THE COGNITIVE DISORDERS

Brian E. Wood, D.O.Associate Professor and Chair

Department of Neuropsychiatry and Behavioral SciencesEdward 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

SpeechMood and Affect

Behavior

Perception

Thought

Memory and Cognition

PHYSICAL EXAM

Mental Status Exam

General Description

Mood and Affect

Thought

Perception

Memory and Cognition

The Mental Status Exam

Cognitive AssessmentSo, 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 SyndromesMCI, 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

Alois Alzheimer

Auguste Deter

Emil Kraepelin

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

• 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

DeliriumRelative condition of CNS

CNSInsult

Tx. Of underlying causes

Relative Conditionof CNS

Neuropsychiatric Model of 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• 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 high-potency 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.