Critical Care Secrets Volume 4 || Status Epilepticus
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STATUS EPILEPTICUS Ala Nozari, MD, PhD, Corey R. Fehnel, MD, and Lee H. Schwamm, MD, FAHA CHAPTER 61 1. What is the definition of status epilepticus (SE)? SE has typically been defined as repetitive seizures lasting 30 minutes or longer, or seizures without full return of consciousness between episodes. This definition was recently challenged because it does not incorporate the practical considerations of patient management and because shorter periods of seizure activity can cause neuronal injury. Therefore others have recommended defining SE as seizures lasting 5 minutes or two or more seizures between which there is incomplete recovery of consciousness or function. 2. Name important features of SE. In patients with no prior seizure history, SE is usually a manifestation of cortical irritation or injury. Treatment of the underlying disorder is therefore critical. Relapse of seizure in patients with known seizure disorder, on the other hand, commonly reflects subtherapeutic levels of antiepileptic drugs (AED) and usually responds to a bolus of the maintenance drug. Most cases of convulsive SE in adults start as partial seizures that generalize. 3. Describe the classification and clinical presentation of SE. SE can be classified in several forms, including convulsive SE, focal SE, myoclonic SE, and nonconvulsive SE (NSE). n Generalized convulsive SE involves tonic flexion of the axial muscles, flexion in the arms and legs followed by extension, clenching of teeth, forced expiration, dilation of the pupils or sluggish pupillary light responses, and upward or lateral eye deviation. The uninterrupted jerking or shivering during the clonic phase may gradually resolve, but tonic spasm may occur again with a similar pattern of jerking and resolution. As the duration of the seizures increases, the movements and muscle contractions may become reduced despite continued generalized electrical activity in the brain. n Focal SE can be simple without loss of consciousness or complex with impaired consciousness. Jerking of one ipsilateral arm or leg or continuous clonic movements of one or two extremities can be observed. When confined to focal motor clonic seizures without Jacksonian march, it is often referred to as epilepsia partialis continua (EPC); the motor activity lasts for hours, days, weeks, or longer. Consciousness is not altered, but postictal weakness is frequent. In most cases, the ictal focus is cortical, and anticonvulsants help prevent generalization but are frequently ineffective at aborting the seizures. EPC is often caused by a structural lesion (e.g., tumor, chronic infarction) or a progressive neurodegenerative disease (particularly in children). Focal SE of all forms is often related to acute hemispheric lesions such as a hemorrhage or brain metastasis. n Myoclonic SE is seen in patients after cardiac arrest or asphyxiation and consists of synchronous brief jerking of the limbs, face, or diaphragm. It can also be seen after electrical injury, drug intoxication, or decompression sickness and often denotes severe cortical laminar necrosis in association with thalamic and spinal cord injuries. 4. What defines NSE? The same principles apply of prolonged duration (>5 minutes) or lack of return to baseline mental status in between seizures. However, NSE can be difficult to diagnose because of lack of 434
Transcript of Critical Care Secrets Volume 4 || Status Epilepticus
STATUS EPILEPTICUSAla Nozari, MD, PhD, Corey R. Fehnel, MD, and Lee H. Schwamm, MD, FAHACH
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1. What is the definition of status epilepticus (SE)?SE has typically been defined as repetitive seizures lasting 30 minutes or longer, or seizureswithout full return of consciousness between episodes. This definition was recently challengedbecause it does not incorporate the practical considerations of patient management and becauseshorter periods of seizure activity can cause neuronal injury. Therefore others haverecommended defining SE as seizures lasting �5 minutes or two or more seizures betweenwhich there is incomplete recovery of consciousness or function.
2. Name important features of SE.In patients with no prior seizure history, SE is usually a manifestation of cortical irritation orinjury. Treatment of the underlying disorder is therefore critical. Relapse of seizure in patientswith known seizure disorder, on the other hand, commonly reflects subtherapeutic levels ofantiepileptic drugs (AED) and usually responds to a bolus of the maintenance drug. Most cases ofconvulsive SE in adults start as partial seizures that generalize.
3. Describe the classification and clinical presentation of SE.SE can be classified in several forms, including convulsive SE, focal SE, myoclonic SE, andnonconvulsive SE (NSE).n Generalized convulsive SE involves tonic flexion of the axial muscles, flexion in the arms andlegs followed by extension, clenching of teeth, forced expiration, dilation of the pupils orsluggish pupillary light responses, and upward or lateral eye deviation. The uninterruptedjerking or shivering during the clonic phase may gradually resolve, but tonic spasmmay occuragain with a similar pattern of jerking and resolution. As the duration of the seizuresincreases, the movements and muscle contractions may become reduced despite continuedgeneralized electrical activity in the brain.
n Focal SE can be simple without loss of consciousness or complex with impairedconsciousness. Jerking of one ipsilateral arm or leg or continuous clonic movements of one ortwo extremities can be observed. When confined to focal motor clonic seizures withoutJacksonian march, it is often referred to as epilepsia partialis continua (EPC); the motor activitylasts for hours, days, weeks, or longer. Consciousness is not altered, but postictal weakness isfrequent. In most cases, the ictal focus is cortical, and anticonvulsants help preventgeneralization but are frequently ineffective at aborting the seizures. EPC is often caused by astructural lesion (e.g., tumor, chronic infarction) or a progressive neurodegenerativedisease (particularly in children). Focal SE of all forms is often related to acute hemisphericlesions such as a hemorrhage or brain metastasis.
n Myoclonic SE is seen in patients after cardiac arrest or asphyxiation and consists ofsynchronous brief jerking of the limbs, face, or diaphragm. It can also be seen after electricalinjury, drug intoxication, or decompression sickness and often denotes severe cortical laminarnecrosis in association with thalamic and spinal cord injuries.
4. What defines NSE?The same principles apply of prolonged duration (>5 minutes) or lack of return to baselinemental status in between seizures. However, NSE can be difficult to diagnose because of lack of
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