Dementia Etiology

• Dementia is a pathological process marked by a progressive cognitive deficit, with preserved consciousness.
• It implies decline from a previous level of functioning, affecting multiple cognitive domains and leading to impairment in social and occupational functions.
• Dementia is not equivalent to poor intellectual function or mental retardation, which are developmental and static disorders.

Etiology of Dementia

• The most frequent causes in individuals over 65 include Alzheimer's disease, vascular dementia, and mixed Alzheimer's and vascular dementia.
• Other causes, representing around 10%, are dementia with Lewy bodies, Pick's disease, frontotemporal dementias, normal pressure hydrocephalus, alcoholic dementia, infectious dementia (like HIV or syphilis), and Parkinson's disease.
• Some dementias evaluated in clinical settings may be attributed to reversible causes such as metabolic alterations (e.g., hypothyroidism), nutritional deficiencies (e.g., vitamin B12 or folate deficiency), or depression-related dementia syndrome.

Clinical Points of Dementia

• Critical clinical points include identifying the syndrome and clinically assessing its cause.
• Dementia can be progressive, static, permanent, or reversible, with an underlying cause always assumed, even if it's sometimes impossible to determine.
• Reversibility of dementia depends on the underlying pathological disorder and the availability and application of effective treatment; approximately 15% of patients experience reversible dementia if treatment starts before irreversible lesions appear.

Diagnosis and Clinical Presentation

• The DSM-5 distinguishes between major and mild neurocognitive disorder (dementia), based on functional levels, while the underlying etiology is similar.
• Diagnosis involves clinical exploration, including mental status examination, and information from the patient's family, friends, and co-workers.
• Personality changes in patients over 40 raise suspicion.
• Physicians should note patient complaints of intellectual decline and forgetfulness, as well as signs of evasion, denial, or rationalization to conceal cognitive deficits.
• Excessive orderliness, social withdrawal, or focusing on minute details can be characteristic, and outbursts of anger or irony may occur.
• Emotional lability, neglect of appearance and personal hygiene, disinhibited comments and inappropriate jokes, blunted affect, apathy, or facial expression emptiness indicate dementia, especially with memory decline.
• Memory loss is often an early and prominent feature, especially in cortical dementias like Alzheimer's.
• Early in Alzheimer's, memory impairment is mild and more pronounced for recent events; individuals forget phone numbers, conversations, and daily events.
• As dementia progresses, the impairment worsens, and only information learned at a young age is retained (e.g., place of birth).
• Orientation to person, place, and time becomes progressively affected; patients may forget how to return to their room after using the bathroom.
• Regardless of disorientation severity, the level of consciousness is not impaired.
• Dementing processes affecting the cortex (primarily Alzheimer's and vascular dementia) can impact language abilities.

Psychiatric and Neurological Changes

• Personality changes are particularly alarming for families of individuals with dementia.
• Pre-existing personality traits may become accentuated.
• Patients can become introverted and less concerned about the effects of their behavior on others.
• Individuals with dementia and paranoid delusions may be hostile towards family and caregivers.
• Patients with frontal and temporal lobe involvement may exhibit substantial personality changes and can be irritable and explosive.
• Delusions and hallucinations are present in 20-30% of dementia patients (mainly Alzheimer's) and delusions in 30-40%, often paranoid or persecutory and unsystematized; complex and systematized delusions can occur.
• Physical aggression and violence are common in demented patients with psychotic symptoms.
• Mood disorders: Depression and anxiety are significant symptoms in approximately 40-50% of dementia patients; full depressive syndrome may be present only in 10-20% of cases.
• Patients may exhibit pathological laughter or crying (extreme emotions) without apparent trigger.
• Cognitive changes: In addition to aphasias, apraxias and agnosias are common. Other associated neurological signs include epileptic seizures (observed in about 10% of Alzheimer's patients and 20% of vascular dementia patients) and atypical neurological presentations, such as parietal lobe syndromes.
• Neurological examination may reveal primitive reflexes and myoclonic seizures.
• Patients with vascular dementia may experience headache, dizziness, syncope, paresis, focal neurological signs, and sleep disturbances, possibly due to cerebrovascular disease location.
• Pseudobulbar palsy, dysarthria, and dysphagia are more common in vascular dementia than in other conditions causing dementia.

Abstraction and Catastrophic Reaction

• Patients with dementia exhibit reduced capacity for "abstract attitude" as defined by Kurt Goldstein.
• There is difficulty generalizing from a single example, forming concepts, and understanding similarities and differences.
• Reduced problem-solving ability, logical reasoning, and judgment is observed.
• Goldstein described a catastrophic reaction characterized by agitation due to subjective awareness of intellectual deficits under stressful circumstances.
• Individuals compensate to avoid demonstrating intellectual failure; they may change the subject, joke, or distract the interviewer.
• Poor judgment and impulse control are frequent, especially in frontal lobe dementias, leading to vulgar language, inappropriate jokes, neglect of appearance and hygiene, and disregard for social norms.

Sundowning Syndrome

• This syndrome is characterized by somnolence, confusion, ataxia, and accidental falls.
• It occurs in excessively sedated elderly individuals and dementia patients who react adversely to low doses of psychoactive drugs.
• Sundowning also occurs in patients when external stimuli are reduced, such as light and interpersonal orientation cues.

Treatment for Dementia

• The first step is confirming the diagnosis; accurate diagnosis is imperative because progression can be halted or even reversed with appropriate treatment.
• Preventive measures are important, especially in vascular dementia, including dietary changes, exercise, and controlling diabetes mellitus and hypertension.
• Medications include antihypertensives, anticoagulants, or antiplatelet agents.
• Blood pressure control should aim for the upper end of the normal range, as this can improve cognitive function in vascular dementia patients.
• Low blood pressure can worsen cognitive function.
• The choice of antihypertensive may be significant as beta-adrenergic receptor antagonists have been associated with increased cognitive decline.
• Angiotensin-converting enzyme (ACE) inhibitors and diuretics have not been linked to increased cognitive decline and may reduce blood pressure without affecting cerebral blood flow, which supposedly correlates with cognitive function.
• Surgical removal of carotid plaques may prevent further vascular events in carefully selected patients.
• The overall therapeutic strategy for patients with dementia includes facilitating supportive medical care, emotional support for patients and families, and pharmacological treatment for specific symptoms, including disorganized behavior.

Pharmacological Treatment

• Hypnotic-sedatives may be prescribed for insomnia and anxiety, antidepressants for depression, and antipsychotics for delusions and hallucinations. Physicians should be aware of adverse effects that may be worse in the elderly (e.g., disinhibition, confusion, and excessive sedation).
• Medications with high anticholinergic activity should be avoided.
• Donepezil, rivastigmine, galantamine, and tacrine are cholinesterase inhibitors used to treat mild to moderate cognitive impairment in Alzheimer's disease.
• They reduce inactivation of the neurotransmitter acetylcholine, enhancing cholinergic neurotransmission, which moderately improves memory and goal-directed thinking.
• These drugs are useful for patients with mild to moderate memory loss who have sufficient cholinergic neurons in the basal prosencephalon to benefit from increased cholinergic neurotransmission.