Cerebral Cortex & Limbic System Ilona Blee & Jonathan Tsun

Useful resource:  I found this book really helped with this lecture and for spinal tracts as well.  Pages for cerebral cortex stuff  Quite short & integrates clinically relevant stuff, which is what will probably come up in the exam

Functional areas of the cortex!  What is the role of the occipital lobe?  Vision  Facial, shape & colour recognition  What is the role of the temporal lobe?  Language  Auditory  Speech  What is the role of the frontal lobe?  Personality & acceptable behaviour  Speech output – planning behaviours  What is the role of the parietal lobe?  Building mental body image  Spatial awareness  In other words sensory

Posterior parietal cortex  What are the TWO roles of this area? 1. Integrates sensory inputs 2. Controls perception of contralateral environment/body  What can damage to this area result in?  Patient ignores or is not aware of the contralateral half of their world  What is this called?  Hemi-spatial neglect  How might this present in a patient?  Patient might say they are getting very bruised on one side, or you might notice yourself when they come to see you, they walk into the chair/desk because they aren’t aware it was there!

A patient comes to you saying Dr. I’ve had a fall and banged the back of my head.  List THREE things you might find as a result of them damaging their occipital lobe. 1. Vision defect eg. Quadrantopia 2. Inability to recognise colours (What is this called?)  Achromatopsia 3. Inability to recognise faces (What is this called?)  Prosopagnosia

Cortical areas: speech & language What is each of these areas called? 1.Broca’s area 2.Wernickes area 3.Angular gyrus 4.Primary auditory cortex What artery supplies the hearing speech & language regions?  Middle cerebral – we will go through this in a couple of slides What can damage to Broca’s area result in? Patient will speak slowly or some words will be missing but content correct Eg. Mother went to the shop today  “Mother shop today” What can damage to Wernickes area result in? Content of the speech is incorrect but the patient will speak fluently This is called receptive aphasia Eg. You ask them how they’re doing and they respond with “Yes, broccoli flew tonight.”

How does it all connect together?  Association fibres  These are interconnections which enable complex functions for example, reading/aloud This is the example I am using here 1.See the text 2.Recognition of letters 3.Understanding the letters & making words 4.Speech output – saying or expressing the words you have understood

Vertebral Carotid What areas are supplied by which artery? PCA MCA ACA PCA

Circle of Willis  Which two arteries make up the Circle of Willis? 1. Internal carotid 2. Vertebral

Circle of Willis continued Which artery is this?

LIMBIC SYSTEM fml.

Limbic system functions?  Sensations of emotion  Visceral responses to emotion  Memories What are some main structures that make up the limbic system?  Cingulate gyrus  Hypothalamus  Amygdala  Thalamus  Hippocampus  Mamillary bodies  Nucleus accumbens  Fornix

Papez Circuit – The “Heart” of the Limbic System 1.Hippocampus 2.Fornix 3.Mamillary Bodies 4.Mamillothalamic tract 5.Anterior thalamic nucleus 6.Cingulum (projections from Cingulate gyrus) 7.Entorrhinal cortex 8.Hippocampus!

Hippocampus  For those of you who were here 2 weeks ago for my Depression session, what happens to hippocampal activity in depression?  Decreases  What symptom does this result in?  Poor memory

Hippocampus  What does it do?  Short-term to long-term memory conversion  Memory recall  Spatial navigation  Damage to hippocampus results in what condition?  Anterograde amnesia  What is anterograde amnesia?  Inability to form new memories  What is retrograde amnesia?  Inability to recall memories formed before onset

Memory  What types of memory are there?  Sensory memory  Short-term (working) memory  Long-term memory

Jane is brought into A&E by her husband. She appears sober and lucid, but smells strongly of alcohol. While taking Jane’s history, she tells you stories about being abducted by fairies 10 years ago, about being eaten alive by a cow while on vacation in the Bahamas 12 years ago. 10 minutes later, you return to ask her some more questions but she has no recollection of ever meeting you.  What condition do you think Jane has?  Korsakoff’s Psychosis  Which elements of her history support this and what are the phenomena called?  Anterograde amnesia  Confabulation  What do you think has caused this?  Excessive alcohol consumption, leading to thiamine (B1) deficiency  Thiamine deficiency leading to mamillary bodies and anterior thalamic damage

Amygdala  For those of you who were here 2 weeks ago for my Depression session, what happens to amygdala activity in depression?  Increases

Amygdala  What does it do?  Brings about reactions of:  Fear  Anger  Behavioural emotions  Impulsivity  Sexual behaviour & emotions  Recognises emotional content of facial expressions

54 year old Jared is brought into the GP surgery by his wife. When you ask Jared to sit on a chair, he looks at it and asks what it is. Jared’s wife complains that he’s been uncharacteristically easy-going, almost completely lacking any extreme emotions. She also tells you he’s being exceptionally randy at work and at home, and has been reprimanded for fondling a female co-worker. During the consultation, Jared eats 14 chocolate bars and complains he’s still hungry.  What condition do you think Jared has?  Kluver-Bucy Syndrome  Which elements of this consultation support your decision?  Visual agnosia – inability to recognise objects  “Easy-going” = docile (lacking fear or anger)  Hypersexual  Excess exploratory behaviours with hands  Increased appetite  What part of the brain has been damaged?  Bilateral damage to amygdala

Thank you!! Any questions? Feel free to find us after Peer Support or send us an !