Case 8 Flashcards
(105 cards)
What is the three functional subdivisions of the striatum?
Sensorimotor - Putamen and caudate
Associative - Globus Pallidus
Limbic/Ventral - Ventral Tegmental Area
What are the dopamine pathways?
Nigrostriatal, Mesocortical, Mesolimbic and Tuberofundibular
Where does the nigrostriatal project from and to?
Substantia nigra to striatum (caudate and putamen)
Dorsal striatum is associated with involuntary motor control (Parkinson’s Disease)
Associative striatum w/ learning, habituation, volition, memory, attention and motivation
What does the nigrostriatal pathway control?
Motor function and movement
What does deficit in Dopamine via nigrostriatal pathway cause?
Movement disorders characterised by rigidity, Akinoso’s/bradykinesia and tremor
What is akathesia?
A type of restlessness produced by dopamine deficiency in basal ganglia
What is dystonia?
Twisting movements especially of the face and neck
What does hyperactivity of dopamine cause in nigrostriatal pathway?
Emotional behaviour - positive symptoms of psychosis (delusion and hallucinations)
Motivation, pleasure and reward
Hyperkinetic movement disorder
What is neuroleptic-induced tardive dyskinesia?
Hyperkinetic movement disorder caused by chronic blockade of D2 receptors
Where does the increased dopamine associated with schizophrenia occur?
Associative striatum of the nigrastriatal pathway
Where does the mesocortical pathway project to and from?
Ventral tegmental area of brain stem to prefrontal cortex
What is the the mesocortical pathway associated with?
Mediating cognitive symptoms (dorsolateral prefrontal cortex,DLPFC) of SCHZ
Mediating affective symptoms (Ventromedial Prefrontal Cortex, VMPFC) of SCHZ
Mediating negative symptoms (DLPFC AND VMPFC) of SCHZ
What causes negative, cognitive and affective symptoms in mesocortical pathway?
Deficit of Dopamine projections
What is the Mesolimbic pathway projections?
Ventral tegmental area (ventral striatum) to nucleus accumbens in ventral striatum
What is the nucleus accumbens?
axon terminals in one of the limbic areas of the brain
What does deficient function of Mesolimbic pathway cause?
Negative Symptoms: Loss of motivation and interest, anhedonia and lack of pleasure
What is anhedonia?
Inability to feel pleasure in normally pleasurable activities
What does an increase dopamine in Mesolimbic pathway cause?
Positive symptoms
What is the projections of the tubetoinfundibular dopamine pathway?
Hypothalamus you’re anterior pituitary gland
What is the activity of projections of tuberoinfundibular pathway?
Inhibition of prolactin release - required for lactation during breastfeeding
What is elevation prolactin associated with?
Breast pathology, amenorhea (loss of ovulation and menstrual periods), sexual dysfunction
Caused by reduced dopamine activity
What is schizophrenia (ICD-10 definition)?
A severe and enduring mental disorder with fundamental and characteristic distortions of thinking and perception l, and affects that are inappropriate or blunted. Clear consciousness and intellectual capacity are usually maintained, although cognitive deficits may evolve in the course of time”
What is schizophrenia?
A major psychosis characterised by disintegration of the process of thinking, of contact with reality and of emotional responsiveness
It can be remittent, run a course with infrequent or frequent relapses or become chronic
What are the positive symptoms
of schizophrenia?
Existence of an abnormal phenomenon, delusions, hallucinations, though disorder, bizarre behaviour and Catatonia
Symptoms are associated with acute episode