Postgrad Med J: first published as 10.1136/pgmj.37.429.427 on 1 July 1961. Downloaded from POSTGRAD. MED. J. (i961), 37, 427

THE SURGICAL TREATMENT OF EPILEPSY JOHN ANDREW, M.B., F.R.C.S. Regional Centre for Neurology and Neurosurgery, Oldchurch Hospital, Romford, Essex

THE surgical treatment of epilepsy is reserved not be included.. The pathological processes for those cases in which the seizures are ' focal ' in giving rise to focal epilepsy are birth injury, origin, and are symptomatic of an underlying local trauma, vascular disease and its sequeke, and pathological condition in the brain. Focal or cieatrix following inflammation. Porencephalic generalized seizures may complicate overt ex- cysts following old head injuries, or vascular ac- panding intracranial lesions, but they will not be cidents, may be found associated with an epilepto- considered in this paper. Suffice it to say that genic focus. Arterio-venous malformations are one-third of patients developing epilepsy in adult rarely encountered. A simple knowledge of life will have intracranial neoplasms, and all such cortical representation will suggest. the site of patients must be investigated bearing this pos- origin of most focal or symptomatic seizures. A sibility in mind. generalized convulsion may be caused by a focus The purpose of this paper is therefore to con- almost anywhere in the hemispheres, but may sider those cases of focal epilepsy not due to an be preceded by a classical Jacksonian 'March', obvious expanding lesion, and their investigation either motor, sensory or sensory-motor. Thbese ' and management. The underlying pathological Marches' may remain unilateral, and are not copyright. conditions to be considered are usually atrophic. necessarily followed by unconsciousness. An These include meningo-cerebral scars, often autonomic aura may arise from wide areas of the resulting from old trauma or inflammatory states, cortex, and speech disturbances likewise in the birth injuries, so frequently sited in the temporal dominant hemisphere. lobes, and vascular lesions. Investigation includes careful history-taking The work of Hughlings Jackson forms the basis and neurological examination, electro-encephalo- of the rational treatment of epilepsy by surgical gram recordings and plain skull X-rays and air means. The detailed investigations of Penfield studies; angiography is called for when a vascular have led to a better understanding of the function malformation is suspected. http://pmj.bmj.com/ of the human cerebral cortex and has made the The most careful assessment is called for in surgical treatment a practical proposition, so that those patients, whose epilepsy is not controlled by it is carried out in all neurosurgical centres today. medication. The excision of an extensive lesion For the purpose of this paper we may con- from the Rolandic or speech area may cure the veniently, if artificially, divide the cases for surgery fits but leave a grossly disabled patient. into three groups: hemispheric lesions not in- There have been no recent advances in the volving the temporal lobe; temporal lobe or surgical technique in the removal of hemispheric psychomotor epilepsy; *and epilepsy associated scars. If possible the operation is carried out on October 1, 2021 by guest. Protected with infantile hemiplegia. under local anaesthesia. A generous bone flap is cut to expose the lesion and surrounding brain. Hemispheric Lesions other than in the Electrocorticographs are made and the area of Temporal Lobe abnormality is outlined. Stimulations are then Experimental data obtained from animals as to carried out. These may give two pieces of useful cortical localization form the basis of human information. Firstly, the focus for the epilepsy observations and the treatment of epilepsy. may be found. Secondly, the sensory and motor Observations during the excision of cortical or cortex can be delineated if close to the lesion, and meningo-cerebral scars in the human have led to a outlining these may prevent their inevitable more precise knowledge of cortical representation. damage and severe neurological deficit. Most of this has been derived from the work of It is from the information gained from cortical Penfield and his colleagues, and will be referred stimulation and excisions that advances in the to freely. knowledge of cerebral localization and function Again, cases of obvious expanding lesions will have been made. Postgrad Med J: first published as 10.1136/pgmj.37.429.427 on 1 July 1961. Downloaded from 428 POSTGRADUATE MEDICAL JOURNAL July i96i The most important findings may thus be the days of Hughlings Jackson, when ' dreamy summarized from Penfield and Jasper (1954). states ' were thought to be of temporal origin, i. Precentral gyrus: Although this has to do numerous strides have been made. with contralateral movements, its stimulation may The pattern oftemporal lobe seizures, or psycho- evoke sensation on the opposite side of the body. motor epilepsy, varies greatly. The focus of abnor- Its removal does not necessarily result in hemi- mality may determine the type of attack. Whether plegia, but renders complicated or skilful move- or not there is a generalized convulsion the ments of the contralateral limbs impossible. primary manifestation of a seizure is psychical. 2. Postcentral gyrus: This is essential for the This may be followed by a period of altered discriminatory elements in contralateral sensation. consciousness or loss of consciousness. The Stereognosis is one of the most important of these. psychic phenomena include illusions, hallu- Its stimulation may also give rise to contralateral cinations, emotional disturbances or forced think- motor activity. Its removal interferes with per- ing (Penfield and Jasper, 1954). The illusions ception of fine sensation in the limbs, maximal include visual, auditory or labyrinthine distur- peripherally. bances, deja vu phenomena and feelings of re- It is believed that the postcentral gyrus is an moteness. The hallucinations may be visual, indispensable relay station of afferents to a cen- auditory or uncinate, and previous experiences trencephalic or integrating system; the precentral may be relived. gyrus is thought to be indispensable for compli- Many sufferers from psychomotor epilepsy cated movements and subserves a higher centre in show behaviour disturbances which are sometimes the upper brainstem. so severe that institutional treatment becomes 3. A second sensory area has been found on the necessary. Others may even commit criminal superior bank of the Sylvian fissure, in which actions during periods of automatism following the there is ipsilateral as well as contralateral repre- seizures. sentation. It is thought to be related to voluntary The investigation of these cases after careful movement. Its excision results in no detectable history-taking and neurological examination is as deficit. follows: copyright. 4. A supplementary motor area has been i. Plain X-rays of skull. Calcification may be demonstrated on the medial aspect of the hemi- seen in one temporal lobe. This may occur in an sphere above the cingulate gyrus and in front of old inflammatory lesion, a hamartoma or other the Rolandic zone. Its stimulation causes postural tumours. The middle cranial fossa may be small or rhythmic movements of either side of the body; on one side in cases of incisural sclerosis (Earle, vocalization; inhibition of voluntary action or of Baldwin and Penfield, 1953). speech; general body sensations; pupillary 2. Pneumo-encephalography. Every attempt is alteration. made to fill both temporal horns to compare their Speech Areas. Four cortical areas have been size and situation. Thus there may be dilatationhttp://pmj.bmj.com/ demonstrated: one in the low post-frontal zone of one horn as a result of atrophy, or displacement (Broca), one behind the sensory strip in the by a neoplasm. parietal lobe, one in the posterior temporal region 3. Carotid angiography. This investigation is and one in the superior frontal area in front of the not indispensable, but is indicated ifthe presence of motor foot area. a neoplasm or an angiomatous malformation is Visual Function. Stimulation of the occipital suspected. lobes produces light flashes, or geometrical pat- 4. Electro-encephalography. This is, of course, on October 1, 2021 by guest. Protected terns, as does a seizure originating here. This the most important of the special investigations. type of hallucination may be distinguished from In addition to the routine scalp recordings, that resulting from a temporal lobe seizure or sphenoidal electrodes are inserted under local stimulation when a familiar scene or object may anwsthesia through the cheek, so that the tip of the be perceived or relived. needle lies on the sphenoid to record activity from Autonomic responses are obtained from stimula- the undersurface of the anterior end of the tem- tion along the Rolandic strip, insula and cingulum. poral lobe. Recordings are made at rest, under Auditory, uncinate, vestibular and memory func- the influence of barbiturate-induced sleep, and tion will be considered with the section on occasionally during stimulation with the strobo- temporal lobe epilepsy. scope or even such drugs as Metrazol. The sleep records are of great value. Spike or delta activity Temporal Lobe Epilepsy may be accentuated or facilitated immediately This form of epilepsy has stimulated the in- after the period when the effect of the short- terest of neurologists, neurosurgeons, pathologists acting barbiturate is wearing off. A diseased area -and psychiatrists and neurophysiologists. Since of cortex may fail to produce the fast activity Postgrad Med J: first published as 10.1136/pgmj.37.429.427 on 1 July 1961. Downloaded from July I961 ANDREW: The Surgical Treatment of Epilepsy 429 induced by the drug in all other areas of the that the maximal abnormality is in the anterior cerebral hemisphere. temporal region, a lobectomy is carried out. The In more obscure cases, where routine electro- pia-arachnoid and cortex are incised just below the encephalograms are difficult to interpret, it is outer end of the Sylvian fissure along the upper possible to place electrodes under the temporal bank of the superior temporal convolution; this in- lobe, and to insert depth electrodes, through a cision is carried in a coronal direction across the lobe trephine opening, bringing the leads out through between 5.5 and 6.5 cm. behind the tip of the lobe. the scalp for serial recordings over a period of The ventricle is cut across. Dissection under the weeks. insula enables the lobe to be removed complete Those cases considered suitable for surgery, with the uncus and anterior end of the hip- that is temporal lobectomy, will all have been given pocampus. a long trial of medical treatment first, and their The results of surgery have been fairly gratify- attacks not brought under control. Serial electro- ing. Northfield (1958) reports a good or fair im- encephalograms will have been made. provement in epilepsy in over 60% of cases during The factors favouring surgery include reduction a follow-up of several years. The mental symp- of barbiturate-fast rhythm beneath one temporal toms have been benefited in over half the cases. lobe, or a unilateral sphenoidal spike focus on The complications include a small but variable electroencephalography; a diseased temporal lobe upper quadrantic homonymous field defect in the in the non-dominant hemisphere; and fits occurring opposite field of vision; when the dominant side in a patient with a normal or aggressive personality. has been operated on there is some mild nominal The contraindications include a spike focus, not at dysphasia and a deficit of learning by auditory the sphenoidal or mastoid electrode, in the modalities (Falconer, I958). dominant side, multiple foci of epileptic activity without dominance at one site; cortical atrophy; Case Report a hysterical or inadequate personality (Hill, I958). C.H., a boy of eleven, was born by normal delivery and had no family history of epilepsy. He developed nor- Bilateral sphenoidal abnormality, on repeated mally, although he was somewhat backward until the examination without a clear preponderance is a age of nine when he commenced to have epilepsy. His copyright. contraindication. Bilateral temporal ablation may seizures were of two types. The first was ushered in by lead to severe intellectual or personality change. an unpleasant taste, and he would then feel remote, and although vaguely aware of his environment was unable The classical changes in monkeys (Kluver and to speak or carry out any action. These attacks would Bucy, I939) following this procedure include a last for two to three minutes, and would occur up to six complete inability to memorize or to learn from times daily. The second type of attack was a typical grand experience and grossly depraved habits. mal seizure, occurring up to six times nightly. Since the onset of the attacks the boy's personality had completely The operation of temporal lobectomy may be altered. He became vicious, began to thieve and would carried out under local or general an.esthesia. The fail to attend school. He lied and had numerous temper pioneer work of Penfield was carried out with the tantrums. Repeated electro-encephalograms over six http://pmj.bmj.com/ patient awake. Cortical stimulation generally re- months confirned a persisting left, dominant, spike produced the seizure focus at the sphenoidal lead. All the routine anti- pattern, and in this way much convulsant drugs failed to control his fits; his behaviour was learnt of functional localization within the deteriorated. At operation a nonnal-appearing left temporal lobe. A sufficiently large scalp and bone temporal lobe was seen, and a 5.5-cm.-long lobectomy flap is cut to expose the whole temporal lobe down was performed. Histologically it showed sclerosis in to the floor of the middle and the uncus. One year later there had been no recurrence cranial fossa, the of either type of attack. The boy's character returned adjacent areas of the frontal and parietal lobes. to that before the onset of his illness, and the only on October 1, 2021 by guest. Protected Inspection of the brain reveals any surface ab- operative complications were a slight nominal dysphasia normality. Electrodes are then placed over the and impairment of auditory learning. In spite of this surface of the brain and under the temporal lobe at he has returned to his former position at school. suitable sites, and depth electrodes may be in- serted into the amygdala or uncus. If the patient Pathological Changes in the Temporal Lobes is amesthetized, he is kept as light as possible; The most common abnormality is found on 2 or 3 cc.s of a 5% pentothal solution may be serial histological examination, when sclerosis or given. This will at first flatten the electrical gliosis is seen in the uncus, amygdala or Ammon's activity, and then fast rhythms will appear, which horn. There is an increase of glia and an overall may be absent over the abnormal area. As re- loss of neurones. The condition is referred to as covery occurs spike activity may then be seen from incisural sclerosis. Earle et al. (1953), reported this area. The leads from which the greatest this finding in 63% of 157 cases operated on. spike amplitude is seen denote the diseased area, They suggest birth trauma as the aetiological as will a phase-reversal. factor. Excessive moulding of the fietal head When the electrocorticograms have confirmed causes herniation ofthe uncus through the incisural Postgrad Med J: first published as 10.1136/pgmj.37.429.427 on 1 July 1961. Downloaded from 430 POSTGRADUATE MEDICAL JOURNAL Yuly I96I opening at the tentorium. Branches of the campus, and first temporal convolution. These posterior cerebral, anterior choroidal and middle may be left in situ and brought out through the cerebral arteries crossing the free edge of the tent scalp for serial recordings and even stimulation. are so placed that herniation at birth would com- If a small focus of marginal abnormality is found press them against the free edge and result in this may be destroyed electrolytically, thus avoid- ischmemic changes in the temporal lobe. ing open craniotomy and full temporal lobectomy. Uncal herniations occurring from acute supra- tentorial expanding lesions may also result in Epilepsy Associated with Infantile psycho-motor epilepsy commencing many years Hemiplegia after the acute illness. The present writer is Krynauw (I950) reported I2 cases of infantile reporting two such cases. One was a boy who hemiplegia in which the diseased contralateral developed classical temporal seizures ten years hemisphere was excised. The majority of these after he had been seriously ill with a frontal lobe suffered from epilepsy in one of its forms, and in abscess, and the other was a man whose attacks all the cases operated on, the epilepsy ceased with- -commenced six years after acute ipsilateral cere- out medication. There was improved post- bral compression following a head injury. operative motor power with lessened spasticity The abnormalities seen within the excised and clumsiness and a marked improvement in temporal lobe are small unsuspected gliomata, personality and behaviour. The experience of hamartomata, and angiomata. other neurosurgeons has not always been so en- Stereotaxic investigation and treatment is still in couraging. In these cases there has been a swing the experimental stage and only carried out at a to a less radical procedure whereby only grossly few centres, under radiological control. Electrodes atrophic and electrically abnormal areas of cortex may be placed into the amygdala, ufcus, hippo- are excised.

REFERENCES EARLE, K. M., BALDWIN, M., and PENFIELD, W. (1953): Incisural Sclerosis and Temporal Lobe Seizures produced copyright. by Hippocampal Hemiation at Birth, Arch. Neurol. Psychiat. (Chicago), 69, 27. FALCONER, M. (1958): Temporal Lobe Epilepsy, Proc. roy. Soc. Med., 5I, 6I3. HILL, D. (I958): Temporal Lobe Epilepsy, Ibid., SI, 6io. KLuvER, H., and BucY, P. C. (I939): Primary Analysis of Functions of the Temporal Lobe of Monkeys, Arch. Neurol. Psychiat. (Chicago), 42, 979. KRYNAUW, R. A. (1950): Infantile Hemiplegia Treated by removing one Cerebral Hemisphere, J. Neurol. Neurosurg. Psychiat., 13, 243. NORTHFIELD, D. W. C. (1958): Temporal Lobe Epilepsy, Proc. roy. Soc. Med., SI, 607. PENFIELD, W., and JASPER, H. (1954): 'Epilepsy and Functional Anatomy of the Human Brain'. London: J. & A.

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