Stereotaxic surgery for cerebral palsy

Size: px

Start display at page:

Download "Stereotaxic surgery for cerebral palsy"

Garey Crawford
5 years ago
Views:

1 Stereotaxic surgery for cerebral palsy V. BALASUBRAMANIAM, M.S. (NEuRO.), PH.D., T. S. KANAKA, M. CHo (NEuno.), PH.D., AND P. B. RAMANUJAM, M. CH. (NEuRO.) Institute o] Neurology, Madras, India An analysis of 94 cases of cerebral palsy treated by stereotaxic surgery is reported. The selection of patients and target areas for surgery are discussed. Hypertonic cases are classified into rigid, rigidospastic, and spastic types on the basis of surface electromyographic studies. For rigidity and rigidospasticity, ventrolateral thalamotomy gives relief, while spastic cases do well with dentatectomy. Centromedian thalamotomy relieves sensory-induced involuntary movements. Involuntary movements unaccompanied by changes in tone are abolished by lesions of the nucleus ventralis intermedius. KEY Wonos stereotaxic surgery cerebral palsy thalamic targets thalamodentate ablation surface electromyography dentatectomy T HE management of cerebral palsy by neurosurgical methods is not new. In 1890 Sir Victor Horsley TM treated a case of athetosis by excision of the motor strip. Many dyskinesias which form part of the symptom complex have been treated by open craniotomy and division of various tracts/4 However, cerebral palsy has mostly been managed along orthopedic lines. The term cerebral palsy is now applied to any condition where there is a nonprogressive disorder predominantly of movement and posture, resulting from damage to the brain sustained in the first few years of life. The management of this disease and its attendant symptoms by stereotaxic surgery probably dates back to 1960, and the pioneering work of Narabayashifl ~ but no unanimity of opinion exists as to the value of stereotaxic surgery in cerebral palsy. At first these cases were treated by pallidotomy, but later the thalamus was the target area.12,14,a6,as,~9. 23 Clinical Material This report is based on 94 cases of cerebral palsy operated on between 1967 and 1971 at the Institute of Neurology, Madras. All cases were studied independently by two neurosurgeons and a neurologist. Clinical assessment excluded conditions resembling cerebral palsy, such as degenerative diseases of the brain, myopathy, and certain metabolic disorders; only definite cases of cerebral palsy were chosen for further selection. Out of 250 cases seen during the period mentioned above, 134 were selected for stereotaxic surgery. Patients with hypertonus, rigidity, rigidospasticity or spasticity as detected by surface electromyographic (EMG) examination, were considered for surgery. Early in the study only the first two varieties were selected, but after the technique of dentatectomy was evolved, the spastic cases were also chosen. If the hypertonus was mild, a J. Neurosurg. / Volume 40 / May,

2 Balasubramaniam, Kanaka and Ramanujam TABLE 1 Age of patients at first stereotaxie surgical procedure Age (yrs) up to to to to to 25 1 TABLE 2 Contraindications for surgery in 116 cases with cerebral palsy Disability mild hypertonus 42 hypotonus 41 severe mental retardation 89 age less than 2 yrs 41 microcephaly 14 course of physiotherapy was given and the patient reassessed periodically. If the hypertonus persisted, surgery was advised. If the hypertonus or involuntary movements were severe at the outset, stereotaxic surgery was advised as the initial treatment because physiotherapy or orthopedic procedures gave better results when the tone was first reduced by neurosurgical methods. We did not consider the young age of the patient a contraindication for surgery (Table 1 ), since we feel that early surgery leads to better physiological development of the limbs. Our youngest patient was 2 years old. Additional screening was carried out involving the psychological status of the patient. Severely mentally retarded children were generally considered unfit for surgery, and only children with a fairly good I.Q. were chosen. There were two exceptions to this policy. First, we operated on five cases with severe mental retardation with the sole purpose of facilitating nursing care. Second, in 11 cases, although the psychologists' score was low, we thought that the children appeared intelligent and hence proceeded with surgery with satisfactory results. Psychometry does not reveal the real intelligence of the patient. We believe that many children with apparently low I.Q. tests are quite intelligent in their own way; they have a considerable insight into their disability, and probably their I.Q. suffers because they have not been exposed to the various environmental influences that shape intelligence. In these 11 cases our psychologists were able to get better scores following relief of the physical handicap. Of the 250 cases of cerebral palsy seen, 134 were chosen for surgery. Up to December, 1971, 94 cases had been operated on; 12 refused surgery and 28 were still awaiting it. The remaining 116 cases were not considered for surgery for the reasons set out in Table 2. The cases selected for surgery were studied by surface EMG, psychological assessment, estimate of motor age, electroencephalography (EEG) and skull films, in addition to the routine investigations. Classification on surface EMG was according to the method of Shimazu, et al. 22 (Table 3). The topographical distribution of the disability is given in Table 4, and the type of involuntary movement seen preoperatively in Table 5. TABLE 3 Classification of 94 patients oll surface electromyography Classification rigid 18 rigidospastic 64 spastic 7 normal 5 TABLE 4 Topographical distribution of cerebral palsy in 94 patients Site quadriplegic 50 triplegic 11 hemiplegic 24 diplegic 6 paraplegic g. Neurosurg. / Volume 40 / May, 1974

Stereotaxic surgery for cerebral palsy TABLE 5 Type of involuntary movement seen preoperatively in 94 patients Type of Movement dystonic 47 choreoathetosis 30 sensory-induced 22 athetosis 19

3 Stereotaxic surgery for cerebral palsy TABLE 5 Type of involuntary movement seen preoperatively in 94 patients Type of Movement dystonic 47 choreoathetosis 30 sensory-induced 22 athetosis 19 intention tremors 12 ballistic 3 Technique Our stereotaxic technique has been described in detail in previous publicationsy ~ Leksell's or Sano's stereotaxic apparatus was used. Most of the cases were operated on under general endotracheal anesthesia. The technique of stereotaxic thalamotomy, described briefly, is as follows. A coronal burr hole is made. The stereotaxic frame is fitted, a lumbar pneumoencephalogram is performed, and lateral and anteroposterior skull films taken. If pneumoencephalography fails or when the Sano apparatus is used, air ventriculography is performed. When satisfactory visualization of the anterior and posterior commissures is not obtained, Conray or Myodil emulsion is used. After the anterior and posterior commissures have been marked, the coordinates for the target in the thalamus are calculated. The circular frame is then set for these. Depth EEG studies are done as the electrode is advanced toward the target. The technique of dentatectomy is practically the same except that only the Leksell apparatus is used. The machine is fixed with the central pin as far posterior as possible. Lumbar pneumoencephalography is performed to visualize the fourth ventricle, but if this fails, Myodil or Conray ventriculography is performed. At the target, stimulation is carried out with 2.5 to 3 volts, 50 cps for 15 to 30 seconds. Once the target has been identified it is destroyed either by diathermy or by injection of oil-wax mixture. In diathermic coagulation, a temperature of 56.5 ~ C is maintained for 2 min 15 sec using an 8-mm coagulating electrode. The oil-wax for injection is prepared in our Institute according to the formula of Narabayashi? 7 Diathermy was used for 98 thalamic lesions and three dentate lesions. Wax was injected in 104 thalamic and 15 dentate lesions. The site of the diathermy lesion is identified by the placement of a stainless steel pellet. In cases where wax is injected, the Myodil content of the wax indicates the site and size of the lesion. Lesions are charted, superimposed on the Schaltenbrand and Bailey atlas, ~ and scattergrams are prepared. Results Assessment of the disability in a case of cerebral palsy poses problems. In addition to the routine neurological examination, surface EMG studies and the motor age estimation test of Johnson, et al.fl 1 have proved useful. The postoperative surface EMG demonstrates not only the abolition of hypertonus but also the return of reciprocity. Narabayashi 17 uses an integrated EMG and movie record of all patients, in addition to the record of hand writing and range of movements of limbs. Laitinen 15 uses a point score system. We have devised a point system involving assessment by everyone concerned with the patient, including the parent and also the patient whenever possible. The common descriptive terms employed are converted into points and marks given: 5 = excellent; 4 = good; 3 = fair; 2 = slight; 1 = not certain; 0 = no change. Similar marks are given to surface EMG analysis and motor age estimation. The eight sets of points are then totalled, and expressed as a percentage of 5 x 8 = 40. This enables the postoperative improvement in involuntary movements and hypertonus to be studied individually. Table 6 gives the overall improvement in the 94 cases following various lesions. It can be seen that 63 of 89 patients with hypertonus had more than 50% improvement. Involuntary movements were similarly relieved in 38 of 69 cases. In a disease complex with multiple symptoms in which lesions have to be made in more than one target it is difficult to assess the part played by each lesion in relieving individual symptoms. Moreover 1. Neurosurg. / Volume 40 / May,

Balasubramaniam, Kanaka and Ramanujam TABLE 6 Postoperative improvement in 94 patients* Improvement (%) Involuntary Hypertonus Movements No. 70 No. 7o 90 to 100 80 to 90 2 8 2.9 11.6 3 13 3.4 14.

4 Balasubramaniam, Kanaka and Ramanujam TABLE 6 Postoperative improvement in 94 patients* Improvement (%) Involuntary Hypertonus Movements No. 70 No. 7o 90 to to to to to to to to to 20 less than total * Out of 94 patients, five had involuntary movements alone, 25 had hypertonus alone, and 64 had hypertonus with involuntary movements. one lesion, for instance that in the centromedian (CM) nucleus, may relieve both hypertonus and involuntary movements. The results of stereotaxic surgery merge imperceptibly into those of physiotherapy, occupational therapy, and orthopedic surgery. Of the 18 patients who showed rigidity with or without involuntary movements, isolated ventrolateral (VL) and sub-vl lesions were made in 14 cases, 11 of which showed 60% to 100% overall improvement. Of the 64 rigidospastic patients with or without involuntary movements, 32 had isolated VL and sub-vl lesions. Only 17 of these showed 60% to 100% overall improvement; the remaining patients needed dentate lesions as well. In 20 of the 22 cases with sensory-induced involuntary movements, CM thalamotomy was done in addition to VL thalamotomy. The results are given in Table 7. TABLE 7 Results of sub-ventrolateral and centromedian lesions for sensory-induced involuntary movements Improvement (%) 80 to to to to 40 4 up to 20 I In Case 16, with quadriplegic rigidity and sensory-induced involuntary movements, the sub-vl thalamotomy done on one side produced only moderate relief; on the opposite side a combined VL and CM thalamotomy resulted in remarkable improvement. Subsequently a CM thalamotomy was added to the first side and produced good results. Thirty-nine patients had relief in both contralateral and ipsilateral limbs. There was no apparent difference in the results following diathermy or wax lesions. There were few complications. One patient died of symptoms and signs suggestive of acute hypothalamic failure. In six cases there was a temporary increase in the neurological deficit in the form of hemiplegia or dysphasia. This cleared in a few weeks. Discussion Target Selection and Identification The target of attack for rigidity and rigidospastic state is the VL nucleus and the area just below it, called the sub-vl area by Narabayashi and Kubota. 18,19 We relied on stimulation and avoidance of a pyramidal response since the technique of evoked potential could not be carried out. 25 The CM nucleus has a role in the maintenance of tone because of the pallidal fibers that go through it and also because of the connections with the cerebellum.s Further, elimination of the CM nucleus is beneficial in cases where there are sensoryinduced involuntary movements. In these cases a mere question or a command initiates an involuntary movement and the child goes into a severe dystonic posture. We feel that the CM nucleus has a sensorymodulating function and that these movements are due to the aberrant conversion of sensory impulses into efferent movement. Direct proof for this is not yet available, but the anatomical connections of the centromedian nucleus (both afferent and efferent) considerably strengthen this possibility. Even more impressive is the fact that the results of centromedian thalamotomy have been encouraging. For cases that show a phasic response 580 J. Neurosurg. / Volume 40 / May, 1974

5 Stereotaxic surgery for cerebral palsy (spastic cases), thalamotomy does not give relief. Actually, Shimazu, et al., "-''2 on the basis of their psychological studies, remarked that in such cases a search must be made for targets other than in the thalamus. Recently Cooper, et al., 7 have reported encouraging results with pulvinectomy for such cases. Strengthened by the work of Heimburger and Whitlock, ~'~ Zervas, et al., 26 and Nashold and Slaughter, 2' we have done 18 dentatectomies for these cases. As in the series of Zervas, et al., z6 the relief was ipsilateral only? '3 Our coordinates are 3 mm below and 6 mm behind the fastigium and 9 to 17 mm lateral to the midline. We prefer to make three diathermy lesions, 9 mm, 14 mm, and 17 mm lateral to the midline, the middle lesion being 2 mm superficial to the medial one and the lateral one 2 mm superficial to the middle one. Infantile Hemiplegia with A thetosis of infantile hemiplegia with athetosis present a peculiar problem. In these cases neither thalamotomy nor dentatectomy alone gives complete relief. A classical VL thalamotomy is not effective. While dentatectomy relieves the spasticity it does not relieve the athetosis. This has been the experience of Heimburger and Whitlock, 9 Laitinen, a~ and Cooper. 6 Following success in one case, we employed a combination of cerebellar dentatectomy and ventrointermedian (VIM) thalamotomy with consid- erable relief in three patients. 1 This combination of thalamotomy and dentatectomy can be done in all hemiplegic patients with athetosis irrespective of the etiology. There is one difficulty in placing the lesion in the ventralis intermedius. Because of the longstanding hemiplegia there is a considerable dilatation of the third ventricle with often a marked ipsilateral shift of the ventricular system. In such cases the placement of the thalamic lesion becomes rather difficult. Here we rely on stimulation studies to delineate the outer border of the VIM nucleus which forms the inner border of the internal capsule. Our results in these cases have been encouraging (Fig. 1). The rationale for a combination of targets has been discussed elsewhere? Ipsilateral Relief After thalamotomy, 39 patients in this series not only had relief in the contralateral limbs but also on the same side. The clinical relief mainly involved rigidity, and was confirmed by surface EMG studies. Occasional temporary ipsilateral relief following thalamotomy has been recorded by others in Parkinsonism? However, in our series the incidence of ipsilateral relief has been high and permanent. We believe that this is due to involvement of uncrossed fibers of the dentatorubrothalamic tract in the lesion. 5 Fl(~. I. Preoperative (left) and postoperative (r(eht) condition of a patient with infantile hemiplegia and athetosis before and after dentatothalamotomy. J. Neurosurg. / Volume 40 / May, "[

6 Balasubramaniam, Kanaka and Ramanujam Acknowledgments Our thanks are due to Professor B. Ramamurthi, Head of the Department, Institnte of Neurology, and to the Dean, Government General Hospital, Madras, for permission to publish this article. References 1. Balasubramaniam V, Kanaka TS: Hemiplegia with athetosis treated by combined dentate thalamotomy. Proe Inst Neurol Madras 2: 33-34, Balasubramaniam V, Kanaka TS, Ramamurthi B: Stereotaxic surgery in cerebral palsy. Ind J Ortho 2:33-36, Balasubramaniam V, Ramamurthi B: Stereotaxic surgery. Neurol India 13:93-96, Beck E, Bignami A: Some neuroanatomical observations in cases with stereotactic lesions for the relief of parkinsonism. Brain 91: , Carrea RME, Mettler FA: The anatomy of the primate brachium conjunctivum and associated structures. J Comp Neurol 101: , Cooper IS: Involuntary Movement Disorders. New York~Evanston/London, Hoeber Medical Division, Harper & Row, Cooper IS, Waltz JM, Amin I, et al: Pulvinectomy: A preliminary report. J Amer Geriatr Soc 19: , Hassler R: Anatomy of the thalamus, in Schaltenbrand GS, Bailey P (eds): Introduction to Stereotaxis with an Atlas of the Human Brain, vol. 1. Stuttgart, Georg Thieme Verlag, 1959, pp Heimburger RF, Whitlock CC: Stereotaxic destruction of the human dentate nucleus. Confin Neurol (Basel) 26: , Horsley VL: The function of the so-called motor area of the brain. Brit Med J 2: , 1909 I1. Johnson KM, Zuck FN, Wingate, K: The motor age test: Measurement of motor handicaps in children with neuromuscular disorders such as cerebral palsy. J Bone Jt Surg 33A: , Kanaka TS: Evaluation of stereotaxic proce- dures in the management of cerebral palsy. PhD Thesis, Madras University, Kanaka TS: Stereotaxic dentatectomy. Ann Ind Acad Med Sei 8: , Kanaka TS, Balasubramaniam V, Ramanujam PB, et al: Stereotaxic surgery in cerebral palsy-study of 57 cases. Neurol India 16 (Suppl 1) :56-59, Laitinen LV: Neurosurgery in cerebral palsy. J Neurol Neurosurg Psychiat 33: ~ Laitinen LV: Short-term results of stereotaxic treatment of infantile cerebral palsy. Confin Neurol 26: , Narabayashi H: Clinical evaluation of thalamic surgery in cerebral palsy. Proc Austr Ass Neurol 5: , Narabayashi H: Further results of thalamic surgery (in the subventrolateral area in the CM) in athetosis and spasticity. Cnnfin Neurol 29:256, Narabayashi H, Kubota K: Reconsideration of ventrolateral thalamotomy for hyperkinesis. Progr Brain Res 21: , Narabayashi H, Shimazu H, Fujita Y, et al: Procaine-oil-wax pallidotomy for double athetosis and spastic states in infantile cerebral palsy: report of 80 cases. Neurology, Minneap 10:61-69, Nashold BS, Jr, Slaughter DG: Effects of stimulating or destroying the deep cerebellar regions in man. J Neurosurg 31: , Shimazu H, Hongo T, Kubota K, et al: Rigidity and spasticity in man. Arch Neurol 6:10-17, Van Manen J: Indications for stereotaxic operations in cerebral palsy. Confin Neurol 26: , Walker AE: Cerebral pedunculotomy for involuntary movements. Surg Gynee Obstet 100: , Yoshida M, Yanagisawa N, Shimazu H, et al: Physiological identification of the thalamic nucleus. Archs Neurol, Chicago 11: , Zervas NT, Horner FA, Pickren KS: The treatment of dyskinesia by stereotaxic dentatectomy. Confin Neurol 29:93-100, 1967 Address reprint requests to: V. Balasubramaniam, F.A.C.S., Ranga Nursing Home, 14-C Mowbray's Road, Madras 18, India Neurosurg. / Volume 40 / May, 1974

Neurosurgery in cerebral palsy

J. Neurol. NVeurosurg. Psychiat., 1970, 33, 513-518 Neurosurgery in cerebral palsy L. V. LAITINEN From the Department of Neurosurgery, University Central Hospital, Helsinki, Finland SUMMARY Stereotaxic