Diseases of the Brain Flashcards
What are the two types of brain disease?
neurological, psychiatric
What neurological conditions are assessed to diagnose brain disease?
state of consciousness, mental state, cognition, cranial nerves
What psychiatric assessments diagnose brain disease?
mood, appearance, behaviour, delusion, hallucinations, cognition
What are the symptoms of Parkinson’s?
bradykinesia, akinesia, tremor, increased muscle tone, shuffling gait
What is bradykinesia
very slow movements
What is akinesia?
little/no movements
What causes Parkinson’s
deficiency in dopamine
What region of the brain is affected in Parkinson’s
basal ganglia of substantia nigra, striatum
What are the four basal ganglia nuclei?
Striatum, globus pallidus, substantia nigra, sub thalamic nuclei
Inputs from where feed the striatum
cortex, thalamus, brainstem, putamen
Describe the pathways of Parkinson’s
direct and indirect
What causes the Parkinson’s symptoms
excessive output from internal pallidal segment
How does loss of dopaminergic input from substantia nigra affect the indirect pathway
increases activity
How does loss of dopaminergic input from substantia nigra affect the direct pathway
decreases activity
What is the effect of injecting patients of Parkinson’s with L-Dopa
brief symptom reversal
What is L-Dopa
precursor to dopamine
What is the effect of taking L-Dopa orally
continuous benefits for ~ 5 years
What are the disadvantages of taking L-Dopa orally?
increased motor fluctuations, drug related dyskinesia
What brain lesion gets rid of symptoms of Parkinson’s?
lesion of internal segment of globus pallidus
What is a treatment of Parkinson’s
L-Dopa, dopamine receptor antagonists
What is the effect of dopamine receptor antagonists
increase activity in indirect pathway
What are the symptoms of the early stages of Huntington’s
hyper/dyskinesia, writhing movements, increased movement
What are the symptoms of the late stages of Huntington’s?
Dementia, dystonia, Akinesia
What is Huntington’s?
autosomal dominant disorder
What does Huntington’s result in?
neuronal death
Where does neuronal death occur in Huntington’s?
primarily external globus pallidus, secondarily internal globus pallidus
What are the causes of Huntington’s associated with
nuclear and cytoplasmic inclusions
What protein is mutated in Huntington’s?
Huntingtin
How are the ventricles affected in patients with Parkinson’s
Ventricle size increases
What is the normal function of huntingtin?
neuronal binding proteins, inhibition of apoptosis
What are the 3 main symptoms/signs of schizophrenia?
prodromal, positive, negative
Which sign of schizophrenia is the hardest to treat
Negative signs
Describe the prodromal signs of schizophrenia
sign the condition is coming on
What are the prodromal signs of schizophrenia
social isolation, neglect, lack of emotion, odd behaviours
Describe the positive signs of schizpohrenia
episodes of psychosis, reflect presence of abnormal behaviour
What are the positive signs of schizophrenia
loss of reality, hallucinations, memory disturbances, delusions
Describe the negative signs of schizophrenia
patient isnt overtly psychotic, chronic,
What are the negative signs of schizophrenia
socially isolated, lack of motivation, low social drive
What causes the negative signs of schizophrenia?
loss of brain matter
When is schizophrenia diagnosed?
at least one psychotic episode, continuous for 6+ months
What are the subtypes of schizophrenia?
paranoid, disorganised, catatonic
Which type of schizophrenia is most common?
paranoid
What is the main characteristic of paranoid schizophrenia
systematic delusions of persecution pre-dominate
What is the main characteristic of disorganised schizophrenia
profound detonation of personality
What is the main characteristic of catatonic schizophrenia
mute, abnormal postures, rare
TRUE or FALSE - environmental factors can cause schizophrenia
False - but they can trigger it
What areas of the brain can be affected in schizophrenia
globus pallidus, temporal lobes, hippocampus, prefrontal cortex
What happens to the globus pallidus in schizophrenia
reduced blood flow, not activated properly
Describe the hippocampus in schizophrenics
reduced size, less blood flow
How is the activation of the prefrontal cortex affected in schizophrenics?
decreased
How is schizophrenia treated?
chlorpromazine, anti-psychotics, psychotherapy, social support
What might be the cause of schizophrenia?
excessive dopamine receptor stimulation
Where are dopamine receptors 1 and 5 expressed
cortex, hippocampus
Which dopamine receptors have a low affinity for anti-psychotic drugs
1, 5
Where are dopamine receptors 2,3 and 4 expressed
basal ganglia
which dopamine receptors have a high affinity for anti-psychotic drugs
2,3,4
Where are dopamine receptors 3 and 4 expressed
limbic system and cortex
What are the symptoms of depression
low mood, altered appetite, reduced ability to concentrate, avolition, anhedonia
Describe the pathology of depression
reduced hippocampal volume, vascular lesions-lesions, reduced nerve growth
What are the two types of cerebrovascular accident - stroke
ischaemic, hemorrhagic
What is the characteristic feature of a stroke?
blood flow to brain is interrupted
What are the features of ischaemic stroke
embolus, thrombus, systemic hypo-perfusion
What are the features of haemorrhagic strokes
entry of blood into CNS via rupture/anuerysm
