Epilepsy/Coma Flashcards
What is epilepsy?
What is epilepsy syndrome?
When a person has recurrent seizures due to an underlying process
Group of clinical and pathological characteristics that suggest underlying etiology but direct cause is unknown
What is a seizure?
What determines the presentation?
A paroxysmal (comes and goes) event which abnormal hype synchronous discharge from CNS neurons.
The presentation is determined by what area of the CNS the hyper synchronized discharge comes from.
Motor cortex- flailing
Hippocampus- feeling of doom
What is the prevalence of epilepsy in America?
1% have recurrent seizures (2.7million people)
NOT A RARE DISORDER
What are certain risk factors that put people at risk for developing epilepsy?
Mental retardation
Cerebral palsy
Alzheimer’s
Strokes
What are the three most common neurological disorders in the US?
Stroke
Alzheimer’s
Epilepsy
Why is the risk of death from epilepsy and epilepsy related causes so high?
People can seize when showering and drown, or when driving and crash, etc.
The treatment only stops seizures in 60-70% of people
When taking a history of a patient with epilepsy, who do you need to take accounts from?
The patient and a witness because often they lose consciousness during the seizure
Does negative testing rule out seizures as a diagnosis?
No, but if the tests are positive, the person definitely has seizures and there is a good chance of epilepsy
How is cerebral electrical activity recorded?
What are 3 major shortcomings with this technique?
Electroencephalogram (EEG) which places electrodes on the persons scalp to record electrical activity .
- The potential difference is 0.01mV and sums local electrical response for 1 cm so it is difficult to localize
- It is difficult to record seizures or irregular activity in th more medial aspects of the brain because the electrodes need to go through too many layers
- Time resolution is compromised so you can’t see events that are happening faster than 1000hz
What can the MRI show for a person with neurological damage?
Hemmohage, stroke, tumors and other structural lesions that put a person at risk for epilepsy
What are the key features to look for on the EEG?
Amplitude, frequency, L/R symmetry and oscillation in the waveform
In adults, what rhythm is interrupted due to the activation of the visual cortex?
The alpha rhythm (10hz)
On the EEG, what do even numbers represent?
What do odd numbers represent?
Even- right side
Odd- left side
What will a seizure do to the amplitude of a spike on the EEG?
It will increase the amplitude because there is a hypersynchronization of neuronal firing
What is the time period between seizures called? What would it look like on an EEG?
What is the time period when the person is having a seizure?
Interictal period would be characterized by isolated spike and wave or normal appearance
Ictal period is characterized by a prolonged run of spike and discharge waves
Why does the failure to detect epileptic discharges not rule out epilepsy?
The reading could have been done during an interictal period
How long is the standard EEG recording temporally?
20 minutes
What is a tonic/clonic stroke disorder?
Involuntary contractions with sustained posture (tonic) followed by rhythmic large amplitude shaking (clonic)
What are absence seizures?
Sudden loss of responsiveness (staring, unable to speak)
What are myoclonic seizures?
Brief shock-like jerks of arms or legs