Anxiety Flashcards
What are the syptoms o anxiety
- Palpitations
- Sweating
- Trembling or shaking
- Dry mouth
- Difficulty breathing
- Chest pain or discomfort
- Nausea or abdominal distress (e.g. butterflies in stomach) • Feeling dizzy, unsteady, faint or light-headed
What are the systems involved in the street respons
- limbic system
2. limbic-hypothalamo-pituitary- adrenal axis
What is the limbic system
Ss Hippocampal formation (hippocampus, dentate gyrus, parts of parahippocampal gyrus)
Septal area Amygdala
+/-
Prefrontal cortex Cingulate gyrus
What is the hippocampus
Curved piece of cortex
Folded into medial surface of temporal lobe
Occupies floor of temporal horn of lateral ventricle
Three parts: subiculum, hippocampus proper, dentate gyrus
Involved in memory and expressions of emotion
How does the hippocampus fucntion?
o Receives inputs from many parts of the cortex and processes their emotional content
o Ultimately projects to the thalamus(and hence back to
the cortex – the Papez circuit) and also to the hypothalamus (causing autonomic features of emotional responses, since the hypothalamus send projections down through the cord to autonomic preganglionic neurones – the hypothalamospinal tract. This will lead to sympathetic nervous system activation, as well as release of adrenaline from the adrenal medulla – the acute stress response)
o Role in memory – already discussed
Papez circuit may be involved in memory consolidation
What is the amygdala
Almond shaped structure sitting near to tip of hippocampus, Buried in the roof of lateral ventricle
Collection of nuclei
Inputs of sensory information, brainstem, thalamus, cortex
Outputs to cortex, brainstem and hypothalamus
Drive related behaviours and processing of associated autonomic emotional responses
What is the role of the prefrontal cortex in aniety
• Prefrontal cortex (classically not part of the limbic system but
definite roles in emotion)
o Modulation of emotional responses (e.g. consciously
suppressing features of anxiety) o ‘Perception’ of emotion?
What are the endocrine elements of the stress response
Endocrine elements of the stress response
• The limbic system is able to act on the hypothalamus to
stimulate the secretion of stress hormones
o Via the familiar hypothalamo-pituitary-adrenal axis
o Release of cortisol from the adrenal cortex is part of the ‘chronic’ stress response
What is the general adaptation syndrome
The general adaptation syndrome refers to three stages that the body goes through during prolonged exposure to stressors
o Stage 1: The alarm reaction
Release of adrenaline and cortisol as well as sympathetic activation
(described above)
o Stage 2: Resistance (effect of adrenaline starts to wear off)
Chronic stress response, prolonged release of cortisol
o Stage 3: Exhaustion (when you cannot escape an ongoing stressor)
Chronic side effects of prolonged cortisol secretion start to occur o The stress response can become pathological when you cannot escape a
stressor(s), or when ‘trivial’ stressors elicit a strong stress response. However, patients with anxiety disorders may go through all of the stages above
What is the classification of anxiety disorders
Anxiety disorders o Classification Social phobia • Anxiety about being in social situations Specific phobias • Spiders, heights etc Generalised anxiety disorder • Persistent anxiety about a variety of things Panic disorder • Recurrent, unexpected panic attacks (severe episodes of acute stress response) Obsessive compulsive disorder (OCD) Post-traumatic stress disorder (PTSD)
Describe the pathophysiology of anxiety
Pathophysiology
Unclear
Equivocal findings in studies of brain activation patterns
GABA levels appear to be low in some anxiety disorders (maybe
explaining action of benzodiazepines)
Increasing serotonin levels can help treat anxiety disorders
(mechanism unclear, but hippocampus may be involved)
What are the treatment options for anxiety
Treatment Biological • Short term benzodiazepines • SSRIs Psychological • Cognitive behavioural therapy o Getting patients to reflect on their feelings/thoughts/behaviours • Support groups, charities etc
What os GABA
- GABA is the main inhibitory neurotransmitter
- GABA levels are decreased in cortex in patients with panic disorder • Benzodiazepines increase GABA transmission so reduce anxiety
What are benzodiazepines
• Benzodiazepines increase GABA transmission so reduce anxiety
But very addictive - instantly feel better. Or can build up tolerance over time. Dont withdraw suddenly bc withdrawal symptoms
Describe Ssris in aniety
- Increased levels of serotonin (due to SSRIs) may stimulate serotonin receptors in hippocampus
- Leads to neuroprotection, neurogenesis and reduction of anxiety