Dementia and Delirium


A. Clouding of consciousness, i.e. reduced clarity of awareness of the environment, with reduced ability to Focus, sustain, or shift attention.
B. Disturbance of cognition, manifest by both:
(1) Impairment of immediate recall and recent memory, with relatively intact remote memory;
(2) Disorientation in time, place or person.
C. At least one of the following psychomotor disturbances:
(1) Rapid, unpredictable shifts from hypo-activity to hyper-activity;
(2) Increased reaction time;
(3) Increased or decreased flow of speech;
(4) enhanced startle reaction.
D. Disturbance of sleep or the sleep-wake cycle, manifest by at least one of the following:
(1) Insomnia, which in severe cases may involve total sleep loss, with or without daytime drowsiness, or reversal of the sleep-wake cycle;
(2) Nocturnal worsening of symptoms;
(3) Disturbing dreams and nightmares which may continue as hallucinations or illusions after awakening.
E. Rapid onset and fluctuations of the symptoms over the course of the day.

F. Objective evidence from history, physical and neurological examination or laboratory tests of an underlying cerebral or systemic disease (other than psychoactive substance-related) that can be presumed to be responsible for the clinical manifestations in A-D.

Comments : Emotional disturbances such as depression, anxiety or fear, irritability, euphoria, apathy or wondering perplexity, disturbances of perception (illusions or hallucinations, often visual) and transient delusions are typical but are not specific indications for the diagnosis

Delirium is marked by short term clouding of consciousness and changes in cognition Commonest organic disorder seen in clinical practice. 5-15% of all medical and surgical inpatients Acute onset, fluctuating course, rapid improvement and generally considered to be reversible disorder New memory registration & retention impaired Clouding of consciousness is or impaired consciousness or altered sensorium is main feature Attention reduced ability to direct, focus, sustain, and shift attention Disorientation (time > place > person)
Illusions & Hallucinations (most commonly visual) Psychomotor disturbance (hypo or hyperactive) carphologia /flocculation (picking movement at bed sheets/clothes Disturbed sleep wake cycle, insomnia, daytime drowsiness, nightmares Diurnal variations – worsening of symptoms in evening & night (sun downing) Emotional disturbance, e.g. depression, anxiety or fear, irritability, euphoria, apathy, or wondering perplexity It may occur at any age but is most common at age of 60 years, most cases recover within 4 weeks or less. However can last up to 6 months
Treatment: benzodiazepines (lorazepam) or antipsychotic (haloperidol)


G1. Evidence of each of the following

(1) A decline in memory, which is most evident in the learning of new information, although in more severe cases, the recall of previously learned information may be also affected. The impairment applies to both verbal and non-verbal material. The decline should be objectively verified by obtaining a reliable history from an informant, supplemented, if possible, by neuropsychological tests or quantified cognitive assessments. The severity of the decline, with mild impairment as the threshold for diagnosis, should be assessed as follows:

Mild: a degree of memory loss sufficient to interfere with everyday activities, though not so severe as to be incompatible with independent living (see comment on cultural aspects of "independent living" on page 24). The main function affected is the learning of new material. For example, the individual has difficulty in registering, storing and recalling elements in daily living, such as where belongings have been put, social arrangements, or information recently imparted by family members.

Moderate: A degree of memory loss which represents a serious handicap to independent living. Only highly learned or very familiar material is retained. New information is retained only occasionally and very briefly. The individual is unable to recall basic information about where he lives, what he has recently been doing, or the names of familiar persons.

Severe: a degree of memory loss characterized by the complete inability to retain new information. Only fragments of previously learned information remain. The subject fails to recognize even close relatives.

(2) A decline in other cognitive abilities characterized by deterioration in judgment and thinking, such as planning and organizing, and in the general processing of information. Evidence for this should be obtained when possible from interviewing an informant, supplemented, if possible, by neuropsychological tests or quantified objective assessments. Deterioration from a previously higher level of performance should be established. The severity of the decline, with mild impairment as the threshold for diagnosis, should be assessed as follows:

Mild : The decline in cognitive abilities causes impaired performance in daily living, but not to a degree making the individual dependent on others. More complicated daily tasks or recreational activities cannot be undertaken.

Moderate : The decline in cognitive abilities makes the individual unable to function without the assistance of another in daily living, including shopping and handling money. Within the home, only simple chores are preserved. Activities are increasingly restricted and poorly sustained.

Severe : The decline is characterized by an absence, or virtual absence, of intelligible ideation. The overall severity of the dementia is best expressed as the level of decline in memory or other cognitive abilities, whichever is the more severe (e.g. mild decline in memory and moderate decline in cognitive abilitiesindicate a dementia of moderate severity).

G2. Preserved awareness of the environment (i.e. absence of clouding of consciousness (as defined in F05, criterion A)) during a period of time long enough to enable the unequivocal demonstration of

G1. When there are superimposed episodes of delirium the diagnosis of dementia should be deferred.

G3. A decline in emotional control or motivation, or a change in social behavior, manifest as at least one of the Following:

(1) Emotional liability;
(2) Irritability;
(3) Apathy;
(4) Coarsening of social behaviour.

G4. For a confident clinical diagnosis, G1 should have been present for at least six months; if the period sincethe manifest onset is shorter, the diagnosis can only be tentative.

Comments: The diagnosis is further supported by evidence of damage to other higher cortical functions, such as aphasia, agnosia, apraxia. Judgment about independent living or the development of dependence (upon others) needs to take account of the cultural expectation and context. Dementia is specified here as having a minimum duration of six months to avoid confusion with reversible states with identical behavioral syndromes, such as traumatic subdural haemorrhage (S06.5), normal pressure hydrocephalus (G91.2) and diffuse or focal brain injury (S06.2 and S06.3).

Syndrome due to disease of brain, usually of chronic or progressive nature There is impairment of higher cortical functions evident for at least 6 months
• Stable level of consciousness

Memory & personality deterioration with lack of personal care Abstract thinking & Intellectual function
• Impulse control& Judgment

* The most common cause of Dementia is Alzheimer’s dementia (50 to60%) followed by Multifarct dementia(10 to15%) The risk factor for Alzheimer’s is female, family history, head injury and Down syndrome. It has gradual and downward progression.
* Reversible dementia ---15% Toxic, Hypothyroid & Multiinfarct
• 20 to 30% hallucinations
• 30 to 40% delusions
• 40 to 50% depression
• Catastrophic reaction
• Perseveration
• Urinary and fecal incontinence
• Aphasia, apraxia, agnosia and executive functions

Treatment : donepezil, rivastigmine, galantamine and tacrine are cholinesterase inhibiters Memantine, esterogen replacement therapy


A. Memory impairment, manifest in both:
(1) a defect of recent memory (impaired learning of new material), to a degree sufficient to interfere with daily living; and
(2) a reduced ability to recall past experiences.

B. Absence of:
(1) a defect in immediate recall (as tested, for example, by the digit span);
(2) clouding of consciousness and disturbance of attention, as defined in FO5, criterion A;
(3) global intellectual decline (dementia).

C. Objective evidence (physical & neurological examination, laboratory tests) and/or history of an insult to or a disease of the brain (especially involving bilaterally the diencephalic and medial temporal structures but other than alcoholic encephalopathy) that can reasonably be presumed to be responsible for the clinical manifestations described under A.
Comments: Associated features, including confabulations, emotional changes (apathy, lack of initiative), and lack of insight, are useful additional pointers to the diagnosis but are not invariably present.

In this syndrome the immediate memory is normal, recent memory is disturbed & remote memory is disturbed. Causes are-
- Thiamine deficiency (most commonly due to alcoholism Wernickes Encephalopathy Korsakoff syndrome)
• Hypoglycemia
• Herpes simplex
• Electroconvulsive therapy
• Lesions involving B/L limbic system (head injury, B/L posterior cerebral stroke)