Abnormal EEGs In The Sleep Lab Patti Baumgartner, R. EEG/EP., CNIM
What to these people have in common? Danny Glover Pope Pius IX Napoleon Sir Isaac Newton Socrates Charles Dickens maybe someone you know?
Answer They all have epilepsy.
What percentage of seizures occur in sleep? It is estimated that at least 2/3 of seizures occur in sleep. Not everyone who has a seizure has epilepsy Some seizures can hardly be noticed, while others are totally disabling.
What is a seizure? A seizure is a sudden surge of electrical activity in the brain that usually affects how a person feels or acts for a short time. Seizures are not a disease in themselves. Instead, they are a symptom of many different disorders of the brain. Not everyone who has a seizure has epilepsy.
Definition of Epilepsy Epilepsy is a medical condition that produces seizures affecting a variety of mental and physical functions. When a person has 2 or more unprovoked seizures they are considered to have epilepsy.
Etiology of Epilepsy Any one of us can have a seizure if the conditions are right. Drugs Hypoglycemia High fever ECT Infectious disease Meningitis/encephalitis
Quick Anatomy Lesson
4 lobes of the brain
Frontal Lobe Plan for the future Solve complex problems Express and control emotional behavior Coordinate complex skilled movements Some aspects of speech
Temporal Lobe In most people the temporal lobes have somewhat different functions The left temporal lobe generally helps us to understand language, and speak. The right temporal lobe helps us to remember things.
Parietal Lobe Includes sensory areas, responsible for feelings of temperature, touch, pressure and pain.
Occipital Primary function is vision
Classification of Epilepsy Seizures are classified into 2 categories or groups: Partial and Generalized
Partial Seizures Involve only a portion of the brain at the ONSET. They are further divided into two parts: Simple partial, in which consciousness is not impaired Complex partial in which consciousness is impaired.
Generalized seizures These seizures are commonly called grand mal. And by definition begin with loss of consciousness. Typically each seizure has 2 phases, tonic and clonic. Tonic Phase consists of an increase in muscle tone which causes stiffening. Clonic Phase consists of alternating tightening and relaxing of muscles--jerking
Generalized seizures Another type of generalized seizure is the Atonic Seizure. The seizure consists of loss of all strength rather than becoming stiff. They last only a few seconds so it is impossible to accurately determine the patient s level of consciousness.
Absence Seizures Brief episodes of staring. May have some associated eye blinking/fluttering, or lip smacking. Spells last only a few seconds Start in Childhood, disappear by late teens
Partial Seizures Seizures that begin with an abnormal electrical discharge from a limited area of the brain are called partial seizures. Two kinds: Simple complex Partial Complex
Simple Partial Seizures The specific area of he brain where each of these seizures begins determines what the seizure looks like. Commonality is that the person having the seizure remains alert and can remember what happened. Sometimes called focal seizures
Complex Partial Seizures These seizures begin in a small area of the temporal or frontal lobe, but they quickly involve areas that affect alertness and awareness Consciousness is lost, the patient has no memory of the event
Secondary generalized seizures Both simple and complex partial seizures can spread, resulting in secondarily generalized tonic clonic seizures. In the EEG world this is called secondary subcortical synchrony
Summary of Clinical & EEG Features of Epileptic Seizures Seizure Simple Partial Complex Partial Absence Gen. Tonic-Clonic Usual Duration Loss of Consc. Post-Ictal Confusion ICTAL EEG 5-10 sec NO NO Focal Spikes (NL) Variable 5-10 sec 1-2 min 5-10 /sec Clustering YES YES Focal or Lat. Spike YES NO Gen. 3 /sec S & W 1-2 min YES YES Gen. High Amp Spikes Rebecca Clark-Bash 23
Medications for Epilepsy Tegretol Carbatrol Zarontin Felbatrol Gabitril Keppra Lamictal Lyrica Dilantin Topamax Trileptal Depakene Depakote
Term Definition Ictal EEG Describes the recording during the event Interictal EEG Describes the recording in between each event Postictal EEG Describes the period of time immediately following an event Rebecca Clark-Bash 25
What is Epileptiform Activity Any paroxysmal rhythmic frequency (e.g. beta, alpha, or even delta) may also be classified as epileptiform. Certainly the most common types of Epileptiform activity are: spikes, sharp waves, spike and waves
Definition of a Spike A wave with a duration of 80 msc or less, usually negative, standing out from the background.
Definition of a Sharp wave A wave with a duration of 120-80 msc, usually negative, standing out from the background.
How to measure a spike/sharp wave 30 second epoch
Spike and Wave Spike followed by a slow wave
What do you see on the EEG The signature of epilepsy: cat 31
Example #1 Sleep parameters
Example #1 EEG Parameters
Example #2 Sleep Parameters
Sample #2 EEG Parameters
Example # 3 Sleep Parameters
Example #3 EEG Parameters
Example #4 Sleep Parameters
Example #4 EEG Parameters
Sample #5 Sleep Parameters
Sample #5 EEG Parameters
Sample #6 Sleep Parameters
Sample #6 EEG
Sample #7 Sleep Parameters
Sample #7 EEG Parameters
Sample #8 Sleep Parameters
Sample #8 EEG Parameters
Sample #9 EEG Parameters
Sample #9 Sleep Parameters
Many Thanks to Those That Helped Bernard M. Abrams, M. D. Susan Gersh, R. EEG T. Rebecca Clark Bash, R. EEG/EP T., CNIM, F.ASNM Terry O Brien
Answers to Sample Wave Forms 1. Eye Blink 2. Asymmetrical Alpha 3. Generalized Spike and Wave 4. Multifocal Spikes 5. C4 focal Spike 6. Generalized spike and wave 7. Generalized Polyspike and wave 8. Focal spikes F7 and T3 9. Focal slowing T3 best seen on Sleep Parameters (slow speed)