epilepsy Flashcards
- Recognize the signs of epileptic seizures (paroxysmal change in behavior or movement, or an alteration of consciousness).
The symptoms of seizures are “positive phenomnena”, meaning they are the presence of something not usually experienced by normal people. Visual and auditory hallucinations are possible as well as motor signs including tonicity, spasms and clonus. Additionally, there may be changes of behavior or alteration of consciousness as in complex seizures.
- Describe the various etiologies of an epileptic seizure.
Children: • Genetic predisposition or disease involving cortex • Infection – (often febrile) • Trauma • Congenital • Metabolic disturbances Adults: • Tumors (examples include meningioma and cavernous angioma) • Trauma • Stroke • Infection Elderly: • Stroke • Tumor • Trauma • Metabolic disorder • Infection
- Regarding the classification of epilepsies, identify the two major type of epilepsy: partial onset and primary generalized, and describe the difference between a primary generalized tonic-clonic seizure and a secondarily generalized tonic-clonic seizure.
a. Seizures begin in one of 2 ways:
1. In a focal, localized region. This is known as a partial seizure.
2. Diffusely around the cortex. This is a generalized seizure.
Partial seizures start in 1 area of the brain, but can spread distantly as the “fire” of the seizure migrates. This is called a secondary generalized seizure. Partial seizures can be simple or complex. In simple partial seizures conscious awareness and memory are intact, but there may be motor, sensory, autonomic and psychic changes. Complex partial seizures are distinguished by their impaired consciousness. They often involve the hippocampus bilaterally and have a post-ictal state.
b. A primary generalized tonic-clonic seizure starts diffusely around the brain probably because the cortex, as a whole is hyper-excitable. It is characterized by alternating stiffening and jerky movement of the body. A secondary generalized tonic-clonic seizures looks exactly the same, however; it is proceeded by a partial seizure in a localized area of the brain.
- Differentiate between a complex partial seizure and a primary generalized absence seizure.
A complex partial seizure has impaired consciousness and memory, usually with a confused post-ictal state. It often preceded by a seizure aura. During the seizure, the patient may display automatisms, which is the spontaneous production of purposeless motor or verbal behavior without conscious control. These seizures often last about a minute. It originates from a localized area of the brain often (but not always!) in the temporal lobe.
In contrast, a primary generalized absence seizure starts diffusely from many areas of the brain, but only affects the afferent layers of the cortex. It presents as blank staring for several seconds without a motor component. Patients are usually children, about 60% of whom outgrow the seizures. These can be precipitates by hyperventilation. Like complex partial seizures, these patients often have no memory of the event.
- Recognize that epilepsy is a disorder of recurrent, spontaneous seizures and that epilepsy can be classified by generalized and partial syndromes or by etiologies.
A diagnosis of epilepsy requires at least 2 unprovoked seizures separated by at least 24 hours. Unprovoked seizures are those which are not due to trauma, fever, alcohol withdrawal, etc. Epilepsy can be the result of a structural abnormality or genetic predisposition.
-Myoclonic seizures are characterized by jerking, absence (petit mal) seizures by staring and blinking, atonic by falling or dropping and tonic-clonic (grand mal) by shaking and stiffness.
Seizures can be either partial or diffuse. Partial epilepsies can be symptomatic, idiopathic or related to special syndromes (ie. neonatal and febrile seizures). Diffuse epilepsy syndromes can by symptomatic, idiopathic (this refers to a genetic predisposition) or cryptogenic.
- Recognize that intractable epilepsies can be defined as seizures which do not respond to a trial of at least 3 anticonvulsants and that approximately 30% of new onset seizure patients may develop intractable epilepsy.
Intractable epilepsies are those which do not respond to a trial of least 3 medications. This is by definition a catastrophic epilepsy which may affect life span and cognitive potential
- Recognize that status epilepticus is a medical emergency and the potential causes of status epilepticus as well as treatment options.
Status epilepticus is defined as continuous clinical or EEG seizures for at least 30 minutes (this includes serial seizures in which consciousness it not regained between seizures). SE is more common in children than in adults. SE can be either convulsive as in tonic-clonic, myoclonic, tonic or epilepsia partialis continua, or non-convulsive as in absence status or atypical complex partial SE (where there are no motor signs).
In children, SE is often the result of febrile seizures or an acute symptomatic seizure. Acute symptomatic seizures are due to an acute insult to the brain, such as infection, trauma or stroke. Adults are mostly likely to have SE due to acute symptomatic seizures. Mortality in adults is about 26%, while mortality in children is 3-15% as the etiologies are more likely to be benign. These should be treated emergently!
Treatment: • ABCs – airway, oxygen, blood pressure • Secure IV access to draw blood • Arterial blood gas should be taken if possible • Within 5 minutes o Lorazepam or diazepam • Between 6 and 10 minutes o Repeat Benzo dose • 10-20 minutes o Phenytoin (Dilantin) • 21-40 minutes o Phenobarbital o After dosing with this, patients will be unlikely to participate in neuro exam • >40 minutes o This is refractory SE! o Midazolam (Versed) o Propofol o Valproic acid o Experimental: • Nasogastric topiramate • Nasogastric levetiracetam • Keppra • If it continues to be refractory: o Burst suppression → medication induced coma to break cycle of seizures o Often accomplished with high dose Phenobarbital o Also by continuous Midazolam infusion • This is less likely to require pressor support
- Discuss the definition and risk for recurrence of febrile seizures.
Febrile seizures are seizures brought on by fever, usually in infants and small children. Children with febrile seizures do not have epilepsy. Most children who have febrile seizures may have other febrile seizures, but are very unlikely to develop epilepsy. Children are more likely to have recurrent febrile seizures if: the first seizure happened before 12 months, there is a family history of febrile seizures or the seizure occurred with a temperature below 102 deg. F.
