Primary Site of Degeneration/ Dysfunction | Profile | Diagnosis | Communication | Behavior | |
Alzheimer's (AD) | Cortical |
insidious onset; more likely after age 65 progressive course; slow course with plateaus not unusual can be familial or non-familial can coexists with other conditions such as Parkinson's disease |
proliferation of neural plaques and neurofibrillary tangles at autopsy |
aphasia is common, starting as either fluent on nonfluent; semantic system is most affected; syntax and phonology are affected later language comprehension deficits, difficulty with topic maintenance, echolalia, lack of meaningful speech, gradual progression to mutism |
depression, insomnia, incontinence, delusions, agitation, restlessness, hyperactivity, disorientation, delusions of persecution, loss of initiative |
Vascular Dementia |
Cortical Called multi-infarct dementia (MID) when multiple lesions/infarcts are present in both gray and white matter |
caused by multiple strokes, some without noticeable clinical signs symptoms may begin suddenly, often progressing in stepwise fashion after each small stroke sometimes co-occurs with Alzheimer's disease |
vascular disease resulting in damage to cortical areas of the brain due to diminished blood flow symptoms similar to Alzheimer's disease makes it difficult to make a firm diagnosis |
motor speech disorders are prominent; slurred speech word retrieval difficulties difficulty following instructions |
depression and mood changes confusion, problems with short-term memory wandering or getting lost in familiar places impaired coordination or balance |
Subcortical Also called Binswanger's Disease |
usually due to chronic, untreated hypertension can co-occur with cortical vascular dementia |
disease results in thickening and narrowing of arteries that feed subcortical areas of the brain pattern of damage can be seen on brain imaging (CT or MRI) |
difficulty with speech (dysarthria) less spontaneous communication difficulty with swallowing (dysphagia) |
progressive loss of memory and other cognitive functions including organization, attention, and decision making apathy, irritability, and depression slowness, poor balance, unsteady gait urinary incontinence not caused by urological disease |
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Lewy Body (LBD) | Cortical |
periods of normal cognition alternate with abnormal cognition progressive course, often rapid |
presence of Lewy bodies (intraneuronal cytoplasmic inclusions) typically found in the substantia nigra at autopsy |
motor speech disorder with hypophonia disorganized speech |
visual and auditory hallucinations pronounced fluctuations in alertness and attention; periods of delirium (confusion) and daytime drowsiness Parkinsonian motor symptoms (e.g., rigidity and loss of spontaneous movement |
Frontotemporal Lobar (FTD) Pick's Disease |
Cortical |
insidious onset, more likely before age 65 progressive course, often slow |
focal cortical atrophy; degeneration in frontal and temporal lobes two kinds of neuronal abnormalites: Pick bodies (dense intracellular formation in cytoplasm) and Pick cells (inflated neurons) |
reduced speech output; speech is nonfluent progressive decrease in expressive vocabulary; word- finding problems reduced spontaneous conversation echolalia and meaningless repetition of phrases |
wide range of behavioral changes, especially frontal lobe variant executive dysfunction (in frontal variant) behavioral (personality) changes and disregard for social conventions uninhibited behavior, including inappropriate social behavior depression, irritability, mood fluctuations |
Frontotemporal Lobar (FTD) Primary Progressive Aphasia (PPA) |
Cortical |
may be caused by a wide variety of underlying diseases possibly inherent genetic preprogramming gradual loss of language function in the context of relatively well-preserved memory, visual processing, and personality until the advanced stages |
a focal dementia (or focal cortical atrophy syndrome) structural and physiological abnormalities typically noted only in the left hemisphere language-related cortices (i.e., frontal, parietal and temporal regions) |
symptoms usually begin with word-finding problems and progress to impaired grammar (syntax) and comprehension (sentence processing and semantics) symptoms associated with impaired speech production can also be present (e.g., dysarthria and apraxia) |
activities of daily living, judgment, insight, and behavior are relatively, if not totally spared |
Parkinson's Disease | Subcortical |
sporadic; gradual course average age of onset 60 years, although a juvenile form exists reported incidence of dementia in patients is variable across studies |
impaired dopaminergic system; reduced dopamine levels degeneration of nuclei; widened sulci; loss of cells from substantia nigra; neurofibrillary tangles and neuritic plaques; presence of Lewy bodies |
hypokinetic dysarthria (hypophonia, rapid rate, voice tremor, monopitch and monoloudness) naming problems, impaired discourse comprehension micrographia (writing in extremely small letters) |
immobility or slow voluntary movements, diminished facial expression, resting tremors, increased muscle tone and resistance to movement disturbed gait and posture memory problems, confusion, hallucinations, executive dysfunction apathy, depression, social withdrawal, anxiety |
Huntington's Disease | Subcortical |
gradual onset rate of progression and age of onset vary from person to person |
inherited (autosomal dominant) neurodegenerative disease; mutation on chromosome 4 genetic test is available for accurate diagnosis loss of neurons primarily in the basal ganglia |
naming difficulties, use of shorter/simpler utterances, grammatical errors, difficulty comprehending subtle aspects of discourse dysarthria of the hyperkinetic type, including variations in loudness, monopitch and harsh voice quality mutism in final stages |
excessive complaining, eccentricity, irritability, emotional outbursts, violence and extreme confusion in final stages spasmodic, involuntary movement of limbs, neck and head impaired memory, attention deficits, slowness with all intellectual activities |
Multiple Sclerosis | Subcortical | chronic neurological disease that affects the central nervous system (CNS) |
damage to the myelin sheath, caused by inflammation that occurs when the body's own immune cells attack the nervous system primarily a white matter disease, but may also involve gray matter |
dysarthria including unclear articulation, difficulty controlling loudness, poor pitch control problems comprehending and using language related to cognitive changes |
fatigue, vision problems, weakness, gait, balance and coordination problems, pain dizziness and vertigo emotional changes, anxiety, depression, cognitive dysfunction |
(Hegde, 2006; Hickey & Bourgeois, 2018; Johnson & Jacobson, 2007; National Institute of Neurological Disorders and Strokes (NINDS), 2013; 2015; National Organization for Rare Disorders (NORD), 2015)