Neurology; New Approaches to Old Symposium on Clinical Neurology: Problems
Epilepsy: Mechanisms and Therapy J. Kiffin Penry, M.D.,~~ M.D.,* and Roger J. Porter,
M.D.':~':~ M.D.~"~
Epilepsy is a disorder of the brain characterized by recurring seizures. The essence of an epileptic seizure is an abnormal and excessive discharge of nerve cells within the brain, which is manifested clinically or electrically, or both. The clinical manifestation of seizures depends on the number and location of discharging neurons. When relatively few motor cortex neurons discharge, there may be only jerking of a contralateral limb, without loss of consciousness (a simple partial seizure). When millions of neurons throughout the brain discharge, loss of consciousness is accompanied by a tonic-clonic phase, and these are followed by postictal confusion as consciousness gradually returns (a generalized tonic-clonic or grand mal seizure). In the former case of these two extremes, the patient is able to give a clear history of what happened; in the latter, there is no memory of the event, and the history must be obtained from observers. Between these two extremes are many different types of generalized or partial (focal) epileptic seizures. 22 The most prevalent type is the complex partial (psychomotor; temporal lobe) seizure. Occurring frequently and dramatically is the complex partial seizure with psychomotor symptomatology, characterized by amnesia, unresponsiveness, and semipurposeful movement or walking in a fugue-like state. On the other hand, subjective manifestations, such as hallucinations or distorted perceptive experiences (for example, micropsia), also occur in complex partial seizures. The electrical manifestations of seizures are recorded by the electroencephalograph. The abnormal activity of cortical neurons during seizures is documented by the epileptiform discharges that appear on the electroencephalogram. Such abnormal discharges occur, .with with rare exceptions, during all seizures and many originate from structures' deep within the brain. The well-known staring spells of childhood (absence or petit mal seizures) are associated with generalized 2 to 4/sec ':'Chief, Epilepsy Branch, and Clinical Epilepsy Section, National Institute of Neurological and Communicative Disorders and Stroke, National Institutes of Health, Bethesda, Maryland *>''
Epilepsy: Mechanisms and Therapy J. Kiffin Penry, M.D.,~~ M.D.,* and Roger J. Porter,
M.D.':~':~ M.D.~"~
Epilepsy is a disorder of the brain characterized by recurring seizures. The essence of an epileptic seizure is an abnormal and excessive discharge of nerve cells within the brain, which is manifested clinically or electrically, or both. The clinical manifestation of seizures depends on the number and location of discharging neurons. When relatively few motor cortex neurons discharge, there may be only jerking of a contralateral limb, without loss of consciousness (a simple partial seizure). When millions of neurons throughout the brain discharge, loss of consciousness is accompanied by a tonic-clonic phase, and these are followed by postictal confusion as consciousness gradually returns (a generalized tonic-clonic or grand mal seizure). In the former case of these two extremes, the patient is able to give a clear history of what happened; in the latter, there is no memory of the event, and the history must be obtained from observers. Between these two extremes are many different types of generalized or partial (focal) epileptic seizures. 22 The most prevalent type is the complex partial (psychomotor; temporal lobe) seizure. Occurring frequently and dramatically is the complex partial seizure with psychomotor symptomatology, characterized by amnesia, unresponsiveness, and semipurposeful movement or walking in a fugue-like state. On the other hand, subjective manifestations, such as hallucinations or distorted perceptive experiences (for example, micropsia), also occur in complex partial seizures. The electrical manifestations of seizures are recorded by the electroencephalograph. The abnormal activity of cortical neurons during seizures is documented by the epileptiform discharges that appear on the electroencephalogram. Such abnormal discharges occur, .with with rare exceptions, during all seizures and many originate from structures' deep within the brain. The well-known staring spells of childhood (absence or petit mal seizures) are associated with generalized 2 to 4/sec ':'Chief, Epilepsy Branch, and Clinical Epilepsy Section, National Institute of Neurological and Communicative Disorders and Stroke, National Institutes of Health, Bethesda, Maryland *>''
