Neuroanatomy

1. Welcome to Neuroanatomy presentation
Presented by:
Dr. Md. Saiduzzaman
MD Resident(Phase B)
Mymensingh Medical College Hospital.

2. Medulla Oblongata

3. Outline:
 Gross appearance of Medulla.
 Internal structures.
 Blood supply of medulla.
 Functions.
 Applied anatomy.

4. Gross appearance:
 The medulla oblongata connects the
Pons superiorly and the spinal cord
inferiorly.
 Conical in shape with the broad
extremity directed upwards.

5. Cont…d
 Central canal of the spinal cord
continues upward into the lower half of
the medulla.
 Upper half of the medulla expands to
contain the fourth ventricle.

6. Pyramid:
 Swelling on each side of anterior
median fissure.
 Composed of bundles of nerve fibers,
(corticospinal fibers) originate from the
precentral gyrus of the cerebral cortex.
 The pyramids taper inferiorly and
majority of the descending fibers
decussate to the opposite side.

7. Olive:
 Olives are the posterolateral oval
elevations produced by the underlying
inferior olivary nuclei.
 From the groove between the pyramid
and the olive, the rootlets of the
hypoglossal nerve emerge.

12. Internal structures:
A. At the level of decussation of
pyramids.
B. At the level of decussation of
lemnisci.

14. Medial lemnisci:
 The great sensory decussation.
 The lemnisci have been formed by the
internal arcuate fibers, which emerge
from the anterior aspects of the
nucleus gracilis and nucleus cuneatus.
 The deussation takes place anterior to
the central grey mater.

16. Fig: At the level of the middle of the olivary
nuclei

17. Fig: superior part of the olivary nuclei just
inferior to the pons.

18. Arterial supply:
Medulla oblongata is supplied by the
branches of vertebral, anterior and
posterior spinal, posterior inferior
cerebellar and basilar arteries.

19. Medulla Oblongata
Arterial supply:
• Vertebral artery
•Anterior spinal artery
• PICA
PICA
Ant sp
Vert

20. Venous drainage:
The medulla oblongata is drained by
veins that open into the spinal veins
and neighboring venous sinuses.

21. Functions:
1. Connects the higher levels of the brain to the
spinal cord.
2. Responsible for regulating several basic functions
of the autonomic nervous system which include:
• Respiration –chemoreceptors.
•Cardiac center – sympathetic and
parasympathetic nervous
system.
•Vasomotor center- baroreceptors.
•Reflex centers of vomiting, coughing,
sneezing, and swallowing.

22. Applied Anatomy

23. Diseases of medulla oblongata
 Genetic
 Developmental
 Vascular
 Degenarative
 Inflammatory
 Infective
 Neoplastic

24. Genetic disease
KENNEDY'S DISEASE
(x-linked bulbospinal neuronopathy)

25. KENNEDY'S DISEASE
(Characteristic features)
Pathogenesis:
 x-linked recessive inheritance.
 Abnormal CAG expansion.
Neurological menifestation:
 Slowly progressive limb-girdle muscular weakness.
 Early tremor.
 Slowly progressive bulbar dysfunction.
 Muscle cramps and fasciculation.

26. KENNEDY'S DISEASE
(continued)
Systemic menifestation:
 Gynaecomastia
 Endocrine abnormality.
 Diabetes insipidus.
Laboratory characterestics:
 Abnormal sensory nerve conduction study.
 Abnormal sex hormone level.
 Genetic study.

27. DEVELOPEMENTAL
 Arnold-chiari malformation
 Syringobulbia

28. Chiari Malformation
Types:
 Type-1
 Type-2
 Type-3
 Type-4
Sign-symptoms:
 Hydrocephalus.
 Cranial nerve palsy
 Features of raised ICP
 Foramen – magnum syndrome

29. CHIARI MALFORMATION

30. Syringobulbia
Presence of syrinx into medulla.
Sign-symptoms:
 palatal and vocal cord palsy.
 Dysarthria.
 Nystagmus.
 Tongue weakness.

32. Vascular diseases:
1. Lateral medullary syndrome.
2. Medial medullary syndrome
3. Opalski syndrome
4. Babiniski-nageotte syndrome
5. Avellis syndrome

33. Fig: Lateral Medullary Syndrome

34. Lateral medullary syndrome

36. Fig: Medial Medullary Syndrome.

37. Medial medullary syndrome

38. Opalski syndrome:
 Lateral medullary syndrome +
ipsilateral hemiparesis.
 Corticospinal fibers involment caudal
to pyramidal decussation.

39. Babinski-Nageotte syndrome
 Combined medial and lateral medullary
syndrome.
 Also called Hemi-medullary syndrome.

40. Avellis Syndrome:
10th cranial nerve involvement
+
contralateral hemi-sensory loss.

41. Degenerative diseases:
Motor Neuron Disease
Progressive bulbar palsy
Pseudobulbar palsy.

42. Differences between Bulbar and Pseudobulbar
palsy

43. Infective diseases:
1. Brainstem encephalitis (Viral,
Bacterial, Fungal,Protozoal)
2. Lyme disease(Borellia)
3. Post-infectious (Bickerstaff
encephalitis)

44. Bickerstaff encephalitis:
•Following infection by CMV, Campylobacter
jejeuni, Mycoplasma pneumonia.
• criteria:
 External ophthalmoplegia.
 Ataxia.
 Lower limb areflexia.
 Extensor plantar response.
 Altered level of consciousness.

45. Cont…d
•Differential diagnosis:
> Miller-Fisher syndrome
> ADEM.
•Investigations:
◦ CSF analysis- increased protein.
◦ Anti-GQ1b IgG Antibody- may be present.
◦ Anti-Ganglioside Antibody
◦ MRI of brain-Hyperintense lesion in
brainstem.

46. Inflammatory diseases:
 Bulbar GBS.
 Multiple sclerosis.
 CNS vasculitis.

47. Polyneuritis cranialis:
 Multiple cranial nerve palsy.
 Can occur in case of
- Variant of GBS
- TB meningitis.
- Lyme disease
- Lymphoma
- Herpes simplex(type-2)

48. Neoplastic diseases:
1. Glioma
2. Glioblastoma multiforme
3. Schwannoma
4. Haemangioblastoma.