PRAXIS Types of Dementias

Alzheimer's disease (AD) primarily affects the cortical regions of the brain.

Insidious onset: The disease develops gradually over time.

More likely after age 65: AD is more common in older adults, especially those above the age of 65.

Progressive course: The disease worsens over time.

Slow course with plateaus not unusual: Although it progresses, there may be periods of stability or plateaus in symptoms.

Can be familial or non-familial: AD can be hereditary (familial) or sporadic (non-familial) in its occurrence.

Can coexist with other conditions such as Parkinson's disease: AD may occur concurrently with other neurodegenerative disorders like Parkinson's disease.

AD is characterized by the proliferation of neural plaques and neurofibrillary tangles in the brain, which can be observed during autopsy.

Aphasia is common: Language deficits are often observed in individuals with AD.

Starting as either fluent or non-fluent: Aphasia may manifest as either fluent (with normal speech flow) or non-fluent (with difficulty in producing speech).

Semantic system most affected: The ability to understand and use meaningful words and concepts is significantly impacted.

Syntax and phonology affected later: As the disease progresses, difficulties with sentence structure and speech sounds may arise.

Language comprehension deficits: Difficulty understanding spoken or written language.

Difficulty with topic maintenance: Trouble staying on topic during conversations.

Echolalia: Repeating others' words or phrases without meaningful intent.

Lack of meaningful speech: The speech becomes less coherent and meaningful.

Gradual progression to mutism: A gradual loss of the ability to speak.

Depression: Feelings of sadness and hopelessness.

Insomnia: Difficulty falling or staying asleep.

Incontinence: Loss of control over bladder or bowel movements.

Delusions: False beliefs or perceptions not based on reality.

Agitation and restlessness: Feelings of anxiety and restlessness.

Hyperactivity: Increased level of activity or restlessness.

Disorientation: Confusion about time, place, and identity.

Delusions of persecution: Belief that one is being targeted or harmed by others.

Loss of initiative: Decreased motivation and initiation of activities.

Also known as Multi Infarct Dementia (MID), it is called so when multiple lesions or infarcts are present in both gray and white matter of the brain.

Vascular Dementia is caused by multiple strokes, some of which may not have noticeable clinical signs.

Symptoms may begin suddenly and often progress in a stepwise fashion after each small stroke.

Vascular Dementia may coexist with Alzheimer's disease in some cases.

Vascular Dementia results from vascular disease, which leads to damage in cortical areas of the brain due to reduced blood flow.

The symptoms of Vascular Dementia can be similar to those of Alzheimer's disease, making it difficult to make a firm diagnosis.

Motor Speech Disorders: Motor speech disorders are prominent in Vascular Dementia, leading to slurred speech and difficulties in word retrieval.

Cognitive Symptoms: Difficulty following instructions, confusion, problems with short-term memory, and getting lost in familiar places are common cognitive symptoms.

Mood and Emotional Changes: Depression and mood changes may also be observed in individuals with Vascular Dementia.

Impaired Coordination: Problems with coordination and balance are among the physical symptoms of the condition.

This form of dementia is also referred to as Binswanger's Disease.

It is usually caused by chronic, untreated hypertension (high blood pressure).

The disease results in the thickening and narrowing of arteries that supply blood to subcortical areas of the brain.

Speech and Communication: Individuals with this form of dementia may experience difficulty with speech (dysarthria) and have less spontaneous communication.

Swallowing Difficulties: Dysphagia, or difficulty with swallowing, can also be observed.

Cognitive Symptoms: Subcortical Vascular Dementia leads to progressive loss of memory and other cognitive functions, including difficulties with organization, attention, and decision-making.

Emotional Symptoms: Apathy, irritability, and depression may be present in affected individuals.

Motor Symptoms: Slowness, poor balance, and an unsteady gait can be observed.

Urinary Incontinence: Individuals with Subcortical Vascular Dementia may experience urinary incontinence, which is not caused by urological disease.

LBD is a type of dementia characterized by the presence of Lewy bodies, which are intraneuronal cytoplasmic inclusions found typically in the substantia nigra area of the brain at autopsy.

- Cognitive Fluctuations: In LBD, there are periods of normal cognition alternating with abnormal cognition, leading to cognitive fluctuations.

- Motor Speech Disorder: Individuals with LBD may experience a motor speech disorder, characterized by hypophonia (soft speech) and disorganized speech.

- Hallucinations: Visual and auditory hallucinations are common in LBD. These individuals may perceive things that are not present in reality.

- Fluctuations in Alertness and Attention: There are pronounced fluctuations in alertness and attention in LBD, and individuals may experience periods of delirium (confusion) and daytime drowsiness.

- Parkinsonian Motor Symptoms: LBD is associated with motor symptoms similar to Parkinson's disease, such as rigidity and a loss of spontaneous movement.

LBD has a progressive course, and the disease often advances rapidly.

FTD is a type of dementia that primarily affects the frontal and temporal lobes of the brain.

Pick's disease is a specific subtype of FTD characterized by focal cortical atrophy and degeneration in the frontal and temporal lobes.

FTD typically has an insidious onset, with symptoms appearing gradually. It is more likely to develop before the age of 65. The disease has a progressive course, often progressing slowly over time.

FTD is associated with two kinds of neuronal abnormalities: Pick bodies, which are dense intracellular formations in the cytoplasm, and Pick cells, which are inflated neurons.

Speech and Language Symptoms: Individuals with Pick's disease may experience reduced speech output and nonfluent speech. There is a progressive decrease in expressive vocabulary, and they may have word-finding difficulties. Spontaneous conversation may be reduced, and echolalia (repetition of others' words) and meaningless repetition of phrases can occur.

Behavioral Changes: FTD is characterized by a wide range of behavioral changes, particularly in the frontal lobe variant. There may be executive dysfunction in the frontal variant, leading to difficulties in planning and decision-making. Personality changes and disregard for social conventions may be observed. Uninhibited behavior, including inappropriate social behavior, can also occur.

Emotional Symptoms: Emotional symptoms such as depression, irritability, and mood fluctuations may be present in individuals with Pick's disease.

PPA is a specific subtype of FTD that primarily affects language function while preserving other cognitive abilities until the advanced stages.

PPA may be caused by various underlying diseases, and there is a possibility of inherent genetic preprogramming in some cases.

Primary Progressive Aphasia (PPA) is characterized by gradual language loss, while memory, visual processing, and personality are relatively preserved until advanced stages. PPA is a focal dementia, primarily affecting specific brain regions, especially the left hemisphere language-related cortices. Symptoms progress from word-finding difficulties to impaired grammar, comprehension, and speech production. Despite language impairments, individuals with PPA can maintain daily living activities, good judgment, insight, and relatively normal behavior.

Parkinson's disease is a subcortical neurodegenerative disorder that typically develops gradually and is most commonly sporadic in nature.

The average age of onset for Parkinson's disease is around 60 years, although there is a juvenile form that can occur in younger individuals.

The incidence of dementia in Parkinson's disease patients can vary across studies, and not all individuals with Parkinson's disease develop dementia.

Parkinson's disease involves impaired dopamine transmission and brain changes, leading to various symptoms. These include hypokinetic dysarthria, motor difficulties, cognitive changes, and emotional symptoms like apathy and depression.

Huntington's disease is a subcortical neurodegenerative disorder with a gradual onset of symptoms.

The rate of disease progression and the age of onset can vary from person to person, making it challenging to predict how the disease will manifest in each individual.

Huntington's disease is an inherited condition and follows an autosomal dominant pattern of inheritance. The disease is associated with a mutation on chromosome 4.

A genetic test is available for accurate diagnosis of Huntington's disease, which can confirm the presence of the mutated gene.

The disease primarily leads to the loss of neurons in the basal ganglia region of the brain.

Individuals may experience naming difficulties, shorter utterances, grammatical errors, and discourse comprehension challenges. Dysarthria is common, causing variations in loudness, monopitch, and harsh voice quality. Behavioral changes include complaining, eccentricity, irritability, emotional outbursts, violence, and confusion. Involuntary movements known as chorea are characteristic, and cognitive impairment may lead to memory, attention, and processing deficits.

MS is a chronic neurological disease that affects the central nervous system, including the brain and spinal cord.

In MS, there is damage to the myelin sheath, which is the protective covering around nerve fibers. This damage is caused by inflammation resulting from the body's immune cells attacking the nervous system.

MS is primarily a white matter disease, affecting the myelin in the white matter of the brain and spinal cord. However, it may also involve gray matter to some extent.

Speech Symptoms: Individuals with MS may experience dysarthria, which includes unclear articulation, difficulty controlling loudness, and poor pitch control in speech.

Language and Cognitive Changes: Language difficulties may be present due to cognitive changes associated with MS. Problems in comprehending and using language can occur.

Physical Symptoms: MS can cause a range of physical symptoms, including fatigue, vision problems, weakness, gait issues, balance problems, coordination difficulties, pain, dizziness, and vertigo.

Emotional Changes: Emotional changes are common in MS and may include anxiety, depression, and cognitive dysfunction.