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Electroacupuncture direct to spinal nerves as analternative to selective spinal nerve block inpatients with radicular sciatica - a cohort studyMotohiro Inoue, Tatsuya Mojo, Tadashi Yam), Yasiikazu Katsumi

AbstractWe applied electroaciiputicture to the spinal nerve root by itiserting needles under .s: ray imaging in threecases with radicular sciatica, as a non-pharmacological substitute for lumbar spinal nerve block. In allthree cases, symptoms were markedly redueed immediately after electroacupuncture to the spinal nerveroot. The sustained effect was noticeably longer than that of spinal nerve blocks previously performed intwo out of the three cases. We suggest that descending inhibitory control, inhibitory control at the spinallevel, inhibition of potential activity by hyperpolarisation of nerve endings, or ehatiges in nerve bloodflow may be involved in the mechanism of the effect of electroacupuncture to the spinal nerve root. Theseresults suggest that electroacupuncture to the spinal nerve root may be superior to lumbar spinal nerveblock when it is applied appropriately in certain cases of radicular sciatica, taking into considerationpatient age, severity of symptoms and duration of the disorder.

KeywordsRadicular sciatica, electroacupunclure. selective lumbar spinal nerve block.

IntroductionIt is generally known that acupuncturetherapy applied to lumbar muscle and fascia iseffective for relieving low back pain originatingfrom these tissues.' Since acupuncturehas little effect in treating radicular sciatica,however, there is a call for the developmentof more effective acupuncture therapy. On theother hand, at pain clinics and orthopaedicdepartments and centres, one conservativetreatment frequently employed forradiculopathy is selective spinal nerve block(SNB). While used as a highly effectivetreatment to alleviate the symptoms ofradieulopathy, SNB is also a valuable diagnostictool for determining the lumbar level at whicha disorder is located.-'

We employed a technique similar to theselective SNB to treat radicular sciatica,inserting an acupuncture needle as close aspossible to the relevant nerve root, to investigatethe effects of applying low frequency electro-acupuncture directly to the spinal nerve root(EASNR).

MethodsCohort

The three cases selected as subjects suffered fromradicular sciatica and intermittent claudieationdue to lumbar spinal eanal stenosis {Table 1). Thethree patients had been treated with poultices, oralNSAIDs, injection of local anaesthetic into thelumbar muscle region, and massage of the lowback and leg, before undergoing HASNR. Prior toreceiving EASNR, two of the three casesunderwent SNB, so a comparision could be madeof the relative effectiveness of SNB and EASNR.

The Ethics Committee of Meiji University ofOriental Medicine approved this study. Writteninformed consent to participate in the study wasobtained from all subjects.

EASNR

Having ascertained tbat the symptoms, x ray film

and MRI findings pointed to a nerve root disorder,

two acupuncture needles (90mm in length;

0.24mm diameter) were inserted in the part of the

nerve root that emerges from the intervertcbral

foramen {ventral side of transverse process) under

Motohiro Inouclicensed acupuncturistMeiji University ofOriental Medicine

Tatsuya Hojoortluipa eilic • sui-geon

Kyoto PrefccliiralUniversity

Tadashi Yannlicensed uvupuncturisiMeiji University ofOriental Medicine

Yasukazu Katsumiorthopaedic surgeonMeiji University ofOrientii! Medicine

Cotrespotidetice:

Motohiro liioucni o_i n on e (('., ni uo in. ni e ij i -u.ac.jp

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Table I Details of the cases

Case Sex Age Diagnosis Duration Symptoms .«: ray film. MRI fi Serve rootafTeeled

Male 84 Lumbar spinal 7 years Right baek and lowercanal stenosis extremity pain and numbness

(L4area)Spinal ciaudication (50 m)

.V ray: Inter vertebral space andinter vertebral foramen narrowingat and below L.2 3MRI: Spinal canal stenosis at andbelow L3/4, with narrowingparticularly at the L4/5. L5/SIintervertobral disc level(predominanlly on right side),zygapophyseal join! and yellowligament hypertrophy

L4 right

2 Male 69 Lumbar spinal 5 years Left back and lower extremitycanal stenosis pain and numbness

(L5/'S 1 areas)Spinal claudication (50 m)

-V ray: Intervertebral foramennarrowing (zygapophyseal jointhypertrophy) at and below L3/4MRI: Spinal canal stenosis at andbelow L4/5 intervertebral disclevel, particularly at the L4/5intervortcbral disc level(predominantly on left side)

L5/S1 left

3 Male 74 Lumbar spinal 9 year(* Right back and lowercanal stenosis extremity pain and numbness

(L5/SI areas)Spinal elaudication (100 m)

.V ray: Intervertcbral spaces andintervertebral foramennarrowingat and below L2/3MRI: Spinal canal stenosis at andbelow 1.4/5 intcrvertebriil disclevel (predominantly on right side)

L5/S1 right

Right L4 nerveroot acupuncturestimulation site

Right L5 nerveroot acupuncturestimulation site

: Right SI nerveroot acupuncturestimulation site

Figure I This figure i.s a schematic diagratn of thenerve root acupuncture stitmdation sites. Refctredpain in the distribution controlled by the nerveroot was confirmed on inserting two acupunctureneedles to the affected part of the nerve under xmy fluoroscopy.

X ray fluoroseopy, with at least one of the needleslocated in a position close enough to permitstirnuiation of the nerve root. Electricalacupuncture was conducted using the acupunctureneedles as electrodes as shown in Figures I and 2.The stimulation characteristics were as follows:spike wave-form at 2Hz for 10 minutes, with thestimulation strength set to a level to createsensatioti in the area of innetT/ation of the nerveroot (Pointer F-3, Ito Co Ltd).

L5 nerve rootacupuncture stimulation site

SI nerve rootaeupuncture stimulation site

aeupunctureneedles

Figure 2 This is an x ray image of right L5/SIEASNR.

28 ACUPUNCTURE IN MEDICINE 2005;23(l):27-30.www. medical-acupuncture.eo.uk/aimi mm. htm

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Evaluation method

Each time the subjects received EASNR, the

severity of low back pain, lower extremity pain

and lower extremity dysaesthesia were evaluated

bctbre and directly afterwards using a numerical

scale, with 10 indicating the severity of pain or

dysaesthesia prior to receiving EASNR at the first

consultation, and 0 indicating complete absence of

symptoms. Subjeets were also asked how long the

effect continued after EASNR. Patients with

spinal claudication were asked to walk before and

directly after EASNR, and the walking distance

was recorded. Of the three subjeets, two had

undergone SNB treatment (with the aim of

delivering local anaesthetics into the

intervertebral foramen as both a therapeutic and

diagnostic procedure) before receiving EASNR.

The effectiveness of SNB was evaluated using the

same outcomes.

Results and CourseCase 1 Directly after EASNR. low back painscore decreased from 10 to I, while lowerextremity pain and lower extremity dysaesthesiadecreased from 10 to 2. Extended walkingdistance increased from 50m to 300m. Whenthe patient reattended hospital two weeks later,low back pain, lower extremity pain and lowerextremity dysaesthesia were all still scored at2, and the increase in extended walking distanceof 50m to 300m was maintained, indieatingthe sustained effectiveness of the EASNR.Following further EASNR, low back pain scoredecreased 1, as did lower extremity pain and lowerextremity dysaesthesia. At the last evaluation,12 months after the second EASNR, there hasbeen no elear recurrenee of symptoms, andextended walking distance is now maintained atover 5()()m.

Case 2 Directly after EASNR, the evaluation oflow back pain, lower extremity pain and lowerextremity dysaesthesia decreased from 10 to 2.With regard to spinal claudication, walkingdistance increased from 50m to 150m. However,with this patient, symptoms recurred two daysafter EASNR. and finally a iaminectomy at L4/5was performed. After the operation, low backpain, lower extremity pain and lower extremitydysaesthesia had disappeared, and walking

distance increased to over 500m. Low baek pain,

lower extremity pain and lower extremity

dysaesthesia recurred four months after the

operation. SNBs were performed at L5 and SI

twice, but their effectiveness lasted for just three

or four days. Therefore, L5 and SI EASNR was

conducted once every two weeks for a total of six

sessions. Directly after each of these treatments,

evaluation of low baek pain, lower extremity pain

and lower extremity dysaesthesia decreased from

10 to 0, 10 to 1 and 10 to 2 respectively, and these

improvements were sustained for 7 to 14 days.

Case 3 After the first SNB, symptoms reducedfrom 10 to 6; after the second, from 10 to 7, andon each occasion the effect lasted only one day.Directly after the first and only treatment withEASNR, low back pain, lower extremity pain andlower extremity dysaesthesia decreased from 10 to 0,while walking distance increased fiom I OOin to 2CX)m.At last assessment four months after the EASNR,there had been no recurrence of symptoms, andwalking distance had increased to over 500m.

Diseussion

Selective SNB was first reported by Macnab in1971.- At present it is used both to assist thediagnosis ofthe specific spinal nerve lesion and asa method of treatment, and it has been reportedwidely.-' In selective SNB it is thought thatinjection of local anaesthetic blocks the affeetedsensory nerve and sympathetic nerve to alleviatepain and improve blood flow. Whencorticosteroids are also used, there is also thoughtto be a direct anti-inflammatory action on thenerve root.*

With the three cases reported here, selectiveSNB had been used unsuccessfully to treatradicular sciatica, and subsequently low frequencyEASNR was performed. As a result, in all threecases there was a marked reduetion in the rootsymptoms directly after EASNR together withincreased walking distance. In addition, long-termeffects were observed in two ofthe cases.

We originally thought that EASNR would acton lower extremity pain by activating descendinginhibitory control," and inhibitory control at thespinal level,* the mechanisms of regularacupuncture analgesia. However, the results in this

ACUPUNCTURE IN MEDICINE 2005;23(l):27-30.www.medical-acupiinclure.co.uk/aiminirti.htm 29

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paper indicate that in addition to lower extremity

pain, the EASNR reduced lower extremity

dysaesthesia and increased walking distance, as

well as providing a long-lasting effect. It is

thought that claudication associated with spinal

canal stenosis, results from pressure on the cauda

equina with restriction of blood flow. This in turn

leads to a dramatic reduction in the ability to meet

the oxygen demands of the nerves controlling the

lower extremities during walking. With regard to

the relationship between spinal claudication and

blood supply to nerve tissue, we have previously

demonstrated that acupuncture stimulation in the

lumbar area," electrical stimulation of the sciatic

nerve," and electrical stimulation of the piidendal

nerve in the rat cause a transient increase in nerve

blood flow.'" In light of this, we believe that

increased nerve blood flow from stimulation plays

a major role in the effects of acupuncture and low

frequeney EA on spinal claudication. Thus, we

believe that direct stimulation of the nerve root

with EASNR results in increased nerve blood

flow, which reduces lower extremity dysaesthesia

and increases walking distance, and the effect appears

to be sustained. With the EASNR conducted in

this study, it is thought that, because referred pain

in the innervation area of the nerve root, together

with muscle contraction, can be confirmed during

the procedure, thereby enabling precise electrical

acupuncture at the desired nerve root, direct low

frequency EASNR participates in changes to the

cireulatory dynamics of the sciatic nerve

including the cauda equina and spinal nerve root.

In case 2, no long term effect was obtained, but

it was significant that one EASNR treatment

every two weeks achieved control of the root

symptoms, and it is possible that in cases in which

surgery is not po.ssible. EASNR could be an

effective option for treating eases that do not

respond well to SNB.

In the two cases that had undergone SNB

before receiving EASNR. the etlect directly after

EASNR. and the effect duration, were more

pronouneed than the effect and duration provided

by SNB. It is thought that one reason for this is

that in cases of chronic radicular sciatica and

intermittent claudication associated with the

reduced nerve blood flow, the stimulating

treatment of EASNR raises nerve blood flow more

effectively than the local anaesthetic injection of

SNB. The analgesic meehanisms of SNB and

EASNR are also likely to be different, and it is

thought that stimulation treatment may be more

effective than anaesthetic treatment in some

circumstances, depending on the pathology, stage,

symptoms and other factors.

Although the results in these three cases were

promising, further study of this treatment

teehnique is required in different centres before

general conclusions ean be drawn.

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30ACUPUNCTURE IN MEDICINE 2OO5;23(l):27-3().

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