-
Journal of Neurology, Neurosurgery, and Psychiatry, 1981, 44,
9-18
Electroejaculation: its technique, neurologicalimplications and
usesG S BRINDLEY
From the Department of Physiology, Institute of Psychiatry,
London
SUMMARY An improved technique for electroejaculation is
described, with the results ofapplying it to 84 men with spinal
injuries and five men with ejaculatory failure from othercauses.
Semen was obtained from most patients, but good semen from very
few. Only onepregnancy has yet been achieved. The technique has
diagnostic applications.
"Electroejaculation" is the word generally usedto denote the
obtaining of semen by electricalstimulation with electrodes in the
rectum. Thename is a little misleading, because the semen israrely
or never ejaculated in the strict sense; ittrickles from the
external urinary meatus withoutthe help of contractions of striated
muscles. Thetechnique has been used in domestic animals since1936.
Most veterinary users have employed sinu-soidal alternating current
of frequencies from 15to 100 Hz, delivered through rigid rectal
probes,a substantial fraction of whose surface was coveredwith
electrodes.'
Published accounts of its application to man2-7consider only its
use for rendering paraplegic menfertile. Two pregnancies thus
achieved have beenreported,4 7 one of them7 yielding a live
baby.Stimuli have been sinusoidal at frequencies fromtwo3 to 906 Hz
or have consisted of trains of uni-directional pulses of duration
one" to 156 ms andfrequency five6 to 1405 Hz, and they have
beenapplied through probes similar to those used inveterinary
practice. No writer, I believe, has dis-cussed the rational choice
of stimulus parametersor electrode sizes or positions, and I can
findno substantial body of empirical observation onthese matters in
either the abundant veterinaryliterature or the scanty medical
literature.
Preliminary investigations
Theory What is needed is to stimulate the right nervefibres, and
as few as possible of the wrong ones, with
Address for reprint requests: Professor GS Brindley, Institute
ofPsychiatry, De Crespigny Park, Denmark Hill London SE8 8AF.
Accepted 18 September 1980
9
the least possible risk of thermal and electrolyticdamage to the
rectal mucosa. To select a particularnerve or compact plexus it is
advantageous to havea single circular cathode and a larger anode or
groupof anodes. The diameter of the cathode should beroughly equal
to its least distance from the nerve orplexus; a greater diameter
worsens the discrimination,and a smaller diameter causes the
current densityclose to the electrode to be unnecessarily and
perhapsharmfully high. These desiderata are roughly obviousfrom
theory, and can be confirmed from experiencein stimulating motor
points and cutaneous nervesthrough the skin.
In attempting to stimulate from the rectum ana-tomically defined
structures in the pelvis one wouldexpect discrimination to be
better with an electrodemounted on a glove-finger than with one
mounted ona rigid probe, and probably the risk of doing mech-anical
damage is less with a glove-finger. To minimiseelectrolytic damage,
one should ensure that no netdirect current is passed (which some
earlier workershave done), and also minimise the electrical
chargetransferred per cycle (which none of them have done).To
minimise thermal damage, one should, amongstother things, minimise
the electrical power consumed,and this has never before been
attempted. For boththese purposes, if the fibres that one is
intending tostimulate are myelinated (and it will be argued
belowthat they are), the stimulating pulses should be short.Charge
per pulse at the threshold for a myelinatedfibre falls with
duration down to roughly 80 /is andremains nearly constant below
this. Energy per pulseat such a threshold falls with duration down
toroughly 150 ,us and rises below this. Thus pulses of100 pis
duration will be not very far from minimisingboth charge and
energy; at least they will be muchbetter in both respects than the
sinusoidal currents or1 to 15 ms pulses used in previous published
work.A nimal Experiments All experiments and surgicalprocedures on
animals were done under deep pento-barbitone anaesthesia. In ten
male baboons and four
Protected by copyright.
on March 30, 2021 by guest.
http://jnnp.bmj.com
/J N
eurol Neurosurg P
sychiatry: first published as 10.1136/jnnp.44.1.9 on 1 January
1981. Dow
nloaded from
http://jnnp.bmj.com/
-
10
male rhesus monkeys, I explored what happened whensites
accessible to a cathode of 4 mm diametermounted on a glove-finger
were stimulated electricallythrough the rectum. I was able to
produce separately,on either side, the movements appropriate to
thepudendal, sciatic, inferior gluteal, superior gluteal,obturator,
or genitofemoral nerve. The femoral nervecould be stimulated, but
usually not without alsostimulating the genito-femoral. In all 14
animals,stimulation at sites giving obturator or
genitofemoraleffects gave full or nearly full erection, with
thresholdroughly two or three times that for somatic effects.
In two baboons a urethral catheter was passed andthe bladder
pressure measured. The region from whicha rise in bladder pressure
was obtained with lowestthreshold was centred on the best site for
stimulatingthe obturator nerve. All stimulation which increasedthe
bladder pressure also caused some erection, but inthe more caudal
part of the effective region the erec-tion was slight though the
rise in bladder pressure waslarge (40 mmHg or more). Just rostral
to the effectiveregion was one from which erection could be
pro-voked without any rise in bladder pressure.
In seven of the 10 baboons and three of the fourrhesus monkeys
semen was obtained as a result ofthe procedure, but it was often
not clear which ofseveral sites of stimulation had caused the
emission. Itherefore repeated the procedure in one of thebaboons
and one of the rhesus monkeys with theabdomen opened and the vas
deferens of both sides sur-gically exposed in the spermatic cord
and upper scro-tum. In both animals, the site that gave
contractionof the seminal vesicle and vas deferens with
lowestthreshold was just rostral to the ipsilateral obturatornerve
point. The response fatigued if stimulation wasrepeated at 15
second intervals, but two minutes' restsufficed for its recovery.
The contraction producedfrom either obturator point was restricted
to the ipsi-lateral seminal vesicle and vas deferens. Stimulationin
the midline just rostral to the prostate caused con-traction on
both sides, but with threshold higher by afactor of 1-6 to 1-8. The
contractions involved all thevisible part of the vas deferens, that
is from the upperborder of the testis to about 2 cm below the
pubiccrest and from the lateral inguinal fossa to thebladder. The
most easily visible manifestation of themwas a shortening, so that
undulations of the vas dis-appeared and it took as straight a
course as possiblebetween its points of attachment. No peristaltic
waveswere seen. The strength-duration relation for produc-ing
contraction of the left vas deferens by stimulatingthe left
obturator point was measured in the baboon.The chronaxie was 0-6
ms.
In four male baboons and three male rhesus mon-keys I implanted
electrodes on the hypogastric plexusimmediately in front of the
bifurcation of the aorta.In all animals, stimulation through the
implantedelectrodes caused shrinkage of the penis together witha
contraction of the seminal vesicles and vasa defer-entia very
similar to that seen during electroejacula-tion. In one of the
rhesus monkeys the strength-
G S Brindley
duration relation for producing such contraction wasmeasured.
The chronaxie was 0 4 ms.Experiments on myself In me, trains of 100
lAs pulsespassed through a 6 mm circular cathode mountedeither on a
glove-finger or on a rigid probe will stimu-late both motor and
sensory fibres of the pudendalnerves from the upper part of the
anal canal withoutcausing severe pain, though always with some
pain.It is even possible to produce a maximal contractionof the
muscles innervated by the pudendal nerve.8From the posterolateral
rectal wall, pressing back-wards towards the sacral plexus of one
side, I canproduce ipsilateral toe flexion or plantarfiexion ofthe
foot, and tingling in various parts of the ipsilateralS2 and S3
dermatomes. These are always accompaniedby diffuse deep pelvic
pain, but the pain is not pro-hibitively unpleasant at threshold
for the muscularand "cutaneous" effects. I cannot produce
contractionof the gluteal or adductor muscles, or erection,
ejacu-lation, micturition or the sensation of impending
mic-turition. The strongest stimuli that pain allows me totolerate
are roughly 1/4 (in voltage or current) ofthose needed for
electroejaculation in patients.
Methods
EQUIPMENT FOR ELECTROEJACULATION IN MANElectrode mounts My first
glove-finger electrodemounts were made from dental acrylic. The
rigidityof this material hindered accurate palpation, but notas
severely as one might expect. After about a yearof using acrylic
electrode mounts I changed to siliconerubber. Whatever the material
of the electrodemount, it is made to extend beyond the tip of
thefinger by about 20 mm, and the cathode, whose di-ameter is about
8 mm, lies on the palmar surface ofthis extension. There are two
anodes in parallel, eachof area equal to that of the cathode or a
little greater,on the dorsal surface centred 18 and 50 mm
proximalto the cathode. Such electrode mounts are made byMr C M
Andrew of 43 Landcroft Road, LondonSE22, and can be bought from
him.Stimulator I assume that in man, as in the baboonand rhesus
monkey, electroejaculation depends on thestimulation of myelinated
fibres. I therefore adhererigidly to 100 /As as the duration of the
stimulatingpulses. Until May 1980 I always used 30 pulses
persecond, because I had found in 1977 that this waseffective, and
there seemed to be no reason to changeit. Since May 1980 I have had
reason to use lowerfrequencies, and have often done so. At first I
useda general purpose electrophysiological stimulator, put-ting a
capacitor in series with the output to preventthe passage of direct
current. Now I use a compact(19X 11 X8 cm) battery-driven
stimulator designed by(and purchasable from) Mr C M Andrew, giving
thefollowing stimulus parameters: pulse duration 100 its;peak
voltage of pulse up to 108 V (9 equally-spacedsteps) into 1 MQ2
load, up to 80 V into the usual loadof 250Q2; time-constant of sag
of pulse 800 us; peakcurrent into 250Q up to 316 mA; nett current
less
Protected by copyright.
on March 30, 2021 by guest.
http://jnnp.bmj.com
/J N
eurol Neurosurg P
sychiatry: first published as 10.1136/jnnp.44.1.9 on 1 January
1981. Dow
nloaded from
http://jnnp.bmj.com/
-
Electroejaculation: its technique, neurological implications and
uses
than 0-1 AsA; output impedance 60-902 (highest athighest voltage
setting); time-constant of decay ofreturn current between pulses 10
ms; frequency ofpulses 30, 15 or 10 per second (switchable).
PROCEDUREMy usual practice is to have the patient supine
withknees bent (though it is possible to use the left lateral,or
even the prone position). It is useful to have ahelper standing on
the patient's left to hold the leftleg. I stand on the right and
put the electrode mounton the right index finger over a plastic or
rubberglove. I put some aqueous jelly (KY jelly is suitable)on the
tip of the electrode mount and over the elect-rodes, and insert the
electrode mount into the analcanal until the cathode and distal
anode and half ofthe proximal anode are within the canal. Then
stimu-lation at 9 volts should cause contraction of the
analsphincter, and, with a little adjustment of the rotationand
depth of the electrode mount, the left or rightischiocavernosus
muscle. I next turn my hand so thatits palm faces down and,
pressing gently downwardwith the finger-tip, advance the electrode
mount asfar in as it goes easily with very gentle pressure.
Thecathode is now near the best places for stimulating thesacral
plexus and its somatic branches. Using 36 to54 volt pulses, I
explore the posterior wall of thepelvis for sites giving flexion of
the toes, plantar-flexion at the ankles, visible contraction of the
ham-strings, abduction of the thighs, visible contraction ofthe
buttocks, external rotation at the hips, or palpablecontraction of
the obturator internus muscles. It isusually possible to obtain all
of these, separately orin various combinations, on either side, and
this mayprovide useful diagnostic information. But when
theprocedure is being used solely to obtain semen, itsuffices to
obtain any one of the somatic motor effects.If I get none at 54 V I
try at 80 V. If still none canbe obtained, then either no anterior
horn cells sur-vive from the 5th lumbar to the 2nd sacral
segment,or the stimulator is not working, or there is muchgas in
the rectum, preventing the anodes from makinggood contact. In the
last case the gas can be expelledby pressing on the abdomen,
pulling laterally with thefinger to assist its release.
I next turn the palmar surface of the finger so thatit faces
directly to the patient's right, and advance thefinger as far as
possible, pushing hard. I then explorethe right lateral wall of the
pelvis for the obturatorpoint, that is the site where 80-volt
stimulation causespowerful adduction of the right thigh.
Stimulation hereusually yields semen (if semen can be obtained at
all)after from 5 to 20 seconds. If there is none in 40 sec-onds I
try the left obturator point. To reach the leftobturator point it
is sometimes necessary to transferthe electrode mount to the left
hand and stand on thepatient's left.
Results
In 256 attempts at electroejaculation on 89 men
(84 with spinal injuries and five others), I haveobtained semen
externally in 163 (64'1%), retro-gradely in 44 (17'2%) and not at
all in 49 (19'1%).But these figures are overweighted with men
onwhom I have had many (in one case 31) successes.Table 1
classifies the results on men with spinalinjuries by patients
rather than by attempts. "Ex-ternal success" means that on at least
one occasionliquid containing spermatozoa (not necessarilymotile)
trickled from the meatus. On 11 of these36 men only one attempt was
made. On four ofthem two attempts were made, and both
wereexternally successful. On 21 of them from threeto thirty-three
attempts were made, of which some(usually most) were externally
successful, the re-mainder being either retrograde or
unsuccessful.
"Retrograde success" means a patient fromwhom I have never
obtained semen externally, butwhose next urine passed after an
attempt atelectroejaculation has contained at least 5X
106spermatozoa. On six of these 14 men only oneattempt was made. On
five men two or moreattempts were made, all retrogradely
successful.On three men two attempts were made, oneretrogradely
successful and the other unsuccessful.
"Definite failure" means a patient in whom onone occasion (17
cases) or on three occasions(three cases), attempted
electroejaculation hasyielded no liquid at the meatus (15 cases)
orliquid containing no spermatozoa (five cases), andthe next urine
passed has contained no sperma-tozoa (13 cases) or fewer than 5 X
106 spermatozoa(seven cases).
"External failure" means a patient from whomno semen was
obtained externally, and who failedto provide a specimen of urine.
All such patientswere seen once only.
"Pain prevented" means a patient in whom, atthe only attempt at
electroejaculation, stimulationat less than the strength needed for
success inother patients was intolerably painful.Partly retrograde
ejaculation Ten of the 36 menlisted in table 1 as external
successes also onoccasion gave purely retrograde ejaculation.
Itwould thus not be surprising if ejaculation wassometimes partly
external but partly retrograde.Merely finding spermatozoa in the
next urinepassed after an externally successful electroejacu-lation
is insufficient to prove such an occurrence;it is necessary to
collect the urine in two lots, thefirst (of at least 20 ml) to wash
out the urethra,and the second as a sample of real bladder
con-tents. I have done this on three occasions (differ-ent
patients) when I already suspected that ejacu-lation was partly
retrograde, and on all three
B
I1I
Protected by copyright.
on March 30, 2021 by guest.
http://jnnp.bmj.com
/J N
eurol Neurosurg P
sychiatry: first published as 10.1136/jnnp.44.1.9 on 1 January
1981. Dow
nloaded from
http://jnnp.bmj.com/
-
12
occasions found more spermatozoa in the bladderurine than in the
external ejaculate.Prevention by pain Every patient who
couldrecognise pinprick in no lumbar or sacral derma-tome could
tolerate electroejaculation withoutanaesthesia. Every patient who
could recognise pin-prick in a sacral or L5 or L4 dermatome was
un-able to tolerate it. Patients who could recognisepinprick in an
LI to L3 dermatome but not belowwere unpredictable.General
anaesthesia and neuromuscular blockTable 2 summarises the ten
patients on whom Ihave attempted electroejaculation under
generalanaesthesia, usually with neuromuscular
block(succinylcholine). Six had spinal injuries or spinabifida, and
in four of these the reason for usinggeneral anaesthesia was that
an attempt at electro-ejaculation without anaesthesia had been
preventedby pain. In the other two, the reason was thatattempts
without anaesthesia had been retro-gradely successful. I then tried
under generalanaesthesia with neuromuscular block, and fromone of
the two patients obtained semen externally.A similar conversion
from retrograde to externalejaculation was achieved in one of the
two other-wise healthy men who had never ejaculated in thewaking
state. My first electroejaculation of him,
G S Brindley
done under general anaesthesia without musclerelaxant, was
retrogradely successful. Five sub-sequent electroejaculations, all
done with neuro-muscular block, have yielded semen externally.
SIDE-EFECTS OF ELECTROEJACULATIONContractions of striated
muscles These are a valu-able guide to the position of the
stimulatingcathode. Under general anaesthesia they agreewith what
would be expected from the stimulationof nearby a motor fibres. In
unanaesthetisedpatients these direct motor effects are accom-panied
by reflex effects. Often the reflex effects arevariable from time
to time in the same patient,and they may occur after rather than
duringstimulation; but sometimes they are so repeatableand so
immediately related to the stimulus thatonly their anatomical
inappropriateness shows thatthey are not direct motor effects. The
commonestsuch pseudo-direct response of striated muscle
iscontraction of the abdominal muscles on stimu-lation of branches
of the sacral plexus; I havenotes of its occurring in seven
patients and thinkit occurred in a few others. Almost
simultaneouscontraction of the adductors of both sides in re-sponse
to stimulation of the obturator nerve onone side has occurred in at
least four patients. I
Table 1 Success and failure of electroejaculation in patients
with spinal injuries
Highest clinically External success Retrograde success Definite
failure Externalfailure Pain prevented Totaldamaged cordsegment
C6 to Tl 13 1 5 3 0 22(4 incomplete) (incomplete) (2
incomplete)
T2 to T12 21 11 13 3 2 50(3 incomplete) (1 incomplete) (6
flaccid) (2 flaccid) (both incomplete)
(1 flaccid) (1 incomplete)Ll orbelow 2 2 2 1 5 12
(1 incomplete) (flaccid) (1 flaccid) (flaccid) (2 incomplete)(1
flaccid)
Total 36 14 20 7 7 84
Table 2 Electroejaculation under general anaesthesia
External success Retrograde success Definite failure1 complete
L2 lesion I complete T5 lesion (patient with 1 T12/L2 lesion
(flaccid patient)
transurethral resection of bladder neck)1 incomplete T12 lesion
1 abdomino-perineal excision of rectum for
carcinoma (electrodes inserted throughcolostomy)
I complete T4 lesion I diabetic non-ejaculator without
otherevidence of neuropathy
I lumbar spina bifida2 otherwise healthy lifelong
non-ejaculators(5 and 6 external successes respectively)The fi e
patients in table 2 who had spinal injuries are listed also in
table 1.
Protected by copyright.
on March 30, 2021 by guest.
http://jnnp.bmj.com
/J N
eurol Neurosurg P
sychiatry: first published as 10.1136/jnnp.44.1.9 on 1 January
1981. Dow
nloaded from
http://jnnp.bmj.com/
-
Electroejaculation: its technique, neurological implications and
uses
have never seen pseudo-direct contraction of thequadriceps,
adductors or ilio-psoas in response tostimulation of the sacral
plexus, or pseudo-directcontraction of the gluteal muscles, or of
anymuscle below the knee, to stimulation on the oppo-site side.
In six of the 146 externally successful electro-ejaculations
without general anaesthesia, emissionof semen has been accompanied
by rhythmic con-tractions of the abdominal muscles. The
temporalpattern of these contractions roughly resembledthat of
orgasmic pelvic floor contractions,9 butthey lacked the progressive
increase in intervalthat occurs at orgasm. On two of these six
oc-casions the rhythmic contractions included theanal
sphincter.Rhythmic abdominal contractions (not including
the anal sphincter) were seen in one of 47 unsuc-cessful and in
one of 44 retrogradely successfulelectroejaculations.After-effects
on spasm Several patients havementioned that for a few hours after
electroejacu-lation their legs are less spastic than usual.
Others,when directly questioned, have denied any sucheffect. No
patient has reported increase in spasm.Micturition Stimulation that
is intended to yieldsemen sometimes yields urine instead, or a
mixtureof urine and semen. Of the 15 men whom I
haveelectroejaculated three or more times with exter-nal success
(most of them six or more times), eighthave never given semen mixed
with urine, threehave done so on a minority of occasions, and
fouron the majority of occasions. Of the 22 men whomI have
electroejaculated once or twice with ex-ternal success, three have
given semen mixed withurine.There are two means by which the
release of
urine with semen can sometimes be prevented. Thefirst uses the
anatomical separation of sympatheticand parasympathetic fibres that
might be expectedfrom anatomical textbooks, and was seen in
thebaboon experiments. Stimulation near the bestsite for
stimulating the superior gluteal nerveoften gives urine without
semen. When the bladderhas by this means been made emptier than
thepatient can get it by his own efforts, stimulation ator a little
cranial to the best site for the obturatornerve may give pure
semen. The second methoduses the effect of pulse frequency. In the
baboon'0and in human patients (Brindley, Polkey & Rush-ton,
unpublished), stimulation of preganglionicsacral parasympathetic
fibres at 30 pulses/s givesvery much stronger detrusor contractions
than at15 or fewer pulses/s. For electroejaculation, how-ever, 15
pulses/s are almost as good as 30/s in the
baboon. In man they are at least sometimes ade-quate, and yield
pure semen where 30/s hadyielded mixed semen and urine from the
samepatient.Erection I have done some externally
successfulelectroejaculations without causing any penileerection,
and very many with only a slight erec-tion. But there are men in
whom seminal emissioncannot, with my technique, be achieved
withoutan accompanying full erection, and others inwhom erection
sometimes but not always occurs.Contraction of the dartos muscle A
train of largepulses delivered to almost any site in the
pelviscauses in nearly all patients a conspicuous con-traction of
the dartos after a delay of 3-5 seconds.This response is absent or
very feeble under gen-eral anaesthesia, but I have seen it clearly
andreproducibly present in a patient with a T8 lesionin whom there
was no evidence (unless this dartosresponse be such) of any
functioning cord orsurviving anterior horn cells below the level of
thelesion. In two otherwise similar patients with T6and T7 lesions
the dartos response was absent.Rise in blood pressure In patients
with lesionsat T5 or below I do not usually record the
bloodpressure. No such patient has reported headacheduring the
procedure. In patients with lesionsabove T5, electroejaculation
nearly always raisesthe blood pressure. I formerly used an
automaticsphygmomanometer (Dynamap 845). Now I usean ordinary
sphygmomanometer repeatedly, or feelthe pulse, inflate a
sphygmomanometer cuff to200 mmHg, and not whether the pulse
reappears.If the systolic pressure reaches 200 mmHg or ifthe
patient reports headache I stop stimulating.The blood pressure then
always falls within afew tens of seconds, and I often resume
stimula-tion (if semen has not yet been obtained) within
aminute.
CORRELATES OF FAILUREIn five of the 20 patients classified as
definitefailures, electroejaculation yielded liquid at theexternal
urinary meatus that looked like semenbut contained no spermatozoa.
The volumes were3.5, 2-0, 0 3, 0-2 and 0 1 ml. In another
threepatients, no liquid appeared at the meatus, butacid
phosphatase and fructose were substantiallymore abundant in the
next urine passed afterelectroejaculation than in urine passed
before it.Another patient was of eunuchoid appearanceand had very
small testes. It seems likely that inall or most of these nine
patients the electricalstimulation had its proper effect on the
prostate,seminal vesicles, and vasa deferentia, but the
13
Protected by copyright.
on March 30, 2021 by guest.
http://jnnp.bmj.com
/J N
eurol Neurosurg P
sychiatry: first published as 10.1136/jnnp.44.1.9 on 1 January
1981. Dow
nloaded from
http://jnnp.bmj.com/
-
14
patients were azoospermic from disease or injuryof the upper
genital tract.
Six patients with whom I definitely failed had noevidence of any
surviving anterior horn cellsbelow T6, T7, T8, T9, LI and L2. In
the last twoof these, damage extended on one side up to T12.Two
patients, both with complete Tl 1 lesions,had intact muscles of the
L5 and sacral myotomes,but severe wasting of the quadriceps,
adductors,and iliopsoas. It seems likely that in all or mostof
these patients the sympathetic fibres that theprocedure should
stimulate were lost.There remain two patients where definite
failure
is entirely unexplained. Both had cervical lesions,and only one
attempt at electroejaculation wasmade. Their urines were not
examined for fruc-tose, acid phosphatase or other
genital-tractmarkers (eg arginine or y-glutamyl transferase).
THE INFLUENCE OF SURGICAL OPERATIONS ON THEBLADDER NECK AND
URETHRA
Twelve patients have had transurethral resectionof the bladder
neck; of these, three have also hadtransurethral external
sphincterotomy. Five ofthese patients were external successes, and
fiveretrograde successes. Two were "definite failures",in both
cases with evidence that retrogradeemission of azoospermic semen
had occurred.Thus transurethral resection of the bladder
neckcertainly does not make external emission imposs-ible, though
it probably increases the proportionof retrograde to external
emissions. Only onepatient has had external sphincterotomy and
noresection of the bladder neck. He is the one patientwho has
become a father. Of 33 attempts atelectroejaculation on him, 31
have been externallysuccessful. The other two (both early in the
series)were definite failures.
ELECTROEJACULATION IMMEDIATELY AFTERREMOVING A FOLEY
CATHETERThis lhas been done 34 times on 13 patients.Twenty-one
attempts (seven different patients)were externally successful,
seven attempts (on fourof the preceding patients) were retrogradely
suc-cessful, and six attempts (six different patients)were definite
failures.
QUALITY OF SEMEN IN MEN WITH SPINAL INJURIESI nearly always
measure the specimen, and docounts of motile spermatozoa and all
spermatozoa,within 40 minutes. Paraplegic semen is usuallyliquid;
only for about one specimen in 10 is thereneed to wait for
liquefaction.
G S Brindley
The volume can be from 0-2 ml to 10-5 ml(the latter without
evident contamination byurine). The average is about 2 ml. The
number ofspermatozoa per unit volume can be normal, butis more
often low (less than 40 million/ml). Twopatients have repeatedly
given specimens withcounts exceeding 500 million/ml, and six
otherpatients have at least once had counts exceeding200
million/ml. The fraction of spermatozoa thatswim is almost always
low. Among 166 externalejaculates examined, the highest motilities
were78% (T10 complete lesion of one year's duration),48% and 33%
(T5 complete lesion of 17 years'duration, injured at age 19 and
first electroejacu-lated at age 36), 41% (T5 complete lesion of
1Iyears' duration), 34% (T7 complete lesion ofseven years'
duration), and 26% (C7 completelesion of two years' duration). All
the other 161specimens had motilities under 26%. In the
44retrograde ejaculates (which by definition con-tained at least
five million spermatozoa), motilitieswere zero in 32, and between
1% and 20% in 12.Fourteen wives of men with spinal injuries
have
been inseminated with the husband's semen, all ofthem more than
once. Only one pregnancy hasbeen achieved. Paternity was verified
by exam-ination (by Prof B E Dodd of the London1Hospital) of 17
blood antigens, not includingHLA. The child is healthy, walked at
11 months,and could say six distinguishable words at 14months.
DOMESTIC ELECTROEJACULATIONThe wives of 12 paraplegic men were
askedwhether they wished to learn to electroejaculatetheir
husbands. Ten wished to and two did not.All the 10 who wished to
learn have now learned,and are using the technique successfully at
home.One of these wives is a physician, one a nurse, andone a
physiotherapist. The other seven had norelevant previous knowledge
or experience.
Discussion
SAFETYLocal heating The calculated power dissipationat the
cathode during stimulation at 30/s at thehighest voltage setting is
at most 0- 11 watt cm2.In two recent electroejaculations done at
thesesettings the temperature rise was monitored by abead
thermistor mounted on the centre of thecathode. The temperature
rises in 30 seconds ofstimulation were 0 25 and 0 300C. There is
nokind of single or double failure in the stimulatorthat could
increase the power dissipation by more
Protected by copyright.
on March 30, 2021 by guest.
http://jnnp.bmj.com
/J N
eurol Neurosurg P
sychiatry: first published as 10.1136/jnnp.44.1.9 on 1 January
1981. Dow
nloaded from
http://jnnp.bmj.com/
-
Electroejaculation: its technique, neurological implications and
uses
than a factor of five; such an increase could occuronly if there
were three simultaneous faults, oneof them being the insertion of
the wrong kind offuse in the fuse-holder.Electrolysis The net
direct current passed by theblocking capacitors during stimulation
at 30/s atthe highest voltage-setting is less than 10-7A, thatis at
least 100 times too low to cause electro-lytic damage. In five
patients I examined therectal mucosa with a sigmoidoscope a few
minutesafter electroejaculation. The sites of stimulationwere
indistinguishable from the surroundingmucosa. Blood-staining of the
next faeces passedhas been reported to me after only two of
256electroejaculations on 89 patients. There are twoblocking
capacitors in series, each rated at 160 V,and the potential across
them cannnot exceed 96 V.It is thus very unlikely that either will
fail, andmuch more unlikely that both will.Ventricular fibrillation
The current density atthe heart produced by the pelvic stimulation
usedfor electroejaculation can be calculated if weassume the human
body to be a uniform con-ductor. Though this assumption is
inaccurate, itis unlikely to overestimate or underestimate
thecurrent density by more than a factor of 2 or3. The current
density in a uniform conductor atdistance D from a dipole of length
d carryingcurrent I, where D is substantially greater than d,is
dI/2srD3 along the axis of the dipole and lessat any other
orientation. In the present case thelength of the dipole is at most
3 cm, the distancefrom the dipole to the heart at least 20 cm,
andthe current during a pulse at most 316 mA, givinga peak current
density at the nearest part of theheart of 19 MtAcm-2, and an rms
current densityof 1[0 MAcm-2 at 30 pulses per second and 05[Acm'2
at 15 pulses per second. The official safelimit for 50 Hz
alternating current is 50 uAcm-2rms. In pigs of weight 15-25 Kg,
300 mA peakcurrent from head to knee in trains of 3-7 mspulses was
required to produce ventricular fibrilla-tion." Assuming 600 cm2
(probably a substantialoverestimate) for the non-lung non-fat
cross-sectional area of the chests of such pigs, the peakcurrent
density at the heart would be 500 ltAcm .Even on these criteria the
currents used forelectroejaculation should be safe by a factor of
atleast 25, and the 100 ,us pulses used should be less(and perhaps
very much less) effective in causingventricular fibrillation than
3-7 ms pulses of thesame peak amplitude. To further confirm that
thestimulus parameters used have a large margin ofsafety for the
heart, in one anaesthetised baboonthe 100 us pulse stimulator was
connected between
electrodes of area 5 cm-2 in the mouth and in therectum and
switched on for a minute at maxi-mum amplitude (EMF 108 V) and 30
pulses persecond. This caused very powerful tonic contrac-tion of
the trunk muscles which probably involvedevery motor unit in the
whole trunk. Breathingceased, but the heart continued to beat in
regularsinus rhythm throughout the minute of stimula-tion.
Breathing returned within a few seconds ofthe end of stimulation.
This baboon weighed 12 Kgand the non-lung cross-sectional area of
its chestwas about 350 cm2. The peak current in eachpulse was 520
mA, so the peak current densitythrough the heart was about 1'5 mA
cm-.Elevation of blood pressure When electroejacu-lation is being
done on patients with high lesionsthe blood pressure must be
measured, and stimu-lation stopped if it rises too high or if the
patientreports severe headache. What pressure should beregarded as
too high, and whether mild headacheshould be taken as a ground for
stopping, arematters on which I can give no authoritativeopinion.
But it seems reasonable to suggest thatif the systolic pressure
does not rise above 200mmHg and the headache is neither distressing
tothe patient nor more severe than he has alreadyexperienced in
previous episodes of autonomicdysreflexia, no excessive risk has
been taken.
WHAT IS BEING STIMULATED TO CAUSE EMISSIONOF SEMEN
Electroejaculation works well under generalanaesthesia, and is
then very unlikely to dependbon a reflex. In unanaesthetised
patients, theemission of semen was in all but 2 of 146 exter-nally
successful trials unaccompained by rhythmicpelvic floor
contractions such as occur in normalorgasm. It is thus unlikely
that success in the un-anaesthetised ordinarily depends on
triggering areflex response of the cord; if it did, this
reflexwould have to be very different from the orgasmicreflex of
the intact cord. What of the two oc-casions when rhythmic pelvic
floor contractionsdid accompany seminal emission? One of thesewas
the only electroejaculation of a patient, butthe other was one of
five electroejaculations of apatient who emitted semen externally
on all fiveoccasions, with rhythmic abdominal contractionsincluding
the anal sphincter once, rhythmic ab-dominal contractions without
anal sphincter con-tractions twice, irregular abdominal
contractionsonce, and no obvious skeletal muscular activityonce. It
seems likely that even here the seminalemission depends on
ele_trical stimulation ofefferent fibres; rhythmic reflex activity
can occur
15
Protected by copyright.
on March 30, 2021 by guest.
http://jnnp.bmj.com
/J N
eurol Neurosurg P
sychiatry: first published as 10.1136/jnnp.44.1.9 on 1 January
1981. Dow
nloaded from
http://jnnp.bmj.com/
-
16
simultaneously with it, but is probably a separateand
independent phenomenon.The sites that are best for causing
seminal
emission agree fairly well with those that onewould expect, from
known anatomy, to containsubstantial numbers of sympathetic fibres
to thegenital tract, and they are remote from the sensoryfibres
that serve the known receptive field for re-flex ejaculation. In
me, and in the patients withincomplete or low lesions, the
sensations producedby stimulating at these sites are nongenital,
whollyunpleasant, and not conducive to sexual arousal.These facts
provide further reasons for doubtingwhether the seminal emission
produced by mytechnique is ever reflex.The chronaxies found for
contraction of the vas
deferens in the rhesus monkey and baboon arevery much lower than
those found for unmyelin-ated fibres,12 and are typical of
myelinated fibres.This leads immediately to the conclusion that
therelevant sympathetic fibres are myelinated (andhence presumably
preganglionic) at the sites stimu-lated, that is in front of the
bifurcation of theaorta and between the rectum and the
obturatornerve.
It would be very difficult to measure the chro-naxie for
electroejaculation in men, and I havenot attempted it. But the
relatively low thresholdsfound for 100 ,us pulses make it probable
thatmyelinated fibres are being stimulated. The largestunmyelinated
fibres have electrical thresholdsonly twice those of small
myelinated fibres forlong pulses, but at least 20 times for short
pulses,12so that it is difficult to believe that the present
G S Brindley
stimuli can have excited more than a very fewfavourably placed
unmyelinated fibres.
THE SEGMENTAL ORIGIN OF THE NERVE FIBRESINVOLVED IN SEMINAL
EMISSIONTable 3 shows all patients with complete traumaticlesions
at T6 or below who gave external success,good retrograde success
(>20X 106 spermatozoa)or definite failure without evidence for
azoosper-mic emission. The more stringent criterion ofretrograde
success is to reduce the risk of includ-ing cases where spermatozoa
were released spon-taneously into the urine of expressed
mechanicallyby the electroejaculation procedure. Two patientsare
thus excluded; they have Tl and T12 lesions.Four "definite
failures" in the sense of table 1 areexcluded, two (both T6
lesions) because they gaveazoospermic external ejaculates and two
(T 11 andT12) because of high fructose and acid phospha-tase in the
urine collected after electroejaculation.From cases 1-18 it seems
that no single seg-
ment (unless just possibly T8 or Tl 1) is the sourceof all the
fibres involved in seminal emission. Sincecord lesions are rarely
if ever as short as onesegment, we may even tentatively infer that
nopair of consecutive segments is the source of allthe fibres. Case
17 is very informative. He twicegave good retrograde emission,
despite completeabsence of responses to electrical stimulation
ofmotor nerves in all segments from T12 downwardon the left and
from LI downward on the right.He had no trace of erection, reflexly
or in theelectroejaculation procedure or (he says) psychic-ally.
For him we can say almost certainly that the
Table 3 Patients with complete lesions at T6 or below who gave
external success, good retrograde success,or definite failure not
attributable to azoospermia
External success Good retrograde success Definitefailure
I T6 14 T7 (resection of bladder neck) 19 T6, flaccid2 T6 15 T12
20 T7, flaccid3 T6 16 T12 21 T8, flaccid4 T6 left, T7 right 17 T12
left, Li right, flaccid 22 T9, incomplete, flaccid5 T7 18 T12 left,
L2 right 23 T1 1, partly wasted muscles down to L46 T7 right, T8
left 24 Ti 1, completely wasted muscles down to
L47 T9 25 T12 right, Li left, flaccid8 T9 26 T12 right, L2 left,
flaccid (general
anaesthetic)9 T9, partly wasted muscles down to L310 T91 1 TIO12
T1213 L2 (general anaesthetic)
Protected by copyright.
on March 30, 2021 by guest.
http://jnnp.bmj.com
/J N
eurol Neurosurg P
sychiatry: first published as 10.1136/jnnp.44.1.9 on 1 January
1981. Dow
nloaded from
http://jnnp.bmj.com/
-
Electroejaculation: its technique, neurological implications and
uses
lumbar and sacral segments of the cord are un-necessary for
seminal emission. The only slightreservation is that loss of all a
anterior horn cellsdoes not absolutely prove loss of all
intermediatehorn cells in the same segment.
Cases 25 and 26 seem to conflict with case 17,but both were
failures on a single occasion withoutchemical analysis of the urine
for genital-tractmarkers.
Cases 23 and 24 suggest that loss of all thesympathetic outflow
from Tll downwards prob-ably prevents success in
electroejaculation. Case 9(in whom I have had many external
successes) isnot in sharp conflict, because of the incomplete-ness
of his wasting.
Cases 19-22 all showed no trace of somaticmotor responses in the
electroejaculation pro-cedure. Even the dartos response was absent
incases 19, 20 and 22, though it was present (to mysurprise) in
case 21. Case 22 was incomplete onlyin having slightly preserved
tactile sensation.The predominance of low lesions among the
retrograde successes suggests that a low lesion mayinterrupt the
sympathetic fibres to the bladderneck without destroying all those
to the vasa de-ferentia and seminal vesicles.
IMPROVING THE QUALITY OF SEMENThe figure of merit that I use is
the estimatednumber of motile spermatozoa in the wholeejaculate,
that is the product of volume, count perml, and fraction motile. On
this index the bestparaplegic ejaculate that I have seen does
notmatch average normal semen, and most paraplegicejaculates are
very bad. They are also usually ab-normal in being liquid when
emitted.
Possible reasons for the poor quality includenon-drainage,
chronic infection, and raised scrotaltemperature. I have some
evidence that all thesethree are contributory, and that remedying
themis practicable and beneficial; but this work has along way to
go before it will be fit to publish,except for the firm finding
that deep scrotal tem-peratures are on the average higher in
paraplegicsin wheelchairs than in age-matched and similarlyclothed
seated normal men.13
THE TREATMENT OF MEN WHO EJACULATERETROGRADELYSpermatozoa may
remain motile for three hoursor more in urine provided that it is
not too acid(pH less than about 6-2) or too dilute (total
solutesless than about 150 mosm/Kg). It thus seemspossible that
retrograde ejaculates might be used.after centrifugation, for
inseminating. Sodium bi-
carbonate 5 g, given by mouth one or two hoursbefore, ensures
appropriate pH and concentration.However, centrifugation may not be
harmless,and even the best urine is unlikely to be a
goodenvironment for spermatozoa.
In two men who previously ejaculated retro-gradely I have
obtained semen externally byelectroejaculating under general
anaesthesia withneuromuscular block. It seems likely that
thistechnique will be widely applicable. The same end,that is
relaxation of the striated muscles that closethe urethra, could
doubtless be achieved bypudendal block or sacral epidural
block.
RANGE OF APPLICATION
Diagnostic use The electroejaculation procedureprovides a quick
and simple means of examining,in a patient of either sex with a
complete transec-tion of the spinal cord, which muscles of the
lowerlimbs retain a motor innervation. It is applicableduring the
period of spinal shock, provided thatthree or four days have
elapsed since injury, sothat motor fibres whose perikarya have
beendestroyed have lost their excitability. The sameend can be
achieved by stimulation of motor pointsthrough the skin, but the
electroejaculation pro-cedure is much quicker.
In theory, the electroejaculation procedureshould distinguish
between a deafferented and atotally denervated bladder. These
behave alikein ordinary cystometry. At present the distinctionmakes
little or no difference to treatment, but thismay not remain true
in the future.Fertility of men with injury or disease affectingthe
spinal cord or cauda equina This is the"established" (though as yet
only slightly success-ful) field of application. It will probably
be themost important, if means can be found for improv-ing the
quality of the semen.Fertility of otherwise healthy men with
ejaculatoryfailure Only two such patients have been re-ferred to
me. With both I have been regularlysuccessful, and the counts and
motilities are withinnormal limits. Though no pregnancy has yet
beenachieved, there is ground for optimism.Injuries and disease
affecting peripheral nervefibres in the pelvis It seems likely that
when theseconditions cause ejaculatory failure they usuallydo so by
destroying the efferent pathway, soelectroejaculation will fail.
However, there maybe a few cases where it will succeed.
References
1 Ball L. Electroejaculation. In: Klemm WR, ed.Applied
Electronics for Veterinary Medicine and
17
Protected by copyright.
on March 30, 2021 by guest.
http://jnnp.bmj.com
/J N
eurol Neurosurg P
sychiatry: first published as 10.1136/jnnp.44.1.9 on 1 January
1981. Dow
nloaded from
http://jnnp.bmj.com/
-
18
Animal Physiology. Springfield, CC Thomas, 1976;394-441.
2 Horne HW, Paull DP, Munro D. Fertility studiesin human male
with traumatic injuries of thespinal cord and cauda equina. New
Engl J Med1948; 239:959-61.
3 Bensman A, Kottke FJ. Induced emission ofsperm utilizing
electrical stimulation of theseminal vesicles and vas deferens.
Arch Phys MedRehab 1966; 47:436-43.
4 Thomas RJS, McLeish G, McDonald IA. Eectro-ejaculation of the
paraplegic male followed bypregnancy. M J Aust 1975; 2:798-9.
5 David A, Ohry A, Rozin R. Spinal cord injuries:male
infertility aspects. Paraplegia 1977; 15:11-14.
6 Res P, Plevnik S, Suhel P. Electroejaculation inspinal cord
injured patients. International Con-tinence Society, 7th Annual
Meeting 1977; Paper6:21-22.
7 Francois N, Maury M, Jouannet D, David G,Vacant J.
Electroejaculation of a complete para-
G S Brindley
plegic followed by pregnancy. Paraplegia 1978;16:248-51.
8 Brindley GS, Rushton DN, Craggs MD. Thepressure exerted by the
external sphincter of theurethra when its motor nerve fibres are
stimulatedelectrically. Br J Urol 1974; 46:453-62.
9 Masters WH, Johnson, VE. Human sexual re-sponse. Boston:
Little, Brown & Co., 1966:185.
10 Brindley GS. An implant to empty the bladderor close the
urethra. J Neurol, Neurosurg Psy-chiatry 1977; 40:358-69.
1 1 Jacobsen J. Die Gefahrdung durch phasenange-schnittene und
gleichgerichtete elektrische Strome.Hannover: Technische
Universitat (Dr. Ing.thesis) 1973.
12 Blair EA, Erlanger, J. A comparison of thecharacteristics of
axons through their individualelectrical responses. Am J Physiol
1933; 106:524-64.
13 Brindley GS. Deep scrotal temperature and theeffect on it of
clothing, air temperature, activity,posture, and paraplegia. Br J
Urol (in Press).
Protected by copyright.
on March 30, 2021 by guest.
http://jnnp.bmj.com
/J N
eurol Neurosurg P
sychiatry: first published as 10.1136/jnnp.44.1.9 on 1 January
1981. Dow
nloaded from
http://jnnp.bmj.com/