Surgery for Psychiatric Disorder Flashcards
In anorexia nervosa, which one of the follow- ing surgical targets has been most used?
a. Anterior nucleus of thalamus
b. Hypothalamus
c. Inferior thalamic peduncle
d. Subgenual anterior cingulate
e. Subthalamic nucleus
d. Subgenual anterior cingulate
A number of small recent studies have described the possible use of DBS in the treatment of anorexia nervosa and associated mood include sub- genual anterior cingulate and nucleus accumbens
In Alzheimer’s disease, which one of the fol- lowing targets for deep brain stimulation has shown promise?
a. Caudate
b. Fornix
c. Globus pallidus externa
d. Hippocampus
e. Nucleus accumbens
b. Fornix
The two targets being investigated clinically that hold promise for dementias are the fornix for Alz- heimer’s disease, and the nucleus basalis of Mey- nert for dementia with Lewy bodies.
Circuit pathophysiology in OCD has been localized to which one of the following?
a. Corticoreticular circuit
b. Corticostriatal-thalamocortical circuit
c. Nigro-striatal circuit
d. Nigro-pallidal circuit
e. Thalamocortical circuit
b. Corticostriatal-thalamocortical circuit
Functional neuroimaging studies have implicated corticostriatal-thalamocortical circuitry in the pathophysiology of OCD. More specifically, in patients with OCD, there is abnormal (predom- inately increased) metabolic activity in the orbito- frontal cortex (OFC), the anterior cingulate cortex (ACC), medial prefrontal cortex and the caudate nucleus, particularly its ventral division. OFC and caudate hyperactivity are directly correlated with symptom severity, and these changes partially normalize with successful treatment.
Targets for deep brain stimulation for obsessive-compulsive disorder do not include which one of the following?
a. Anterior limb of the internal capsule
b. Centromedian-parafascicular nucleus of thalamus
c. Inferior thalamic peduncle
d. Subthalamic nucleus
e. Ventral capsule/ventral striatum
b. Centromedian-parafascicular nucleus of thalamus
OCD has a prevalence of 1-3% of the population and is characterized by recurrent, intrusive anx- ious thoughts (obsessions) accompanied by repetitive stereotyped behaviors or mental rou- tines (compulsions) that are frequently per- formed in an effort to reduce distress caused by obsessions. These can significantly hinder interpersonal relationships, social and occupa- tional functioning, and the ability to carry out basic activities of daily living; it is associated with a higher lifetime risk of suicide (up to 27% of patients), as well as major depression. Treatment for OCD typically involves pharmacotherapy (e.g. selective serotonin reuptake inhibitors) which is often combined with psychotherapy (e.g. cognitive behavioral therapy/exposure and response prevention). Up to half of OCD patients do not obtain adequate benefit with standard treatment approaches, and approxi- mately 10% experience severe treatment- refractory symptoms. Identification of DBS tar- gets for OCD has been based on a combination of experience from lesional psychosurgery pro- cedures, following observations of response to surgery for other conditions (e.g. STN DBS for PD) as well as gradual target refinement fol- lowing ongoing evaluation of clinical outcomes in relation to lead location. The neuroanatomi- cal targets used for DBS in the treatment of OCD have included the anterior limb of the internal capsule, nucleus accumbens, ventral capsule/ventral striatum, STN, and the inferior thalamic peduncle.
Which one of the following targets is not currently used in deep brain stimulation for treatment-resistant depression?
a. Anterior limb of the internal capsule
b. Nucleus accumbens
c. Subgenual anterior cingulate
d. Subthalamic nucleus
e. Ventral capsule/ventral striatum
d. Subthalamic nucleus
Depression is extremely common with a lifetime prevalence of 15-20%, with 30% of patients not responding to standard medications or psychotherapy. The management of treatment-resistant depression includes repeated trials of medication, psychotherapy, and forms of brain stimulation (transcranial magnetic stimulation and electrocon- vulsive therapy). However, there is a significant subgroup of patients (10-20%) who remain chron- ically treatment refractory, and relapse and devel- opment of resistance to ECT also poses problems. Targets for DBS applications in depres- sion have been proposed based on (a) extrapolation from sites targeted in lesional psychosurgical procedures and (b) from the results of neuroimag- ing experiments. The majority of research to date has focused on DBS implantation in the white mat- ter adjacent to the subgenual anterior cingulate and
on stimulation of the anterior limb of the internal capsule and the associated ventral capsule/ventral striatum (including the nucleus accumbens). Less commonly described targets include superolateral branch of the median forebrain bundle, inferior thalamic peduncle, and lateral habenula.
Anterior cingulotomy involves which one of the following?
a. Bilateral burr holes and thermocoagulation
b. Parasagittal approach to cingulate gyrus
c. Division of fibers connecting the orbital
cortex to subcortical and limbic areas
d. Exclusion of obsessive-compulsive symp-
toms preoperatively
e. The target site for the lesion is 20-25 mm
posterior to the anterior horn of the lateral ventricles, 7 mm from the midline and 20 mm above corpus callosum.
a. Bilateral burr holes and thermocoagulation
Which one of the following components is LEAST important in the mechanism of vagal nerve stimulation for treatment-refractory depression is most accurate?
a. Amygdala
b. Hippocampus
c. Locus coereleus
d. Prefrontal cortex
e. Red nucleus
e. Red nucleus
Vagus nerve stimulation has become established for treatment-resistant, partial-onset seizure dis- order. The vagus nerve is not only a parasympa- thetic efferent nerve—around 80% of its fibers are afferent sensory fibers transmitting informa- tion to the brain. There are sensory afferent con- nections of the vagus nerve in the nucleus tractus solitarius that, in turn, send ascending projec- tions to the forebrain, mainly through the para- brachial nucleus and locus ceruleus. Further connections offer potential routes of communi- cation with the amygdala, hippocampus, hypo- thalamus, insular cortex, dorsal thalamus, orbitofrontal cortex, and other important limbic regions linked to mood regulation. The initial rationale for using VNS for the treatment of refractory depression resulted from mood improvements in epilepsy patients treated with VNS, irrespective of the presence or absence of beneficial effects on seizure frequency. VNS demonstrated steadily increasing improvement of depressive symptoms with full benefit after 6-12 months, sustained for up to 2 years. These studies reported response rates of 30-40% and remission rates of 15-17% after 3-24 months of treatment. Preclinical animal studies may sug- gest that VNS exerts its antidepressant effects through a rapid increase in the concentration of the monoamines, which then enhance neuro- nal plasticity/neurogenesis in the hippocampus. Newborn cells could then functionally integrate and restore the disturbed corticolimbic networks in depressed patients, and may explain the ther- apeutic lag of VNS in the treatment of depression.
Which one of the following statements regarding indications for lesional neurosurgical procedures for mental disorder is most accurate?
a. Cerebrovascular disease and pre-existing epilepsy are absolute contraindications
b. Patients can be treated in their best inter- ests with neurosurgery for mental disorder
c. Used occasionally to control affective or obsessional symptoms due to active organic or degenerative brain disease
d. Can be considered in personality disorder and schizophrenia if the aim of the surgery is restricted to chronic intractable affective or obsessional comorbid symptoms
e. Not currently performed in a multidisci- plinary team setting
d. Can be considered in personality disorder and schizophrenia if the aim of the sur- gery is restricted to chronic intractable affective or obsessional comorbid symptoms
Neurosurgery for mental disorder has suffered historically from relatively “crude” lesional pro- cedures (e.g. anterior cingulotomy, limbic leucot- omy, subcaudate tractotomy), and a lack of rigorous investigation regarding both effective- ness and adverse effects on personality and cogni- tion. Inclusion criteria are a secure diagnosis and the ability to provide informed consent. In all cases, such surgery can only be offered following careful and detailed consideration of the potential costs and benefits to the individual on a case-by- case basis by the multidisciplinary team. Obvious contraindications include patients with affective or obsessional symptoms due to active organic or degenerative brain disease, or where pervasive developmental disorder is likely (although cere- brovascular disease or pre-existing epilepsy is not an absolute contraindication). There is no evidence that personality disorders, anorexia ner- vosa, or schizophrenia respond to lesional neuro- surgery and these patients should not be considered unless the aim of the surgery is restricted to chronic intractable affective or obsessional comorbid symptoms. Difficulties can arise in determining the suitability of patients where illness onset was at a sufficiently early age to have had an adverse impact on personality development. Neurosurgery for mental disorder is contraindicated if the patient is not fit for sur- gery because of a tendency to bleed, local infec- tion, or a high anesthetic risk.
