Psychological medicine week 3 Flashcards
.Lateral ventricles, 3rd ventricle, cerebral aqueduct, fourth ventricle
The ventricles of the brain are a communicating network of cavities filled with cerebrospinal fluid (CSF) and located within the brain parenchyma. The ventricular system is composed of 2 lateral ventricles, the third ventricle, the cerebral aqueduct, and the fourth ventricle (see the images below). The choroid plexuses are located in the ventricles produce CSF, which fills the ventricles and subarachnoid space, following a cycle of constant production and reabsorption.
Head of hen - third ventricle
Cerebral aqueduct : is the stick of the hammer
Hypothalamus
sits under the eye of the hen
Your hypothalamus, a structure deep in your brain, acts as your body’s smart control coordinating center. Its main function is to keep your body in a stable state called homeostasis
Thalamus
sits ontop of the eye of the hen
- Your thalamus is your body’s information relay station. All information from your body’s senses (except smell) must be processed through your thalamus before being sent to your brain’s cerebral cortex for interpretation. Your thalamus also plays a role in sleep, wakefulness, consciousness, learning and memory
corpus callosum
corpus callosum, bundle of nerve fibres in the longitudinal fissure of the brain that enables corresponding regions of the left and right cerebral hemispheres to communicate.
Pineal body
right behind the wall of the third ventricle
- It’s a part of your endocrine system and secretes the hormone melatonin
Fornix
The fornix is a white matter bundle located in the mesial aspect of the cerebral hemispheres, which connects various nodes of a limbic circuitry and is believed to play a key role in cognition and episodic memory recall.
Coronal view of the brain
Interventricular foramen
Hole found between the thalamus and hypothalamus
Cerebral aqueduct
- It is located in the midbrain
- The cerebral aqueduct is a channel for cerebrospinal fluid (CSF) that connects the third ventricle to the fourth ventricle of the ventricular system of the brain
Lateral sulcus
separates the temporal from the frontal and parietal lobes
Superior and inferior frontal sulci
The superior and inferior sulci split the frontal lobe into the superior frontal gyri, middle frontal gyri and inferior frontal gyri.
Opercular and triangular parts of the inferior frontal gyrus
Opercular and triangular parts of the inferior frontal gyrus
The pars triangularis refers to the triangular shaped cortical region of the inferior frontal gyrus in the frontal lobe of the brain. It sits in between the more rostral pars orbitalis and caudal pars opercularis which altogether make up the inferior frontal gyrus. When coupled with the pars opercularis, the pars triangularis is most commonly associated with Broca’s area and is well known in its involvement in speech production.
The pars triangularis is often referred to by its functional and cytoarchitectural title of Brodmann’s area 45. In the dominant hemisphere, it is one of two regions that make up Broca’s area together with Brodmann’s area 44
Superior and inferior temporal sulci
The superior and inferior temporal sulci split the temporal lobe into the superior temporal gyri, middle temporal gyri and inferior temporal gyri
All of the gyri of the brain
Top: angular gyrus
Bottom: supra marginal gyri
Both of the parietal lobe
The parietal lobe has a superior and inferior parietal lobule
cingulate gyrus is ontop of the corpus callosum and ontop of that is the cingulate sulcus
underneath the cingulate gyrus you have the callosal sulci
Ontop of occipital lobe: Parieto-occipital sulcus
Below the occipital lobe: calcarine sulcus
What is the insula ?
The insula is a cortical region linked with salience detection, self-awareness, interoception, pain processing, and addiction
The parietal, temporal and frontal opercula cover the insula
The arterial supply to the brain comes via two separate pairs of vessels (internal carotid arteries and vertebral arteries) which have an elaborate anastomosis known as the Circle of Willis.
What is stress ?
Pressure’, ‘tension’, ‘body’s reaction to feeling threatened or under pressured’
An imbalance between the demands made on us and our personal resources to deal with these demands
Give examples of life events that contribute to stress ?
-work problems
-changes
- debts
-relationship difficulties (divorce, birth of a child
-family problems
-moving house
- examinations
-diagnosis of physical illness
Physical illnesses can also be linked to stress
Stress response can be broken down into 4 domains
:
- Emotion response:
feeling on edge, feeling sad, irritability, tearful, over-reacting - Cognitive Response:
difficulty concentrating, difficulty switching off, sensitive to criticism, self critical, difficulty making decisions - Behavioral Response:
comfort eating, loss of appetite, drink or smoke more, over activity and underactivity and disturbed sleep - Psychological Response-
increased heart rate, increased rate of breathing, increased perspiration and muscle tension
What are the key elements in CBT in hope of breaking the cycle of perpetuation ?
- Thoughts
- Emotions
- Behavior
- Physical sensations
Stress can increase already existing physical illnesses ?
- can increase relapse
- can increase morbidity
- you may have poorer control of the chronic disease
Stress can indirectly increase physical illnesses ?
- poorer compliance with medication
- increase alcohol intake - epilepsy/ Liver disease
- increase smoking- heart/respiratory disease
- Reduced exercise – heart disease
- Poor diet - diabetes
Stress can also directly increase physical illness ?
Why is cortisol bad? It is a stress horome. Its like a performance enhancing drug, great for short term bursts, but meant for long term use.
Cortisol – high blood pressure, heart disease, type 2 diabetes, osteoporosis, acne, moon face, and other chronic diseases. It causes Weight gain. anxiety and depression, lowers your libido shrinks your brain, thins your skin, and hampers your immunity system.
How does it do all that, because cortisol receptors are responsible for
blood sugar regulation
inflammation process regulation
metabolism regulation
memory formulation
Stress and heart disease ?
What is the association between stress and mental illness ?
Significant association between stressful life events and mental illness
In the 3-6 months preceding the onset of a depressive illness 50-80% patients will have experienced a significant life event compared to 20-30% of non depressed patients
Increased mortality rates – patients with chronic heart failure 8x more likely to die within 30 months if depression untreated. Patients with Type 2 diabetes and depression 2-3 x more likely to die over 5 years compared to patients not depressed
Increased morbidity associated with the physical health problem – treating the mental illness aids self management and rehabilitation
What determines how we react in the face of illness ?
Individual factors:
- Premorbid personality - worrier, obsessional
- Prior experience of illnesses
- Mental state e.g. depression. Chronic medical illness associated with increased levels of depression. Those who are depressed report more physical symptoms, are more disabled and are less likely to adhere to treatment and lifestyle recommendations
- Childhood difficulties e.g. early trauma/chaotic backgrounds, cope less well with difficult treatment regimes, difficult interactions with health professionals
-Appraisal and coping styles
What determines how we react in the face of illness ?
The actual illness:
- Is the illness immediately life threatening
- Uncontrollability - excess pain
- Ambiguity - regarding outcome/treatment
- Undesirability - unpleasant treatment regimes or disfiguring treatments
Coping strategies for when your ill ?
- Problem solving and Emotion focused coping
Problem solving:
-Seeking information
-Seeking support
-Learning new procedures and behaviours e.g. appropriate participation in treatment /lifestyle changes
-Identifying alternative rewards/new activities
-Developing a realistic action plan
Emotion focused coping:
-involves managing emotions and maintaining emotional equilibrium. Generally works well but only transiently. Best reserved for brief stresses or where nothing realistically can be done to modify the stress
-Emotional discharge – talking about the problem (fears, anger, despair)
-Making and maintaining supportive friendships
-Gaining emotional support from e.g religion
-Resigned acceptance – coming to terms with the inevitable
Define medically unexplained symptoms ?
Medically unexplained symptoms: Physical symptoms not explained by organic disease causing distress and impairing function
And for which there is positive evidence or a strong assumption that the symptoms are linked to psychological factors (stress/distress)
Medically unexplained symptoms is sometimes called functional symptoms overlay.
What is the sick role ?
- A role assigned to the patient by society and it has certain connotations. One is that their exempt from their usual or certain responsibilities. It gives the patient the right to expect help and seek care.
Sick role:
(1) exempts them from certain responsibilities
(2) gives them the right to expect help and seek care
(3) obligation to seek and co-operate with treatment
(4) the expectation of a desire to recover
What is illness behavior ?
Illness behaviour on the other hand, is how the patient internalises the meaning of being ill, and adjust their own behaviour
The ways in which given symptoms may be differentially perceived, evaluated and acted (or not acted) upon by the individual
Behaviours associated with the adjustment to physical or mental illness
The changes in behaviours may be appropriate or not
Give examples of two illness behavior’s which are inappropriate or maladaptive
- Illness denial: Behaviours to avoid the ‘stigma’/inability to accept physical/mental disease
- Illness affirmation:
Behaviours which inappropriately affirm illness
Disproportionate disability in relation to symptoms / signs
How is stress linked to medically unexplained symptoms ?
Some MUS may arise from ‘normal’ bodily sensations (physiological processes) with misinterpretation. Eg: if you have an increased heart rate you might think you have a heart attack.
Some MUS may arise from minor pathology and are exaggerated at times of stress
Defective attachment style in younger years can learn itself to pathological care seeking as an adult.
Imagine a child in their early years, if the child was avoiding school for example they were being bullied. In the process of being anxious about school they have a tummy ache and headache. The child would get extra support from social workers, school staff and parents. The child would learn being ill with getting more attention. And thus illness become a portal to support- as an adult it is not uncommon for these individual to unconsciously manifest with physical ailments as a means of attaining support. Its important to stress these people are not consciously pretending to be sick, but always a the body’s programme response in ascertaining health.
Outline models of medically unexplained symptoms ?
Explanatory Models 1: Biological model
- Help them to see the positive
Use of analogy is helpful to help them wrap their head round a concept. Funnily enough, often a lot of idioms we use captures these presentations
Explanatory Model 2: Psychosocial model
Describe management of MUS ?
Explanation is the key
Symptom management – analgesics (non-opioid), laxatives, antispasmodics, exercise, acupuncture, physiotherapy
Promote self efficacy (web sites/self help literature)
Initiate treatment for depression/anxiety if present
Psychotherapies - attention is directed away from the symptoms to the problems that have provoked the MUS
Aim is not for symptom cure but to help patient cope, which in turn minimises impact
What is teh chronic pain MDT ?
Holistic model of pain ?
What are stressors ?
- Any stimulus that produces a stress response
- External stressors, Internal stressors, psychosocial events and physiological events
What is general adaption syndrome ?
Physiological response to stressors in an attempt to regain homeostasis (Hans Selye)
What are the 3 stages in stress response ?
Stress response occurs in three main stages:
1. Alarm phase (short-term stress response): Initial ‘fight-or-flight’ response
2. Resistance or adaptation phase (long-term stress response): Body attempts to cope with prolonged stress
3. Exhaustion phase: Resources are depleted - body unable to maintain function
Describe the long term and short term response to stress ?
- The cerebral cortex processes stress and sends information to the hypothalamus.
Short term: the hypothalamus immediately activates the sympathetic nervous system, which in turn activates the medulla of the adrenal glands, the adrenal medulla releases catecholamines.
So if the stressor doesn’t resolve and you have a sort of chronic stressor, over time you can activate the long term stress response.
Long term: This activates the pituitary gland which activates the adrenal cortex, another part of the adrenal gland . And theses cells release glucorticoids such as cortisol.
Describe the short term stress response in more detail ?
- The release of catecholamines causes a number of responses.
So the first is that it mobilizes glucose reserves so that glucose is ready to provide energy to the muscles and the rest of your body to prepare for the fight or flight response.
It involves increasing the heart rate and respiratory rate to provide blood and oxygen to the tissues.
There is a general increase in energy use by all the cells.
Describe long term stress response in more detail ?
Long term stress response is also known as the HPA axis.
Stress activates the HPA axis (hypothalamic-pituitary-adrenal) axis:
1.Neurosecretory cells in hypothalamus to release CRH (corticotropin releasing hormone)
2.CRH activates anterior pituitary gland
3.Anterior pituitary secretes ACTH (adrenocorticotropic hormone)
4.ACTH travels through blood to adrenal glands (above kidneys)
5.ACTH stimulates cells in adrenal cortex to release cortisol (a glucocorticoid)
What are glucocorticoids ?
Describe the exhaustion phase ?
Prolonged exposure to high levels of cortisol causes:
-Muscle breakdown
-Suppression of immune response
-Ulceration of gastrointestinal tract
-Depression / psychosis
-Failure of pancreatic beta cells
-Aging
Amygdala and Hippocampus ?
There is also a couple of brain areas that also are affected by the stress response. They are the amygdala and hippocampus.
- The amygdala is activated when you are exposed to a fearful stimulus. The central nucleus of the amygdala is activated and this is what sends signals to the hypothalamus causing activation of the sympathetic nervous system, the short term stress response aswell as the long term stress response ( HPA activation system).
- The central nucleus also activates the peri aqueduct grey matter, which leads to avoidance behavior’s so the person tends to avoid or close their eyes or run away from that stressful or fearful stimulus.
- It also activates the diffuse modulatory systems which causes increased vigilance. The body is alert and ready to react to that fearful stimulus, maybe by running away or fighting it.
Amygdala and Hippocampus ?
- The amygdala works in conjunction in a feedback loop with the hippocampus.
So the hippocampus, they form this feedback loop where the amygdala will activate the HPA axis and that stimulates the release of cortisol in the body. And this maintenance of this long term stress response.
-But eventually this activates the hippocampus, which in turn inhibits the HPA axis.
So it’s a way of regulating that stress response. So it’s a feedback mechanism.
-So if you have too much cortisol, the hippocampus says. Oh wait, that’s way too much cortisol, we need to down regulate that. So it does some inhibition. And this is so the body doesn’t go crazy continuously releasing more and more cortisol.
-So that’s that feedback loop between the amygdala and the hippocampus. So they’re very involved, especially in the long term stress response.
What is teh relationship between stress and memory ?
Give examples of anxiety disorders ?
- Generalized anxiety disorder
- Panic disorder
- Phobias
- Obsessive Compulsive Disorder (OCD)
- Post traumatic stress disorder (PTSD)
What is PTSD ?
How do we treat anxiety disorders ?
First response: CBT
Second response: Benzodiazepines
What is the mechanism of action of benzodiazepine’s ?
Give some stress reduction strategies ?
Classical conditioning
Habituation describes a decreased response to a stimulus over time.
Operant conditioning: involves voluntary changes in behavior due to punishment and reinforcement.
Classical conditioning: involves unconditioned (natural) responses to learned stimuli.
Sensitization: heightened response to a stimulus
Operant conditioning
Classical conditioning
Transtheoretical model of change
ADHD
What is the primary mechanism of action of amphetamines in ADHD?
First line treatments are aphetamines
Increase dopamine release by the presynaptic neuron, leading to increased dopaminergic activity on the synaptic cleft.
Secondary effects of amphetamines include reducing dopamine reuptake by the presynaptic neuron.
Autism
Sleep Physiology
Much of the circadian rhythm is controlled by light input. Light is detected by the retina, which in turn signals to the suprachiasmatic nucleus (SCN) of the hypothalamus. The suprachiasmatic nucleus is the master regulator of the circadian rhythm.
“SupraChiasmatic makes you Super Cozy”.
Sleep stages
Depression is associated with increased REM sleep and decreased REM latency.
This can be remembered by understanding that many patients with depression can suffer from chronic nightmares (nightmares occur during REM). Depression is also associated with decreased N3 sleep and earlier wake times.
Orexin is the opposite of melatonin and causes awakeness. It us secreted from the lateral hypothalamus.
- People with narcolepsy have decreased orexin so feel more sleepy, less awake.
What is Korsakoffs syndrome ?
- Type of amnesia you get after drinking too much alcohol. Most commonly presents with anterograde amnesia.
- irreversible damage
- The initial treatment for Korsakoff syndrome (and Wernicke’s encephalopathy) is to administer IV thiamine. This is done prior to the administration of glucose-based fluids.
Anxiety and panic disorders
- Buspirone is used to treat anxiety only . Its is a Serotonin 5-HT1A receptor agonist
Phobias
Agoraphobia: irrational intense fear related to specific environments.
Primary management for agoraphobia includes CBT and SSRIs.
Benzodiazepines may sometimes be used but are not the primary treatment of choice.
Social anxiety disorder is the fear of embarrassment or poor performance in social or work settings.
Performance type social anxiety disorder is often associated with work settings involving meetings, presentations, and speeches. Primary management for social anxiety in these settings is typically a prophylactic beta-blocker (e.g., propranolol) before giving a speech or presentation.
- Olanzapine is an antipsychotic medication that improves the psychological symptoms associated with anorexia nervosa as well as promotes weight gain.
What is OCD ?
-OCD is recurring obsessive thoughts or feelings relieved by reactionary compulsions. Obsessive-compulsive disorder (OCD) is an urge disorder characterized by recurring thoughts or feelings (obsessions) that are only relieved through reactionary actions (compulsions). These behaviors are ego-dystonic, meaning that they do not line up with the goals and desires of the patient.
-Trichotillomania is the urge to pull out one’s hair. It is most common in children and presents with hair loss that causes significant distress or social impairment.
PTSD ?
Adjustment Disorder: Derangement in emotional management in response to a stressor. Symptoms begin within 3 months of stressor and subside before 6 months.
PTSD: Symptoms last from 1 month after events to indefinitely
Acute stress disorder: Symptoms last between 3 days and 1 month
