Neurology Lecture

1. Dr Paul Strutton p.strutton@imperial.ac.uk

2. • Organisation of the nervous system: Compare and contrast the structure of the central, peripheral and autonomic (sympathetic and parasympathetic) nervous systems.
• Nervous system disorders: Summarise the pathology and pathophysiology of central and peripheral nervous system disorders.
Session Plan
Microscopic cortical structure
General organisation
Internal structure and fibre tracts
Localisation of function
Assessment of cortical function
Effects of lesions on cortical function

3. • Organisation of the nervous system: Compare and contrast the structure of the central, peripheral and autonomic (sympathetic and parasympathetic) nervous systems.
• Nervous system disorders: Summarise the pathology and pathophysiology of central and peripheral nervous system disorders.
Cerebral cortex
Covers entire surface of the brain
Together with deep nuclei, contains
grey matter
Highly folded with gyri and sulci
Organised into lobes

4. • Organisation of the nervous system: Compare and contrast the structure of the central, peripheral and autonomic (sympathetic and parasympathetic) nervous systems.
• Nervous system disorders: Summarise the pathology and pathophysiology of central and peripheral nervous system disorders.
Microscopic organization
Organised into layers and columns

5. • Organisation of the nervous system: Compare and contrast the structure of the central, peripheral and autonomic (sympathetic and parasympathetic) nervous systems.
• Nervous system disorders: Summarise the pathology and pathophysiology of central and peripheral nervous system disorders.
Classification based on cytoarchitecture
52 regions identified by German
Neurologist, Korbinian Brodmann
in 1909
Based on cytoarchitecture - cell
size, spacing or packing density and
layers
Many areas shown to relate to
function e.g. primary
somatosensory (1,2,3), primary
motor (4)
4
1
2
3

6. Frontal
Parietal
Temporal
Occipital
Servier medical art
• Organisation of the nervous system: Compare and contrast the structure of the central, peripheral and autonomic (sympathetic and parasympathetic) nervous systems.
• Nervous system disorders: Summarise the pathology and pathophysiology of central and peripheral nervous system disorders.
Lobes

7. • Organisation of the nervous system: Compare and contrast the structure of the central, peripheral and autonomic (sympathetic and parasympathetic) nervous systems.
• Nervous system disorders: Summarise the pathology and pathophysiology of central and peripheral nervous system disorders.
Frontal lobe
Regulating and initiating motor function
cognitive functions (executive function
[e.g. planning])
attention
memory
Servier medical art
language

8. Servier medical art
• Organisation of the nervous system: Compare and contrast the structure of the central, peripheral and autonomic (sympathetic and parasympathetic) nervous systems.
• Nervous system disorders: Summarise the pathology and pathophysiology of central and peripheral nervous system disorders.
Parietal lobe
Sensation - touch, pain
sensory aspects of language
spatial orientation and self-perception

9. Servier medical art
• Organisation of the nervous system: Compare and contrast the structure of the central, peripheral and autonomic (sympathetic and parasympathetic) nervous systems.
• Nervous system disorders: Summarise the pathology and pathophysiology of central and peripheral nervous system disorders.
Occipital lobe
Processing visual information

10. Servier medical art
• Organisation of the nervous system: Compare and contrast the structure of the central, peripheral and autonomic (sympathetic and parasympathetic) nervous systems.
• Nervous system disorders: Summarise the pathology and pathophysiology of central and peripheral nervous system disorders.
Temporal lobe
Processing auditory information
emotions
memories

11. • Organisation of the nervous system: Compare and contrast the structure of the central, peripheral and autonomic (sympathetic and parasympathetic) nervous systems.
• Nervous system disorders: Summarise the pathology and pathophysiology of central and peripheral nervous system disorders.
Limbic lobe
Includes the amygdala,
hippocampus, mamillary
body, and cingulate gyrus
Concerned with learning,
memory, emotion,
motivation and reward

12. • Organisation of the nervous system: Compare and contrast the structure of the central, peripheral and autonomic (sympathetic and parasympathetic) nervous systems.
• Nervous system disorders: Summarise the pathology and pathophysiology of central and peripheral nervous system disorders.
Insular cortex
lies deep within lateral
fissure
Concerned with visceral
sensations, autonomic
control, and interoception,
auditory processing, visual-
vestibular integration

13. • Organisation of the nervous system: Compare and contrast the structure of the central, peripheral and autonomic (sympathetic and parasympathetic) nervous systems.
• Nervous system disorders: Summarise the pathology and pathophysiology of central and peripheral nervous system disorders.
Internal structure
grey matter
neuronal cell bodies
and glial cells – around
85 billion of each
Myelinated neuronal
axons arranged in
tracts
white matter
Q: What plane of section is this?
Coronal

14. • Organisation of the nervous system: Compare and contrast the structure of the central, peripheral and autonomic (sympathetic and parasympathetic) nervous systems.
• Nervous system disorders: Summarise the pathology and pathophysiology of central and peripheral nervous system disorders.
Internal structure
grey matter
white matter
Horizontal (axial)
Q: What is the plane of section?

15. • Organisation of the nervous system: Compare and contrast the structure of the central, peripheral and autonomic (sympathetic and parasympathetic) nervous systems.
• Nervous system disorders: Summarise the pathology and pathophysiology of central and peripheral nervous system disorders.
White matter tracts
Connect cortical areas
Association fibres
Commissural fibres
Projection fibres
connect areas within the same hemisphere
Connect homologous structure in left and
right hemispheres
connect cortex with lower brain structures
(e.g. thalamus, brain stem and spinal cord)

16. • Organisation of the nervous system: Compare and contrast the structure of the central, peripheral and autonomic (sympathetic and parasympathetic) nervous systems.
• Nervous system disorders: Summarise the pathology and pathophysiology of central and peripheral nervous system disorders.
Association fibres
connect areas within the
same hemisphere
Short fibres
Superior Longitudinal Fasciculus
connects frontal and occipital lobes
Arcuate Fasciculus - connects frontal
and temporal lobes
Inferior Longitudinal Fasciculus -
connects temporal and occipital lobes
Uncinate Fasciculus - connects
anterior frontal and temporal lobes
Long fibres

17. • Organisation of the nervous system: Compare and contrast the structure of the central, peripheral and autonomic (sympathetic and parasympathetic) nervous systems.
• Nervous system disorders: Summarise the pathology and pathophysiology of central and peripheral nervous system disorders.
Commissural fibres
connect homologous
structures in left and
right hemispheres
Corpus callosum
Anterior commissure

18. • Organisation of the nervous system: Compare and contrast the structure of the central, peripheral and autonomic (sympathetic and parasympathetic) nervous systems.
• Nervous system disorders: Summarise the pathology and pathophysiology of central and peripheral nervous system disorders.
Projection fibres
connect cortex with lower
brain structures (e.g.
thalamus, brain stem and
spinal cord)
Afferent – towards cortex
Efferent – away from cortex
Deeper to cortex radiate as the
corona radiata
Converge through internal
capsule between thalamus and
basal ganglia

19. • Organisation of the nervous system: Compare and contrast the structure of the central, peripheral and autonomic (sympathetic and parasympathetic) nervous systems.
• Nervous system disorders: Summarise the pathology and pathophysiology of central and peripheral nervous system disorders.
Projection fibres - internal capsule

20. • Organisation of the nervous system: Compare and contrast the structure of the central, peripheral and autonomic (sympathetic and parasympathetic) nervous systems.
• Nervous system disorders: Summarise the pathology and pathophysiology of central and peripheral nervous system disorders.
Localisation of function
Function predictable
Primary cortices Secondary/association cortices
Organised topographically
Symmetry between left and right
function less predictable
not organised topographically
left-right symmetry weak or absent

21. • Organisation of the nervous system: Compare and contrast the structure of the central, peripheral and autonomic (sympathetic and parasympathetic) nervous systems.
• Nervous system disorders: Summarise the pathology and pathophysiology of central and peripheral nervous system disorders.
Frontal lobe - motor areas
controls fine, discrete, precise voluntary
movements.
Provides descending signals to execute
movements.
Supplementary area
Primary motor cortex
Premotor area
involved in planning movements (e.g.
externally cued)
Involved in planning complex movements (e.g.
internally cued)
Primary
Supplementary
Premotor area

22. Servier medical art
• Organisation of the nervous system: Compare and contrast the structure of the central, peripheral and autonomic (sympathetic and parasympathetic) nervous systems.
• Nervous system disorders: Summarise the pathology and pathophysiology of central and peripheral nervous system disorders.
Parietal lobe
processes somatic sensations arising from
receptors in the body (e.g. fine touch, vibration,
two-point discrimination, proprioception, pain
and temperature.
Central sulcus
Primary somatosensory
Somatosensory
association
Primary somatosensory
Somatosensory association
Interpret significance of sensory information,
e.g. recognizing an object placed in the hand.
Awareness of self and awareness of personal
space

23. • Organisation of the nervous system: Compare and contrast the structure of the central, peripheral and autonomic (sympathetic and parasympathetic) nervous systems.
• Nervous system disorders: Summarise the pathology and pathophysiology of central and peripheral nervous system disorders.
Occipital lobe
Primary visual
Visual association
processes visual stimuli
Primary visual
Visual association
Gives meaning and
interpretation of visual input
Servier medical art

24. • Organisation of the nervous system: Compare and contrast the structure of the central, peripheral and autonomic (sympathetic and parasympathetic) nervous systems.
• Nervous system disorders: Summarise the pathology and pathophysiology of central and peripheral nervous system disorders.
Temporal lobe
Primary auditory
Auditory association
processes auditory stimuli
Primary auditory
Auditory association
Gives meaning and
interpretation of auditory input
Servier medical art

25. • Organisation of the nervous system: Compare and contrast the structure of the central, peripheral and autonomic (sympathetic and parasympathetic) nervous systems.
• Nervous system disorders: Summarise the pathology and pathophysiology of central and peripheral nervous system disorders.
Other association areas
decision making
personality expression
Production of language
attention
Broca’s area
Wernicke’s area
Understanding of language
Prefrontal cortex
planning
adjusting social behaviour

26. • Organisation of the nervous system: Compare and contrast the structure of the central, peripheral and autonomic (sympathetic and parasympathetic) nervous systems.
• Nervous system disorders: Summarise the pathology and pathophysiology of central and peripheral nervous system disorders.
Cortical function after lesions
Changes in personality
Frontal lobe lesions
Inappropriate behaviour
Phineas Gage – accident in
1848
He is fitful, irreverent, indulging at times in the grossest profanity (which was not previously his custom), manifesting but little
deference for his fellows, impatient of restraint or advice when it conflicts with his desires.... …he has the animal passions of a
strong man.... His mind was radically changed, so decidedly that his friends and acquaintances said he was ‘no longer Gage.’”

27. • Organisation of the nervous system: Compare and contrast the structure of the central, peripheral and autonomic (sympathetic and parasympathetic) nervous systems.
• Nervous system disorders: Summarise the pathology and pathophysiology of central and peripheral nervous system disorders.
Cortical function after lesions
Contralateral neglect
Parietal lobe lesions
Lack of awareness of self on
left side
e.g. lesion in right
hemisphere
Lack of awareness of left side
of extrapersonal space

28. • Organisation of the nervous system: Compare and contrast the structure of the central, peripheral and autonomic (sympathetic and parasympathetic) nervous systems.
• Nervous system disorders: Summarise the pathology and pathophysiology of central and peripheral nervous system disorders.
Cortical function after lesions
Temporal lobe lesions
Leads to agnosia, inability to recognise
Lateral Medial
Patient HM - bilateral resection of anterior medial temporal lobe structures to cure epilepsy.
Could not form new memories - anterograde amnesia

29. • Organisation of the nervous system: Compare and contrast the structure of the central, peripheral and autonomic (sympathetic and parasympathetic) nervous systems.
• Nervous system disorders: Summarise the pathology and pathophysiology of central and peripheral nervous system disorders.
Cortical function after lesions Production of language
Expressive aphasia – poor production
of speech, comprehension intact
Broca’s
area
Wernicke’s
area
Understanding of language
Lesions to Broca’s or Wernicke’s areas Arcuate fasciculus
Broca’s area
Wernicke’s area
Receptive aphasia – poor
comprehension of speech,
production is fine

30. • Organisation of the nervous system: Compare and contrast the structure of the central, peripheral and autonomic (sympathetic and parasympathetic) nervous systems.
• Nervous system disorders: Summarise the pathology and pathophysiology of central and peripheral nervous system disorders.
Cortical function after lesions
Primary visual
Visual association
Servier medical art
blindness in the
corresponding part of
the visual field
Primary visual cortex
Visual association
deficits in interpretation of
visual information e.g.
prosopagnosia: inability to
recognise familiar faces or
learn new faces (face
blindness)

31. • Organisation of the nervous system: Compare and contrast the structure of the central, peripheral and autonomic (sympathetic and parasympathetic) nervous systems.
• Nervous system disorders: Summarise the pathology and pathophysiology of central and peripheral nervous system disorders.
Assessing cortical function – imaging
Positron emission tomography (PET) Functional magnetic resonance imaging (fMRI)
blood flow directly to a brain region
Cortical activity
during movement
of the right hand
amount of blood oxygen in a brain region

32. • Organisation of the nervous system: Compare and contrast the structure of the central, peripheral and autonomic (sympathetic and parasympathetic) nervous systems.
• Nervous system disorders: Summarise the pathology and pathophysiology of central and peripheral nervous system disorders.
Assessing cortical function – encephalography
Electroencephalography (EEG) Magnetoencephalography – (MEG)
Measures electrical signals
produces by the brain
Measures magnetic signals
produces by the brain
Event-related potentials / evoked-potentials

33. • Organisation of the nervous system: Compare and contrast the structure of the central, peripheral and autonomic (sympathetic and parasympathetic) nervous systems.
• Nervous system disorders: Summarise the pathology and pathophysiology of central and peripheral nervous system disorders.
Assessing cortical function – encephalography
Visual evoked potentials
Event-related potentials / evoked-potentials

34. • Organisation of the nervous system: Compare and contrast the structure of the central, peripheral and autonomic (sympathetic and parasympathetic) nervous systems.
• Nervous system disorders: Summarise the pathology and pathophysiology of central and peripheral nervous system disorders.
Assessing cortical function – encephalography
Somatosensory evoked potentials
series of waves that reflect sequential
activation of neural structures along the
somatosensory pathways
Stimulus to median nerve
impulses arriving at shoulder
Mid cervical cord activity
Thalamic activity
Somatosensory activity

35. • Organisation of the nervous system: Compare and contrast the structure of the central, peripheral and autonomic (sympathetic and parasympathetic) nervous systems.
• Nervous system disorders: Summarise the pathology and pathophysiology of central and peripheral nervous system disorders.
Assessing cortical function – brain stimulation
assess the functional integrity of neural circuits
Uses electromagnetic induction to stimulate neurons
Transcranial magnetic stimulation (TMS)

36. • Organisation of the nervous system: Compare and contrast the structure of the central, peripheral and autonomic (sympathetic and parasympathetic) nervous systems.
• Nervous system disorders: Summarise the pathology and pathophysiology of central and peripheral nervous system disorders.
Assessing cortical function – brain stimulation
Stimulate primary motor cortex

37. • Organisation of the nervous system: Compare and contrast the structure of the central, peripheral and autonomic (sympathetic and parasympathetic) nervous systems.
• Nervous system disorders: Summarise the pathology and pathophysiology of central and peripheral nervous system disorders.
Assessing cortical function – brain stimulation
investigate neural interactions
controlling movement following
spinal cord injury
Investigate whether a specific brain area is
responsible for a function, e.g. speech (link to video
above - https://www.youtube.com/watch?v=FMR_T0mM7Pc)

38. • Organisation of the nervous system: Compare and contrast the structure of the central, peripheral and autonomic (sympathetic and parasympathetic) nervous systems.
• Nervous system disorders: Summarise the pathology and pathophysiology of central and peripheral nervous system disorders.
Assessing cortical function – brain stimulation
Widely researched

39. • Organisation of the nervous system: Compare and contrast the structure of the central, peripheral and autonomic (sympathetic and parasympathetic) nervous systems.
• Nervous system disorders: Summarise the pathology and pathophysiology of central and peripheral nervous system disorders.
Assessing cortical function – brain stimulation
Transcranial direct current stimulation (tDCS)
Uses low direct current over the scalp to increase or decrease
neuronal firing rates

40. • Organisation of the nervous system: Compare and contrast the structure of the central, peripheral and autonomic (sympathetic and parasympathetic) nervous systems.
• Nervous system disorders: Summarise the pathology and pathophysiology of central and peripheral nervous system disorders.
Assessing cortical function – brain stimulation
Transcranial direct current stimulation (tDCS)
Uses low direct current over the scalp to increase or decrease
neuronal firing rates

41. • Organisation of the nervous system: Compare and contrast the structure of the central, peripheral and autonomic (sympathetic and parasympathetic) nervous systems.
• Nervous system disorders: Summarise the pathology and pathophysiology of central and peripheral nervous system disorders.
Assessing structure – imaging
Diffusion tensor imaging (DTI) DTI with tractography
Based on diffusion of water molecules 3D reconstruction to assess neural tracts

42. • Organisation of the nervous system: Compare and contrast the structure of the central, peripheral and autonomic (sympathetic and parasympathetic) nervous systems.
• Nervous system disorders: Summarise the pathology and pathophysiology of central and peripheral nervous system disorders.
Session Plan
• Columns, layers, cytoarchitecture
• Covers entire brain
• With nuclei, contains grey matter
• Highly folded
• Organised into lobes
• Primary and association cortices
• Functions of frontal, parietal, occipital and temporal lobes
• Association cortices and languages areas
• Imaging – PET and fMRI
• Encephalography – EEG and MEG
• Brain stimulation – TMS and tDCS
• Imaging – assessment of structure (DTI and tractography)
• Frontal – personality and behaviour changes
• Parietal – neglect
• Temporal – agnosia, amnesia
• Language regions – aphasia
• Occipital - visual disturbances
Microscopic cortical structure
General organisation
Internal structure and fibre tracts
Localisation of function
Assessment of cortical function
Effects of lesions on cortical function
• Grey matter - neuronal cell bodies
• White matter – myelinated tracts
• White matter tracts connect cortical regions
• Association, projection, commissural fibres