Dementia


Dementia (brain area) (usual age of onset)

Protein error

Cognitive symptoms

Neurologic symptoms

Psychiatric symptoms

Cortical dementias (early onset cognitive not motor)

Alzheimer’s disease (temporal-parietal cortex) (>65 years)

Tauopathy

• Significant memory deficits: first episodic and recent memory, without benefit from cuing. Later remote memory deficits

• Motor symptoms only in later stages: extrapyramidal or Parkinsonian rigidity

• Apathy and depression in early stage

• Language: starts with word-finding difficulties, later impaired comprehension, and empty speech

• Delusions and agitation in middle stage with disinhibition

• Visual-spatial impairment with spatial confusion

• Apraxia in the moderate stage

• Difficulties with organization

Frontal-temporal dementia (Pick’s disease—frontal-temporal cortex) (50–60 years)

Tauopathy

All

All

All

• Frontal subtype (behavioral variant)

• Memory is relatively preserved

• Can have Parkinsonism later in course of disease

• Apathy

• Temporal subtype (primary progressive aphasia)

Frontal subtype

• Can have incontinence

• Loss of insight

○ Semantic dementia

• Executive and behavioral dysfunction

• Compulsive-like behavior, perseveration

○ Progressive nonfluent aphasia

Temporal subtype

Frontal subtype

○ Logopenic variant

Semantic dementia

• Early prominent social or interpersonal misconduct

• Receptive language problems, with poor comprehension and loss of word meaning

• Disinhibition

• Fluent speech that is empty of content

Temporal subtype

• May also have impaired naming

• Apathy, disinhibition

• Preserved repetition

Semantic dementia

• Prosopagnosia

• Loss of empathy

Progressive nonfluent aphasia

• Expressive language problems, nonfluent

• Impaired naming, phonemic paraphasias, agraphia

• Impaired repetition

• Preserved comprehension

Logopenic variant

• Paucity of output

• Impaired naming

• Impaired repetition

• Slowed speech

• Preserved word meaning and grammar

• Phonological alexia (selective deficit in pseudo-word reading)

Posterior cortical atrophy (occipital cortex) (50–65 years)

Tauopathy

• Impaired visual-spatial processing

• Visual agnosia and prosopagnosia

• Impaired spatial navigation

• Impaired praxis

• Impaired reading and calculation

• Possible transcortical sensory aphasia aphasia

• Impaired ability to visually id entify and/or locate objects.

• Motor symptoms only in later stages: extrapyramidal or Parkinsonian rigidity

• Anxiety as a prominent symptom

• Apathy and depression

• Visual hallucinations and agitation in middle stage

Argyrophilic Grain disease (cingulate [limbic] cortex) (80–85 years)

Tauopathy

• Memory loss

• Limbic system dysfunction

• Agitation, irritability

• Executive dysfunction

• Depression

• ADL and IADL dysfunction in excess of overall cognitive dysfunction

• Delusions

Subcortical dementias (early onset motor not cognitive)

Parkinson’s disease (>65 years)

Synucleinopathy

• Dementia in 20–40 % with later stages of disease

• Parkinsonism: asymmetric tremor, bradykinesia, axial rigidity, gait abnormalities with small stride length, postural instability

• Hallucinations, delusions in 40 % in later stages (primary or related to treatment with dopaminergic agents)

• Executive dysfunction

• Autonomic dysfunction, dysphagia later in course

• Depression in 40 %

• Visuospatial deficits

• REM sleep behavior disorder

• Fluctuation of attention

• Impaired memory recall aided by cues

Huntington’s disease (35–45 years)

Polyglutamine disease

Cognitive problems may co-occur with motor and emotional symptoms (not entirely consistent with cortical/subcortical distinction)

• Involuntary jerking or writhing movements (chorea)

Emotional symptoms may co-occur with cognitive and motor symptoms (not entirely consistent with cortical/subcortical distinction)

• Difficulties with executive functioning, word finding, and memory

• Muscle problems, such as rigidity or muscle contracture (dystonia)

• Depression

• Slow or abnormal eye movements

• Irritability

• Impaired gait, posture and balance

• Obsessive-compulsive symptoms

• Dysarthria and dysphagia
 
Parkinson’s plus dementias (early onset cognitive and motor)

Dementia with Lewy bodies (>65 years)

Synucleinopathy

• Fluctuating cognition, especially fluctuations in attention and alertness

• 70 % have Parkinsonism, including axial rigidity, bradykinesia, postural instability, gait abnormalities

• Psychiatric features in early stage

• Transient disturbances of consciousness in 50–70 % may be mistaken for transient ischemic attacks

• Tremors less common than PD

• Especially visual hallucinations (usually colorful, often people and animals)—rarely happen early in other dementias

• Deficits in executive function, memory, attention, and language

• Autonomic dysfunction with falls and syncope in up to one third

• Psychosis similar to Parkinson’s disease with dementia but more common

• REM sleep behavior disorder

• Also other hallucinations, delusions

• 40 % have depression; similar to Parkinson’s disease with dementia but more than in Alzheimer’s disease

Multiple system atrophy (45–55 years)

Synucleinopathy

All

• Parkinsonism with axial rigidity, bradykinesia, postural instability, gait abnormalities

All

• Olivopontocerebellar atrophy (OPCA)

• Dementia uncommon

• Autonomic symptoms—urinary incontinence, postural hypotension, impotence, and syncope

• May have depression

• Striatonigral degeneration (SND)
 
• Mild frontal-subcortical system dysfunction involving attention and executive deficits

• Ataxia
 
• Shy-Drager syndrome (SDS)

• REM sleep behavior disorder

OPCA

• Greater ataxia and less prominent Parkinsonism and autonomic dysfunction

SND

• Prominent Parkinsonism and autonomic failure

SDS

• Ataxia, Parkinsonism, and autonomic dysfunction

Cortical-basilar degeneration (55–65 years)

Tauopathy

• Executive dysfunction

• Parkinsonism with bradykinesia, postural instability, gait abnormalities

• Depression common

• Aphasia in over 50 %

• Asymmetric akinetic-rigid syndrome

• Anxiety, irritability, disinhibition

• Asymmetric apraxia

• Alien limb phenomenon

Progressive supranuclear palsy (45–75 years)

Tauopathy

• Subcortical pattern

• Parkinsonism with axial rigidity, bradykinesia, postural instability, gait abnormalities

• Early personality changes

• Severe dementia is rare

• Vertical gaze palsy

• Pseudo-bulbar dysfunction (e.g., emotional incontinence)

• May have prominent executive dysfunction

• Dystonia of facial muscles

• Irritability, apathy, disinhibition
 
• Speech dysfunction

• Personality change frequent and early

Parkinsonism dementia—amyotrophic lateral sclerosis complex (30–70 years)

Tauopathy

• Executive dysfunction

• Axial rigidity, bradykinesia, without tremor

• Abulia-apathy

• Bradyphrenia

• Muscle weakness of extremities, face, tongue

• Hallucinations

• Impaired fine-motor coordination

• Falls

• Dysarthria and dysphagia

• Spasticity and hyperreflexia

Familial frontal-temporal dementia—amyotrophic lateral sclerosis complex (30–70 years)

Two subtypes:

Usually frontal/behavioral variant of FTD

• Axial rigidity, bradykinesia, without tremor

Usually frontal/behavioral variant of FTD

• TDP-43 proteinopathy

• Memory is relatively preserved

• Muscle weakness of extremities, face, tongue

• Apathy

• Protein C9orf72 error

• Prominent executive and behavioral dysfunction

• Impaired fine-motor coordination

• Loss of insight

These two subtypes are not well understood or differentiated

• May also have some language disturbance

• Falls

• Compulsive-like behavior, perseveration

• Dysarthria and dysphagia

• Social or interpersonal misconduct

• Spasticity and hyperreflexia

• Disinhibition

• Pseudo-bulbar palsy (emotional behaviors without subjective emotional experience)


Adapted from Hickey C, Chisholm T, Passmore M, O’Brien J, Johnston J. Differentiating the dementias: revisiting synucleinopathies and tauopathies. Curr Alzheimer Res. 2008;5:52–60



However, recent work suggests that the tauopathies and synucleinopathies have many similarities. For example, many patients with Alzheimer’s disease (a tauopathy) have numerous Lewy bodies (composed of synuclein). In addition many patients with progressive supranuclear palsy and cortical-basilar degeneration (both tauopathies) exhibit extrapyramidal dysfunction as is seen in synucleinopathy-related Parkinson’s disease. Patients with frontal-temporal dementia, which is a tauopathy, have also been shown to have synuclein-immunoreactive lesions [2]. In addition, although Alzheimer’s disease is categorized in this schema as a tauopathy, recent findings show that this disease also involves independent Aβ amyloid deposits [3].

In addition to the idiopathic degenerative dementias described above, there are some additional genetic disorders that result in dementia, and these are listed below but will not be discussed in further detail here:



  • Trinucleotide repeat disorders :



    • ○ Fragile X syndrome


    • ○ Fragile XE MR syndrome


    • ○ Friedreich’s ataxia


    • ○ Myotonic dystrophy


    • ○ Spinocerebellar ataxia types 8 and 12


  • Polyglutamine diseases :



    • ○ Spinocerebellar ataxia types 1, 2, 6, 7, 17


    • ○ Machado-Joseph disease


    • ○ Dentatorubral-pallidoluysian atrophy


    • ○ Spinal and bulbar muscular atrophy, X-linked 1

There are also a number of other conditions that can lead to dementia, and these are listed below but will not be discussed in further detail here:

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Jun 25, 2017 | Posted by in PSYCHOLOGY | Comments Off on Dementia

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