Brain Disease Flashcards
Symptoms of Parkinson’s disease
Resting tremor in limbs - disappears on movement or during sleep
Akinesia general paisley of voluntary movement
Musc,e rigidity resistance to passive movement jerky cogwheel movement movement
Stooped posture
Shuffling gait
Small handwriting
Excessive sweating and salivation altered cognitive function and depression or dementia
Parkinson’s
Peak onset 55-60 years
Progressive leads to severe debilitation in10 to 15 years
Defects in movement controlled by extra pyrimidial motor pathways
Neuropathology of Parkinson’s disease-basal ganglia
Basal ganglia - a group of subcortival forebrain nuclei includes striatum modulates patterns motor activity provides fine motor control
Neuropathology of Parkinson’s disease
Main neuropathology is in basal gangalia -degeneration of the pathway from substantiated Niger to the striatum leading to depletion of dopamine in striatum
Treatment of Parkinson’s disease
In 1960 was no effective treatment
Realisation of dopamines involve t led to use of drugs which increase brain dopamine
Dopamine it’s
Ed cannot cross from blood to brain uses a precursor L-dopa which enters the brain and is converted there into dopamine
Side effects of treatment for Parkinson
Uncontrollablenmovemnts psychotis, many alternative pharmacology and surgical treatments are under inverstigation as alternative therapies
Huntingtons disease
Progressive disease causing involuntary muscle jerks
Ultimately affect the whole body
Intellectual deterioration depression and occasionally psychotism
Onset symptoms usually 30 to45 years
Genetically determined
Causes degeneration of the output neurones from the triatomic. Reducing inhibitory modulation of motor function
Treatment of huntingtons disease
No effective treatment
GABA replacement or dopamine antagonist provide some relief
No means of halting the progression of the disease
Addiction - Substance abuse
Frequent and/or excessive use of a substance for non medics
Reasons bringing damage to relationships and or dailing functioning
Substance dependence or addiction
Compulsive substance taking
Lives centred around a substance
Tolerance and or withdrawal symptoms
Critical role of dopamine
Drugs that have ability to increase domains release in brain(amphetamine,cocaine,morphine,heroine,nicotine,LSD,phencyclidine,cannabis,alchohol) are callled nucleus accumbens the terminal region of the Mesolithic pathway
Provide motivational drive to perform behaviour essential for survival
Mesolithic dopamine pathway
Critically involved in normal motivated behaviour
Actions in this pathway may underlie the addictive potential of drugs
Dysregulation of mesomlimbic dopamine function also implicated in schizophrenia
Emil Kraepelin 1856-1926
First formal description of symptoms of schizophrenia
Eugene bleuler 1857-1939
First used term schizophrenia spitting of the mind dissociative thinking impaired relationships with outside world
Positive and negative symptoms of schizophrenia
Positive systems -Hallucinations,delusions,thought derailment
Negative- behavioural with drawl
Cognitive symtoms disturbances of attention and cognitive
Neurochemical basis of schizophrenia drugs causing similar effects to schizophrenia
Amphetamine -increase dopamine dopamine in schizophrenia
LSD-5ht agonist
Phencyclidine glutamate antagonist
Treatment. Of schizophrenia typical antipsychotic drugs
Chloropazine drugs used to treat surgical shock patients reported a feeling of well being therfore tried on psychotic patients found to reduce psychotic symptom
Chloromazine is antagonist at dopamine receptors blocks Acton a of dopamine in brain
Other dopamine receptors antagonist are antipsychotic
The dopamine theory
AmphetMine causes symptoms similar very similar to,positive symtoms of schizophrenia- amphetamine does not cause negative symptoms
Dopamine antagonist provide the first pharmacology treatment for schizophrenia pharmacological treatment for schizophrenia dopamine anatagonist do not treat negative symptoms
Some evidence of increased dopamine function in schizophrenia changes seen in dopamine function may be a response to long term drug treatment
Therfore schizophrenia may be associated with increased dopamine function but can’t account for the whole spectrum of the conditions
Treatment of schizophrenia atypical drugs
Ever antipsychotic drugs show fewer side effects also more efffective at treating negative and cognitive symptoms mixed pharmacology interact with both dopamine and serotonin more effective that typical still around 25% of patients do not respond well and associated with side effects which limit compliance
