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I. Definitions

A. Intelligence - the ability to have ideas and to reason about them; the sum of multiple functions the most important of which are:

1. Attention

2. Language

3. Memory

4. Spacial orientation

B. Mental retardation - static, subnormal intelligence

C. Dementia - usually (but not always) progressive deterioration of intellect

D. Pseudo dementia - disorders of affect, mood and thought which interfere with intellectual functions

E. Benign senescent forgetfulness

II. Measurements of Intelligence

A. Office or bedside evaluation

1. Neuropsychological tests

III. Evaluation of Patients with Intellectual Dysfunction

A. History

1. Mental retardation and/or dementia?

2. Time of onset and rate of progression

3. Birth and developmental history

4. Medical history including drugs

B. Mental Status Examination

1. Psychiatric

2. Neurologic

C. General Physical and Neurologic Examination

D. Laboratory depends on specific syndrome but most would include:

1. Brain image (MR is superior to CT for this purpose)

2. EEG

3. CBC and ESR

4. Electrolytes, renal and liver function tests, blood sugar

5. Thyroid function tests

6. Spinal fluid tau and amyloid precursor protein

7. Apoprotein genotyping is controversial

8. Genetic testing is premature

IV. Major Dementia Syndromes

A. Cortical Dementia

1. Alzheimer Disease

2. Pick Disease

3. Some multi-infarct dementias

4. Spongiform encephalopathies (prion diseases)

5. Neuronal storage diseases

6. Encephalitis (including HIV)

7. Neurosyphilis

B. Subcortical Dementia

1. Parkinsonism (eg, Parkinson disease; Lewy body disease; cortical basal ganglionic degeneration: multisystem atrophy; dementia pugilistica; toxins; encephalitis)

2. Huntington disease

3. Some multi-infarct dementias

4. Demyelinating and dysmyelinating diseases

5. Some post-traumatic encephalopathies

C. Amnestic Dementia

1. Wernicke-Korsakoff syndrome

2. Postischemic dementia

3. Herpes simplex encephalitis

4. Some post-traumatic encephalopathies

D. Frontal Dementia (Abulia)

1. Hydrocephalus

2. Some space occupying lesions

E. Confusional State

1. Most intoxications and metabolic encephalopathies

2. Some right hemisphere lesions

F. Pseudo Dementia

1. Schizophrenia ("dementia praecox")

2. Depression

3. Fear of dementia

V. Some ideas about Alzheimer's Disease

A. Chemistry of senile plaques (SP) and neurofibrillary tangles (NFT)

1. Role of amyloid (does it initiate the plaque or is it the result?) in SP formation

2. What produces the NFT?

3. What are the paired helical filaments (PHF) and is it the same in all NFT's?

4. The aluminum model is probably not applicable

5. What is amyloid beta protein and where does it come from?

B. The cholinergic theory and the basal nucleus of Meynert

C. Viruses and Prions

D. Toxins

E. The Genetics of AD

1. Amyloid precursor, protein (APP) on chromosome 21 (Down's)

2. Apoprotein E on chromosome 19 (E4 is a major risk factor)

3. Presenilin 1 & 2 on chromosomes 14 and 1 (may be gamma secretase)

VI. Specific treatment of dementia depends on the diagnosis; general measures include the following:

A. Short-acting benzodiazepines are the best for behavior control (eg, lorazepam 0.5mg tid)

B. Sleep disturbances: choral hydrate 25-50 mg hs. Or melatonin 0.3-3 mg hs.

C. Haloperidol is the best neuroleptic in demented patients (eg, haloperidol 0.5 - 3 mg q.d.); respiridol 1-3 mg q.d. may also sometimes be helpful

D. No role for vasodilators

E. Specific serotonin reuptake inhibitors are best for depression (eg fluoxetine 20-40 mg q.d.)

F. Slight benefit of cholinergic therapy

1. Tetrahydroaminoacridine or tacrine (Cognex) - a cholinesterase inhibitor

2. Donepezil (Aricept) - another cholinesterase inhibitor

3. Pp-coming cholinesterase inhibitors (exelon, metrifonate, galanthamine, physostigmine)

4. Pre-synaptic releasing drugs and post-synaptic receptor agonists also in development

J. Estrogen may delay onset in 

K. Anti-inflammatories (eg NSAID's) may delay onset and/or 

L. Anti-oxidants (eg vitamin E) may 

M. Neuroprotectors (eg, selegiline) may 

N. Nicotine may delay onset and/or