EEG

DR MANDAR HAVAL

• EEG is about pattern recognition

• ECG is about precision

EEG – systematic approach

• Minimal technical requirements

• 16 channels• Atleast 3 montages• Longitudinal bipolar, horizontal bipolar, referential• Atleast 20 min recording and in neonates 1 hour

International 10-20 system of Electrode placement

Montages

Bipolar: the potential difference between 2 active electrodes

Referential: potential difference between 1 active and 1 inactive electrode

EEG- what to look at?

• Background

• Activity – rhythmic, arhythmic, periodic

• Evolution of the rhythm

EEG- describing the waves

• Frequency :delta(0-4hz), theta(4-8hz), alpha(8-13hz), beta(>13 hz)

• Amplitude: low(<25 uv), moderate(25-75uv), high(>75uv)

• Location• Symmetry• Synchrony• Reactivity• Rhythmic, periodic, arhythmic• Morphology (spike, sharp, biphasic, triphasic)

Normal EEG in a child

Normal EEG in adult

Spike and wave complex

Case 1

• 10 year old girl• Developmentally normal• Slight deterioration in school performance last

2 months• Multiple episodes of brief staring 5 -10 sec• No loss of tone• Examination normal

EEG

Absence seizure

• Onset 4-10 yrs• Hundreds per day; 4-20 secs• Eyes open, voluntary activity stops

• EEG – 3per sec spike wave activity. Ppt by hyperventilation

• Drug of choice – ethosuxamide/ valproate/ lamotrigine

Case 2

• 5 month male• HIE stage 2 at birth

• Clusters of sudden tonic flexion of entire body several times in a day, especially on awakening - 2 weeks

Diagnosis?

West syndrome

• Infantile spasms with hypsarrythmia

• EEG – chaotic• High amplitude, multifocal spikes and

polyspikes, asynchronous, arrrhythmic

• Drugs of choice- ACTH/ steroids

Case 4

• 7 year old boy

• Nocturnal seizure, jerky movements of the lips, eyes wide open, unable to sleep, hypersalivation

BECTS- benign childhood epilepsy with centro-temporal spikes (Rolandic epilepsy)

• Onset 1-14 yrs• Unilateral facial sensorimotor seizures• Hypersalivation• Speech arrest• Oropharyngeal manifestations

• Prognosis- most remit in 2-4 yrs• Treatment- nil/ CMZ/LVT

Case 4

• 8 year old boy• h/o delayed milestones – walking 2 yrs,

speech 3 years• Multiple types of seizures several times a day

– 2 months• Tonic seizures, atonic falls, myoclonic seizures• Regression of milestones

EEG

EEG of Lennox Gastaut Syndrome

• Background – slow and disorganised

• Slow generalized spike wave ( < 2.5 cps)• Multiple independent spike foci• Very fast ( 10-20 cps) paroxysmal activity s/o

tonic seizures

Management of LGS

• Multiple anti epileptic drugs• Poor response• Non AED’s- IVIG, steroids, ketogenic diet• Surgery – corpus callosotomy

Case 5

• 4 year old girl• Fever & recurrent focal seizures – 2 days• Comes in status epilepticus• Seizures stop after lorazepam and phenytoin• Patient remains comatose > 24 hours after all

motor seizures have stopped.

EEG

EEG of NCSE (non convulsive status epilepticus)

• Spikes, waves, rhythmic activity• Focal or partial features, discrete or

continuous• Cyclic or recurrent patterns• May correlate with changes in behaviour and

responsiveness• Significant improvement in discharges and

sensorium on giving IV anti epileptics

Case 7

• 11 year old boy• Cognitive decline last 6 months• Repetitive extensor myoclonus last 1 month• Stopped walking, speaking, swallowing last 15

days• Past h/o measles at 3 years

EEG

SSPE

• EEG: stereotyped, generalized and synchronous high amplitude periodic complexes

• Diagnosis: Elevated CSF anti measles antibodies

• Prognosis: grim

• 8 mts old female child with delayed development milestones flexor spasm EEG done.

• Describe characteristic EEG findings• What is diagnosis?• What is T/t?• Which type having the good prognosis?

04/12/2023 55CME,Pune

• Hppsarrythmia• Infartile spasms• ACTH and glucocorticoids• Cryptogenic infantile spasms

04/12/2023 56CME,Pune

12.Child with fever , convulsions, altered sensorium

CSF picture : protein 62, cells 95 P10 L90, sugars 45/80, RBCs 80/ hpf• Additional 2 investigations of choice• Treatment with dose

• EEG - PLEDS-periodic lateralizing epileptiform discharges

• HSV PCR,( ? HSV IgG, IgM ), CT scan / MRI with contrast – bi/ uni temporal hyperintensities

• Acyclovir 10mg/kg/dose 8 hrly for 14 -21 days

6) What does this EEG show?

• What is the drug of choice?

• Prognosis?

• One OPD procedure to confirm diagnosis

• 3 Hz spike and wave activity in Absence seizure – childhood /Juvenile

• Valproate, Lamotrigine, clobazam

• Good in childhood, slightly less for juvenile

• Hyperventilation

Jerk jerk

7) Diagnosis

• Confirmatory test

• 3 therapeutic options

• SSPE –burst suppression pattern

• CSF measles IgG

• Ribavarine, interferons, inosiplex, amantidine

8) Diagnosis

• Commonest etiology

• Drug of choice

• PLEDS• Herpes encephalitis• Acyclovir

9) 6 yr old male admitted with prolonged generalised seizures.

• Immediate AEDs –name 2 with dose• 2nd line AEDs –2 with dose• 3rd line – name 2

• Lorazepam [0.05mg/kg], • Diazepam [0.3mg/kg],• midazolam[ 0.2mg/kg]

• Phenytoin[ 20mg/kg],• phenobarb[20/kg]

• Midazolam drip,• propofol,• thiopentol

10) 6 months old child with h/o perinatal insult comes with regression of social milestones and clusters of startles on awakening .

• Diagnosis• Name 2 investigations you will ask for?

• Infantile spasms, West syndrome• EEG, MRI• Hypsarrhythmia• ACTH / steroids, Vigabatrin, Valproate

/Topiramate / Nitrazepam

• Station No : A term newborn who required resuscitation at birth with a 5 minute APGAR of 5 is admitted in NICU. The neonate had seizures in first 12 hrs of life

• Identify the findings-[1]

• What is the significance of this finding- [1/2]

• Name of the staging system other than Sarnat and Sarnat and

give its component- [1]

• EEG of neonate showing Burst Suppression

pattern

• It indicates serious outcome in HIE patients

• Levene’s staging system (Mild, Moderate and

Severe)– Consciousness

– Tone

– Seizures

– Sucking/Respiration