DrBruceBomans ECT for 20 century

 Uses a protocol Of increasing electrical stimuli  To determine the lowest electrical stimulus which will generate  A generalised seizure in that patient  This electrical stimulus

Bruce Boman Director of Training South West Sydney Psychiatry Training Network

 How is ECT administered in Australia?

 Are there irreversible cognitive

impairments resulting from ECT?

 What new techniques are available for minimising cognitive impairments?

 What experimental techniques are

being trialled in convulsive therapy?

How is ECT administered

in Australia?

ECT is administered either in operating

theatre recovery rooms, operating theatres

or in specialised ECT suites set up like an operating theatre recovery room

 The following monitoring equipment is applied:

Anaesthetic monitor

EEG monitor on ECT apparatus

 The psychiatrist applies the ECT stimulus electrodes

 Uses a protocol

 Of increasing electrical stimuli

 To determine the lowest electrical stimulus which will generate

 A generalised seizure in that patient

 This electrical stimulus is called the

 The patient is still paralysed

 And needs to be oxygenated by the anaesthetist

 Till begins to breathe spontaneously

 To be effective a bitemporal stimulus

needs to be just a little above seizure threshold

 But for a right unilateral stimulus to be effective it needs to be between 3 and

6 times seizure threshold

 This is what patients find most

distressing

 Not being able to recall important

events in their life before the course of ECT

 ECT can result in retrograde amnesia

demonstrated on psychometric testing six months after completion course of

ECT in community settings,

Neuropsychopharmacology, 2007)

 Associated with: bitemporal electrode placement high stimulus level sine wave stimulus

Six months post ECT

 Is there anything else we can do to minimise ECT related cognitive

impairments?

 Let me tell you about a new form of ECT & how it came about

The most efficient electrical

stimulus to depolarise a neuron has a pulse width between

0.1 & 0.2 msec

Now I want you to remember high school physics

This is the electrical current that

comes out of here

This is the electrical stimulus that is delivered from here

Normally set at

1 msec

 You can markedly reduce the size of

the electrical stimulus needed to

generate a seizure

 Or in other words you have a markedly reduced seizure threshold

Seizure

threshold

milicoulombs

 You would expect to have much less cognitive impairment

 So the patients who have had 0.3 msec pulse ECT have no

detectable change in their ability to

remember past events compared with people who have not had ECT

Healthy

Controls

RUL 0.3 msec pulse

RUL1 msec pulsef

 Despite good

efficacy, 0.3 msec right unilateral

ECT has less

intense EEG

seizure activity

Right 99

Left

102

Right 94

Computational modelling

electric field

generated by FEAST &

standard ECT stimulus

electrode

placements

Lee et al, 2012

 If you place a coil in a

changing

magnetic field then you’ll

induce an

electric current

 If you send an electric current through

a coil then you’ll generate a magnetic field

 And putting it all together

Current in coil from capacitator

Transcranial magnetic stimulation (TMS)

Harold Sackeim & Holly Lisanby then had the bright idea

of linking up a

whole bunch of

TMS machines like this array in their lab at the NY State Institute of

Psychiatry

depolarize enough

neurons to

 Trigger a seizure

 .

 Increased blood flow fronto

parietal

cortex & basal

ganglia

 Pretty much same as ECT

 General anaesthetic

 Muscle relaxant

 Oxygenation

 Titrate seizure threshold

 Performed 3 times a week