Notes on Cerebral Cortex
Rahul's Noteblog
Notes on Neurology
Notes on Cerebral Cortex
Cerebral cortex:
• Blood supply: two internal carotid arteries, and two vertebral arteries; basilar artery + branches of internal carotid arteries = circle of Willis, which gives rise to middle, posterior and anterior cerebral artries.
Middle cerebral artery occlusion:
• Spastic contralateral paresis of lower face and upper limb, and anesthesia of contralateral face and upper limb; Broca or Wernike aphasia.
• MCA also supplies Meyer's loop fibers.
Anterior cerebral artery occlusion:
• Spastic paresis of contralateral lower limb and anesthesia of the contralateral lower limb; transcortical apraxia of left limbs.
Posterior cerebral artery occlusion:
• Homonymous hemianopia of contralateral visual field with macular sparing.
Premotor cortex damaged:
• Apraxia.
Prefrontal area lesions:
• Frontal lobe syndrome.
• Lack of concentration.
• Lack of initiative, foresight, perspective.
• Apathy.
• Slowed thinking, speech, etc.
• Emergence of infantile suckling or grasp reflexes.
Expressive aphasia:
• Damaged Broca areas 44 and 45.
• Difficulty piecing words.
• Understanding of written and spoken language is normal.
• Handwriting also affected.
Lesion in posterior parietal association cortex:
• Involves Brodmann areas 5 and 7.
• Constitutiona apraxia: inability to draw a simple diagram.
• Astereognosia - inability to recognize objects by touch.
Wernicke's aphasia:
• Damaged area 22 in temporal lobe, and area 39 or 40 in parietal lobe.
• Patient cannot comprehend spoken language.
• May also include understanding written language.
Visual agnosia:
• Damaged parts of temporal lobes involving cone stream.
• Can't recognize objects by touch.
• Eg., prosopagnosia: inability to recognize faces.
Additional Notes:
• Optic nerve: thalamus.
• Transcortical sensory aphasia: parietal-temporal-occipital junction.
• Broadmann motor cortex: areas 4 and 6.
• Broadmann primary sensory cortex: areas 1, 2, 3.
• Broadmann primary auditory cortex: areas 41 and 42.
• Broadmann primary visual cortex: area 17.
• Cerebral commissurotomy in right-handed individual: verbal command cannot be carried out by left hand.
• Arcuate fasciculus: connects Wernicke's area and Broca's area.
• Neglect syndrome: damaged parietal cortex.
• Broadmann area origin of motor tracts: area 4.
• Postcentral gyrus associated with: sensation.
• Optical tract lesion: contralateral homonymous hemianopsia.
Additional Readings:
Basic Neurology
1. Peripheral Nervous System
2. Central Nervous System
3. The Ventricular System
4. The Spinal Cord
5. The Brain Stem
6. The Cerebellum
7. Visual Pathways
8. Diencephalon
9. Basal Ganglia
10. Cerebral Cortex
11. Sleep Disorders
12. Autonomic Nervous System
13. Cranial Nerves and Parasympathetic Ganglia
14. Cells of the Nervous System
15. Cerebrospinal fluid
16. Additional short notes on Cerebrum
17. Functions and Diseases of Cerebrum
18. Subcortical Grey Matter
19. Notes on The Spinal Cord
20. Regulation of Heart Rate by Autonomic Nervous System
21. Action Potentials, Axon Conduction, and Neuromuscular Junction
22. Types of Seizures
23. What is a Cough Reflex?
24. Notes on Congenital Prosopagnosia
25. Findings in Parkinson's Disease
26. Types of Heat Strokes
27. Types of Strokes
28. What is Benign Intracranial Hypertension?
29. What is Cauda Equina Syndrome?
30. Cranial Nerve Locations in Brain Stem
31. What is a Cluster Headache?
32. What is a Subarachnoid Hemorrhage?
33. What is a Tension Headache?
Neurology Videos
1. Video of Neurology Examination in a Clinical Setting
Medical Images
Useful Medical Images & Diagrams (link opens in a new window)
Related Topics
1. Nervous System Disorders
2. Histology of Nervous Tissue
3. Cranial Nerve Reflexes
4. Motor System Examination
Random Pages:
Please Do Not Reproduce This Page
This page is written by Rahul Gladwin. Please do not duplicate the contents of this page in whole or part, in any form, without prior written permission.
