Organic Mental Disorders Flashcards
What makes a disorder an OMD?
Recognised as having an organic explanation Acquired (i.e. not a LD) Primary (brain) or secondary (e.g. endocrine)
What areas of mental health do OMDs affect?
Cognitive impairment Sensorium Mood changes Psychotic symptoms Personality and behavioural disturbance
What are the major acute OMDs?
Delirium Organic Mood disorder Organic Psychotic disorder
What is delirium?
Transient & fluctuating global cognitive impairment with ass. behavioural changes
What are the defining characteristics of delirium?
- Impaired attention/conc - Disorientated (Time, place, person) - Fluctuating arousal (quiet/drowsy –> agitated outburst) particularly at night - Perceptual problems e.g. hallucination - Mood changes - Delusions - Disorganised thinking & speech Also ant memory, sleep/wake cycle and psychomotor problems
Virtually any neuro or systemic problem can –> delirium, what are the most common?
Infection Drugs e.g. steroids/opioids (both common post-op) Withdrawal e.g. alc Alc use Liver/kidney disease Hypoxia Lot’s of others in brain, vit deficiencies, metabolic problems and endocrinopathies
What are the commonest chronic OMDs?
Dementia Amnesic Syndrome ORganic Personality Change
What makes dementia different to Delirium?
It’s a chronic and progessive global cognitive impairment, It also doesn’t fluctuate much
Define amnesic syndrome?
Ant AND Retrograde amnesia with preserved intellectual abilities, working memory & procedural memory
What can cause amnesic syndrome>?
Hippocampal damage e.g. HSV or bilateral post-cerebral art occlusion Diencephalic damage e.g. Korsakoff’s syndrome, 3rd ventricle tumours and post-subarachnoid haemorrhage problems such as ant communicating art aneurysm
How may cognitive function be affected in OMDs?
Memory Intellect Learning
How may sensorium be affected in OMDs?
Consciousness Attention
How may mood be affected in OMDs?
Depression Elation Anxiety
How may psychosis be affected in OMDs?
Hallucinations Delusions
When do OMDs onset?
Any age Most tend to start in adult or later life
Hw chronic are OMDs?
Some irreversible and progressive Some transient/respond to treatments
How may an OMD be classified and what are some subtypes?
Acute/sub-acute -Delirium -Organic mood disorder -Organic psychotic disorder Chronic -Dementia -Amnesic syndrome -Organic personality change
How is delirium tremens treated?
Benzodiazepines
If Wernicke’s encephalopathy goes untreated, how many will develop Korsakoff psychosis?
84% (after 2 week untrusted acute phase)
How is Wernicke-Korsakoff Syndrome treated?
High potency parenteral B1 replacement -3-7 days -Oral thiamine -Avoid carbohydrate load until thiamine replacement completed -All patients with symptoms of Wernike’s encephalopathy or at high risk should be treated with parenteral thiamine -Others undergoing detoxification or under investigation should be commenced on oral thiamine -Concurrent treatment for alcohol withdrawal
What can Korsokoff’s psychosis also be known as?
Alcohol Amnesic Syndrome
How does Korsokoff’s present?
-Characterised by marked impairment of anterograde memory (ability to learn new information), disturbance of time sense -No clouding of consciousness, absence of defect in immediate recall or global impairment -Variable degrees of cognitive impairment -Personality changes, apathy, loss of initiative -Confabulation in the early stage -Can improve with prolonged abstinence
What is hepatic encephalopathy?
-Normally seen in advanced alcohol liver disease -General psychomotor retardation, drowsiness fluctuating levels of confusion -Related to build up of toxic products (e.g. ammonia) -Improves if and as liver function recovers
What is alcohol-related brain damage?
-Part of a spectrum of alcohol related medical disorders, not a specific diagnosis -Can result from neurotoxic effects of alcohol, head injury, vitamin deficiencies, cerebrovascular disease, hypoxia, hypoglycaemia, seizures
What percentage of alcohol dependent persons will exhibit post-mortem evidence of alcohol related brain damage?
35%
When do men and women present with alcohol-related brain damage?
Women - 40s/50s Men - 50s/60s
What percentage of heavy drinkers display cognitive impairment when sober?
50-80% -Impairment in short-term memory, long-term recall, new skill acquisition, set-shifting ability -Visuospatial ability decline greater than language ability decline -Imaging: cortical atrophy (mainly white matter loss) and ventricular enlargement
What does the Adults with Incapacity (Scotland) Act 2000 use to determine if an adult has capacity?
A person is unable to make a decision for him/herself if, due to mental disorder or inability to communicate because of physical disability, he/she is incapable of acting; or making decision; or communicating decisions; or understanding decisions; or retaining the memory of decisions.
What is dementia?
A syndrome which characterised by global cognitive impairment which is chronic in nature. The underlying brain pathology is variable and usually, but not always progressive.
How does dementia differ from depressive pseudodementia?
D - Progressive onset PD - Rapid onset D - Long-term symptomatology PD - Short-term symptomatology D - Mood variations PD - Consistently depressed mood D - Patient tries to answer questions PD - Short answers; “I don’t know”, negativism D - Patient concealing amnesia PD - Highlighting amnesia D - Constant cognitive decline PD - Fluctuating cognitive impairment
What is steroid-induced psychosis?
-Mild-moderate psychiatric symptoms in 28% patients treated with steroids -Approximately 6% severe reaction -Dosage related to incidence but not timing, duration or severity -Subsequent events not predicted by previous (or lack of previous) reaction
How is steroid-induced psychosis managed?
Consider tapering steroids Consider antipsychotic/mood stabiliser
How might endocrine and metabolic disorders affect mental function?
-Wide variety of clinical presentations -CNS requires “stable biochemical and metabolic milieu” for proper functioning -Psychiatric presentations may be reversible if detected -Likely to first present to GP/General medicine but some conditions (i.e. Hypothyroidism, Addison’s disease) may present first to psychiatry and there is risk of mistaken diagnosis
What is Anti-NMDA Receptor encephalitis?
-Autoimmune disease that targets NMDA receptors Ionotropic glutamate receptor involved in synaptic plasticity and memory function -Around half associated with malignancy -Often presents initially with psychiatric symptoms
How is Anti-NMDA Receptor encephalitis managed?
Immunotherapy and tumour resection if indicated -IVIg, plasmapheresis, rituximab -Prognosis, with treatment, generally good
What is an ICD-10 F05?
Delirium due to an unknown condition
How does delirium present?
Rapid onset Diurnally fluctuating Duration less than 6 months Symptoms: -Impairment of consciousness and attention -Global disturbance of cognition -Psychomotor disturbances -Disturbance of sleep-wake cycle -Emotional disturbance
What may cause delirium?
Medications Drug abuse Withdrawal syndromes Metabolic Vitamin deficiencies Endocrinopathies Infections Neurological causes Toxins and industrial exposures Others e.g. SLE, hyperviscosity syndromes
What is the mechanism of delirium?
-Pathophysiology unclear -GABAergic and cholinergic neurotransmitter systems? -Central cholinergic deficiency? -Increased risk associated with GABAa agonists and anticholinergic drugs -Increased dopaminergic activity? -Direct neurotoxic effect of inflammatory cytokines?
How does delirium differ from dementia?
How does delirium differ from fucntional psychosis?
What is the prognosis for delirium?
-Gradual resolution of symptoms with effective treatment of underlying cause
- May improve more quickly at home
- Slower symptom resolution in the elderly
-Often patchy amnesia for delirious period following recovery
-Mortality – 20% die during this admission, up to 50% at 1 year
-May be a marker for subsequent dementia
Which factors contribute to delirium?
¡Disorientation
¡Dehydration
¡Constipation
Hypoxia
Immobility/limited mobility
Infection
Multiple medications
Pain
Poor nutrition
Sensory impairment
Sleep disturbance
How might delirum be managed with environmental and supportive measures?
Education of relatives, medical and nursing staff
Make environment safe
Optimise stimulation
Orientation
How may delirium be managed with medication?
Avoid sedation unless required to maintain safety
Evidence base and guidelines do not support use of medications in delirium
-Antipsychotics
- Benzodiazepines
- Promethazine
Whcih antipsychotics may be used in delirium?
Risperidone 0∙5 – 1mg
Quetiapine 25-50mg
If IM required – consider olanzapine/aripiprazole
Which benzodiazepines may be used in delirium?
Can prolong delirium
Lorazepam 0∙5 – 1mg
Use in withdrawal states – diazepam/chlordiazepoxide; cautionin liver failure
What is Promethazine and how is it used in deliruim?
Oral/IM 10-25mg
Off-licence use
Caution: in elderly (anticholinergiceffect); prolongs QTc; lowers seizure threshold
Why might anti-psychotics be avoided in delirium?
Avoid antipsychotics in alcohol/drug withdrawal states unless patient well covered with benzodiazepines due to lowering of seizure threshold
