Case 8 - Yaffas Notes

Question 1

what are the three functional divisions of the striatum

Answer 1

sensorimotor - putamen
associative - globus pallidus
limbic/ventral - ventral tegmental area

Question 2

what are the four main dopamine pathways

Answer 2

nigrostriatal pathway
mesocortical pathway
mesolimbic pathway
tuberoinfundibulnar pathway

Question 3

where does increase of dopamine happen

Answer 3

occurs in the associative striatum of the nigrostrital pathway not the mesolimbic

Question 4

what does chronic blockage of the nigrostrital pathway cause

Answer 4

hyperkinetic movement disorder known as neuroleptic induced tardive dyskenesia

Question 5

what does the tuberoinfundibulnar pathway originate

Answer 5

projects from the hypothalamus to the anterior pititary gland

Question 6

what do neurones do in this pathway

Answer 6

inhibit prolactin release

Question 7

what happens in the postpartum state

Answer 7

the activity of these dopamine neurones is decreased and prolactin levels can therefore rise during breastfeeding so that lactation can occur

Question 8

what are elevated prolactin levels associated with

Answer 8

breast pathology such as amenorrhea and sexual dysfunction

such problems can occur after antipsychotics that block the D2 receptors

Question 9

what are the classification of schizophrenia

Answer 9

paranoid schizophrenia - dominated by delusions and hallucinations - positive symptoms

residual schizophrenia - predominant negative symptoms

Question 10

what receptors affect dopamine release

Answer 10

D3 receptors

Question 11

what receptors does resperidone have high affinity for

Answer 11

the 5HT and the dopamine D2 receptors

Question 12

mode of action of resperidone

Answer 12

effective for treating the positive and negative symptoms owing to its loose binding affinity for the D2 receptors and additional 5HT antagonism compared to first generation antipsychotics which are strong, non specific dopamine D2 receptor antagonists

Question 13

what is the mechanism of action

Answer 13

blockade of D2 receptors in the ventral striatum, alleviating positive symptoms of schizophrenia such as hallucinations and delusions
Blockade of serotonergic 5HT receptors in the mesocortical tract, cause an excess of dopamine, resulting in an increase in dopamine transmission, and an elimination of core negative symptoms
Dopamine receptors in the nigrostrital pathway are not affected by resperidone and extrapyrimdal effects are avoided

Question 14

what is the main side effect of resperidone

Answer 14

weight gain

Question 15

what is clozapine

Answer 15

atypical antipsychotic

combination of antagnosistc effects at D2 receptors in the mesolimbic pathway and 5HT2A receptors in the frontal cortex

D2 antagonism relieves positive symptoms while the 5HT2A antagonism alleviates the negative symptoms

Question 16

what is the main side effect of clozapine

Answer 16

sedation

Question 17

what is the psychoactive substance in weed

Answer 17

THC

Question 18

what are the CB1 receptors

Answer 18

mediate most effects of cannabinoids on the CNS

these are involved in physiological processes such as appetite, pain, sensation and memory. these receptors are responsible for the euphoric and anti convulsive effects

Question 19

what are the CB2 receptor

Answer 19

found in the periphery and are expressed mainly in the immune system and hamemopeitic cells

Question 20

what are cannabinoid receptors activated by

Answer 20

THC - through the production of an endocannabinoid (ligand known as anandamide)

endocannabunoids - produced by humans

Question 21

what are endocannabinoids

Answer 21

substances produced in the brain
They are used in retrograde signalling between neurones, in to temporarily reduce the amount of conventional neurotransmitter released
Their production is Ca+ dependent
They are produced in post synaptic GABA neurones

Question 22

what is the mode of action of euphoria

Answer 22

GABA is released into the synaptic cleft and binds to the endocannabinids source
This lead to the production of endocannabinoids
Endocannabinoids released from the depolarised post synaptic GABA neurone bind to CB1 receptors In the pre-synpatic GABA. Neurone and cause a reduction in GABA release
This causes a decrease in the inhibitory effects in the brain, thus leading to euphoria

Question 23

what is the mode of action of anticonvulsives

Answer 23

cannabinoids are thought to have a regulatory role in the striatum in terms of glutamatergic signals from the corticostriatal fibres
Intense firing of corticostrital neurones leads to release of glutamate which causes an influx of Ca ions in the post synaptic membrane
Constant glutamate release causes Ca2+ ions to build up in the post synaptic membrane
This accumulation causes Ca2+ ions to synthesise endocannabinoids in the medium sized striatal neurones
These stimulate CB1 receptors on the pre-synpatic corticostrital fibres leading to a decreased release of glutamate

Question 24

some extra regulations for section 2 under the MHA

Answer 24

For section 2 under the MHA, must be signed by two approved health professions and nearest relative or other approved health professions
doctors must have seen you within 5 days of each other
One of the two AMPH must be approved under section 12
Section 2 can’t be renewed but the patient may be transferred onto section 3

Question 25

what is the difference between the mental health act and the mental capacity act

Answer 25

The Mental Health Act 1983 applies if you have a mental health problem, and sets out your rights if you are sectioned under this Act. The Mental Capacity Act applies if you have a mental health problem and you do not have the mental capacity to make certain decisions.

Question 26

why do women periods stop when they have schizophrenia

Answer 26

Lack of FSH due to prolactin in females and this means problems with periods

Question 27

how do people die from eating too much after starving

Answer 27

Massive flux of ions when people re feeding syndrome after people have starved for ages - potassium to the heart

Question 28

which ECG interval is prolonged in antipsychotics

Answer 28

QT interval

Question 29

what other problems arise from H1 receptor affinity

Answer 29

weight gain

Question 30

what are persecutory delusions

Answer 30

are the most common type. this type causes a person to believe that someone or something is out to get them. this can include another person, machine or an entire institution or organisation

Question 31

what delusions are considered an extreme form of paranoia

Answer 31

persecution delusions

Question 32

what other symptoms often occur with persecutory delusions

Answer 32

anxiety
difficult sleeping
depression
negative thoughts about ones self

Question 33

what are erotomanic delusions

Answer 33

cause a person to believe that another person is in love with then. the person who is the target of these delusions is usually of a higher status Thant he person with delusions, and the targets are often celebrities

Question 34

what are grandiose behaviours

Answer 34

believe that they are superior to other people. these beliefs can give a person a sense of belonging and self worth

Question 35

how common are grandiose delusions

Answer 35

affect about two thirds of people with bipolar disorder and half of people with schizophrenia

Question 36

what are some examples of grandiose delusions

Answer 36

having special powers
being famous
being very wealthy
thinking you are god
believing that you can cure cancer

Question 37

what are somatic delusions

Answer 37

these are focused on the physical body. a person with somatic delusions falsely believes that something is wrong with their body.

these delusions can be about illnesses or conditions that occur in real life, such as having cancer or being pregnant, or bizarre things like bones twisting around each other, missing internal organs or veins running in the wrong direction

people with somatic delusions often undergo many different types of medical testing but still believe that there is something wrong with them despite normal test results