Psychiatry Flashcards
What is the most common inherited cause of learning disability?
Fragile X syndrome
What is the most common avoidable cause of learning disability?
Foetal alcohol syndrome
What are 4 known, predisposing medical conditions for ASD?
1) Fragile X syndrome
2) Infantile spasms
3) Congenital rubella
4) Tuberous sclerosis
What genetic mutation is seen in Fragile X syndrome?
An expansion of the CGG trinucleotide repeat in the FMR1 gene on the X chromosome.
What gene is implicated in Fragile X syndrome?
FMR1 gene on X chromosome
What trinucleotide is implicated in Fragile X?
CGG
Classic features in Fragile X syndrome?
1) Learning disabily
2) Delayed speech & motor development
3) Large testes
4) Long, narrow face
5) Prominent jaw & forehead
6) Large, protruding ears
What 3 conditions may be associated with Fragile X?
1) Autism
2) ADHD
3) Epilepsy
How is Fragile X diagnosed?
DNA test that counts number of CGG repeats (FMR1 testing)
What condition is ASD most commonly associated with?
ADHD (50%)
What is trisomy 18?
Edward’s syndrome
What is trisomy 13?
Patau syndrome
People with learning disabilities may present differently with depression.
What type of symptoms are often more prominent?
Biological e.g. agitation, appetite, sleep
What valve defect can be seen in Fragile X?
Mitral valve prolapse
What CNS abnormalities can be seen in foetal alcohol syndrome?
1) Decreased cranial size
2) Structural brain abnormalities
3) Problems with attention
4) Cognitive difficulties
Prevalence of ASD in UK?
1 in 100
What may depressive features in people with learning disability also indicate the onset of?
Dementia
What IQ score defines a learning disability?
<70
Stepwise management of PTSD?
1st –> trauma-focused CBT or eye movement desensitisation and reprocessing (EMDR) therapy
2nd –> venlafaxine or SSRI
3rd –> risperidone (severe cases)
What SNRI is indicated in PTSD?
Venlafaxine
What antipsychotic is indicated in severe cases of PTSD?
Risperidone
What is de Fregoli syndrome?
The delusion of identifying a familiar person in various people they encounter.
What is Capgras syndrome?
The delusion that a person closely related to the patient has been replaced by an impostor.
When lithium levels are stable, how often are levels checked?
Every 6 months, 12 hours after last dose
If a first line SSRI such as sertraline is ineffective or not tolerated in GAD, what is next step?
Try another SSRI or SNRI
Diagnostic criteria for mild depression
2 core + 2 other
Diagnostic criteria for major depression
3 core + 4 other
What is the mechanism of action of memantine?
Glutamate antagonist (NMDA receptor antagonist)
When is memantine indicated 1st line over cholinesterase inhibitors (e.g. donepezil)?
1) Bradycardia (<60bpm)
2) Heart block
Which lobes are affected in Alzheimer’s?
Atrophy of medio-temporal lobes
What 2 medications are indicated in OCD?
1) SSRIs
2) Clomipramine
Which Alzheimer’s medication is contraindicated in bradycardia?
Donepezil
Disruption to which pathway produces the positive symptoms of schizophrenia?
Increased dopamine activity in the MESOLIMBIC pathway.
Disruption to which pathway produces the negative symptoms of schizophrenia?
HYPOactivity of dopamine in the MESOCORTICAL pathway causes negative, cognitive & affective symptoms.
What investigations are needed prior to starting lithium?
1) Weight
2) U&Es
3) ECG
4) Pregnancy test
5) TFTs
6) Ca2+
What is the link between sodium and lithium?
The kidneys treat lithium and sodium similarly.
This is the reason why sodium DEPLETION can significantly ELEVATE lithium reabsorption.
Causes of sodium depletion (that can predispose to lithium toxicity):
1) diuretics
2) dehydration
3) febrile illness
4) GI loss
Use of which diuretic is most likely to cause lithium toxicity?
Thiazide diuretics
How does lithium use affect sodium levels?
Lithium can cause sodium depletion.
How can a low sodium diet affect lithium levels?
A low-sodium (salt-restricted) diet can decrease lithium elimination, leading to increased risk of toxicity in lithium users who reduce their salt intake.
What are 3 possible renal effects of lithium use?
1) Decrease in eGFR
2) Nephrogenic diabetes insipidus
3) Increased risk of CKD
Why is lithium contraindicated in Cardiac disease or Addison’s disease?
As it causes salt depletion.
What does a prolonged QT interval represent?
Delayed ventricular depolarisation
How can lithium affect the thyroid?
Can cause hypothyroidism
What is typically the most prevalent adverse effect experienced by patients treated with clozapine?
Clozapine-induced hypersalivation
What cardiac adverse effect can clozapine cause?
Myocarditis
Clozapine and epilepsy?
Clozapine LOWERS the seizure threshold.
Which SSRI is licensed for treatment in bulimia?
Fluoxetine
How can TCAs affect the BP?
Can cause hypotension due to inhibition of a1 receptors (causing smooth muscle relaxation).
Cardiac effect of SSRIs?
Can prolong QT interval
What are 2 major contraindications of clozapine?
1) history of neutropenia
2) severe heart disease
Impact of TCAs on dopamine?
TCAs block D2 receptors –> raised prolactin (e.g. menstrual disturbance, galactorrhoea, sexual dysfunction)
What class of drug is mirtazapine?
NaSSA - noradrenergic and specific serotonergic antidepressants
What is the mechanism of sodium valproate?
Increases activity of GABA (relaxing effect on brain)
What is the effect of a prolonged QT interval?
Long QT syndrome can cause sudden fainting and seizures.
Young people with LQTS syndrome have an increased risk of sudden death.
What are some side effects of sodium valproate?
- enzyme inhibitor
- hair loss
- hepatitis
- weight gain
- GI upset
- ataxia
- tremor
- teratogenic
- thrombocytopenia
Which medication can exacerbate absence seizures?
Carbamazepine
1st line antiepileptic for tonic clonic seizure?
Males: sodium valproate
Females: levetiracetam or lamotrigine
1st line antiepileptic for absence seizures?
Ethosuximide
2nd line antiepileptic for absence seizures?
Male: sodium valproate
Female: lamotrigine or levetiracetam
1st line management of myoclonic seizures?
Male: sodium valproate
Female: levetiracetam
1st line management of tonic or atonic seizures?
Males: sodium valproate
Females: lamotrigine
1st line antiepileptic for focal seizures?
Lamotrigine or levetiracetam
2nd line antiepileptic for focal seizures?
carbamazepine
What is the 1st line management of trigeminal neuralgia?
Carbamazepine
1st line management of neuropathic pain?
Amitriptyline, duloxetine, gabapentin or pregabalin