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African Journal of Neurological Sciences
Pan African Association of Neurological Sciences
ISSN: 1015-8618
Vol. 16, Num. 1, 1997
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Afri
Afri. J. Neuro. Sci. Vol. 16 No. 1 Jan
1997
SURGERY OF INTRACTABLE EPILEPSY IN AFRICA.
R.F. RUBERTI
African Neurological Diseases Research Foundation Nairobi.,
Kenya.
Code Number:NS97002
SUMMARY
The Author discusses the possibilities of
surgery in intractable epilepsies (I.E) in Africa. He has operated
97 cases of I.E. of which great part of them (64 cases or 66 per
cent) were post traumatic epilpsies with an exisable scar, 19 cases
(19 per cent) were mesial temporal sclerosis in whom a temporal
lobectomy was performed, seven cases (7 per cent) were cases of
infantile spastiz hemiparesis with I.E. and severe behavioural
changes treated by hemispherectomy, seven cases (7 per cent) had an
anterior callosotomy. No post operative mortality or relevant
morbidity has been observed. The best results were obtained in the
excision of the scar, hemispherectomies and temporal 1obectomies.
For the callosotomies a longer period of observation and larger
number of cases are needed to have a clear opinion of its
effectiveness in the treatment of non focal I.E.
RESUME
L'auteur discute des résultats
obtenus par un traitement chirurgical dans les epilepsies rebelles
aux therapeutiques medicamenteuses: 97 patients ont
été opéré 64 fois (66%) l'epilepsie
etait d'origine traumatique avec une 1esion cicatricielle
extirpable; 19 fois (19%) il existant une sclerose temporale pour
laquelle une 1obectomie rut effectuee; 7 patients (7%) presentaient
une hémiparsie spastique infantile avec de graves anomalies
du comportement; ces patients ont ete traites par mispherectomie;
les 7 derniers patients eurent une callosotomie anterieure. Il n'ya
eu ni morrolite ni morbidite post-operatoire. Les resultats les
meilleurs ont ete obtenus dans les cas d'excisions cicatricielles,
d'hemispherectomies et de 1obectomies temporales. En ce qui
concerne les callosotomies, une periode d'observation plus 1ongue
et un plus grand nombre de cas sont necessaires pour avoir une
opinion valable sur l'efficacite de ce traitement pour les
epilepsies non focales.
Key words: Intractable epilepsy - Surgery
-Africa
Epilepsy is one of the commonest serious
neurological conditions in most countries and this undoubtedly true
in Africa. Recent epidemiological studies carried out in Kenya
(FEKSI et all 1991 ) shows that the incidence of epilepsy is around
two percent, much higher than in the western countries. Studies in
four developing countries, Ecuador, Kenya, the Philippines and
Pakistan have shown that only a small proportion of patients
(8-20%) with active epilepsy are at any one time actually receiving
drug treatment. The reason for this failure of treatment are
complex, and may involve such no-pharmacological aspects as
cultural attitudes to treatment, the acceptability of drugs as a
method of treatment, the cost of treatment, and the system for the
delivery of health care. In many developing countries there is a
shortage of medical manpower and a lack of well organised system of
referral, records or health care delivery. The high proportion of
untreated epileptic patients may be the cause of the high number of
intractable epilepsies seen in the developing countries.
The primary therapy for patients suffering for
any type of epileptic seizures is medical:anticonvulsive therapy,
psychotherapy and social and occupational rehabilitaion. If the
epilepsy is only syptomatic evidence of a progressive lesion of the
brain, such as neoplasms, abscesses, haematomas, vascular
malformations, congenital or other infectire lesions appropriate
surgical measures are imperative: we have a large series of these
secondary epilepsies but we will not consider them in this paper.
In chronic epilepsies medical treatment should be given a fair
trial and considered unsuccessful only when all drugs appropriate
to the type of epilepsy have been given alone or in a combination
to toxic limits. Such anti-convulsive medication will control the
attacks in more than fifty per cent of cases and markedly decrease
the seizures in another 25 per cent of cases, thus only 20-25% of
the epileptics may become candidates for surgical intervention. The
preliminary criteria to be satisfied to consider an epileptic
patient for surgical treatment are insufficiency of the
pharmacotherapy, the evidence of an organic brain lesion and the
handicapping characters of the seizures. Two main groups of
surgical approaches are recognised: the first aims at suppressing
the seizures by resecting the primary epileptogenic focal area
(topectomy, 1obectomy, hemi spherectomy):the second approach aims
only at reducing the epileptogenicity by preventing the diffusion
of the epileptic discharges, by enhancing inhibiting or by reducing
facilitatory influences (cingulectomy, callosotomy, electrical
stimulation of the cerebellum, stereotactic deep lesions and
others). In general, surgical procedures that aim to remove
epileptogenic tissue together with any identifiable lesion are
fnore common and more successful than those that attempt to modify
brain activity.
Some neurosurgeons find the subject of epilepsy
of no special interest and operations for its relief do not excite
them as much as complicated surgical procedures for vascular
malformations or particularly difficult tumours. That is not my
case: I had my neurosurgical training and worked for fifteen years
at the Neurosurgical Institute of the Medical School, University of
Padua, Italy, where the surgery of epilepsy was highly advanced, so
far that when I left the Institute to start pioneering neurosurgery
in Kenya, the Institute of Padua was amongst the highest recognized
centres for the treatment of epilepsy. When I started single handed
neurosurgery in East Africa in 1967, the load of neurosurgicaI work
was such that for several years I did little in the field of
surgery of chronic intractable epilepsies also because of lack of
EEG services, difficulties with neuroradiological investigations
and mainly because of other priorities in the Neurosurgical field.
With improved EEG services and neuroimaging facilities later on my
interest in the surgery of epilepsy revived.
At the present time we are using only two
surgical approaches to the treatment of medically intractable
epilepsy. One is the older approach of resection of an epileptic
focus, and the other is a newer procedure of division of all or a
portion of the corpus caIlosum (Callosotomy). Several other
procedures mentioned before and enjoying popularity in the past,
including cyngulectomy, cerebellar stimulation, streotactic
subcortial lesions and others have now been abandoned. Of the two
surgical options in common use now, resection of the epileptic
focus has a much higher probability of completely controlling the
seizures, thus, the initial evaluation of patients with medically
intractable epilepsy should be directed at establishing whether
they are candidates for resective surgery.
For the selection of patients for resective
surgery we follow the classic criteria enumerated by the Montreal
School. A focus of origin of the seizures must be identified, and
that focus must be in an area of brain where the resection is not
likely to lead to an unacceptable neurological deficit: resection
is not advisable in the sensorimotor area if a hemiparesis is not
already present, or in areas essential for speech or recent memory.
The basic lines of inquiries used in our clinic are the following:
accurate clinical history and neuropyschological examination
(patients should be asked clinical features of their attacks, which
will give a clue to the origin; should be asked about interictal
events, about past medical history, which may reveal an event
sufficient to cause brain damage (as for localized head injuries)
and hence the seizures. Other clinical details such as family,
developmental, educational and psychiatric history should be
investigated - The neurological examination is often negative. EEG
examinations: serial EEG is obtained to localize a cortical
epileptogenic area if possible. Recordings during drowsiness and
sleep (or activation) and sphenoidal electrodes placements are
frequently useful. Brain imaging: Computed tomography (CT) scanning
makes the detection of small discrete lesions more likely. The
CTScans following contrast enhancement of the cerebro spinal fluid
with metrizanide may be useful to detect some lesions at the level
of the temporal lobe of the lateral ventricles. The magnetic
resonance imaging (MRI) detect even greater proportions of such
lesions, and is essential in the surgical treatment of
epilepsy.
The greatest number of intractable epilepsies operated in Kenya
are partial post traumatic epilepsies. In the aetioIogy of partial
epilepsy there is a great number of head injuries,
particularly depressed skull fractures, unduly common in East
Africa. These localized trauma are caused mainly by road traffic
accidents and also very common by assaults with a panga (a sort of
machete in large use mainly in, the rural areas) or other sticks.
These depressed skull fractures are often incorrectly
treated in the peripheral hospitals of the country, leading to a
meningo-cerebral scar that is highly epileptogenic, leading often
to an intractable epilepsy. I will recall here the case of a taxi
driver involved in an assault in which he had a bad left frontal
depressed skull fracture for which he was surgically treated. Seven
months later he became a post-traumatic epileptic and his
epilepsy became intractable: he could not work and he and his
family were facing misery. He came to see me and after all the
routine investigations, we excised the left frontal brain scar. As
a result of this, he has had no more epileptic fits since 8 years,
back happily to his job of driving taxis and I use him often if I
need a taxi. Examples as this one are plenty in East Africa and in
the whole of Africa and I see no reason and no particular
difficulty in treating this type of epilepsies also without
sophisticated equipment. We have operated 64 cases of focal post
traumatic intractable epilepsy with good results and in over fifty
per cent of cases the treatment has been stopped, and acceptable
results in the other where the epilepsy is well controlled on
medical treatment. In the aetiology of partial epilepsy there is
also a relatively high number of patients with either a history of
birth trauma, again very frequent in East Africa, or infective or
congenital neurological damage. It is often impossible in
retrospect to distinguish which of this factors is responsible for
the neurological damage but perhaps there is a higher incidence of
birth trauma in Africa because of inadequate obstetric services. We
have found 19 cases of mesial temporal sclerosis with intractable
epilepsy in whom we performed a temporal 1obectomy with
considerable clinical and EEG improvement in all cases. In seven
cases of infantile hemiplegia with pharmacoresistant epilepsy and
severe behavioral changes we performed a hemispherectomy with good
results in the control of the seizures and a considerable
improvement of the behaviour.
Since a few years we have adopted the
callosotomy in the non focal intractable epilepsy: the indications
were intractable epilepsies associated with injuries and usually
characterized by drop attacks of the tonic or atonic types often
accompanied by generalized tonic clonic convulsions in patients in
whom there was no evidence for well defined removable epileptogenic
focus after standard EEG and CT Scan investigations. We usually
perform and anterior callosotomy of 4-6 cm depending on the
gravity of the symptoms. We have operated 7 cases with important
reduction on the drop attacks, a certain improvement of the control
of the epilepsy with medication. We have observed some transient
episodes of mutism and akinesia due most probably to interference
with cingulate gyri with disruption of cingulum fibres bilaterally.
Our experience is limited but the feeling is that perhaps more
patients may benefit from this type of surgery. We have no
experience at all in subpial transections.
Out of 97 patient operated in Kenya for
intractable epilepsy we have had no surgical mortality and no
relevant morbidity. Improvement in instrumentation,
electrophysiological methods and surgical techniques when combined
with more precise selection of patients may be expected to provide
more benefits in the future. The rationale for surgical excision in
epilepsy, therefore, is based on the concept that the removal of a
part of an epileptogenic area is rarely effective, but excision of
most of this area may lead to progressive disappearance of the
seizure tendency. RASMUSSEN emphasised the concept that extensive
epleptic activity may interfere with the function of the rest of
the brain and that the removal of the epileptogenic focus may
improve brain function and that the scar of the surgical excision
rarely becomes epileptogenic if scrupulous care is taken to
preserve the pial surface at the margins of the excision. In
conclusion, even in Tropical Africa, we have today in many centres
better tools and surgical experience than when the surgery of
epilepsy started with PENFIELD and we can help more and more
intractable epileptics in this part of the world.
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Copyright 1997 Pan African Association of Neurological Sciences
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