Organic Mental Disorders Flashcards
1
Q
Definition of Organic Mental Disorder
A
- Mental disorders due to common and demonstrable causes in cerebral disease, brain injury or other insult leading to neurological dysfunction → the cross between neurology and psychiatry
- Acquired → (differentiation from intellectual disability)
- Alternative to the more common ‘functional’ mental illnesses
- Primary → direct effect on the brain
- Secondary → systemic disorder with secondary effects on the brain
2
Q
Problems in defining functional and organic mental disorders
A
- Most mental disorders have an ‘organic’ component → schizophrenia, bipolar affective disorder, melancholia
- Many present with a mixture of both mental and physical features
- Physical disorders can also have psychological and functional elements
3
Q
Common presentation of organic mental disorders
A
- Cognitive
- Memory
- Intellect
- Learning
- Sensorium?
- Consciousness
- Attention
- Mood
- Depression
- Mania
- Anxiety
- Psychosis
- Hallucinations
- Delusions
- Personality and behavioural disturbances
- Onset
- Any age
- Most commonly later in life
- Some irreversible and progressive → neurodegenerative
- Some transient/ respond to treatment
4
Q
Classification of organic mental disorder
A
- Acute/ sub-acute
- Delirium
- Organic mood disorder
- Organic psychotic disorder
- Chronic
- Dementia
- Amnesic syndrome
- Organic personality changes
5
Q
Management of Organic Mental Disorder
A
- Varies according to cause
- Correct diagnosis
- Medications ineffective unless for acute situations
- MDT approach
- Consider management of patient environment
6
Q
Delirium tremens
A
- Acute alcohol withdrawal
- Fluctuating confusion
- Disorientation to time and place
- Memory impairment
- Psychotic features → hallucination and delusional thinking
- Mainstay treatment → benzodiazepines (prevents alcohol-related seizure)
7
Q
Wernicke-Korsakoff Syndrome
A
- Acute deficiency of thiamine (vitamin B1)
- Difficult to distinguish from delirium tremens
- Presentation
- Acute confusional state
- Ataxia
- Opthalmoplegia
- Nystagmus
- Untreated acute phase lasts 2 weeks → majority develop Korsakoff psychosis
- Prognosis
- Confusional state and opthalmoplegia can resolve in days
- Nystagmus, neuropathy and ataxia prolonged or permanent
- Treatment
- High potency parenteral B1 replacement → oral thiamine
- Avoid carbohydrate until thiamine fully replaced
- Concurrent alcohol withdrawal treatment → benzodiazepines
8
Q
Alcohol amnesic Syndrome (Korsakoff psychosis)
A
- Marked impairment of anterograde memory → ability to learn new memories
- Disturbed time sense
- No clouded consciousness, no defect in immediate recall or global impairment
- Variable cognitive impairment
- Personality changes, apathy, loss of initiative
- Early stages → confabulations
- Can improve with prolonged abstinence
9
Q
Hepatic encephalopathy
A
- Psychomotor retardation, drowsiness, confusion caused by build up of toxic products (ammonia) in the blood stream
- Often seen in advanced alcoholic liver disease
- Improves as liver function recovers
10
Q
Alcohol related brain damage
A
- Due to neurotoxic effects, head injury, vitamin deficiencies, cerebrovascular disease, hypoxia, hypoglycaemia, seizures
- Evidence of increasing prevalence
- Trend of people presenting earlier than in the past
- Impairment in short-term memory, long-term recall, new skill acquisition
- Greatest decline in visuospatial ability
- Can cover spontaneously with absence or reduced drinking
11
Q
Difference between dementia and depressive pseudo dementia
A
- Dementia
- Progressive onset
- Long-term symptomology
- Mood variations
- Patient concealing absnesia
- Patient willing to answer questions
- Constant cognitive decline
- Depressive pseuodementia
- Rapid onset
- Short-term symptomology
- Consistent depressed mood
- Answers are short and with negativism
- Highlighting amnesia
- Fluctuating cognitive decline
12
Q
Steroid-induced psychosis
A
- Mild-moderat psychiatric symptoms → 28% of steroid-treated patients
- 6% with severe reaction
- Dose-dependent, not timing, duration or severity
- Always taper steroids
- Consider antipsychotic or mood stabiliser
13
Q
Endocrine and metabolic disorder in psychiatric symptomology
A
- Manifests a variety of presentation → psychiatric
- CNS requires homeostatic biochemical and metabolic conditions
- Psychiatric disorders reversible if cause is detected
- I.e correcting hypothyroidism, Addison’s disease
14
Q
Anti-NMDA receptor encephalitis
A
- Autoimmune disease targeting NDMA receptor
- NMDA receptor → ionotropic glutamate receptor in synaptic plasticity and memory
- ½ associated with malignancy
- Presents most commonly with psychiatric symptoms
- Treatment
- Immunotherapy → IVIg, plasmapheresis, rituximab
- Tumour resection (when indicated)
- Benzodiazepines → symptomatic
- Prognosis → generally good
15
Q
Delirium
A
- Non-specific neurological syndrome characterised by disturbances in consciousness, attention, perception, thinking, memory, psychomotor behaviour, emotion and circadian rhythm
16
Q
Presentation of delirium
A
- Impaired consciousness and attention
- Generalised cognitive disturbances
- Psychomotor dysfunction
- Disturbed sleep-wake cycle
- Emotion disturbances
- Rapid onset
- Diurnal fluctuating
- Duration less than 6 months
- Physical symptoms
- Autonomic activation → tachycardia, hypertension, dilated pupils, sweating, fever
- Dysgraphia
17
Q
Causes of delirium (exhaustive list)
A
- Medications → anticholinergics, sedative-hypnotics, decongestants, glucocorticoids
- Drug abuse → amphetamines and cocaine
- Withdrawal syndromes → alcohol, benzodiazepines,
- Metabolic → hepatic encephalopathy, uraemia, hypoglycaemia, hypoxia, hypo/hypercalcaemia,
- Vitamin deficiencies → thiamine, vitamin B12, nicotinic acid
- Endocrinopathies → hypo/hyperthyroidism, bushings, Addison’s disease, hypopituitarism
- Infections → systemic infection, AIDS, meningitis encephalitis, brain abcess
- Neurological → head injury, stroke, hypertensive encephalopathy, intracranial neoplasm, status epileptics,
- Toxins → Carbon monoxide, carbon disulphide, organic solvents, heavy metals
- Others → SLE, cerebral vasculitis, paraneoplastic syndrome
18
Q
Mechanisms of delirium
A
- Unclear pathogensis
- GABAergic and cholinergic neurotransmitter pathways
- Increased dopaminergic activity
- Direct neurotoxic effects of cytokines
19
Q
Delirium vs dementia
A
- Delirium
- Acute and often at nighy
- Fluctuating course
- Hours to weeks
- Impaired attention
- Disorganised and delusion thinking
- Disrupted sleep-wake cycle
- Generalised slowing on EEG
- No atrophy on CT, MRI
- Dementia
- Insidious onset
- Stable course in day
- Months to years
- Attention unaffected
- Impoverished thinking
- Normal sleep-wake cycle
- No slowing in EEG
- Atrophic finding on CT, MRI
20
Q
Delirium vs functional psychosis
A
- Delirium
- Almost always clouded consciousness
- Concrete > abstract thinking
- Transient and changing delusions
- Impaired cognitive function
- Visual hallucination predominate
- Functional psychosis
- No clouding of consciousness
- Abstract > concrete thinking
- Systemised delusions
- No impairment to cognitive function
- Auditory hallucinations predominate
21
Q
Prognosis of delirium
A
- Fluctuating course
- Gradual resolution with effective treatment
- Slower resolution in elderly
- 20% mortality during admission
- 50% within one year
- Marker for dementia
22
Q
Management of delirium
A
- Correct factors
- Disorientation
- Dehydration
- Constipation
- Hypoxia
- Immobility/ limited mobility
- Infection
- Polypharmacy
- Pain
- Poor nutrition
- Sensory impairment
- Sleep disturbances
- Environmental and supportive measures
- Education of relatives, staff
- Safe environment
- Medication
- Avoid sedation unless necessary
- Antipsychotic
- Benzodiazepines
- Promethazine
