Transcript Deep Brain Stimulation for Psychiatric Disorders

Deep Brain Stimulation for
Psychiatric Disorders
JAHDIEL FRANCO
BME 482
What is DBS?
 A surgically implanted
medical device called a
brain pacemaker.
 Sends electrical impulses
to the brain.
 Traditionally used to
treat movement
disorders such as chronic
pain, Parkinson’s
disease, tremor, and
dystonia.
Components
Three Major Components
 Implanted pulse generator (IPG)

battery-powered neurostimulator
encased in a titanium housing, which
sends electrical pulses to the brain to
interfere with neural activity at the
target site
 Lead

coiled wire insulated in polyurethane
with four platinum iridium electrodes
and is placed in one of three areas of
the brain
 Extension

insulated wire that runs from the head,
down the side of the neck, behind the
ear to the IPG, which is placed
subcutaneously below the clavicle or in
some cases, the abdomen
How DBS affects the Brain
 DBS directly changes




brain activity in a
controlled manner
It’s effects are reversible
Often kicks in only after
a number of weeks for
psychiatric disorders
This phenomenon
cannot be wholly
explained by a directly
inhibiting mechanism
Not yet fully understood
Procedure
 All three components are
surgically implanted into
the body
 A hole about 14mm is
drilled in the skull and the
electrode inserted under
local anesthesia
 IPG and lead installed
under general anesthesia
 Lead is placed in one of
three areas of the brain
depending on patient
condition
Cost and Recovery Time
 Costs about $30,000 plus physician and MRI fees
 Typically covered by insurance with doctor’s




recommendation
Patients typically go home the next day after the lead
implantation surgery
After surgery, swelling of the brain tissue, mild
disorientation and sleepiness are normal
After 2–4 weeks, there is a follow-up to remove sutures,
turn on the neurostimulator and program it
The batteries in the pulse generator must be replaced
every three to five years

done with a small incision as an outpatient procedure
Relation to Psychiatric Disorders
 Psychiatric adverse effects
were observed in DBStreated Parkinson’s disease
patients.
 Modern knowledge of
psychiatric disease, due to
modern brain imaging
procedures, allows for
identification of potential
stimulation sites for DBS.
 Being studies for treatment
of Tourette’s, OCD, and
depressive disorders
Psychiatric Disorders
 Tourette’s Syndrome

chronic but often fluctuating occurrence of vocal (throat clearing,
coughing, coprolalia) and motor (blinking, grimacing, jumping) tics
 Obsessive-Compulsive Disorder

mental disorder characterized by intrusive thoughts that produce
anxiety, by repetitive behaviors aimed at reducing anxiety, or by
combinations of such thoughts (obsessions) and behaviors
(compulsions)
 Major Depression Disorder

mental disorder characterized by an all-encompassing low mood
accompanied by low self-esteem, and loss of interest or pleasure in
normally enjoyable activities
Statistics of Psychiatric Disorders
 Tourette’s, OCD, and
depressive disorders
affect about 17 million
people in the US alone
(7.7% of population)
 Depressive disorder is
the leading cause of
disability in the US for
ages 15-44 (14.8 million
affected in US)
Tourette’s Syndrome Study
 In 2007, the Neurosurgical Division of Istituto Galeazzi
IRCCS in Italy performed a study on 18 patients
 The greatest experience in the DBS treatment has been
assembled in the thalamus—the internal ventro-oral
nucleus, centromedian nucleus, and parafascicular
nucleus
 The average improvement rate for tic symptoms was
around 70%, as measured using the most frequently
employed scale, the Yale Global Tic Severity Scale
(YGTSS)
 The 24-month results of 15 of the 18 patients,
documented continued amelioration of the symptoms
Other Tourette’s Syndrome Studies
Obsessive-Compulsive Disorder Study
 In 2006, a study in Korea performed a study on 17
patients
 Patients underwent stereotactic bilateral anterior
cingulotomies and were followed for 24 months

surgical procedure is the severing of the supracallosal fibres of
the cingulum bundle
 The mean improvement rate of the Y-BOCS score
achieved from the baseline was 48%
 Study allowed for identification of possible DBS sites
Other OCD Studies
Depressive Disorder Study
 In 2008, a study in Ontario, Canada was performed
on 6 patients
 The subgenual cingulum was the target area for DBS
 In four of six patients with otherwise refractory
depression DBS achieved clear relief of symptoms
after 6 months
 There was an average 71% reduction in score on the
Hamilton Rating Scale for Depression (HAM-D)
Other Depressive Disorder Studies
Side Effects of DBS
 possibility of
 Apathy
 Hallucinations
 Compulsive gambling
 Hypersexuality
 Cognitive dysfunction
 Depression
 These are temporary and
related to correct
placement and calibration
of the stimulator and so are
potentially reversible
 Because the brain can shift
slightly during surgery,
there is the possibility that
the electrodes can become
displaced or dislodged

May cause more profound
complications such as
personality changes
 Electrode misplacement is
relatively easy to identify
using CT or MRI
 Complications of surgery
include bleeding within the
brain
Conclusion
 The results of DBS for
psychiatric disorders that
have been published to
date are encouraging
 They open up a new
perspective in the
treatment of otherwise
intractable disorders.
 The efficacy, mechanism of
action, and adverse effects
of DBS for this indication
still need to be further
studied