THE COGNITIVE
DISORDERS
Brian E. Wood, D.O.
Associate Professor and Chair
Department of Neuropsychiatry and Behavioral Sciences
Edward Via Virginia College of Osteopathic Medicine
brwood6@vcom.vt.edu
Associate Professor of Psychiatry and Neurobehavioral Sciences
University of Virginia School of Medicine
2/2012
The Clinical Workup
Mental Status
Behavior
Perception
Mood and Affect
Memory and Cognition
Thought
Speech
The Mental Status Exam
PHYSICAL EXAM
Mental Status Exam
General Description
Mood and Affect
Thought
Perception
Memory and Cognition
Cognitive Assessment
So, How Do We Start?
• Subjective assessment of cognition
– May be very sensitive and is often useful
– Not reproducible and difficult to compare
• Objective Assessment of Cognition
– Often useful for reproducibility and comparison
– Sometime overlooks subtleties
• Combination Assessment can take advantage of strengths of both and
provide context.
Objective Screens of Cognition
• Screen area of Cognition (well validated)
• Provides quantified data
– allows professionals to “speak the same language” (
reliability)
– Reproducible
– Provides data for comparison and tracking particularly
of serial examinations.
Cognitive Screening Instruments
• MOCA
• Folstein Mini Mental State
Exam
• SLUMS
• Mini-Cog
• ADAS-COG
• Other neuropsychiatric
screens.
Other Clinical Elements for
Differential Diagnosis
•
•
•
•
Cognitive Impairment
Acquired vs. Congenital
Reversible vs. Irreversible
Other Psychiatric Illnesses
• Depression, primary psychotic disorders
• Primary Cognitive Illnesses
– Dementias
– Delirium
– Amnestic Syndromes
The Dementias…..
Dementia: What is it?
• Primarily cortical disease or results
from cortical disruption.
– Cortical neuronal loss
– Disruption of communication pathways
• General class of diseases, probably many illnesses
that present with Dementia.
• May be a common pathway of brain disease.
How Do We Make
the Diagnosis?
• Work up
– History
(general medical, family, social)
– Complete examination including thorough mental
status examination
– Labs and testing
• Differential Diagnosis
DSM IV TR
Criteria for Dementia
• Memory impairment
• One or more of the following:
– aphasia
– apraxia
– agnosia
– disturbance in executive functioning (planning, sequencing)
• Decline in cognitive functioning
• Functional impairment
Amnestic Syndromes
MCI, AAMI, etc.
• Isolated memory deficits
• Does not meet criteria for dementia because other
cortical dysfunctions are not present.
• Needs to be differentiated from Cognitive Disorder
NOS (MCI) and Dementia which are
characteristically different diseases
Other Dementia Criteria
• Illness vs. Phenomenalogical models
– Often making a clinical diagnosis based on symptoms.
• Clinical Probability models
– Consensus criteria
– More symptoms = greater likelihood of disease
– May add thresholds (ex. DSM)
Alzheimer’s Dementia
• Most common
• Definitive Diagnosis with brain
tissue only
– usually diagnosis of
“probable” AD
– Correct about 85% of
time
• insidious onset and
progressive course
Emil Kraepelin
Alois Alzheimer
Auguste Deter
Dementia with Lewy Bodies
• Prevalence varies according to criteria.
• Arguable existence
• Clinically distinct from AD
– variations in alertness and attention
– prominent visual hallucinations.
– Motor features of Parkinsonism (EPS)
Vascular Dementia
• Multiple clinical
variations depending on
location of lesions.
• Classic “stepping off”
phenomena associated
with multi-infarct variety
• May look clinically similar
to other Dementias.
ETOH Dementia
•
•
•
•
Diagnosis by history of ETOH abuse/dependence.
Neuro-toxic effects of Alcohol.
Classic presentation of “spotty” cognitive loss.
Korsakoff’s syndrome:
– confabulation
– rambling, garrulous speech
Other Dementias
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•
•
•
•
Pick’s disease (FTD)
Creutzfeldt-Jakob disease
Parkinson’s Disease (PD)
Secondary Dementias
Mixed Dementias
Treatment
• Supportive treatment (medical and psychosocial)
• Minimize complications
• Treatment of secondary neuropsychiatric symptoms
(depression, psychosis, etc.)
• Cholinesterase inhibitors (donepezil, rivastigmine and
galantamine)
• NMDA receptor blockers (memantine) block rapid glutamate
uptake in the neuron
The Future: What does it hold?
• Increasing emphasis on genetic
markers
– possible genetic treatment
• Much more specific
pharmacologic treatment
• Better understanding of
relationships to other psychiatric
illnesses and treatments.
• Increased social awareness of
needs.
Delirium
Disease Characteristics
• Disease of the subcortical areas of the
brain.
• By definition a secondary disorder.
• Many synonymous terms.
• Prominent in other areas of medicine.
– Post-op
– chronic medical illness
• Represents risk for significant
morbidity and mortality
Neuropsychiatric Model of Delirium
CNS
Insult
Tx. Of underlying
causes
Relative
condition
of CNS
Relative
Condition
of CNS
Delirium
Hypo
Hyper
How Do We Make the Diagnosis?
• Arises from sub-cortical brain areas and
subsequently affects cortical areas.
• Predominant presentation of confusion and
disorientation (sub-cortical predominance)
• Varying levels of alertness/consciousness.
• Fluctuating mental status during course.
DSM IV TR Criteria
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•
•
•
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Attentional deficit
Disorganized thinking and speech
At least two of the following:
– reduced level of conciousness
– perceptual disturbances
– sleep-wake cycle disturbances
– changes in psychomotor activity
– disorientation
– memory impairment
Relatively rapid onset
Evidence or assumption of secondary cause
Treatment
• Identification and
correction of underlying
causes if possible.
• Minimize complicating
factors.
• Possible low dose highpotency typical or atypical
neuroleptics.
Comparison of Dementia and Delirium
• Dementia
– insidious onset
– persisting, stable
– predominant memory
impairment with mild
confusion
– possible contributory
reversible causes.
• Delirium
– Rapid onset
– Varying, fluctuating
– predominant confusion
– By definition a reversible
cause.
Summary
• Almost any illness can present with cognitive dysfunction
and secondary dysfunction is more likely than primary.
• Dementia as a syndrome or class of diseases increases in
prevalence with age.
• Look for cortical symptoms – Dementia
• Look for sub-cortical symptoms – Delirium.
• Think about the foundations for a solid differential.