trigeminal neuralgia.* BY
H. H. Carleton, M.D., M.R.C.P., Lond., Assistant Physician, Bristol General Hospital.
*
Y excuse ?r
for
bringing
discussion
c?niplaint,
?Ccurs
is that,
it is not
treatment is
should be
|^0as discussed Geu
quite
in this
subject before the meeting
although not a very exceedingly rare, and of urgency,
matter
a
clear cut.
Secondly,
common
when it and
our
it has not
Society in recent years. Thirdly,
ni0tli?ds of treatment ey differ
this
are
considerably
by
no means
either in
stereotyped;
general principles
or
and it is worth while, therefore, to review e Various procedures. However, before considering treatment we must consider diagnosis. Let us be we are sure as to the definition of the malady
111
detail,
^Ulte
discussing.
Spasmodic trigeminal neuralgia, or tic douloureux, clear-cut clinical syndrome with certain well-known c aracters. There are conditions giving rise to pain 111 the focal sepsis, region of the face ; for instance, ete., but they do not give rise to tic douloureux. The ls a
and it would
of the pain is entirely different, ^haracter mistake the pain of, in diagnosis grave e
a
Say> j
sinus Communicated to acute
January,
47
to
error
1932.
disease, the
Bristol
of
alveolar
abscess,
Medico-Chirurgical Society
or
on
48
Dr. H. H. Carleton
glaucoma,
for
the mistaken
trigeminal neuralgia supposition.
The character of the should
legitimately
of irritation
in the
pain
lead to
a
spasmodic trigeminal draw a blank, in fact
history neuralgia we
is
one
we
should
on
I refer to
cases
search for local
but if the
;
proper and act
sources
of
typical
shall
expect
always to
draw
blank.
a
What, then,
are
the characteristic features of tic
douloureux ?
(1) The pain is of terrific intensity ; (2) it is intermittent, usually lasting a few seconds at a time ; (3) it is lancinating or stabbing in character, never a dull, continuous boring pain ; (4) it is always unilateral in any attack, though the while it lasts
side of the face may be involved in subsequent attacks ; (5) it is strictly limited in its anatomical
opposite
distribution to trunks radiates
never
is
never
beyond
or
twigs
nerve
nerve ;
and
(6)
it
associated with focal disease
focal disease does not we
of the fifth
the field of this
; that is to say, the type of pain which
produce identify as tic douloureux. Pathology.?What do we know
of the
pathology
of the condition, and where is the lesion which gives The answer to both questions is rise to the pain ? that
we
simply
am
operations
are
in order to
ganglion is the seat of disease ; words, that we are dealing with a ganglionitis. not aware of the slightest evidence in support of
prone to in other I
Because
the Gasserian
ganglion destroy that some should be unnatural is not it pain,
devised to relieve
do not know.
assume
that the
assumption. I cannot conceive of a ganglionitis lasting for years. Such inflammation must necessarily be destructive, and the condition should cure itself such
an
Trigeminal Neuralgia
49
111
time. Furthermore, when we do get indisputable evidence of a Gasserian ganglionitis, as for instance in erpes of the fifth nerve, the symptoms are not those tic
douloureux. There is evidence that in certain cases of tic oureux pathological changes may be present in 10 ^rain stem. We have a number of cases on record spasmodic
trigeminal neuralgia
Seminated sclerosis,
c?llateral
affecting
cases
associated
with
in which there has been
evidence of plaques of insular sclerosis the brain stem. In such cases we have
^pulses initiated in the field of first sensory
j^d
conducted er? to become
physiologically altered that
to
the
neurone
brain
stem,
interpreted they agonizing pain. The problem is difficult to understand. Speculations on the subject are hardly Profitable ; they savour of arm-chair pathology, for geminal neuralgia does not supply post-mortem Material. We come back, then, to the admission that know little or nothing of the pathology of spasmodic so
are
as
^Vegeminal neuralgia.
Having defined what we mean spasmodic trigeminal neuralgia, we may pass on to c?nsider the general principles of treatment. The first outstanding fact which impresses me the futility of medical treatment by drugs. Ccasionally drugs are credited with affording some relief, but the position is unsatisfactory. Obviously it y
^
^ .
S
Possible to relieve some of the distress of individual tacks with potent sedatives or narcotics, but since e
Malady
a^Vays
is
characterized
by long
remissions it
remission may follow the ministration of almost any drug, and the last remedy ^ 0 be used is prone to get undeserved credit. I am ^?L. XLTY ALIX.
possible that
a
e
tvt No. 183.
50 not
Dr. H. H. Carleton aware
of any
drug
treatment which
can
be said
to have
produced a lasting cure. Turning to surgical measures, we have to distinguish three broad lines of treatment: (1) open operation ; (2)
alcohol
injections;
(3)
local
avulsions.
has
in recent
The
technique of open operations years a vast This improvement. undergone improvement time when the dates from Hutchinson roughly began to practise partial gasserectomy, in which he removed the lower two-thirds of the ganglion, leaving the ophthalmic division intact. By this proceeding he greatly reduced the risk of injury to the cavernous sinus, for the ophthalmic division courses along within the wall of the sinus, and total extirpation of the ganglion cannot be carried out without the risk of very severe haemorrhage and a consequent high mortality. Hutchinson's method also obviated the risks of neuroparalytic keratitis by sparing the first division of the fifth nerve. Fortunately the ophthalmic division is seldom primarily involved in tic douloureux. In this connection one may emphasize the importance In the majority of cases careful of history taking. inquiry will elicit the fact that the pain started in the second or third divisions, and only spread later to the first. In these cases it is sufficient to put the two
lower divisions out of action to effect
a
cure.
Consequently, Hutchinson's partial gasserectomy was generally successful, and in his hands enjoyed a low mortality. A more recent surgical procedure is partial division of the sensory root behind the ganglion. In the hands of a certain few neurological surgeons, who have devoted much time and study to the details of the
51
Trigeminal Neuralgia latter method has
?peration, an(i the
proved very successful low.
must
One
mortality is exceedingly results obtained however, that the statistical
^member, three surgeons with very special experience o or
^
not
and represent average results,
surgecm
can
hardly expect
to
a
good general
figures necessarily pass
approach
their
^th the limited material that must for the through his hands. The dissection necessary and is exposure of the sensory root is a difficult one, be mitigated by wide eset can with
dangers
experience. The third
dually
only
that
surgical procedure
of the supra-
or
of local avulsions,
infra-orbital
nerves,
requires
has it brief consideration. Very seldom, if ever, Proved successful. One is reminded of the common u
experience of surgeons of the futility of resecting usual a^eged neuromata in amputation stumps. The branches of c inical of avulsions of peripheral result
e '
fifth
nerve
is
anaesthesia
over
the
of the
111
corresponding
neuralgic pain.
area, but with a persistence nerve procedure of local avulsion or peripheral of the 0ck betokens a lack of understanding If one may use a principles involved. of the c?mparison, it may be said that the position avulsion sufferer from neuralgia after a local le
Physiological
trigeminal
patient with after amputation.
similar
|slmb
to that of
a
a
painful phantom
discussion of the alternative Procedure, alcohol injection of the Gasserian ganglion, estimate of its value. ail(l we must try and form a true which attaches to it lacks the
We
come now to
Vl?usly
a
precision
of the open operation in the hands SUrgeon, but it seems that the questions
^
e
experienced we
have to
52
Dr. H. H. Carleton
decide
are:
(1) Is
it
adequate procedure pitfalls ? (2) Are the
an
present unavoidable injection within our control
?
or
does it
results of
(3) What advantages,
if any, does it possess over the open operation ? (4) How far does alcohol injection justify itself from the of view of permanency of results ? Before describing the technique of alcohol
point
and the relative merits of the various routes the
ganglion may be approached, it will be
to
consider
some
injection by which
advantage points in the surgical anatomy of an
the Gasserian middle and is sinus.
ganglion. The latter is situated in the fossa immediately above the foramen ovale, bounded on its inner side by the cavernous It is hemmed in above by tightly-stretched
dura?an
remember, because the dura, together with the adjacent bone, forms a important point
to
restricted space into which alcohol in small quantities may be injected under pressure. It is important for the success of the operation that this roof of dura should not be
pierced by a needle. If it is, there is a danger of the alcohol travelling far and damaging neighbouring cranial nerves. A second point of importance is the short course of the third division of the fifth nerve as it leaves the ganglion to pass through the foramen ovale. So short is this course that the moment the needle enters the foramen it is
practically within the ganglion itself, and an alcohol injection implanted at this point can be relied upon to perfuse the whole of the ganglion and even reach the sensory root on the proximal side of it. The
arrangement
of
the
nerve
which is worthy of
fibres
constitute the sensory root and ganglion notice. They pursue a parallel course on the
proximal
Trigeminal Neuralgia
53
Slde of the
ganglion, and this parallelism is in the main observed right through into the three main divisions. This anatomical feature probably has an importance, taking for the success of a well-placed alcohol injection, ^be path of least resistance for injected fluids will be and follow the of the ^nterstitial highly probable, therefore, though
nerve
course
is
difficult
to
direct
of
fibres. course
that small
observation, prove by quantities of alcohol slowly injected into the lower
Fig. 1.1. Fig. .
l> 2, 3.?The the of the ?The three divisions of three divisions intrao ranial course division. r&cranial third division. course of the third of the
nerve. fifth nerve. fifth
short the very Note the Note very short
Wall of sinus. C.S.-?"Wall of cavernous cavernous sinus. '
"
_
er the sinus, sinus,toget together of the wall of the wall in the nerves running ?Cranial nerves IV., VI.?Cranial running in withthe th 6 the general Note the parallelism parallelism nerve. Note fifthnerve. general the fifth of the of division division ophthalmic ophthalmic ?f ner Vofibres n?rve Gasserianganglion. the Gasserian "bresas ganglion. as theycourse coursethrough through the
they
Part of the
ganglion will track backwards to the sensory that a complete anaesthesia of the fifth nerve is achieved by blocking the sensory root behind the ganglion, and without complete destruction of all 6 cells belonging to the ophthalmic division of the
r??t,
so
ll0rve which
?aftglion.
are
This
situated in the inner
probably danger neuroparalytic Ejection, if excessive quantities the
of
part of the
accounts for the
slightness
keratitis after alcohol of alcohol
are
avoided
54
Dr. H. H. Carleton
and if the little
injection is made very slowly. minims
Usually
of alcohol is sufficient to
eight produce complete anaesthesia. Other points in the topographical anatomy of the Gasserian ganglion can perhaps be dealt with when we come to the detailed technique of alcohol injection. The technique for injection of the Gasserian ganglion.?I prefer the lateral mode of approach and as
as
technique instituted by Wilfred Harris.
The necessary
Fig. 2.
Roofed, Roofed Note the confined space in which the Gasserian ganglion lies. in by dura, bounded on the inner side by the wall of the cavernous sinus, in the and bounded below by bone. The gap bony floor is the foramen ovale.
above, the slight concavity to be felt on the lower border of the zygoma immediately in front of the zygomatic tubercle ; below, a line
skin
markings
joining
are :
the incisurse formed
by
the lobe of the
ear
by the alse nasi with the upper lip. This line marks the lower limit of the sigmoid notch
with the cheek and of the mandible.
zygomatic
A vertical line is
tubercle
quarter of
an
from the
cutting the above base line
second vertical line is drawn a
dropped
intersecting
vertically deep
a
the base line
inch in front of the former.
foramen ovale lies
;
to the
The
zygomatic
Trigeminal Neuralgia
55
tubercle, but normally it points slightly forwards aild outwards. If, therefore, the needle is entered a quarter of an inch in front of this plane, and is passed aud
the
through
backwards,
sigmoid
notch
slightly upwards
it should reach the foramen at such
an
ailgle that the point of the needle can be insinuated through the opening. The operation can be done quite satisfactorily,
Surface
Fig. 3. 3. Fig. the lateral markings for approach markings for the lateral approach
t}lrffUr/ace r?ugh notch. ugh the the sigmoid sigmoid notch. ail
H. H. Carleton, M.D., M.R.C.P., Lond., Assistant Physician, Bristol General Hospital.
*
Y excuse ?r
for
bringing
discussion
c?niplaint,
?Ccurs
is that,
it is not
treatment is
should be
|^0as discussed Geu
quite
in this
subject before the meeting
although not a very exceedingly rare, and of urgency,
matter
a
clear cut.
Secondly,
common
when it and
our
it has not
Society in recent years. Thirdly,
ni0tli?ds of treatment ey differ
this
are
considerably
by
no means
either in
stereotyped;
general principles
or
and it is worth while, therefore, to review e Various procedures. However, before considering treatment we must consider diagnosis. Let us be we are sure as to the definition of the malady
111
detail,
^Ulte
discussing.
Spasmodic trigeminal neuralgia, or tic douloureux, clear-cut clinical syndrome with certain well-known c aracters. There are conditions giving rise to pain 111 the focal sepsis, region of the face ; for instance, ete., but they do not give rise to tic douloureux. The ls a
and it would
of the pain is entirely different, ^haracter mistake the pain of, in diagnosis grave e
a
Say> j
sinus Communicated to acute
January,
47
to
error
1932.
disease, the
Bristol
of
alveolar
abscess,
Medico-Chirurgical Society
or
on
48
Dr. H. H. Carleton
glaucoma,
for
the mistaken
trigeminal neuralgia supposition.
The character of the should
legitimately
of irritation
in the
pain
lead to
a
spasmodic trigeminal draw a blank, in fact
history neuralgia we
is
one
we
should
on
I refer to
cases
search for local
but if the
;
proper and act
sources
of
typical
shall
expect
always to
draw
blank.
a
What, then,
are
the characteristic features of tic
douloureux ?
(1) The pain is of terrific intensity ; (2) it is intermittent, usually lasting a few seconds at a time ; (3) it is lancinating or stabbing in character, never a dull, continuous boring pain ; (4) it is always unilateral in any attack, though the while it lasts
side of the face may be involved in subsequent attacks ; (5) it is strictly limited in its anatomical
opposite
distribution to trunks radiates
never
is
never
beyond
or
twigs
nerve
nerve ;
and
(6)
it
associated with focal disease
focal disease does not we
of the fifth
the field of this
; that is to say, the type of pain which
produce identify as tic douloureux. Pathology.?What do we know
of the
pathology
of the condition, and where is the lesion which gives The answer to both questions is rise to the pain ? that
we
simply
am
operations
are
in order to
ganglion is the seat of disease ; words, that we are dealing with a ganglionitis. not aware of the slightest evidence in support of
prone to in other I
Because
the Gasserian
ganglion destroy that some should be unnatural is not it pain,
devised to relieve
do not know.
assume
that the
assumption. I cannot conceive of a ganglionitis lasting for years. Such inflammation must necessarily be destructive, and the condition should cure itself such
an
Trigeminal Neuralgia
49
111
time. Furthermore, when we do get indisputable evidence of a Gasserian ganglionitis, as for instance in erpes of the fifth nerve, the symptoms are not those tic
douloureux. There is evidence that in certain cases of tic oureux pathological changes may be present in 10 ^rain stem. We have a number of cases on record spasmodic
trigeminal neuralgia
Seminated sclerosis,
c?llateral
affecting
cases
associated
with
in which there has been
evidence of plaques of insular sclerosis the brain stem. In such cases we have
^pulses initiated in the field of first sensory
j^d
conducted er? to become
physiologically altered that
to
the
neurone
brain
stem,
interpreted they agonizing pain. The problem is difficult to understand. Speculations on the subject are hardly Profitable ; they savour of arm-chair pathology, for geminal neuralgia does not supply post-mortem Material. We come back, then, to the admission that know little or nothing of the pathology of spasmodic so
are
as
^Vegeminal neuralgia.
Having defined what we mean spasmodic trigeminal neuralgia, we may pass on to c?nsider the general principles of treatment. The first outstanding fact which impresses me the futility of medical treatment by drugs. Ccasionally drugs are credited with affording some relief, but the position is unsatisfactory. Obviously it y
^
^ .
S
Possible to relieve some of the distress of individual tacks with potent sedatives or narcotics, but since e
Malady
a^Vays
is
characterized
by long
remissions it
remission may follow the ministration of almost any drug, and the last remedy ^ 0 be used is prone to get undeserved credit. I am ^?L. XLTY ALIX.
possible that
a
e
tvt No. 183.
50 not
Dr. H. H. Carleton aware
of any
drug
treatment which
can
be said
to have
produced a lasting cure. Turning to surgical measures, we have to distinguish three broad lines of treatment: (1) open operation ; (2)
alcohol
injections;
(3)
local
avulsions.
has
in recent
The
technique of open operations years a vast This improvement. undergone improvement time when the dates from Hutchinson roughly began to practise partial gasserectomy, in which he removed the lower two-thirds of the ganglion, leaving the ophthalmic division intact. By this proceeding he greatly reduced the risk of injury to the cavernous sinus, for the ophthalmic division courses along within the wall of the sinus, and total extirpation of the ganglion cannot be carried out without the risk of very severe haemorrhage and a consequent high mortality. Hutchinson's method also obviated the risks of neuroparalytic keratitis by sparing the first division of the fifth nerve. Fortunately the ophthalmic division is seldom primarily involved in tic douloureux. In this connection one may emphasize the importance In the majority of cases careful of history taking. inquiry will elicit the fact that the pain started in the second or third divisions, and only spread later to the first. In these cases it is sufficient to put the two
lower divisions out of action to effect
a
cure.
Consequently, Hutchinson's partial gasserectomy was generally successful, and in his hands enjoyed a low mortality. A more recent surgical procedure is partial division of the sensory root behind the ganglion. In the hands of a certain few neurological surgeons, who have devoted much time and study to the details of the
51
Trigeminal Neuralgia latter method has
?peration, an(i the
proved very successful low.
must
One
mortality is exceedingly results obtained however, that the statistical
^member, three surgeons with very special experience o or
^
not
and represent average results,
surgecm
can
hardly expect
to
a
good general
figures necessarily pass
approach
their
^th the limited material that must for the through his hands. The dissection necessary and is exposure of the sensory root is a difficult one, be mitigated by wide eset can with
dangers
experience. The third
dually
only
that
surgical procedure
of the supra-
or
of local avulsions,
infra-orbital
nerves,
requires
has it brief consideration. Very seldom, if ever, Proved successful. One is reminded of the common u
experience of surgeons of the futility of resecting usual a^eged neuromata in amputation stumps. The branches of c inical of avulsions of peripheral result
e '
fifth
nerve
is
anaesthesia
over
the
of the
111
corresponding
neuralgic pain.
area, but with a persistence nerve procedure of local avulsion or peripheral of the 0ck betokens a lack of understanding If one may use a principles involved. of the c?mparison, it may be said that the position avulsion sufferer from neuralgia after a local le
Physiological
trigeminal
patient with after amputation.
similar
|slmb
to that of
a
a
painful phantom
discussion of the alternative Procedure, alcohol injection of the Gasserian ganglion, estimate of its value. ail(l we must try and form a true which attaches to it lacks the
We
come now to
Vl?usly
a
precision
of the open operation in the hands SUrgeon, but it seems that the questions
^
e
experienced we
have to
52
Dr. H. H. Carleton
decide
are:
(1) Is
it
adequate procedure pitfalls ? (2) Are the
an
present unavoidable injection within our control
?
or
does it
results of
(3) What advantages,
if any, does it possess over the open operation ? (4) How far does alcohol injection justify itself from the of view of permanency of results ? Before describing the technique of alcohol
point
and the relative merits of the various routes the
ganglion may be approached, it will be
to
consider
some
injection by which
advantage points in the surgical anatomy of an
the Gasserian middle and is sinus.
ganglion. The latter is situated in the fossa immediately above the foramen ovale, bounded on its inner side by the cavernous It is hemmed in above by tightly-stretched
dura?an
remember, because the dura, together with the adjacent bone, forms a important point
to
restricted space into which alcohol in small quantities may be injected under pressure. It is important for the success of the operation that this roof of dura should not be
pierced by a needle. If it is, there is a danger of the alcohol travelling far and damaging neighbouring cranial nerves. A second point of importance is the short course of the third division of the fifth nerve as it leaves the ganglion to pass through the foramen ovale. So short is this course that the moment the needle enters the foramen it is
practically within the ganglion itself, and an alcohol injection implanted at this point can be relied upon to perfuse the whole of the ganglion and even reach the sensory root on the proximal side of it. The
arrangement
of
the
nerve
which is worthy of
fibres
constitute the sensory root and ganglion notice. They pursue a parallel course on the
proximal
Trigeminal Neuralgia
53
Slde of the
ganglion, and this parallelism is in the main observed right through into the three main divisions. This anatomical feature probably has an importance, taking for the success of a well-placed alcohol injection, ^be path of least resistance for injected fluids will be and follow the of the ^nterstitial highly probable, therefore, though
nerve
course
is
difficult
to
direct
of
fibres. course
that small
observation, prove by quantities of alcohol slowly injected into the lower
Fig. 1.1. Fig. .
l> 2, 3.?The the of the ?The three divisions of three divisions intrao ranial course division. r&cranial third division. course of the third of the
nerve. fifth nerve. fifth
short the very Note the Note very short
Wall of sinus. C.S.-?"Wall of cavernous cavernous sinus. '
"
_
er the sinus, sinus,toget together of the wall of the wall in the nerves running ?Cranial nerves IV., VI.?Cranial running in withthe th 6 the general Note the parallelism parallelism nerve. Note fifthnerve. general the fifth of the of division division ophthalmic ophthalmic ?f ner Vofibres n?rve Gasserianganglion. the Gasserian "bresas ganglion. as theycourse coursethrough through the
they
Part of the
ganglion will track backwards to the sensory that a complete anaesthesia of the fifth nerve is achieved by blocking the sensory root behind the ganglion, and without complete destruction of all 6 cells belonging to the ophthalmic division of the
r??t,
so
ll0rve which
?aftglion.
are
This
situated in the inner
probably danger neuroparalytic Ejection, if excessive quantities the
of
part of the
accounts for the
slightness
keratitis after alcohol of alcohol
are
avoided
54
Dr. H. H. Carleton
and if the little
injection is made very slowly. minims
Usually
of alcohol is sufficient to
eight produce complete anaesthesia. Other points in the topographical anatomy of the Gasserian ganglion can perhaps be dealt with when we come to the detailed technique of alcohol injection. The technique for injection of the Gasserian ganglion.?I prefer the lateral mode of approach and as
as
technique instituted by Wilfred Harris.
The necessary
Fig. 2.
Roofed, Roofed Note the confined space in which the Gasserian ganglion lies. in by dura, bounded on the inner side by the wall of the cavernous sinus, in the and bounded below by bone. The gap bony floor is the foramen ovale.
above, the slight concavity to be felt on the lower border of the zygoma immediately in front of the zygomatic tubercle ; below, a line
skin
markings
joining
are :
the incisurse formed
by
the lobe of the
ear
by the alse nasi with the upper lip. This line marks the lower limit of the sigmoid notch
with the cheek and of the mandible.
zygomatic
A vertical line is
tubercle
quarter of
an
from the
cutting the above base line
second vertical line is drawn a
dropped
intersecting
vertically deep
a
the base line
inch in front of the former.
foramen ovale lies
;
to the
The
zygomatic
Trigeminal Neuralgia
55
tubercle, but normally it points slightly forwards aild outwards. If, therefore, the needle is entered a quarter of an inch in front of this plane, and is passed aud
the
through
backwards,
sigmoid
notch
slightly upwards
it should reach the foramen at such
an
ailgle that the point of the needle can be insinuated through the opening. The operation can be done quite satisfactorily,
Surface
Fig. 3. 3. Fig. the lateral markings for approach markings for the lateral approach
t}lrffUr/ace r?ugh notch. ugh the the sigmoid sigmoid notch. ail
