): 5.21 ± 0.96 → 3.10 ± 0.42 (p < 0.05)IG < CG (p < 0.05) 2. IG (25): 96.00CG (25): 76.00IG > CG (p < 0.05)	NR NR	NR
Chen et al. [15]	IG 39 CG 39	1. VAS 2. Clinical efficacy (after 6 months)	1. IG (39): 7.1 ± 0.5 → 2.4 ± 0.8 (p < 0.001)CG (39): 7.2 ± 0.4 → 3.5 ± 1.2 (p < 0.001)IG < CG (p < 0.001) 2. IG (39): 97.4CG (39): 79.5IG > CG (p < 0.05)	None NR	6 months
Wang [16]	IG 46 CG 46	1. VAS 2. Clinical efficacy	1. IG (46): 6.65 ± 1.77 → 0.98 ± 1.57CG (46): 6.59 ± 1.76 → 2.41 ± 2.36IG < CG (p < 0.05) 2. IG (46): 100.00CG (46): 86.96IG > CG (p < 0.05)	NR NR	NR
Wang and Cai [20]	IG 43 CG 43	1. VAS 2. Clinical efficacy	1. IG (43): 6.37 ± 1.20 → 0.84 ± 0.03 (p < 0.05)CG (43): 6.40 ± 1.19 → 2.29 ± 0.71 (p < 0.05)IG < CG (p < 0.05) 2. IG (43): 97.67CG (43): 83.72IG > CG (p < 0.05)	NR NR	NR

IG, intervention group; CG, control group; VAS, visual analog scale; HIT-6, Headache Impact Test; NR, non-recorded; BRS6, 6-point Behavioral Rating Scale; SF-MPQ, Short-Form McGill Pain Questionnaire; PRI, pain rating index; ROM score, range of motion..

11) Treatment results

In 10 studies (90.90%) that used the clinical efficacy evaluation scale, values were significantly higher in the intervention group (p < 0.05 [1-3,9,15-20], p = 0.007 [13]) [1-3,9,14-17,19,20]. One study revealed that the clinical efficacy after 3 months of treatment was also significantly higher in the intervention group (p < 0.05) [1]. Of the 10 studies (90.90%) using the VAS assessment scale, 8 (72.72%) showed significantly lower values in the intervention group compared with the control groups (p < 0.05 [14], p < 0.001 [15], p < 0.01 [1,18], p < 0.05 [2,17,19,20]), indicating a significant difference between the intervention and control groups (p < 0.05 [14], p < 0.001 [15], p < 0.05 [1,2,17-20]) [1,2,14,15,17-20]. One study observed a significant difference in VAS values after treatment (p < 0.05) [16]. The study by Chen [9] revealed no significant difference in VAS values after 1 week of treatment, but values significantly decreased after 3 weeks of treatment (p < 0.05), indicating a significant difference between the intervention and control groups (p < 0.05).

In two studies (18.18%) that used the HIT-6 assessment scale, values significantly decreased in both the intervention and control groups (p < 0.05 [14], p < 0.05 [1], respectively), with a significant difference between the groups after treatment (p < 0.05 [14], p < 0.05 [1]) [1,14]. Two studies (18.18%) using the BRS6 assessment scale revealed significantly lower values after treatment in both the intervention and control groups (p < 0.05), indicating a significant difference between the groups (p < 0.05) [2,9]. One study revealed no significant difference in BRS6 values after 1 week of treatment, but the values significantly decreased after 3 weeks of treatment (p < 0.05), indicating a significant difference between the intervention and control groups (p < 0.05) [9].

One study using the symptom score revealed no significant difference in values after 1 week of treatment, but values significantly decreased after 3 weeks (p < 0.05), with a significant difference between the intervention and control groups after 3 weeks (p < 0.05) [9]. Another study using the cervical ROM score revealed that ROM values significantly improved in both the groups after treatment (p < 0.05), with a significant difference between the groups (p < 0.05) [2]. A study using the functional evaluation of cervical spondylosis as an evaluation scale found significant improvement in both groups (p < 0.01), indicating a significant difference between the groups (p < 0.01) [17].

One study using the pressure meter as an evaluation scale revealed significantly increased values in both groups after treatment (p < 0.01), indicating a significant difference in each group (p < 0.05) [18]. The same study used infrared thermal imaging, which revealed a significant decrease in values in both groups after treatment (p < 0.01), with a significant difference between the groups (p < 0.05) [18]. For the study that used pain relief time as an evaluation scale, the time to complete pain relief was significantly shorter in the intervention and control groups (p < 0.05) [3]. Moreover, the study using the analgesic effect scale found that the analgesic effect value significantly decreased in both groups before and after treatment (p < 0.0001), with a significant difference between the intervention and control groups after treatment (p < 0.05) [3] (Table 5).

12) Adverse events

Adverse reactions were reported in two (18.18%) studies. One study noted local bleeding after autotomy, while the other reported no side effects [14,15] (Table 5).

13) Risk of bias assessment

The risk of bias was assessed using Cochrane’s RoB2 tool. Regarding the risk of bias arising from the randomization process, five studies (45.45%) were judged to have low risk due to clear randomization and allocation concealment [2,9,14-16], while six studies (54.54%) raised concerns due to lack of allocation concealment [1,3,17-20]. Regarding deviations from intended interventions, blinding was impossible in all studies (100%). Ten studies (90.90%) [1-3,9,15-20] were rated low risk for missing outcome data, as there were no dropouts, expect for the study by Tan [14], which raised concerns owing to unclear dropout information. One study (9.10%) had a high risk of bias due to missing outcome data, as the reasons for dropouts were not detailed, and target data were not available for review [14]. The remaining 10 studies (90.90%) had low risk for missing outcome data as the target data were accessible to the researchers [1-3,9,15-20].

For outcome measurement, all studies (100%) were rated low risk because they used multiple standardized assessment tools to evaluate both intervention and control groups, minimizing subjective bias. Moreover, participants completed questionnaires independently, reducing bias, regardless of whether the outcome assessor knew the intervention type [1-3,9,13-19]. Regarding bias in the selection of reported results, two studies (18.18%) had a low risk due to a detailed pre-study protocol and analysis plan, ensuring transparency [9,13]. The remaining nine studies (81.81%) raised concerns due to insufficient information on pre-study planning or result selection criteria [1-3,14-19] (Figs. 2–4).

Figure 3. Risk of the randomized controlled trial bias summary.

Figure 4. Risk of the randomized controlled trial bias.

This study searched domestic and international databases and selected 11 RCT studies on autotomy treatment for occipital neuralgia. It investigated the latest trends in autotomy treatment for occipital neuralgia based on publication year and country, number of participants, duration of illness, treatment methods, type of autotomy, stimulation site, stimulation method and depth, treatment frequency and period, evaluation tools, treatment effects, side effects, and bias assessment.

The publication years of the selected studies ranged from 2008 to 2021, with 7 of 11 studies published in the past 5 years, indicating a consistent trend in related research. Moreover, as interest in the use of autotomy is increasing in Korea, active research in this area is needed.

Of the 11 studies, 9 had participants numbering between 60 and 120, while only one study had > 120 participants. The duration of illness varied greatly, ranging from 3 months to 12 years. One study [4] recommends additional examinations and interventional procedures if occipital neuralgia does not improve with conservative treatment after > 3 months. This suggests that the treatment of occipital neuralgia is increasingly being approached with more invasive treatments as conservative methods become less effective, failing to resolve nerve compression directly. Based on the duration of illness of the participants in this study, it can be inferred that they suffered from chronic occipital neuralgia. Therefore, autotomy could be an alternative to surgery for patients with chronic occipital neuralgia who do not respond effectively to conservative treatment after > 3 months.

Of the 11 studies, only 5 used autotomy as a single intervention in the intervention group. The remaining six studies combined autotomy with various other treatments.

The type of autotomy was described in 7 of the 11 studies. Of these, five studies used needles with a thickness of 0.6 mm, and five studies used needles with a length of 50 mm, indicating that needles with these dimensions were primarily used to stimulate the soft tissue associated with occipital neuralgia. In 10 of the 11 studies, the stimulation site was described by anatomical location. The stimulation sites could be divided into three areas through which the greater occipital nerve, lesser occipital nerve, and third nerve pass. Moreover, several points were inferred as stimulation targets for the greater occipital nerve, such as the medial one-third point connecting the occipital process and the mastoid process [14,16], 2.5 cm on both sides of the nuchal line from the occipital process [1,3,9], midpoint connecting the occipital process and the mastoid process [15], midpoint connecting the mastoid process and the spinous process of the second cervical vertebra [16,17,20], 17–20 mm horizontally from the point where the horizontal line connects both the ears and the vertical line in the center of the occipital region intersect [18], and 2.5 cm horizontally and 4 cm vertically below the occipital process [19]. The points inferred as targets for stimulation of the lesser occipital nerve were the lateral one-third point connecting the occipital process and the mastoid process [14], 5 cm lateral to the nuchal line from the occipital process [1,3,9], and 5 cm horizontally and 4 cm vertically below the occipital process [19]. This classification, which was not specified in the selected studies, was inferred based on the anatomical locations described in the included studies.

Of the 11 studies, only 5 specified the patient group with the word occipital neuralgia caused by the greater occipital nerve, while the remaining 6 included the patient group with the word occipital neuralgia. With regard to the treatment site and patient group selection, many of the studies mainly treated the greater occipital nerve area, followed by the lesser occipital nerve. Occipital neuralgia encompasses neuropathies of the greater occipital nerve, lesser occipital nerve, and third occipital nerve. Ninety percent of all occipital neuralgia cases are caused by the greater occipital nerve. As each nerve has different soft tissues can be compressed, conducting comparative studies on the effects of autotomy for occipital neuralgia targeting each nerve separately could provide more precise evidence.

Of the 11 studies, most of the insertion methods comprised vertical insertions (7 studies), with 3 studies performing adhesion dissection by rotating the needle 90° after vertical insertion to ensure safety when considering the direction of movement of the posterior cervical soft tissues. Furthermore, seven studies set the insertion depth to < 0.5 cm, suggesting that finding the exact location of nerve entrapment is more important than the depth of the insertion, as occipital nerve occurs in relatively superficial tissues such as the upper trapezius, sternocleidomastoid, and semispinalis muscles. Future research should focus on investigating the effects of needle thickness and depth of stimulation, rather than the length of the autotomy needle.

In each study, the treatment period for the intervention and control groups was generally the same (1–4 weeks), but a significant difference in the frequency of treatment was observed. In the studies [1,2,14,15,17] that used acupuncture and electroacupuncture as a control group, the number of treatments per treatment period was higher in the control group, except for one study [1]. However, in addition to the common evaluation scale VAS, the intervention group exhibited higher effects than the control group in individual evaluation sections, showing statistical significance. Three studies [1,3,15] that conducted follow-up observations indicated that the intervention group maintained a statistically significant improvement compared to the control group even after 3 and 6 months of follow-up (p < 0.05, p < 0.05, and p < 0.05, respectively). This suggests that autotomy treatment can provide long-term effects with less time and cost compared with acupuncture and electroacupuncture treatments. In the follow-up studies [1,3,15], the treatment methods in the control group was not unified.

Clinical efficacy evaluation scale and VAS were the most frequently used assessment tools, applied in 10 studies each. Although less frequently used, additional evaluation tools, such as the symptom score, analgesic effect evaluation score, ROM score, infrared thermal imaging, and pain relief time score added objective indicators to supplement the subjectivity of the VAS and BRS6. These methods, which aim to minimize patient subjectivity, are noteworthy for improving the quality and objectivity of the research.

In the analysis of the treatment effects, all 11 studies revealed significant effects in the intervention group compared with the control group, indicating a total of seven treatment methods used in the control group treatment. Autotomy treatment was effective not only in comparison with acupuncture and electroacupuncture but also with Western medicine interventions. The sustainability of the effects was confirmed in the follow-up studies. Thus, autotomy may be considered a safe alternative treatment for chronic occipital neuralgia that does not respond to conservative treatment. However, the number of participants in the intervention studies included in this review was limited. Additionally, some studies combined multiple complex interventions, and not enough studies implemented follow-up observations, suggesting the need for further research on this topic.

Two studies reported side effects of autotomy, which appeared minimal, such as blood oozing, which is considered a minor side effect.

In the bias assessment of the 11 studies, randomization was mentioned, but the concealment of allocation order was not fully addressed. Regarding outcome measurement bias, four studies relied solely on the clinical efficacy evaluation scale and VAS scale as assessment tools, which may have introduced a risk of bias.

However, this study has several limitations. First, all studies were conducted in China, which may limit the generalizability of the findings and suggests the need for more research in other countries. Moreover, the sample sizes were relatively small, with only one study having > 120 participants, suggesting that larger-scale studies are necessary to improve the reliability of the results. Second, the variation in the duration of illness (from 3 months to 12 years) may have influenced the consistency of the observed treatment effects. Furthermore, six studies combined autotomy with other treatments, making it difficult to isolate the effect of autotomy alone. Future studies should aim for single-intervention designs. The variation in needle types and insertion techniques may introduce inconsistencies, as factors like needle thickness and insertion depth could affect the treatment outcomes. Lastly, only two studies have reported side effects, suggesting that more research is needed to thoroughly assess the safety of autotomy treatment. Furthermore, these limitations indicate that future studies should include larger sample sizes, more diverse populations, and standardized protocols to establish more robust evidence for the effectiveness and safety of autotomy for occipital neuralgia.

This study investigated the latest trends in autotomy treatment of occipital neuralgia by selecting 11 RCT studies conducted from October 2008 to January 2021. The findings suggest that autotomy may be a potentially effective and safe treatment for occipital neuralgia, but further research is needed to confirm these findings. Future studies should focus on implementing larger sample sizes, long-term follow-up periods, and standardized protocols to better assess the efficacy and safety of autotomy.

Conceptualization: HEJ, YGM, HGL, JHL, HJL, JSK. Data curation: HEJ, YGM. Formal analysis: All authors. Investigation: All authors. Methodology: HEJ, YGM, HGL, JHL, HJL, YKL, JSK. Project administration: All authors. Supervision: All authors. Visualization: HEJ. Writing - original draft: All authors. Writing - review & editing: All authors.

The authors have no conflicts of interest to declare.

None.

This research did not involve any human or animal experiment.