Cognitive DisordersCognitive Disorders

Thomas Bowers, Ph.D.

Penn State Harrisburg

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ContributorsContributors

• Samuel Adams, an undergraduate, for assisting in preparing the pages and synopses.

• Kathy Houseman, laboratory assistant, for helping with the samples.

• Donna Marie Struck, a graduate assistant in psychology, for taking the photographs.

• Dr. Jay Towfighi, for providing the neuropathology samples.

AcknowledgementsAcknowledgements

• These examples are from the Penn State Hershey Medical Center's Neuropathology Laboratory, Hershey, PA, operated under the direction of Dr. Jay Towfighi.

Cognitive DisordersCognitive Disorders

• Two fundamental types– I. Delirium - relatively acute state, due to

intoxication, withdrawal, poisoning or similar transient source of impairment of consciousness

– II. Dementia - more fixed impairment of memory and other higher cognitive processes

DementiaDementia

• Multiple sources– 1. Deteriorating disorders– 2. Disease processes– 3. Head injury– 4. Vascular disorders– 5. Constitutional impairment

Deteriorating DisordersDeteriorating Disorders

• I. Alzheimer’s disease– Remarkably common

• Farmington study estimates incidence of 11% for those over 85 years of age

• Progressive atrophy of the cortex, with notable impairment in the hippocampus in particular

• Diagnosis by exclusion, definitive diagnosis only on autopsy

Deteriorating DisordersDeteriorating Disorders

• I. Alzheimer’s disease– Decrement in recent memory functioning,

probably due to problems in consolidation– Recent appreciation of the role of

acetylcholine

Example of Alzheimer’s Example of Alzheimer’s DiseaseDisease

Deteriorating DisordersDeteriorating Disorders

• II. Pick’s Disease– Relatively rare– Selective atrophy of frontal and temporal

regions of the cortex– Unknown cause and etiology

Example of Pick’s DiseaseExample of Pick’s Disease

Deteriorating DisordersDeteriorating Disorders

• III. Huntington’s Disease– Subcortical impairment, also eventually

impacts on cortical functions– Grimacing, unusual and eccentric

presentation, gradual deterioration– Some strong genetic components

Deteriorating DisordersDeteriorating Disorders

• IV. Parkinson’s Disease– Deficiency in dopamine (DA) – Tremors, as pill rolling tremors, akinesia

(inability to initiate movement)– Late stages impact on frontal region

functions

Disease ProcessesDisease Processes

• There is a remarkable array of rare infectious processes which impact on the brain

• Sources of impairment– 1. Encephalopathy– 2. Encephalitis

Disease ProcessesDisease Processes

• I. Meningitis - Inflammation of the outer lining of the brain– Viral - Most common– Bacterial - much more problematic– Relatively common among children, rarer

for adults (and far more serious)

Disease ProcessesDisease Processes

• II. Herpes Simplex Encephalitis– Sudden clinical course and presentation – Many early deaths until late 1980s– Now largely effectively treated with antiviral

medications (as acyclovir)

Disease ProcessesDisease Processes

• III. Neurosyphilis – Now extremely rare– Initial presentation mild, maybe

asymptomatic– Later manifestation as severe neurological

disorders• general paresis - Alzheimer’s like presentation

Disease ProcessesDisease Processes

• IV. Lyme encephalopathy - documented memory deficits

• V. Creutfeld-Jakob Disease - slow viral agent

• VI. Progressive multifocal leukoencephalopathy - viral demyelinating disorder

Disease ProcessesDisease Processes

• VII. HIV and AIDS related dementia complex– Both mild and severe cognitive difficulties

could arise– Focus of considerable new research

interests

AIDS Dementia ComplexAIDS Dementia Complex

Disease ProcessesDisease Processes

• VIII. Chronic Fatigue Syndrome (CFS)– Controversial area– Severe enough to reduce activity more

than 50% below premorbid levels– At least six months– Associated low-grade symptoms, memory

dampened

Disease ProcessesDisease Processes

• VIII. Chronic Fatigue Syndrome (CFS)– Some (but not all) demonstrate Epstein-Barr

virus antibodies– Important to rule out other disorders– Often helped by antidepressants and

cognitive behavioral therapy for depression– Also display problems in memory and speed

of processing not attributable to depression