2. What is ECT
• ECT- Application of electric current to the
head with the aim of inducing a controlled
tonic-clonic seizure, usually at regular
intervals, to achieve an improvement in an
abnormal mental state.
• Modified ECT- Induction of cerebral
seizure under anaesthesia.
• Unmodified ECT- Induction of cerebral
seizure without anaesthesia.
3. History
• In 16th century, the
Swiss alchemist
Paracelsus gave
camphor by mouth to
induce convulsions and
“cure lunacy.”
• In 18th & 19th century,
several cases of
convulsions induced by
chemical means were
documented.
4. History
• Manfred Sakel was the
developer of insulin
shock therapy.
• He noted that insulininduced coma and
convulsions had a change
in the mental state of
drug addicts and
psychotics.
• Complications were high.
5. History
• In 1934, Lazlo Meduna, a
Hungarian psychiatrist,
injected camphor in oil
into a catatonic
schizophrenia, causing
grand mal seizure.
• After series of such
treatments pts recovered.
• Later Camphor was
replaced by
pentylenetetrazol.
6. History
• Pentylenetetrazol
caused lot of
unpleasant
sensations.
• The concept of
applying electricity
was developed.
• Swiss scientists
induced seizures in
dogs using direct
electrical current.
7. Birth of ECT
• Italian scientists, Cerletti and Bini
subsequently succeeded in applying
electricity directly to the human scalp.
• In 1938, they treated an unidentified
39-year-old man who was found
delusional in a train station.
• He recovered fully after 11 treatments
without adverse Effects.
9. Effects of ECT
• During ECT, brain imaging showsHypermetabolic state
– increases in cerebral blood flow (CBF).
– increase cerebral metabolic rate (CMR).
• Post-ictal state- functional suppression
– decreases in CBF.
– decrease in CMR.
• Also during & after ECT, there are δ waves
indicating reduction in neural activity.
10. Mechanism of action
• No “definitive theory” regarding the
mechanisms of action.
• Psychological theories- patient
expectation, placebo effects, forced
regression, and contribution of
retrograde amnesia to clinical response.
• These were proved to be incorrect.
11. Mechanism of action
• Biological theories- they are related to
ECT's anticonvulsant effects.
• These effects manifest during a course
of ECT.
• They include
–
–
–
–
progressive increases in seizure threshold.
progressive decrease in seizure duration.
increases in inhibitory neurotransmitters.
decreases in excitatory neurotransmitters.
12. Mechanism of action
• Recent studies– Transient induction of increased proinflammatory cytokines,
– Increased expression of brain-derived
neurotrophic factor (BDNF),
– Gene polymorphism,
– Enhanced activity in the GABAergic,
glutaminergic and dopaminergic systems,
– Enhance neurogenesis, synaptogenesis and
remodelling of synapses in hippocampus.
13. Electrical principles
• Waveforms
– Sine wave- more cognitive deficits
– Brief square wave- better efficacy & less
adverse effects.
• An adequate seizure is defined as
–
–
–
–
Motor seizure > 25 sec.
EEG seizure of 30-120 sec.
Rise of HR by > 50% during seizure.
Post-ictal rise in PRL.
14. Electrode placement
Bilateral
Unilateral
• Electrodes are placed
apart over each
hemisphere.
• More rapid therapeutic
response.
• Mc- Bitemporal,
Bifrontal.
• Both electrodes placed
apart over non dominant
hemisphere.
• Less marked cognitive
deficits.
• Mc- Right unilateral.
15. Electrode placement
• Bilateral- electrode
is placed 2.5 -4cm
above the midpoint
of line joining tragus
& lateral canthus.
• Unilateral- another
electrode at vertex.