epilepsy Flashcards
What are common triggers/precipitants for seizures?
What are the common facilitators of seizures in susceptable individuals?
Obligatory triggers: flashing lights, hyperventilation
Facilitators: stress, alcohol, febrile illness, sleep deprivation
What is the difference between epilepsy and seizures?
Epilepsy is a condition where brain disorders predispose to seizures.
seizures are the clinical manifestation of abnormal, excessive excitation of cortical neurons. Excessive excitation can be brought on by many things including epilepsy, drug intoxication or metabolic problems
If you suspect a patient has epilepsy, what disorders must you keep on the differential?
syncope attacks from orthostatic hypertention (but jerks can make it look like seizures)
cardiac arrhythmias - can lead to syncope
migraine - basilar migrane can make someone lose consciousness
hypoglycemia
narcolepsy
pain attacks
pseudoseizures
What patient populations have high incidences of epilepsy? What is the most common etiologies in each population?
children - developmental abnormality
elderly - strokes and scars from strokes
What is the concept of kindling in regards to epilepsy?
Seizures may be progressive and the number of foci might grow over time if not treated
What are the two main categories of epilepsy? How is the onset of the seizures different? How is the etiology different?
1) generalized epilepsy: seizure starts diffusely all over the brain at once. Usually due to genetic defect.
2) focal epilepsy: seizure starts at a particular focus in the brain. Can be due to trauma, infection, tumors, stroke or unknown
What are the types of seizures seen in generalized epilepsy? What are the types of seziures seen in focal epilepsy?
Generalized: absence seizures (“petit mal”), myoclonic jerks, primary generalized tonic-clonic seizures (“grand mal”)
focal: temporal, occipital, frontal lobe seizures, secondary generalized tonic-clonic seizures. Focal seizures can be simple (no loss of awareness) or complex (loss of awareness).
What are some of the common auras at the beginning of epileptic seizures?
sudden intense fear
deja vu
olfactory or gustatory hallucinations
rising abdominal sensation
What are the clinical findings in a generalized tonic-clonic seizure (grand mal seizure)?
generalized spikes on EEG
no auras (because no focus)
last for 2-3 minutes
post-ictal (post-epileptic episode) period of confusion
don’t remember the event
Tonic phase - The patient will quickly lose consciousness, and the skeletal muscles will suddenly tense, often causing the extremities to be pulled towards the body or rigidly pushed away from it
Clonic phase - The patient’s muscles will start to contract and relax rapidly, causing convulsions
What are the clincial findings in an absence seizure?
sudden behavioral arrest
staring, unresponsive
abrupt onset and abrupt return to normal
don’t remember the event/pick up conversation right where they left off/don’t know they had an episode
What are the clinical features of juvenile myoclonic seizures?
affect adolescents
myoclonus in the morning (makes them drop things)
usually a family history/genetic
initially exhibit myoclonic seizures, then absence seizures and generalized tonic-clonic seizures
What are the areas of the brain that are most prone to epilepsy?
amygdala, hippocampus, enterorhinal complex (all three are in the medial temporal lobe)
Temporal lobe seizures are most common
frontal lobe seizures are 2nd most common
occipital lobe seizures are rare
What is Todd’s postictal paralysis/Todd’s paresis?
The parts of the brain that have a seizure can be paralyzed for hours to days after the seizure. This leads to a transient weakness of a hand, arm, or leg after partial seizure activity within the motor cortex. The weakness may range in severity from mild to complete paralysis.
Must be distinguished from a stroke!
How does mesial temporal sclerosis present? What is the pathogenesis of MTS? What is the treatment?
MTS presents as temporal lobe epilepsy with an aura of rising stomach sensation, lip smacking and impaired consciousness.
Pathogenesis is neuronal loss in the hippocampus that forms a glial scar. The scar is the focus of the seizures. These seizures are commonly intractable so the treatment is to excise the glial scar.
Patients are usually not aware when then get bilateral seizures. What is the exception to this?
Frontal seizures can be bilateral but the patient is aware.
