Dementia
Dr.Balan Stephen
Definition
The dementias are heterogeneous group of psychiatric disorders
They are characterized by loss of previous levels of cognitive, executive and memory (anterograde/retrograde) functions in a state of full alertness.
The loss of socioeconomic productivity and burden to family care givers are profound.
Incidence
Dementia is most common in the elderly.
With the increasing age of population, the prevalence of dementia is expected to double by 2030.
Patients with dementia have increased rates of institutionalization and mortality.
Clinical Features
Changes in personality:
Patients with frontal and temporal lobe involvement are likely to have marked personality changes and may be irritable and explosive. Changes in personality of a person with dementia are especially disturbing for the families and caretakers of the affected patients.
They may also become introverted
They are less concerned about the effect of their behaviour on others.
Those with paranoid delusions are generally hostile to family members.
Hallucinations and delusions:
20 to 30% patients with dementia, (primarily Alzheimer's dementia) have hallucinations.
30 to 40 % have delusions, primarily of a paranoid or persecutory and unsystematized nature.
Physical aggression and other forms of violence are common in demented persons who also have psychotic symptoms.
Mood
Depression and anxietyare major symptom in 40 per cent of patients with dementia.
May also exhibit pathological laughter or crying - that is extremes of emotions- with no apparent provocation.
Cognitive Changes
Aphasias
Apraxia
Agnosias are common, and they are included as potential diagnostic criteria.
Neurological signs
Seizures,
Primitive reflexes such as grasp. Snout, palmo- mental reflexes. Myoclonic jerks.
In vascular dementia : neurological symptoms such as headache, dizziness, faintness, weakness and sleep disturbances. Pseudo bulbar palsy and dysarthria and dysphagia are common.
Catastrophic Reaction
Patients with dementia have reduced ability to apply abstract attitude. Patients have difficulty generalizing from a single instance, forming concepts, and grasping similarities and differences among concepts.
Furthermore the ability to solve problems, to reason logically and to make sound judgement is compromised.
Marked by agitation secondary to subjective awareness of intellectual deficits under stressful circumstances.
Patient attempts to compensate for deficits by using strategies to avoid demonstrating failures in intellectual performance.
They change the subject. Make jokes, or otherwise divert the interviewer.
Lack of judgement and poor impulse control appear (frontal lobe). Examples of these impairments include coarse language, inappropriate jokes, neglect of personal appearance and hygiene and a general disregard for the conventional rules of social conduct.
Sundowner Syndrome
Characterized by drowsiness, confusion, ataxia, and accidental falls. it occurs in older people who are overly sedated and in patients with dementia who react adversely to even small dose of a psychoactive drug.
It occurs in demented patients when external stimuli such as light and interpersonal orienting cues are diminished.
Causes of Dementia
Degenerative:
Alzheimer's disease
fronto- temporal dementias including picks disease
Parkinson's disease
Huntington's chorea
Vascular dementia
cerebro vascular disease
Cerebral emboli
Demyelination : Multiple sclerosis
Head Trauma
Repeated injury (e.g. boxing).
Space occupying lesions
Tumour(secondarytumours more common than primary)
Subarachnoid, subdural haemorrhages ( reversible)
Infections : HIV, Syphilis
Prion diseases
cruetzfeldt - Jacob disease
Physilogical : Epilepsy (reversible), Normal pressure hydrocephalus (reversible)
Anoxic Damage
Cardiac or respiratory arrest
Cardiacfailure
Carbon monoxide poisoning
Metabolic : Chronic vitamin deficiencies (reversible), Metabolic disturbances (reversible), Endocrinopathies(reversible), Liver or renal failure
Drugs and Toxins
Alcohol induced dementia, Substance misuse, Heavy metals
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