Clinical features

• Delirium
• Dementia
• Alzheimer’s disease
• Vascular dementia
• Dementia with Lewy Bodies (DLB)
• Fronto-temporal dementia (Pick’s disease)
• AIDS dementia complex (HIV encephalopathy)
• Prion diseases
• Huntington’s disease

Delirium (Acute confusional state, acute organic syndrome)

The onset is acute in nature. The course fluctuates with periodic lucid intervals. Clinical features may include the following:

• Drowsiness and disorientation in time and place
• Abnormalities of perception
• Anxiety
• Poor concentration and impaired memory
• Delusions and paranoid ideas.

Dementia

The usual mode of presentation is poor memory, usually short-term memory, but altered personality or behaviour can also feature in the early stages. The onset is often slow and insidious. Early symptoms may not be recognised by others or may be difficult to detect. An impaired attention span or reduced concentrations are common non-specific features.

As dementia progresses, difficulty in learning becomes more conspicuous and recent memory loss more noticeable. People become inflexible and less able to adapt to new situations. When the restricted abilities become stretched beyond their capacity, the person may experience a "catastrophic reaction" comprising an explosive outburst of grief or rage.

Although they may overlap, two major behavioural syndromes are recognised, having the following features:

• Apathy, inertia and loss of interest in work and hobbies.
• Restlessness, dis-inhibition, distractibility and loss of empathy and social skills.

Inability to self-care and disorientation are later features. Behaviour may become stereotypical or feature mannerisms (a peculiar or unusual characteristic mode of movement, action or speech). Irritability, anxiety, aggression and depression are all common features. Although insight is lost as the condition progresses, it may be retained to some degree early on, and can cause the person great distress.

Eventually speech and thought processes become incoherent to the point where the person can become mute.

Certain sub-types or syndromes have been described. Although there may be overlap, these are useful clinical descriptions -:

• Sub-cortical dementia is characterised by slowness of thought, difficulty with complex, sequential intellectual tasks, impoverishment of affect/mood and personality.
• Cortical dementia is characterised by early and prominent impairment of memory; reduced visuo-spatial abilities and difficulty with word finding.
• Semantic dementia can prove particularly disabling. It is characterised by selective, progressive loss of meaning for verbal and non-verbal material. Comprehension is impaired and the person has great difficulty with naming and categorising. Autobiographical memory (event based memory unique to each individual) is not usually affected. Semantic dementia is associated with temporal lobe atrophy.

Alzheimer’s disease

The onset of Alzheimer’s disease is often insidious and there are several stages.

The minimal stage:

The earliest cognitive deficit is impairment of episodic memory (memory for events or episodes, including day to day memory and new learning). People in this stage are said to have minimal or mild cognitive impairment (MCI) and may not fulfil the criteria for a diagnosis of dementia. The main clinical features at this stage are severe forgetfulness with often repetitive questioning and impairments in social function and / or job performance particularly concerning the retention of new information.

The mild stage:

As the disease progresses to mild Alzheimer’s disease, memory function worsens, particularly affecting recall (for example, forgetting recent visits or family events), increasing disability in managing complex day-to-day activities such as finances and shopping, mental inflexibility and poor concentration. Insight is variably affected often people retain a partial awareness of their difficulties but tend to underestimate the extent of the problem. Remote memory is relatively well preserved, with sparing of the most distant memories.

The moderate stage:

As the disease continues to progress, people often develop impairments in language, most typically word finding difficulties, a shrinking vocabulary and poor understanding of complex words and concepts. Visuo-spatial impairments and apraxia, which may develop at this stage, are particularly disabling, causing difficulty in dressing, cooking and performing other activities of daily living. In a small subgroup of people, language or visuo-spatial difficulties can be the first or most prominent presenting feature. As the cognitive deficits progress there is a worsening of language function and semantic memory and behavioural problems can be prominent. Non-cognitive psychiatric symptoms are common. In the earliest stages, apathy, anxiety and mood disturbance frequently occur. In the later stages, delusions occur in up to 50% and hallucinations in up to 30% of people. Agitation, restlessness, wandering and dis-inhibition cause considerable problems for carers.

The final stage:

The final stages of the disease are characterised by reduced speech output (or mutism), ambulatory difficulties, dependence and incontinence. Seizures and myoclonus (muscle spasm) are common late features.

Vascular dementia

The clinical features vary according to the site of the infarction.

Large infarcts are associated with language impairment, visuo-spatial disturbance, amnesia, apraxia, aphasia, agraphia, acalculia, right-left

disorientation and finger agnosia.

Smaller (or lacunar) infarcts are associated with impaired attention, forgetfulness,

apathy, emotional lability, speech disorder and amnesia. Both small and large infarcts may co-exist giving rise to a mixed picture.

Dementia with Lewy Bodies (DLB)

Lewy bodies are brain cell constituents that can be identified using specific staining techniques.

People typically present with a progressive cognitive decline, similar to that seen in Alzheimer’s disease. There are however, a number of characteristic and distinguishing features that include -:

• Spontaneous fluctuation in cognitive abilities, particularly alertness and attention, lasting days or even weeks
• Visual hallucinations
• Parkinsonism
• Repeated falls
• Sensitivity to anti-psychotic medication
• Compared to people with Alzheimer’s disease, those with DLB tend to have greater deficits in attention and visuo-spatial processing, but memory loss may be less prominent.

Fronto-temporal dementia (Pick’s disease)

People with fronto-temporal dementia present with symptoms related to either frontal or temporal lobe degeneration. However as the disease progresses there is considerable overlap of symptoms.

Frontal lobe degeneration results in impaired judgment, an indifference to domestic and professional responsibilities and apathy. Social skills deteriorate and there can be socially inappropriate behaviour, jocularity, abnormal sexual behaviour and theft. Many patients are restless with obsessive-compulsive behaviour such as hoarding food. People become rigid and stereotyped in their daily routines and food choices.

Temporal lobe degeneration results in an expressive aphasia. The person typically complains of “loss of memory for words” and has fluent empty speech, with incorrect naming of words (for example, the person says animal for zebra).

Memory is relatively spared in the early stages but does deteriorate as the disease progresses.

AIDS dementia complex (HIV encephalopathy)

Characteristic symptoms are decreased memory and concentration or low mood and apathy. It may be difficult to differentiate in the early stages from a depressive illness. The dementia progresses to cause global intellectual impairment with major neurological signs such as ataxia.

Prion diseases

Variant Creutzfeldt-Jacob disease (vCJD) presents with psychiatric symptoms including depression, anxiety and withdrawal followed after a period of month’s progressive ataxia, dementia and involuntary movements.

Creutzfeldt-Jacob disease (CJD) causes a rapidly progressive dementia.

Huntington’s disease

Clinical features include choreiform (purposeless writhing) movements. Psychiatric features such as depression, irritability and personality changes often precede the choreiform movements. Progressive cognitive impairment appears later on in the illness. Characteristically this involves deficits in attention and cognitive slowing causing problems with thinking and information retrieval. Memory is moderately impaired but not as severely as in Alzheimer’s disease.

Click on the links for details of -:

 

Delirium (Acute confusional state, acute organic syndrome)

The onset is acute in nature. The course fluctuates with periodic lucid intervals. Clinical features may include the following:-

• Drowsiness and disorientation in time and place
• Abnormalities of perception
• Anxiety
• Poor concentration and impaired memory
• Delusions and paranoid ideas.

Dementia

The usual mode of presentation is poor memory, usually short-term memory, but altered personality or behaviour can also feature in the early stages. The onset is often slow and insidious. Early symptoms may not be recognised by others or may be difficult to detect. An impaired attention span or reduced concentrations are common non-specific features.

As dementia progresses, difficulty in learning becomes more conspicuous and recent memory loss more noticeable. People become inflexible and less able to adapt to new situations. When the restricted abilities become stretched beyond their capacity, the person may experience a “catastrophic reaction” comprising an explosive outburst of grief or rage.

Although they may overlap, two major behavioural syndromes are recognised, having the following features:

• Apathy, inertia and loss of interest in work and hobbies.
• Restlessness, dis-inhibition, distractibility and loss of empathy and social skills.

Inability to self-care and disorientation are later features. Behaviour may become stereotypical or feature mannerisms (a peculiar or unusual characteristic mode of movement, action or speech). Irritability, anxiety, aggression and depression are all common features. Although insight is lost as the condition progresses, it may be retained to some degree early on, and can cause the person great distress.

Eventually speech and thought processes become incoherent to the point where the person can become mute.

Certain sub-types or syndromes have been described. Although there may be overlap, these are useful clinical descriptions -:

• Sub-cortical dementia is characterised by slowness of thought, difficulty with complex, sequential intellectual tasks, impoverishment of affect/mood and personality.
• Cortical dementia is characterised by early and prominent impairment of memory; reduced visuo-spatial abilities and difficulty with word finding.
• Semantic dementia can prove particularly disabling. It is characterised by selective, progressive loss of meaning for verbal and non-verbal material. Comprehension is impaired and the person has great difficulty with naming and categorising. Autobiographical memory (event based memory unique to each individual) is not usually affected. Semantic dementia is associated with temporal lobe atrophy.

Alzheimer’s disease

The onset of Alzheimer’s disease is often insidious and there are several stages.

The minimal stage:

The earliest cognitive deficit is impairment of episodic memory (memory for events or episodes, including day to day memory and new learning). People in this stage are said to have minimal or mild cognitive impairment (MCI) and may not fulfil the criteria for a diagnosis of dementia. The main clinical features at this stage are severe forgetfulness with often repetitive questioning and impairments in social function and / or job performance particularly concerning the retention of new information.

The mild stage:

As the disease progresses to mild Alzheimer’s disease, memory function worsens, particularly affecting recall (for example, forgetting recent visits or family events), increasing disability in managing complex day-to-day activities such as finances and shopping, mental inflexibility and poor concentration. Insight is variably affected often people retain a partial awareness of their difficulties but tend to underestimate the extent of the problem. Remote memory is relatively well preserved, with sparing of the most distant memories.

The moderate stage:

As the disease continues to progress, people often develop impairments in language, most typically word finding difficulties, a shrinking vocabulary and poor understanding of complex words and concepts. Visuo-spatial impairments and apraxia, which may develop at this stage, are particularly disabling, causing difficulty in dressing, cooking and performing other activities of daily living. In a small subgroup of people, language or visuo-spatial difficulties can be the first or most prominent presenting feature. As the cognitive deficits progress there is a worsening of language function and semantic memory and behavioural problems can be prominent. Non-cognitive psychiatric symptoms are common. In the earliest stages, apathy, anxiety and mood disturbance frequently occur. In the later stages, delusions occur in up to 50% and hallucinations in up to 30% of people. Agitation, restlessness, wandering and dis-inhibition cause considerable problems for carers.

The final stage:

The final stages of the disease are characterised by reduced speech output (or mutism), ambulatory difficulties, dependence and incontinence. Seizures and myoclonus (muscle spasm) are common late features.

Vascular dementia

The clinical features vary according to the site of the infarction.

Large infarcts are associated with language impairment, visuo-spatial disturbance, amnesia, apraxia, aphasia, agraphia, acalculia, right-left

disorientation and finger agnosia.

Smaller (or lacunar) infarcts are associated with impaired attention, forgetfulness,

apathy, emotional lability, speech disorder and amnesia. Both small and large infarcts may co-exist giving rise to a mixed picture.

Dementia with Lewy Bodies (DLB)

Lewy bodies are brain cell constituents that can be identified using specific staining techniques.

People typically present with a progressive cognitive decline, similar to that seen in Alzheimer’s disease. There are however, a number of characteristic and distinguishing features that include -:

• Spontaneous fluctuation in cognitive abilities, particularly alertness and attention, lasting days or even weeks
• Visual hallucinations
• Parkinsonism
• Repeated falls
• Sensitivity to anti-psychotic medication
• Compared to people with Alzheimer’s disease, those with DLB tend to have greater deficits in attention and visuo-spatial processing, but memory loss may be less prominent.

Fronto-temporal dementia (Pick’s disease)

People with fronto-temporal dementia present with symptoms related to either frontal or temporal lobe degeneration. However as the disease progresses there is considerable overlap of symptoms.

Frontal lobe degeneration results in impaired judgment, an indifference to domestic and professional responsibilities and apathy. Social skills deteriorate and there can be socially inappropriate behaviour, jocularity, abnormal sexual behaviour and theft. Many patients are restless with obsessive-compulsive behaviour such as hoarding food. People become rigid and stereotyped in their daily routines and food choices.

Temporal lobe degeneration results in an expressive aphasia. The person typically complains of “loss of memory for words” and has fluent empty speech, with incorrect naming of words (for example, the person says animal for zebra).

Memory is relatively spared in the early stages but does deteriorate as the disease progresses.

AIDS dementia complex (HIV encephalopathy)

Characteristic symptoms are decreased memory and concentration or low mood and apathy. It may be difficult to differentiate in the early stages from a depressive illness. The dementia progresses to cause global intellectual impairment with major neurological signs such as ataxia.

Prion diseases

Variant Creutzfeldt-Jacob disease (vCJD) presents with psychiatric symptoms including depression, anxiety and withdrawal followed after a period of month’s progressive ataxia, dementia and involuntary movements.

Creutzfeldt-Jacob disease (CJD) causes a rapidly progressive dementia.

Huntington’s disease

Clinical features include choreiform (purposeless writhing) movements. Psychiatric features such as depression, irritability and personality changes often precede the choreiform movements. Progressive cognitive impairment appears later on in the illness. Characteristically this involves deficits in attention and cognitive slowing causing problems with thinking and information retrieval. Memory is moderately impaired but not as severely as in Alzheimer’s disease.

• Specific Neuro-psychiatric syndromes
• Secondary psychiatric syndromes
• Memory disorders
• Head Injury – Introduction and Clinical Features
• Mini Mental State Examination
• TYM Screening Test for Alzheimer’s disease

Amended May 2011