Neuroanatomy

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This article covers very basic neuroanatomy. It is essential to have a good grasp on neuroanatomy and neurohistology... before doing neuropathology.

This article has some overlap with the neurohistology article, as there isn't a clear divider between microscopic and macroscopic.

Anatomy

Important

  • Uncus (as in uncal herniation).
  • Cerebellar tonsils (as in tonsillar herniation).
  • Longitudinal fissure - divides cerebrum into hemispheres.
  • Lateral sulcus (Sylvian fissure, lateral fissure) - separates temporal lobe from frontal lobe & parietal lobe.
  • Central sulcus - separate parietal lobe from frontal lobe.
  • Brain stem = medulla oblongata, pons, mesencephalon (midbrain).[1]

Less important

Trivia

  • Claustrum - thin band of grey mater in the external capsule; function uncertain.[2]
  • Nerve root vs. nerve:[3]
    • Nerves have epineurium.
    • Nerve roots does not have epineurium.
      • Nerve anatomy:[4]
        • Nerve (surrounded by epineurium) -> Fascicle (surrounded by perineurium) -> Nerve fibre (surrounded by endoneurium).

Vascular structures

  • Posterior cerebellar arteries.
    • Inferior of posterior cerebral arteries.
  • Anterior inferior cerebellar arteries.
    • Branch off basilar artery.
  • Posterior inferior cerebellar arteries - AKA PICA.
    • Branch off vertebral arteries.

Images:

Meninges

Deep to superficial:

  1. Pia mater.
  2. Arachanoid membrane.
    • Subarachanoid space - contains blood vessels.
  3. Dura mater.
    • Tough outer covering.

Lesion location in relation to meninges

Locations:[5]

  1. Intra-axial = inside the (middle) of spinal cord/brain.
    • AKA intramedullary.
  2. Intradural = not intra-axial, but deep to the dural.
    • AKA extramedullary.
    • AKA extra-axial.
  3. Extradural = outside of dura.
  • The above descriptors are often found in radiology reports.

DDx based on location[6]

Intra-axial:[7]

  • Glioma (astrocytoma, oligodendroglioma, ependymoma).
  • Non-glial tumours (hemangioblastoma, CNS lymphoma).
  • Metastases.
  • Non-tumour:
    • Abscess.
    • Infarct.
    • Hematoma.

Intradural:

  • Meningioma.
  • Neurofibromas.
  • Schwannoma.
  • Arachnoid cyst.

Extradural:

  • Chordoma.
  • Schwannoma.
  • Sarcoma.
  • Plasmacytoma.
  • Primary bone tumors - osteosarcoma, osteochondroma, chondrosarcoma.
  • Mets (lung, breast, etc.).

Sampling - sections (autopsy)

See autopsy.

Standard histologic sections:

Routine[8] Head injury[9] Epilepsy[10] Dementia[11]
Frontal cortex Y [1] Y - bilateral parasagittal [2] N Y - middle frontal gyrus [1]
Cingulate gyrus N N Y - parasagittal [1] Y [1]
Basal ganglia &
internal capsule
Y [1] Y - bilateral with corpus callosum [2] Y - caudate, putamen,
globus palidus [1]
Y - putamen,
globus palidus [1]
Basal ganglia,
internal capsule,
thalamus
N Y [2] N N
Temporal lobe N N Y - superior & middle temporal gyri [2] Y - superior & middle temporal gyri [1]
Hippocampus Y [1] Y - bilateral [2] Y - also parahippocampal gyri [2] Y - also parahippocampal gyri [1]
Splenium of corpus callosum N Y [1] N N
Parietal lobe N Y - centrum semiovale (unilateral) [1] N Y - inferior [1]
Occipital cortex Y [1] N N Y [1]
Midbrain Y [1] Y [1] N Y [1]
Cerebellum (with
dentate gyrus)
Y [1] Y - bilateral [2] Y - also vermis [2] Y [1]
Pons N Y [1] N Y [1]
Medulla Y [1] Y [1] N Y [1]
Total sections [7] [15] [8] [11]

An absolute minimum:[12]

  1. Hippocampus.
  2. Cerebral cortex.
  3. Brainstem (midbrain).
  4. Cerebellum.

See also

References

  1. Martini, Frederic H. (2003). Fundamentals of Anatomy & Physiology (6th ed.). Benjamin Cummings. pp. 466. ISBN 978-0805359336.
  2. URL: http://commons.wikimedia.org/wiki/File:Telencephalon-Horiconatal.jpg. Accessed on: 22 September 2010.
  3. MUN. 25 November 2010.
  4. Martini, Frederic H. (2003). Fundamentals of Anatomy & Physiology (6th ed.). Benjamin Cummings. pp. 438. ISBN 978-0805359336.
  5. URL: http://www.nervous-system-diseases.com/spine-tumor.html. Accessed on: 21 September 2010.
  6. URL: http://www.nervous-system-diseases.com/spine-tumor.html. Accessed on: 21 September 2010.
  7. Perry, Arie; Brat, Daniel J. (2010). Practical Surgical Neuropathology: A Diagnostic Approach: A Volume in the Pattern Recognition series (1st ed.). Churchill Livingstone. pp. 57. ISBN 978-0443069826.
  8. Burton, Julian L.; Rutty, Guy N. (2010). The Hospital Autopsy A Manual of Fundamental Autopsy Practice (3rd ed.). Oxford University Press. pp. 164. ISBN 978-0340965146. }}
  9. Burton, Julian L.; Rutty, Guy N. (2010). The Hospital Autopsy A Manual of Fundamental Autopsy Practice (3rd ed.). Oxford University Press. pp. 176. ISBN 978-0340965146. }}
  10. Burton, Julian L.; Rutty, Guy N. (2010). The Hospital Autopsy A Manual of Fundamental Autopsy Practice (3rd ed.). Oxford University Press. pp. 179. ISBN 978-0340965146. }}
  11. Burton, Julian L.; Rutty, Guy N. (2010). The Hospital Autopsy A Manual of Fundamental Autopsy Practice (3rd ed.). Oxford University Press. pp. 180. ISBN 978-0340965146. }}
  12. MUN. 15 November 2010.

External links