EEG patterns Flashcards
Antipsychotics
-slowing of beta activity with increase in alpha, theta and delta activity
Antidepressants
-slowing of beta activity with increase in alpha, theta and delta activity
Lithium
-slowing of alpha or paroxysmal activity
Anticonvulsants
-no effect on awake EEG
Benzos
- increased beta
- decreased alpha
- overdose leads to diffuse slowing
opioids
- decreased alpha
- increased voltage of theta and delta
- in overdose slow waves are seen
Barbiturates
- effects are opposite to that of alcohol
- increased beta activity
- spikes in withdrawal
Alcohol
- increased alpha
- increased theta activity
- withdrawal increases beta
- beta are fast in DTs
Marijuana
- increased alpha activity in frontal area of brain
- overall slow alpha activity
Cocaine
-Same as marijuana; longer lasting
Nicotine
-increased alpha activity, in withdrawal marked decrease in alpha activity
Caffeine
-withdrawal causes increase in amplitude or voltage of theta activity
Absence seizures
-regular 3 Hz complexes
Alzheimers
-rarely normal in advanced dementia
Angelman’s syndrome
-prolonged runs of 2-3hz frontal activity
Antisocial personality disorder
-increased incidence of abnormal EEGs in those with aggressive behaviour
ADHD
-up to 60% have EEG abnormalities (spike/spike waves)
Borderline personality disorder
-positive spikes in 25%
CJD
- generalised periodic 1-2Hz sharp waves seen in nearly 90% patients with sporadic CJD
- not seen in variant or familiar
Closed head injuries
- focal slowing
- focal delta slowing
Diffuse atherosclerosis
-slowed alpha frequency and increased generalised theta slowing
Herpes simplex encephalitis
-episodic discharges are recurring every 1-3 seconds with variable focal waves over the temporal areas
Huntingtons
- initial loss of alpha
- latter flattened trace
Infantile spasms
- seen in tuberous sclerosis
- hypsarrhythmia (diffuse giant waves) with chaotic background of irregular, asynchronous multifocal spikes and sharp waves
- clinical seizures are associated with a marked suppression of the background- called the electrodecremental response
Infectious disorders
-diffuse, often synchronous, high voltage slowing
Metabolic and endocrine disorders
- diffuse generalised slowing
- triphasic waves 1.5-3.0 per second high-voltage slow-waves especially in hepatic encephalopathy
Neurosyphilis
-non-specific increase in slow waves occurring diffusely over the scalp
Panic disorder
- paroxysmal EEG changes consistent with partial seizure activity in one third
- focal slowing in about 25% of patients
Seizures
-generalised, hemispheric or focal spike/spike wave discharge
Stroke
-focal or regional delta activity
Structural lesions
-focal slowing/focal spike activity
