SPECIAL ARTICLES * ARTICLES SPECIAUX
Surgery for epilepsy: summary of a consensus statement O f the 150000 people in whom epilepsy develops each year 10% to 20% prove to have seizures that cannot be controlled by medication. Brain surgery is an alternative that is being used more often. To clarify which surgical procedures should be done, which patients are candidates for surgery and how to assess outcome after surgery the National Institute of Neurological Disorders and Stroke and the Office of Medical Applications of Research of the National Institutes of Health held a consensus development conference Mar. 19 to 21, 1990, on surgery for epilepsy. The following is a summary of the consensus panel's report. Increasing numbers of patients, including many children, are being referred for surgery. Improved technology has made it possible to identify more accurately where seizures originate in the brain, and advances in surgical techniques have made operations safer. As a result, some investigators believe that 2000 to 5000 new patients in the United States may be candidates for surgery each year, compared with the present annual rate of about 500. There are several reasons to consider surgery for the treatment of uncontrolled seizures. Repeated seizures can result in progressive cerebral degeneration and handicap. Also, the long-term use of antiepileptic drugs is costly and can have toxic effects. For patients facing a lifetime of ineffective therapy, social and intellectual development and job performance may be compromised. Yet surgery has risks and costs that must be considered. Current data suggest that three categories of seizures may be ameliorated by surgery: partial seizures of temporal or extratemporal origin, secondarily generalized seizures (attacks that begin locally and spread to both sides of the brain) and unilateral, multifocal epilepsy associated with infantile hemiplegia. As a first step, patients with these types of
seizures should be referred to a neurologist or specialized epilepsy centre for further evaluation. Before surgery is considered the neurologic evaluation should confirm the following: a diagnosis of epilepsy, including seizure type and syndrome, and a defined metabolic or structural cause. The patient should have had a reasonable trial of the appropriate drugs, with adequate monitoring of compliance and side effects. Patient and family should receive detailed information about the seizure disorder, drug treatments and their side effects, and alternative treatments such as surgery. If evaluation and treatment by a neurologist show that drug therapy is unlikely to result in further benefit the patient should be referred to an epilepsy centre to be evaluated specifically for surgery. Coexisting disorders may affect the decision to operate. Specialized epilepsy centres should have the following personnel: neurologists, neurosurgeons, neuropsychologists and others with training in and experience of epilepsy. Neurodiagnostic equipment should also be available. In all cases electroencephalography and magnetic resonance imaging should be used to identify and exclude other forms of neurologic disease. It is not yet clear when it is necessary to use more extensive tests, such as surface electroencephalography during seizures, invasive intracranial electrode recording, positron-emission tomography or single-photon-emission computed tomography. A program should be developed to assess the value of these tests. It is recommended that data from major epilepsy centres be combined to clarify many unanswered questions about the use of these and other diagnostic methods. Surgical removal of epileptogenic tissue in patients who have partial seizures or seizures of temporal lobe origin has resulted in success rates of 55% to 70%, if success is defined as no seizures for 5
Free single copies of the full statement may be obtained from William H. Hall, Director of communications, Office ofMedical Applications ofResearch, National Institutes of Health, Bldg. 1, Rm. 259, Bethesda, MD 20892, USA CAN MED ASSOC J 1991; 144 (2)
145
years after surgery (regardless of whether anticonvulsant medication is still taken). Combined disability and death rates for this procedure are below 5%. The median cost of diagnostic evaluation and surgery in the United States ranges from $40 000 to $60 000
complications is a major consideration in the selection of surgical technique, and this has led to a consensus that a functional hemispherectomy (in which some tissue is left but is disconnected from the rest of the brain) is preferable to an anatomic one. The success rates for functional hemispherecto(US). Patients with partial seizures of frontal and my are 50% to 70%, compared with disability and other extratemporal sites are candidates only when death rates of up to 50% for anatomic hemispherecthe epileptic region is in an area from which tissue tomy in the past. can be removed. Surgery can result in improvement When assessing surgical outcome one should in 30% to 50% of these patients, and the death rate is consider certain factors: physical and mental health, less than 2%. In the United States costs are slightly neuropsychologic factors, social and general health, higher than for temporal lobe resection. and short-term surgical complications, disability and Some patients with generalized seizures, specifi- death. The evaluation of children should include cally those who are prone to violent falls resulting in developmental progress and school performance. head injury, can be helped by section of the corpus Because epilepsy affects the whole family an assesscallosum. This procedure is also recommended in ment should be made of the family's overall wellpatients with the Lennox-Gastaut syndrome (a being, including economic factors. Outcome should childhood seizure disorder marked by brain injury be evaluated repeatedly for several years, and epilepand falls) or drop attacks. After surgery the seizures sy centres should pool data. become less frequent, less disabling and less violent. Many patients have intractable epilepsy for 10 Evaluation and selection of candidates have not to 20 years before being referred for surgery. A been standardized, and there is variability of surgical controlled clinical trial of early versus late surgery technique. Complications may occur in as many as should be done to determine whether early surgery 20% of patients, but the postoperative death rate is can result in better health and better quality of life as low. The procedure can involve two operations: the well as prevent additional brain damage and chronic anterior two-thirds of the corpus callosum is usually social disability. sectioned first and the remaining portion several Research in the following areas is recommmonths later. There are higher charges for this ended: the effects of uncontrolled seizures and anprocedure, but the preoperative evaluation costs are tiepileptic drug therapy on the developing brain; the often less than for other surgical techniques. circumstances in which each surgical technique is Hemispherectomy or callosotomy may benefit maximally effective; psychiatric and behavioural patients with seizures associated with infantile hemi- functions before and after surgery; and the basic plegia. These patients account for about 2% of all sciences of epilepsy, including the development of those treated surgically for epilepsy. Avoidance of antiepileptic drugs..
In search of health There is nothing men will not do, there is nothing they have not done, to recover their health and save their lives. They have submitted to be half-drowned in water, and half-choked with gases, to be buried up to their chins in earth, to be seared with hot irons like galley-slaves, to be crimped with knives, like cod-fish, to have needles thrust into their flesh, and bonfires kindled on their skin, to swallow all sorts of abominations, and to pay for all this, as if blisters were a blessing, and leeches were a luxury. What more can be asked to prove their honesty and sincerity? -
146
CAN MED ASSOC J 1991; 144 (2)
Oliver Wendell Holmes (1809-1894)
Surgery for epilepsy: summary of a consensus statement O f the 150000 people in whom epilepsy develops each year 10% to 20% prove to have seizures that cannot be controlled by medication. Brain surgery is an alternative that is being used more often. To clarify which surgical procedures should be done, which patients are candidates for surgery and how to assess outcome after surgery the National Institute of Neurological Disorders and Stroke and the Office of Medical Applications of Research of the National Institutes of Health held a consensus development conference Mar. 19 to 21, 1990, on surgery for epilepsy. The following is a summary of the consensus panel's report. Increasing numbers of patients, including many children, are being referred for surgery. Improved technology has made it possible to identify more accurately where seizures originate in the brain, and advances in surgical techniques have made operations safer. As a result, some investigators believe that 2000 to 5000 new patients in the United States may be candidates for surgery each year, compared with the present annual rate of about 500. There are several reasons to consider surgery for the treatment of uncontrolled seizures. Repeated seizures can result in progressive cerebral degeneration and handicap. Also, the long-term use of antiepileptic drugs is costly and can have toxic effects. For patients facing a lifetime of ineffective therapy, social and intellectual development and job performance may be compromised. Yet surgery has risks and costs that must be considered. Current data suggest that three categories of seizures may be ameliorated by surgery: partial seizures of temporal or extratemporal origin, secondarily generalized seizures (attacks that begin locally and spread to both sides of the brain) and unilateral, multifocal epilepsy associated with infantile hemiplegia. As a first step, patients with these types of
seizures should be referred to a neurologist or specialized epilepsy centre for further evaluation. Before surgery is considered the neurologic evaluation should confirm the following: a diagnosis of epilepsy, including seizure type and syndrome, and a defined metabolic or structural cause. The patient should have had a reasonable trial of the appropriate drugs, with adequate monitoring of compliance and side effects. Patient and family should receive detailed information about the seizure disorder, drug treatments and their side effects, and alternative treatments such as surgery. If evaluation and treatment by a neurologist show that drug therapy is unlikely to result in further benefit the patient should be referred to an epilepsy centre to be evaluated specifically for surgery. Coexisting disorders may affect the decision to operate. Specialized epilepsy centres should have the following personnel: neurologists, neurosurgeons, neuropsychologists and others with training in and experience of epilepsy. Neurodiagnostic equipment should also be available. In all cases electroencephalography and magnetic resonance imaging should be used to identify and exclude other forms of neurologic disease. It is not yet clear when it is necessary to use more extensive tests, such as surface electroencephalography during seizures, invasive intracranial electrode recording, positron-emission tomography or single-photon-emission computed tomography. A program should be developed to assess the value of these tests. It is recommended that data from major epilepsy centres be combined to clarify many unanswered questions about the use of these and other diagnostic methods. Surgical removal of epileptogenic tissue in patients who have partial seizures or seizures of temporal lobe origin has resulted in success rates of 55% to 70%, if success is defined as no seizures for 5
Free single copies of the full statement may be obtained from William H. Hall, Director of communications, Office ofMedical Applications ofResearch, National Institutes of Health, Bldg. 1, Rm. 259, Bethesda, MD 20892, USA CAN MED ASSOC J 1991; 144 (2)
145
years after surgery (regardless of whether anticonvulsant medication is still taken). Combined disability and death rates for this procedure are below 5%. The median cost of diagnostic evaluation and surgery in the United States ranges from $40 000 to $60 000
complications is a major consideration in the selection of surgical technique, and this has led to a consensus that a functional hemispherectomy (in which some tissue is left but is disconnected from the rest of the brain) is preferable to an anatomic one. The success rates for functional hemispherecto(US). Patients with partial seizures of frontal and my are 50% to 70%, compared with disability and other extratemporal sites are candidates only when death rates of up to 50% for anatomic hemispherecthe epileptic region is in an area from which tissue tomy in the past. can be removed. Surgery can result in improvement When assessing surgical outcome one should in 30% to 50% of these patients, and the death rate is consider certain factors: physical and mental health, less than 2%. In the United States costs are slightly neuropsychologic factors, social and general health, higher than for temporal lobe resection. and short-term surgical complications, disability and Some patients with generalized seizures, specifi- death. The evaluation of children should include cally those who are prone to violent falls resulting in developmental progress and school performance. head injury, can be helped by section of the corpus Because epilepsy affects the whole family an assesscallosum. This procedure is also recommended in ment should be made of the family's overall wellpatients with the Lennox-Gastaut syndrome (a being, including economic factors. Outcome should childhood seizure disorder marked by brain injury be evaluated repeatedly for several years, and epilepand falls) or drop attacks. After surgery the seizures sy centres should pool data. become less frequent, less disabling and less violent. Many patients have intractable epilepsy for 10 Evaluation and selection of candidates have not to 20 years before being referred for surgery. A been standardized, and there is variability of surgical controlled clinical trial of early versus late surgery technique. Complications may occur in as many as should be done to determine whether early surgery 20% of patients, but the postoperative death rate is can result in better health and better quality of life as low. The procedure can involve two operations: the well as prevent additional brain damage and chronic anterior two-thirds of the corpus callosum is usually social disability. sectioned first and the remaining portion several Research in the following areas is recommmonths later. There are higher charges for this ended: the effects of uncontrolled seizures and anprocedure, but the preoperative evaluation costs are tiepileptic drug therapy on the developing brain; the often less than for other surgical techniques. circumstances in which each surgical technique is Hemispherectomy or callosotomy may benefit maximally effective; psychiatric and behavioural patients with seizures associated with infantile hemi- functions before and after surgery; and the basic plegia. These patients account for about 2% of all sciences of epilepsy, including the development of those treated surgically for epilepsy. Avoidance of antiepileptic drugs..
In search of health There is nothing men will not do, there is nothing they have not done, to recover their health and save their lives. They have submitted to be half-drowned in water, and half-choked with gases, to be buried up to their chins in earth, to be seared with hot irons like galley-slaves, to be crimped with knives, like cod-fish, to have needles thrust into their flesh, and bonfires kindled on their skin, to swallow all sorts of abominations, and to pay for all this, as if blisters were a blessing, and leeches were a luxury. What more can be asked to prove their honesty and sincerity? -
146
CAN MED ASSOC J 1991; 144 (2)
Oliver Wendell Holmes (1809-1894)
