Organic Disorders Flashcards
what is the definition of organic mental disorders? (ICD10)
Mental disorders that are “due to common, demonstrable aetiology in cerebral disease, brain injury, or other insult leading to cerebral dysfunction”
Acquired (differentiation from intellectual disability)
Distinction from from “functional” mental illness (Separated from psychiatric illnesses due to brain dysfunction)
organic mental disorders can be primary or secondary - what does that mean?
Primary – direct effect on the brain
Secondary – systemic diseases that affect the brain in addition to other systems/organs (e.g. endocrine, substance induced problems)
what is the problem with the definition of organic mental disorders?
Many (if not all) psychiatric disorders have an “organic” basis (Schizophrenia, bipolar affective disorder, melancholia)
Many mental disorders present with a mixture of mental and physical features
Physical disorders also have effect on psychological functioning
what are some common features of organic mental disorders?
Cognitive - Memory, Intellect, Learning
Sensorium - Consciousness, Attention
Mood - Depression, Elation, Anxiety
Psychotic - Hallucinations, Delusions
Personality & behavioural disturbance
Onset - Any age, Most tend to start in adult or later life
Some irreversible and progressive
Some transient/respond to treatments
what is an Acute/sub-acute organic mental disorder?
a recently appearing state of mental impairment, as a result of intoxication, drug overdose, infection, pain, and many other physical problems affecting mental status. In medical contexts, “acute” means “of recent onset”. As is the case with most acute disease problems, acute organic brain syndrome is often temporary–however this is not guaranteed (may continue to be chronic or long term)
e.g. Delirium, Organic mood disorder, Organic psychotic disorder
what is a chronic organic mental disorder?
Chronic organic brain syndrome is long-term. For example, some forms of chronic drug or alcohol dependence can cause organic brain syndrome due to their long-lasting or permanent toxic effects on brain function. Other common causes of chronic organic brain syndrome sometimes listed are the various types of dementia which result from permanent brain damage due to strokes, Alzheimer’s disease, or other damaging causes which are not reversible
e.g. Dementia, Amnesic syndrome, Organic personality change
the management of organic mental disorders Varies depending on cause but key points are what?
Correct diagnosis
Medication usually not that useful except for acute situations
Requires MDT approach
Management of environment important
Alcohol Withdrawal can result in delirium tremens, what is it?
can complicate acute alcohol withdrawal
fluctuating confusion
disorientation in time & place
memory impairment
psychotic phenomena, e.g. hallucinations, delusional thinking
Treatment with benzodiazepines
Wernicke-Korsakoff Syndrome:
what symptoms are seen in Wernike’s Encephalopathy?
Acute Confusional State
Ataxia
Opthalmoplegia
Nystagmus
what causes Wernike’s Encephalopathy?
related to acute deficiency of Thiamine (vitamin B1)
can be difficult to distinguish from delirium tremens
Untreated acute phase lasts about 2 weeks, 84% develop Korsakoff psychosis - 15% mortality
With treatment confusional state and opthalmoplegia can resolve within days, nystagmus, neuropathy and ataxia may be prolonged or permanent
what is the treatment of Wernike’s Encephalopathy?
High potency parenteral B1 replacement
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 (benzodiazepines)
what is seen in Alcohol Amnesic Syndrome (Korsakoff’s psychosis)?
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
Hepatic encephalopathy - normally seen in advanced alcohol liver disease
what i seen in it and when doe sit improve?
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
~ 35% of alcohol dependent persons will exhibit post-mortem evidence of alcohol related brain damage
women tend to present in the 40-50s, usually a decade younger than men
trend towards people presenting earlier than in the past
50-80% heavy drinkers display cognitive impairment when sober
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
Ability may recover spontaneously with abstinence/greatly reduced drinking
Adults with Incapacity (Scotland) Act 2000:
For the purposes of the 2000 Act 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 what?
acting; or
making decision; or
communicating decisions; or
understanding decisions; or
retaining the memory of decisions
Dementia can be confused with Depressive “pseudodementia”
what is the difference?
depressive illness severe enough it looks like dementia
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
what are the types of dementia?
Alzheimer
Vascular
(Mixed)
Lewy body
Frontotemporal
Due to other brain disorders - Huntington’s chorea, Head injury, Parkinson’s disease
(Alzheimer and vascular dementia the most common)
what are the differences between dementia and depressive pseudodementia?
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
how do you manage Steroid-induced psychosis?
Consider tapering steroids
Consider antipsychotic/mood stabiliser
what are Endocrine and metabolic disorders?
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
Immunotherapy and tumour resection if indicated - IVIg, plasmapheresis, rituximab
Prognosis, with treatment, generally good
what is the ICD10 definition of delirium?
An aetiologically nonspecific syndrome (Therefore can be caused by lots of different things) characterised by concurrent disturbances of consciousness and attention, perception, thinking, memory, psychomotor behaviour, emotion, and the sleep-wake cycle
what are the presenting features of delirium?
a) Impairment of consciousness and attention
b) Global disturbance of cognition (delusions, hallucinations)
c) Psychomotor disturbances
d) Disturbance of sleep-wake cycle
e) Emotional disturbance
how does delirium prresent and how long does it last?
Rapid onset
Diurnally fluctuating
Duration less than 6 months
what are the causes of delirium?
almost anything
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?
what is the difference between delirium and dementia?
Key thing is to take a good history and often not possible so take a good collateral history to get an idea of onset and what was going on before that
Delirium vs. Functional Psychosis
“Functional psychosis” or more correctly “primary psychosis”
Delirium hallucinations tend to be more visual but in primary psychosis they tend to be more stable
what is the prognosis of delirium?
Fluctuating course
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
Management:
Correct factors contributing to delirium - what may they be?
Disorientation
Dehydration
Constipation
Hypoxia
Immobility/limited mobility
Infection
Multiple medications
Pain
Poor nutrition
Sensory impairment
Sleep disturbance
Management of delirium:
Environmental and supportive measures - what could be done?
Education of relatives, medical and nursing staff
Make environment safe
Optimise stimulation
Orientation
management of delirium:
what medicaiton could be used?
Avoid sedation unless required to maintain safety
Evidence base and guidelines do not support use of medications in delirium
Antipsychotics – none better than any other. Caution in withdrawal states – seizure risk
Benzodiazepines – can prolong delirium
Promethazine – anticholinergic; sedative but can worsen delirium, caution in elderly
