Notes on Organic Disorders
Rahul's Noteblog
Notes on Psychiatry
Notes on Organic Disorders
Tourette syndrome:
• Motor and vocal tics; simple and complex.
• ~ age 7 onset.
• Increased levels of dopamine.
• First reported as ADHA, OCD, learning problems.
Treatment:
• Haloperidol, pimozide, clonidine.
HIV-related dementia:
• Caused by HIV encephalitis and myelitis.
• Behavioral problems (apathy, withdrawal, etc), cognitive problems (forgetfulness, lack of concentration, etc.), and motor symptoms (ataxia, poor handwriting).
Delirium:
• Acute onset; reversible; impaired cognitive functioning; lasts days to weeks.
Dementia:
• Insidious onset; personality change, slow onset, 15% reversible, memory loss; loss of cognitive ablilities; lasts months to years.
Dementia types:
Primary degenerative dementia of Alzheimer type (DAT):
• 20% greater than 80 years of age; more common in women.
• Memory loss.
• Can't perform familiar tasks.
• Language problems.
• Disorientation.
• Poor judgment.
• Poor abstract thought.
• Misplaced things.
• Mood/behavior changes.
• Personality change.
• Loss of initiative.
• Linked to chromosomes 1, 14, 19, and 21.
• Accumulations of NF tangles, amyloid beta-peptides, senile plaques.
• Atrophy of brain; reduced blood flow to brain; reduced choline acetyl transferase; reduced metabolism in temporal and parietal lobes.
Treatment:
• Donepezil hydrochloride.
Vascular dementia (multi-infarct):
• Disorientation due to cerebrovascular disease.
• Between ages 60-70; more in men.
• Predisposing factor: hypertension.
Pick disease:
• Affects temporal and frontal lobes.
• Rare.
Creutzfeldt-Jakob disease:
• Prion induced dementia.
• 40-50 years of age.
• Cortex/cerebellum atrophy.
• Fatal in 2 years.
Huntington chorea:
• AD disease.
• Progressive onset.
• Chromosome 4.
• Basal ganglia and caudate atrophy.
• 30-40 years of age.
• Fatal in 15-20 years.
• Suicide is common.
Parkinson disease:
• Decreased dopamine in substantia nigra.
• Pill-rolling tremor, masklike face, cogwheel rigidity, shuffling gait.
• Depression is common.
• Treatment: L-dopa or deprenyl.
Wilson disease:
• Defective chromosome 13.
• Ceruloplasmin deficiency.
• Kaiser-Fleischer rings.
Normal pressure hydrocephalus:
• Triad: dementia, urinary incontinence, gait apraxia.
• Treat with shunt.
Hemispheres:
• Left: language, math; damage can lead to depression; larger and faster.
• Right: artistic, visual perception, intuition-type problem solving; more 5-HT receptors.
Aphasias:
Broca's:
• Frontal lobe lesion; area 44; speech/comprehension is impaired.
Wernicke's:
• Superior temporal gyrus lesion; comprehension impaired; speech fluent but incoherent; can't repeat sentences.
Conduction:
• Lesion in parietal lobe or arcuate fasciculus; connection between Broca and Wernicke broken; can't repeat statements.
Global:
• Wide lesions in presylvian speech area; both Broca and Wernicke areas damaged; can't repeat statements.
Transcortical:
• Lesion in prefrontal cortex; can't repeat statements; can't speak spontaneously.
Brain functions:
Frontal cortex:
• Functions: speech, personality, abstract thought, memory, concentration.
• Lesions: indifferent attitude / apathy, loss of interest, poor grooming, Broca aphasia, fearfulness, explosive mood, violent.
Temporal cortex:
• Language, emotion, memory.
• Lesions of dominant lobe: dementia, euphoria, delusions, auditory hallucinations, Wernicke.
• Lesions of non-dominant lobe: irritability, dysphoria, decreased verbal and musical ability.
Parietal cortex:
• Intellectual processing of sensory information.
• Left: verbal processing (dominant).
• Right: visual-spatial processing (non-dominant).
Lesions of dominant lobe / Gerstmann syndrome:
• Agraphia, acalculia, finger agnosia, right-left disorientation; learning disabilities.
Lesions of non-dominant lobe:
• Anosognosia, construction apraxia, neglect to opposite side of body.
Occipital cortex:
• Visual.
• Destruction: blindness.
• PCA occlusion: Anton syndrome: cortical blindness and denial of blindness; can't see camouflaged objects; visual hallucinations.
Limbic system:
• Hippocampus, hypothalamus, anterior thalamus, cingulated gyrus, amygdala.
• Motivation, memory, emotions, conditioned responses, violent and sexual behaviors.
• Destruction: apathy, aggression, vegetative-endocrine disturbances; can't learn new material.
Hypothalamus:
• Heart and respiration; endocrine balance, appetite, body temperature, circadian cycle.
• Endocrine balance.
• Hunger, thirst, body temperature, sleep-wake cycle.
Thalamus:
• Pain and memory.
Reticular activating system (RAS):
• Motivation, arousal, wakefulness.
Amygdala:
• Links limbic and motor systems.
• Memory and rudimentary learning.
• Unconscious mind.
• Destruction can lead to Kluver-Bucy syndrome and Korsakoff syndrome.
Basal ganglia:
• Movement, depression, dementia.
• Damage can cause: Parkinson, Huntington, Wilson, Fahr diseases.
Pons:
• NE pathay; REM sleep.
• Damage can cause: autism.
Cerebellum:
• Balance, skill-based memory.
• Damage can cause: some learning disabilities.
Additional Reading:
Basic Psychiatry
1. Diagnostic and Statistical Manual IV (DSM IV)
2. Organic Disorders
3. Major Depressive Disorder vs Dysthymic Disorder
4. What is Classical Conditioning?
5. What is Observational Conditioning?
6. What is Operant Conditioning?
7. How to break bad news to a patient
8. What is Dementia?
9. What is Normal Aging?
10. Factors Promoting Poor Prognosis in Schizophrenia
11. Factors Promoting Good Prognosis in Schizophrenia
12. What are Temper Tantrums?
Related Topics
1. Mechanics of Defense Mechanisms
2. Types of Antipsychotics
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