Download - Lesson 1 - Cognitive Disorders
Cognitive Disorders
7.10.2006
DeliriumA. Disturbance of consciousness
i.e. Reduced clarity of awareness of the environment
Reduced ability to focus, sustain, or shift attention
B. Change in cognition E.g. Memory deficit, disorientation, language
disturbance
C. Disturbance develops over a short period of time (hours to days) and tends to fluctuate over the course of the day
D. Evidence that the disturbance is caused by the direct physiological consequences of a GMC, substance, or both
Facts about Delirium Prevalence: At any point in time…
0.4% of adults age 18 and older1.1% of adults age 55 and olderUp to 60% of nursing home residents
age 75 and older Gender: Males might be at higher risk Age of onset: Most common in the elderly and medically
ill Course: Develops over hours to days
Majority of cases resolve (could be hours, days, weeks, or months…)
Some cases progress to coma, stupor, or death
Increases risk of mortality for hospital patients
Causes of Delirium Psychoactive substances of abuse Medications other than above (e.g.
steroids) Infection, especially in the brain (e.g.
bacterial, viral, etc.) Toxins (e.g. heavy metals like mercury) Surgery Head injury Shock
DementiaA. Development of multiple cognitive deficits
manifested by both:1. Memory impairment (either old or new information)2. One or more of the following cognitive disturbances:
a. Aphasia (impaired speech)b. Apraxia (impaired ability to carry out motor activities)c. Agnosia (failure to recognize/identify objects)d. Disturbance in executive functioning (planning, organizing,
sequencing complex activities)
B. Cognitive deficits cause significant impairment in functioning and represent a significant decline from a previous level of functioning
Facts about Dementia Prevalence: 0.5-1% adults age 65 and above
10-15% adults age 85 and above20-25% adults 90 and above35-40% adults 95 and above
Gender: Slightly more common in females Age of onset: Typically in the elderly (depends
on cause) Course: Typically gradual onset, chronic,
progressive (depends on cause)
Causes of Dementia Alzheimer’s (Cause of 70% of dementias) Vascular lesions in the brain (reduces
blood flow to the brain) HIV Head trauma Parkinson’s Disease Huntington’s Disease Pick’s Disease Creutzfeldt-Jakob Disease
Alzheimer’s Disease: Forms Early Onset – develops prior to age 60
Runs more strongly in families Progresses more rapidly
Late Onset – develops at age 60 or later
Risk for developing Alzheimer’s increases with age
Alzheimer’s Disease: Pathology Neuropathology
Plaques, neurofibrillary tangles of tau protein Plaques of amyloid and protein
Protein that is present in all kinds of tissues Responsible for “housekeeping” Abnormal growth creates plaques Plaque count positively correlated with cognitive decline
Research in mice also implicate excessive iron in the brain
Small holes in neural tissue (granulovacuoles) Atrophy (“wasting away”) of the brain Firm diagnosis is only possible after death, at
autopsy
Alzheimer’s Disease: Pathology
Brain of someone with Alzheimer’sDisease – plaques, tangles, and overall brain atrophy are present
Brain of a healthy person
Alzheimer’s Disease: Genetics All Down syndrome kids get Dementia of
Alzheimer’s type Down syndrome due to trisomy on
Chromosome 21 Chromosome 21 is also linked to early onset
form of Alzheimer’s Disease Production of the amyloid protein is linked to
Chromosome 21 However, we don’t know if the amyloid
tangles are the cause of Alzheimer’s Disease or an additional symptom of the real cause…thus, we still don’t know if Chromosome 21 has a causal role in Alzheimer’s
Alzheimer’s Disease: Treatment No effective treatment exists to restore lost
functioning Behavioral therapy works to control
wandering, incontinence, inappropriate sexual behavior, and poor self-care behaviors
Drugs that enhance the availability of the neurotransmitter acetylcholine (acetylcholine depletion has also been found in Alzheimer’s patients) Slows, but doesn’t stop decline
Trying to pursue medications or vaccines that will clear away the tangles and plaques
Alzheimer’s Disease: Caregivers Caregivers of Alzheimer’s patients must
deal with the “social death” of the patient even before the actual physical death
Financial burden Chronic stress High risk for depression
Vascular Dementia Second most common cause of dementia (19% of
cases), more common in men Damage caused to specific areas of the brain Stroke – interruption of blood flow to the brain,
results in lack of oxygen to parts of the brain, which may die
Aneurism – rupture of blood vessels in the brain, blood floods the brain, pushing blood against the skull, crushing cells and killing parts of the brain
Abrupt, sudden onset of symptoms with fast decline
May be normal functioning in parts of brain not affected
Dementia due to HIV Researchers found that HIV could result in
the destruction of brain cells Causes generalized atrophy, edema
(swelling), inflammation, and patches of demyelination
May lead to psychotic phenomena as well 30-60% of untreated AIDS/HIV patients will
develop dementia Only 20% of AIDS/HIV patients who receive
antiviral treatment develop dementia
Huntington’s Disease Inherited disease caused by an autosomal
dominant gene 100% determined by your genes (i.e. if you
have the genes for it, you will develop Huntington’s Disease)
Age of onset: approximately 35 – 45 Progressive deterioration of motor skills,
personality, cognitive functions (dementia), and mood
Results in death within 10-20 years of developing symptoms
Parkinson’s Disease Slowly progressive neurological disorder More common in men Age of onset is typically between ages 50-70,
although Michael J. Fox developed symptoms at age 30
Causes rigidity, tremors, lack of balance, diminished small motor control, and difficulties communicating
Caused by both genetic and environmental factors
20-60% of cases result in dementia