General Information
Dementia is a disorder in brain functions that develops as a result of damage to the central nervous system.
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Dementia |
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cognitive |
Memory |
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Attention |
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Language |
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visual spatial functions |
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Praxis (using tools, dressing) |
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Gnosis (recognition of objects) |
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Behaviour |
personality changes |
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Perception disorders (hallucination) |
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Thought Disorder |
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functional |
Daily life activity on the street |
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Daily life activity at home |
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self care |
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Cognitive disorders: Memory; inability to remember events from the recent past
Attention; difficulty concentrating
Language; difficulties in finding words, understanding, reading and writing
Visual spatial functions; roaming in foreign places
Behaviors: Personality changes, mood disorders (irritable, restless, reluctant)
Functional: Going to work, being able to travel, cooking, dressing, shaving, going to the toilet.
In addition to these, complaints related to motor (gait disturbance, slowness of movement, weakness), autonomic (incontinence, constipation, sweating), sleep (REM behavior disorder, etc.) may be seen.
Classification
primary (degenerative)
1. Alzheimer's (most common cause 60%)
2. Dementia with Lewy bodies
3. Fronto-temporal dementia
4. With movement disorder
Parkinson's disease
Huntington's disease
Wilson's disease
Neuroacanthocytosis
5. Prion diseases
Creutzfeldt-Jakob Disease
Secondary
1. Vascular dementia
2. Normal pressure hydrocephalus
3. Toxic-metabolic causes
Vitamin B12 deficiency
Wernicke-Korsakoff disease (thiamine deficiency)
hypothyroidism
Organic solvents-drugs
4. Intracranial space-occupying lesions
neoplasia
Subdural hematoma
5. Infection
6. Autoimmune-Inflammatory (MS, Behçet's disease)
7. Psychiatric causes (depression)
Primary (Degenerative) Dementias
Alzheimer's Disease
• It is the most common cause of dementia.
• It has an insidious and slow course.
• Full criteria; Dementia table confirmed in mini mental test and similar tests,
• Disruption in two or more cognitive processes
• No unconsciousness
• The age of onset is often after 65 years.
Genetic features:
They have autosomal dominant inheritance. Three distinct genes have been identified; Amyloid precursor protein (APP) presenilin 1 and 2 (PSEN1 and PSEN2)
Because the APP gene is located on the 21st chromosome, patients with Down syndrome develop Alzheimer's dementia at the age of 30.
The biggest risk factor in etiology is aging. Being female, low education, family history of dementia, APOE-E4 allele, head trauma, aluminum exposure, autoimmunity, other etiologic causes.
High education level APOE-E2 is protective.
In morphology, sulci and ventricles are enlarged and gyri are narrowed.
Atrophy is most prominent in the amygdala, hippocampus, parietal, temporal, frontal cortex, and basal forebrain.
Microscopic findings
amyloid plaques
neurofibrillary tangles
Hirano bodies
Loss of cholinergic innervation
Neuron and synapse loss
It is granulovacuolar degeneration.
Neurofibrillary tangles contain hyperphosphorylated tau, ubiquitin, and A-ᵝ amyloid deposits.
Neurofibrillary tangles first form in the hippocampus (responsible for memory) as
Diagnosis
1. Diagnosis is made by excluding other possible causes of dementia.
2. An increase in tau proteins can be seen in CSF.
3. MRI and CT can show atrophic brain tissue and enlarged ventricles. With the help of SPECT, areas of hypoperfusion can be shown.
4. Definitive diagnosis of Alzheimer's is made by biopsy.
Treatment
NMDA-glutamate receptor antagonists (memantine)
Tacrine, galantamine, rivastigmine, donezepil, which are centrally acting anticholinesterases, are used.
Prognosis
The disease usually starts insidiously and progresses slowly.
Average life expectancy is 8 years.
With cholinergic agents, life expectancy can be extended by 1-2 years.
Dementia with Lewy Bodies
• Progressive cognitive impairment that will affect normal social or occupational work
• Mental fluctuation with severe changes in attention and alertness
• Repetitive visual hallucinations
• Parkinson's motor features are spontaneously present. (If the dementia starts before or together with parkisonism, it becomes dementia with Lewy bodies.)
Frontotemporal Dementia
• There is frontotemporal lobar atrophy on MRI and CT.
• Personality changes due to frontal lobe atrophy are prominent in the clinic.
• It differs from Alzheimer's disease in that behavioral disorders precede cognitive disorders in the beginning.
• Acetylcholine is normal. Anticholinesterases are ineffective.
Dementias Associated with Movement Disorder
Parkinson's disease:
It is the addition of a dementia picture to a patient with Parkinson's over the years. Visual hallucinations are present.
Huntington's disease:
It starts at the age of 40-50 years.
There are autosomal dominant, trinucleotide repeats (CAG).
The initial finding is chorea (difficulty in writing, impaired fine motor movements).
Dementia develops after chorea and psychiatric symptoms.
Aphasia, apraxia, agnosia, global cognitive dysfunction are seen in the late period.
Wilson's disease:
The young patient enters the differential diagnosis in dementia.
Neuroacanthocytosis:
Distorted blood cells (acanthocytes) and neurological abnormalities are a group of diseases, especially with movement disorders. It is most common in chorea. Seizures may accompany dementia
Creutzfeldt-Jakob Disease
• It is a prion disease characterized by rapidly progressive dementia.
• Cerebral cortex, basal ganglia, cerebellum, brain stem and spinal cord are involved.
• 3 other prion diseases in humans:
Kuru (dementia)
Gerstmann-Straussler syndrome (dementia)
Fatal familial insomnia (dementia)
• Psychiatric symptoms may occur (anxiety, euphoria, depression, delusion).
• The most important clinical finding is myoclonus.
• Apart from this, rigidity, bradykinesia, tremor, chorea may be seen.
• Death occurs in an average of 1 year.
Secondary Dementias
Vascular Dementia
• Also known as multiinfarct dementia.
• It is characterized by multiple bilateral supratentorial infarcts.
• Its neuropathology is in the form of bleeding, infarction, neuronal loss and dementia.
• Dementia that occurs within 3 months of a detectable stroke.
• They do not benefit from treatment as much as Alzheimer's patients.
Normal Pressure Hydrocephalus
• It is seen together with gait disturbance, urinary incontinence and forgetfulness. They benefit from treatment.