Dementia Overview: Causes, Symptoms, and Management

Dementia ACQUIRED GLOBAL IMPAIRMENT OF HIGHER CEREBRAL FUNCTION, (usually >40yrs, but HIV/CJD earlier, acquired means NOT a learning disability) MEMORY, INTELLECT, COMPREHENSION, PERSONALITY, EMOTION & BEHAVIOUR (not delirium because onset slower – 6months+) A SYNDROME (not a single illness but includes specifics such as Alzheimers) & NOT TO BE CONFUSED WITH THE SYNDROME OF DELIRIUM/ACUTE CONFUSIONAL STATE DEMENTIA – ICD - 10 An acquired clinical syndrome characterised by global cognitive impairment, representing decline from previous level of functioning associated with impairment in functional abilities and often behavioural and psychiatric disturbances. ‘a syndrome due to disease of the brain, usually of a chronic or progressive nature, in which there is disturbance of multiple higher cortical functions, including memory, thinking, orientation, comprehension, calculation, learning capability, language, and judgement. Consciousness is not impaired. Impairments of cognitive function are commonly accompanied, occasionally preceded, by deterioration in emotional control, social behaviour, or motivation. The syndrome occurs in Alzheimer’s disease, in cerebrovascular disease, and in other conditions primarily or secondarily affecting the brain’. • • • Affects occupation & social functioning must be > 6 months distinguish early-onset dementia, before age of 65 and late-onset (over 65 = majority) GENERAL FEATURES Multiple Cognitive “Losses” sufficient interfere with social and occupational functioning • Memory (first & most prominent – recent memory worse affected) o Mild = forgetfulness in daily life o Later à long term with all aspects of memory affected o Impaired abstract thinking (e.g. proverbs) • Dysphasia – central language control – affects read, write, understand. Memory related • Dyspraxia – sequencing problem – also memory related • Judgement • Changes in personality and behaviour – due to frontal lobe involvement • Impaired judgement – loss of inhibitions due to frontal lobe involvement • Accentuation of personality traits (e.g. aggression, paranoia) – frontal lobe • Behavioural & Psychological Symptoms o Some get depressed o Challenging behaviour o Apathy o Agitation & Aggression o Disinhibition o Psychosis (delusions & Hallucinations (may develop in moderate severity, but usually short-lived)) o Wandering • Often Die from bronchopneumonia due to dysphagia NB: Avoid antipsychotics for as long as possible & only use with full assessment NB: Check if its delirium on mild dementia (if so its treatable to restore to prev. state) MANAGEMENT OF BEHAVIOURAL AND PSYCHIATRIC DISTURBANCES Most commonly a person with dementia who has become agitated and/or aggressive Thorough assessment: • Physical health • Mental state • Medication • Environment Commonly due to physical illness eg. UTI, chest infection but may be environmental/ emotional cause Check: ABC • Antecedents of behaviour • Behaviours themselves • Consequences Non-pharmacological/environmental/behavioural approaches first Avoid drug therapy but may be essential for serious aggression or psychosis “Start low, go slow”, perhaps refer INCIDENCE @ 5% prevalence 65+ population Rises with age, higher in low socio-economic class (education is protective) @ 20% of 80 +’s @ 25% of 85 +’s @ 30% of 90 +’s 20% in care, 80% at home Increased risk if +ve FH APP gene on Chr21 Presenilin 1 on Chr 14 (membrane proteins assoc with ER. If wrong cant support Presenilin 2 on Chr 1 brain architecture. Not AR/AD but multifactorial) Apo E type E4 (ApoE should carry cholesterol, E4=increased risk, E2 = protective) CAUSES IN >65s 60% 15-20% 15-20% Alzheimer’s disease = DEGERATIVE Vascular dementia (inc multiinfarct) RISK FACTORS = smoking, high cholesterol, male, heart disease, DM, HT DLB (Parkinsons = in substantial nigra, dementia = widespread) >5% Alcohol-related ‘Reversible’ (mostly young people) (30-70% of parkinsons patients develop dementia) CAUSES IN >65s 1st Alzheimer’ s 2nd Frontotemporal dementia (FTD) Other causes:Huntington’s disease Prion disease (CJD) – very rapid progression Infective – e.g. HIV Dementia, Herpes simplex encephalitis Toxic/metabolic causes (E.g. Copper) Picks Disease Neoplastic – mets cause infarct, short life expectancy Trauma – e.g. boxing à increased plaques and tangles REVERSIBLE CAUSES Space occupying lesion – e.g. tumour / subdural haematoma. (Focal picture) Normal Pressure Hydrocephalus – unusual gait, “heavy feet”, early urinary incontinence, atypical dementia. Due to increased pressure but brain atrophies (ventricles enlarge) à normal pressure. Manage with CSF shunt Vit B12 deficiency Severe hypothyroidism (often very ill if sever enough to affect brain) Neurosyphillis (increasing in incidence due to STDs) AGGRAVATING FACTORS Physical ill health (worsens coping) e.g. cardiac failure à decreased flow. Stroke rehab improves coping & lessens effect Psychological – carer stresses à depression à patient stressed Social – housing & financial stress ALZHEIMER’S DISEASE (very) gradual progressive decline in cognition and ability to function; may be brief plateaus; usually presents loss of memory, especially new learning & then later higher cortical functions (eg. language, praxis, executive (planning & decisions) function) affected and behavioural & psychiatric disturbance may be seen. PHYSIOLOGY Cortical atrophy, cerebellum less affected Neurofibrillary tangles seen in the grey matter & hippocampus Hyperphosphorylated tau proteins are insoluble à form paired helical filaments à disrupts axon transport & cells die NB: tangles occur in normal brain (increase with age), also parkinsons, post meningitis, SSPE and head injury (e.g. boxing) Senile plaques with “halo” are also seen in alzheimers Amyloid Precursor Protein (APP) from Chr 21 should be broken down by B-secretase. If G-secretase à Beta Amyloid à Insoluble & disrupts function forming plaques & tangles. Alzheimers more common in Downs Syn bec extra APP from extra Chr21 Genetic links are seen, but most cases are sporadic Disease modifying drugs are now available MANAGEMENT CHOLINESTERASE INHIBITORS (slows progression, not cure) cholinergic receptors very important for memory. Act to increase Ach, no effect on tangles/plaques NB: Also useful in other types of dementia donepezil (aricept) – licenced for warly-mod, improves memory NICE said NOT cost effective rivastigmine (exelon) galantamine (reminyl) GLUTAMATERGIC MODULATOR memantine (ebixa) OTHER TECH. APPROACHES neuroprotective tx’s, nerve growth factors vit.e & antioxidants (help preserve cognitive function) nsaids (for vascular dementia) hormone replacement therapy (rarely used) ? gene therapy – antibody to knock out G-secretase (success in mice, made humans very ill) ? stem cells VASCULAR DEMENTIA due to brain blood vessel disease; can present after acute vascular event (eg. stroke) or sub-acutely with accumulating events or more gradually with small vessel disease, presenting with more patchy deficits, perhaps attentional & executive/planning problems, gait disturbance and apraxia; fluctuation, neurological signs and behaviours that challenge are common Saw tooth progression with improvement between but never recovery to initial level DEMENTIA WITH LEWY BODIES (DLB) presents with recurrent visual hallucinations, fluctuating cognitive disturbance and motor features of Parkinsonism (these following/proceeding the cog. imp. within 1 year); often associated are falls, disturbed consciousness and autonomic dysfunction Lewy Bodies (containing ubiquitin & A-synuclein) are in the substantia nigra of Parkinsons patients BUT found everywhere inc cerebral cortex of DLB NB: important to diagnose as parkinsonian symptoms worsen if given antipsychotics for hallicinations FRONTOTEMPORAL DEMENTIA syndrome with various causes (eg. MND, AD & Pick’s), usually presents with language disturbance and/or behavioural difficulties (either disinhibition or apathy), more prominently impaired function than cognition; mainly “pre-senile” & relatively uncommon in older people; frontal type may be associated with overspending, poor hygiene, criminal or sexual behaviour, poor eating habits or repeated odd stereotyped behaviour PICKS DISEASE – affects frontal & temporal lobes Controls social skills à shoplifting, sexual dis-inhibitions Rapidly progressive with hyperaurality & no satiety Can occur in younger patients Pick bodies seen in grey matter general definition. general features. its prevalence. common causes. some reversible causes. aggravating factors. treatments appearing.