Anxiety, OCD Flashcards
What is the stress response made up of?
Limbic system
Limbic-hypothalamo-pituitary-adrenal axis
What is the limbic system made up of?
Hippocampal formation
Amygdala
Prefrontal cortex
What is the hippocampus?
Curved piece of cortex
Where is the hippocampus located?
Medial surface of temporal lobe
How does the hippocampus relate to the ventricular system?
Floor to temporal horn of lateral ventricle
What are the parts of the hippocampus?
Subiculum
Hippocampus proper
Dentate gyrus
What is the amygdala?
Collection of nuclei
Where is the amygdala located?
Roof of lateral ventricle
What are the inputs to the amygdala?
Sensory information
Brainstem
Thalamus
Cortex
What are the outputs of the amygdala?
Brainstem
Hypothalamus
Cortex
What are the functions of the amygdala?
Drive related behaviours, processing of associated emotions
What are the functions of the prefrontal cortex?
Modulators effect on processes associated with the hypothalamus
What does a prolonged stress response cause?
Continued cortisol secretion
- muscle wastage
- suppression of immune system
- hyperglycaemia
What is anxiety?
Feeling of nervousness or unease about something with an uncertain outcome
What are the signs and symptoms of anxiety?
Palpitations
Sweating
Trembling
Dry mouth
Nausea
Dizziness, light-headedness
Difficulty breathing
What are the types of anxiety disorders?
Generalised anxiety disorder
Panic disorder
Phobias
Obsessive compulsive disorder
Post-traumatic stress disorder
What is the pathophysiology of anxiety?
GABA levels decreased in cortex in patients with panic disorder
How is anxiety treated?
Selective serotonin reuptake inhibitors
Pregabalin
Cognitive behavioural therapy
How do selective serotonin reuptake inhibitors treat anxiety?
Increased levels of serotonin
Increased stimulation of serotonin receptors in hippocampus
Leads to neuroprotection
What is neuroprotection?
Refers to a preservation of neuronal structure and function
How does cognitive behavioural therapy treat anxiety?
Look at trigger, thoughts, emotions, behavioural and physical reaction of patient’s anxiety together with the patient
How does pregabalin treat anxiety?
Pregabalin is a GABA analogue
Increased stimulation of GABA receptors in the cortex
Increased inhibition of neurones
Why are benzodiazepines not used to treat anxiety?
Addictive, dangerous in overdose
What are the functions of the hippocampus?
Memory
Expressions of emotion
What is an obsession?
Thought that persists and dominates an individual’s thinking
Even though they are aware that the thought is entirely without purpose, or is beyond the point of relevance and usefulness
What is a compulsion?
Obsessional motor acts
Obsessional mental acts
What causes a compulsion?
Obsessional impulses that lead directly to the action
Obsessional mental image that leads to the action
How is OCD diagnosed?
Obsessions or compulsions or both present on most days, for at least 2 weeks
Obsessions and compulsions
- originate in mind of patient
- repetitive
- acknowledged as unreasonable
- unpleasant
- patient tries to resist, but unsuccessful
Interfere with patient’s individual or social functioning
What age group is OCD most common in?
Younger people, before age 30
What sex is OCD more common in?
In adults, equally common in men and women
In children, more common in boys
What is the pathophysiology of OCD?
Re-entry circuits in basal ganglia
Reduced serotonin
Paediatric autoimmune neuropsychiatric disorder associated with streptococcal infection PANDAS
How does PANDAS present?
Sudden onset of OCD symptoms as well as other psychiatric symptoms after infection with Group A beta-haemolytic strep
What is the pathophysiology of PANDAS?
Antibodies cross-react with neurons in basal ganglia
How is OCD treated?
Cognitive behavioural therapy
Selective serotonin reuptake inhibitors, high dose and longer treatment course
Antipsychotics
Deep brain stimulation
How does cognitive behavioural therapy treat OCD?
Exposure response prevention, meaning the patient learns to resist the compulsion after their obsessional thoughts
What antipsychotic drug is used to treat OCD?
Clomipramine
What is post-traumatic stress disorder?
After a severely traumatic event
Repetitive recollection of the event in memories, daydreaming, dreaming
Avoiding stimuli that might arouse recollection of the event
What is the timing of PTSD?
Within 6 months of the severely traumatic event
When is deep brain stimulation used to treat OCD?
OCD that has been resistant to other methods of treatment
How is PTSD treated?
Selective serotonin reuptake inhibitors
Pregabalin
Cognitive behavioural therapy
Eye movement desensitisation reprocessing
What is eye movement desensitisation reprocessing?
Patient follows visual stimulus while recollecting event
To distract brain
What is the pathophysiology of PTSD?
Hyperactivity of amygdala, causing exaggerated stress response to perceived threat
However low levels of cortisol, more recollection of event
