EEG

Question 1

EEG

• uses
• how does it work

Answer 1

Test of choice in diagnosis and classification of seizures
21 contacts at 10 degrees apart on brain
-red right
-blue left

Assess electrical activity of synaptic potentials

Spatiotemporal average of synchronous post synaptic activity
-cannot show you asynchronous or AP activity

Question 2

Clinical use of EEG for epilepsy

Answer 2

Most important tool for epilepsy diagnosis and treatment

• classify, quanity seizures
• localise epileptogenic focus
• cannot guide treatment efficacy

BUT THIS MUST BE IN THE CONTEXT OF THE HISTORY

Question 3

Clinical uses of EEG in sleep studies

Answer 3

Polysomnography

-assess NREM and REM patterns

Question 4

Types of EEG

Answer 4

Routine - 20mins
Sleep recording - 90mins
-extra face and muscle electrodes
Long term video monitoring (home, hospital telemetry) - 48hrs-3wks
-watch for seizure activity

Provocation EEG
-try to trigger seizures (reading lights, hyperventilation)

Question 5

Positives of EEG

Answer 5

Cheap
Can be repeated often
Can

Question 6

Negatives of EEG

Answer 6

Detects cortical dysfunction but rarely discloses cause
Influenced by state of alertness, hypoglycemia, drugs
Subject to both electrical, physiological artifacts

Question 7

Long EEG - days-weeks

Answer 7

Record habitual seizures
Assess for any behavioural links (epilepsy or NEAD)
Classification of seizures
Quantify seizures
Assess for causes

Question 8

Most common foci for seizures

Answer 8

Hippocampus in temporal lobe