2. Case
A 58 y/o was referred to you because of recent
onset of left hemiparesis, left-sided loss of
propioception and right-sided tongue
deviation. What CNS structures are affected?
Explain the symptoms with regards to
structures affected. Where is the lesion?
6. Rules of 4*
1. 4 structures in ‘midline’ and begin with ‘M’
2. 4 motor nuclei in midline and are those that
are divisors of 12 (3,4,6,12)
3. 4 structures to the ‘side’ (lateral) and begin
with ‘S’
4. 4 CN in medulla, 4 in pons and 4 above
pons
*Gates, P. The rule of 4 of the brainstem: a simplified method for understanding
brainstem anatomy and brainstem vascular syndromes for the non-neurologist. Internal
Medicine Journal 2005; 35: 263-266
7. 1 2
4 Motor nuclei in
4 Structures in midline midline and are divisors
and begin with ‘M’ of 12
( 3, 4, 6, 12)
RULE of
FOUR*
3 4
4 CN in medulla
4 Structures to the side
4 CN in pons
and begin with ‘S’
4 CN above pons
*Gates, P. The rule of 4 of the brainstem: a simplified method for understanding brainstem anatomy and brainstem
vascular syndromes for the non-neurologist. Internal Medicine Journal 2005; 35: 263-266
8. 2
4 Motor nuclei in
4 Structures in midline midline and are divisors
and begin with ‘M’ of 12
( 3, 4, 6, 12)
3 4
4 CN in medulla
4 Structures to the side
4 CN in pons
and begin with ‘S’
4 CN above pons
*Gates, P. The rule of 4 of the brainstem: a simplified method for understanding brainstem anatomy and brainstem
vascular syndromes for the non-neurologist. Internal Medicine Journal 2005; 35: 263-266
9. 4 Motor nuclei in
4 Structures in midline midline and are divisors
and begin with ‘M’ of 12
( 3, 4, 6, 12)
3 4
4 CN in medulla
4 Structures to the side
4 CN in pons
and begin with ‘S’
4 CN above pons
*Gates, P. The rule of 4 of the brainstem: a simplified method for understanding brainstem anatomy and brainstem
vascular syndromes for the non-neurologist. Internal Medicine Journal 2005; 35: 263-266
10. 4 Motor nuclei in
4 Structures in midline midline and are divisors
and begin with ‘M’ of 12
( 3, 4, 6, 12)
4
4 CN in medulla
4 Structures to the side
4 CN in pons
and begin with ‘S’
4 CN above pons
*Gates, P. The rule of 4 of the brainstem: a simplified method for understanding brainstem anatomy and brainstem
vascular syndromes for the non-neurologist. Internal Medicine Journal 2005; 35: 263-266
11. 4 Motor nuclei in
4 Structures in midline midline and are divisors
and begin with ‘M’ of 12
( 3, 4, 6, 12)
4 CN in medulla
4 Structures to the side
4 CN in pons
and begin with ‘S’
4 CN above pons
*Gates, P. The rule of 4 of the brainstem: a simplified method for understanding brainstem anatomy and brainstem
vascular syndromes for the non-neurologist. Internal Medicine Journal 2005; 35: 263-266
18. ne s
li e
DE
id ur FIC
M ct I T
S tru
Motor pathway
Contalateral weakness
(Corticospinal tract)
More Info
Medial lemniscus
Medial longditudinal
fasciculus
Motor nucleus and
nerve
19. ne s
li e
DE
id ur FIC
M ct I T
S tru
Motor pathway
Contalateral weakness
(Corticospinal tract)
Contralateral propioception/
Medial lemniscus vibration loss
More Info
Medial longditudinal
fasciculus
Motor nucleus and
nerve
20. ne s
li e
DE
id ur FIC
M ct I T
S tru
Motor pathway
Contalateral weakness
(Corticospinal tract)
Contralateral
Medial lemniscus propioception/ vibration
loss
Medial longditudinal Ipsilateral internuclear
fasciculus ophthalmoplegia
More Info
Motor nucleus and
nerve
21. ne s
li e
DE
id ur FIC
M ct I T
S tru
Motor pathway
Contalateral weakness
(Corticospinal tract)
Contralateral
Medial lemniscus propioception/ vibration
loss
Medial longditudinal Ipsilateral internuclear
fasciculus ophthalmoplegia
Motor nucleus and Ipsilateral CN
nerve function loss
22. al DE
er es
at ur FIC
L ct IT
S tru
Spinocerebellar
Ipsilateral ataxia
pathway
More Info
Spinothalamic
Sensory nucleus of
CN5
Sympathetic pathway
23. al DE
er es
at ur FIC
L ct I T
S tru
Spinocerebellar
Ipsilateral ataxia
pathway
Contralateral pain/temp
Spinothalamic sensory loss
More Info
Sensory nucleus of
CN5
Sympathetic pathway
24. al DE
er es
at ur FIC
L ct I T
S tru
Spinocerebellar
Ipsilateral ataxia
pathway
Contralateral pain/temp
Spinothalamic sensory loss
Sensory nucleus of Ipsilateral pain/ temp
CN5 loss in face
More Info
Sympathetic pathway
25. al DE
er es
at ur FIC
L ct I T
S tru
Spinocerebellar
Ipsilateral ataxia
pathway
Contralateral pain/temp
Spinothalamic sensory loss
Sensory nucleus of Ipsilateral pain/ temp
CN5 loss in face
Ipsilateral Horner’s
Sympathetic pathway
syndrome
More Info
26. DE
CN lla
4 u
FIC
I T
ed
M
Glossopharyngeal Ipsilateral pharyngeal
CN9 sensory loss
Vagus CN10
Spinal accessory CN11
Hypoglossal CN12
27. DE
CN lla
4 u
FIC
I T
ed
M
Glossopharyngeal Ipsilateral pharyngeal
CN9 sensory loss
Ipsilateral palatal
Vagus CN10
weakness
More Info
Spinal accessory CN11
Hypoglossal CN12
28. DE
CN lla
4 u
FIC
I T
ed
M
Glossopharyngeal Ipsilateral pharyngeal
CN9 sensory loss
Ipsilateral palatal
Vagus CN10
weakness
Ipsilateral shoulder
Spinal accessory CN11
weakness
Hypoglossal CN12
29. DE
CN lla
4 u
FIC
I T
ed
M
Glossopharyngeal Ipsilateral pharyngeal
CN9 sensory loss
Ipsilateral palatal
Vagus CN10
weakness
Ipsilateral shoulder
Spinal accessory CN11
weakness
Ipsilateral weakness of
Hypoglossal CN12
tongue
More Info
30. DE
CN
4 ns
FIC
IT
Po
Ipsilateral facial
Trigeminal CN5
sensory loss
More Info
Abducent CN6
Facial CN7
Auditory CN8
31. DE
CN
4 ns
FIC
IT
Po
Ipsilateral facial
Trigeminal CN5
sensory loss
Ipsilateral eye
Abducent CN6
abduction weakness
More Info
Facial CN7
Auditory CN8
32. DE
CN
4 ns
FIC
IT
Po
Ipsilateral facial
Trigeminal CN5
sensory loss
Ipsilateral eye
Abducent CN6
abduction weakness
Ipsilateral facial
Facial CN7
weakness
More Info
Auditory CN8
33. DE
CN
4 ns
FIC
IT
Po
Ipsilateral facial
Trigeminal CN5
sensory loss
Ipsilateral eye
Abducent CN6
abduction weakness
Ipsilateral facial
Facial CN7
weakness
Auditory CN8 Ipsilateral deafness
34. DE
4 CN ons FIC
P IT
ve
A bo
Olfactory CN1 Not in midbrain
Optic CN2 Not in midbrain
Eye turned out and
Occulomotor CN3
down
More Info
Trochlear CN4
35. DE
4 CN ons FIC
P I T
ve
A bo
Olfactory CN1 Not in midbrain
Optic CN2 Not in midbrain
Eye turned out and
Occulomotor CN3
down
Eye unable to look down
Trochlear CN4 when looking towards nose
More Info
37. Always remember
“Pathways and tracts pass through the
entire length of the brainstem and can be
likened to ‘meridians of longitude‘ whereas
the various cranial nerves can be regarded
as ‘parallels of latitude‘.
If you establish where the meridians of
longitude and parallels of latitude intersect
then you have established the site of the
lesion.”
Gates, P. The rule of 4 of the brainstem: a simplified method for understanding brainstem
anatomy and brainstem vascular syndromes for the non-neurologist. Internal Medicine
Journal 2005; 35: 263-266
38. Case
58 year old woman
•Left hemiparesis
•Left-sided loss of
propioception
•Right-sided
tongue deviation
39. Case Structure
58 year old woman
•Left hemiparesis •Motor (CS tract, R)
•Left-sided loss of •Medial
propioception lemniscus, R
•Right-sided •CN12, R
tongue deviation
43. Case
58 year old woman
•Left-sided
meiosis,
anhydrosis, ptosis
•Left-sided ataxia
•Uvula deviated
to right
44. Case Structure
58 year old woman
•Left-sided •Sympathetic
meiosis, tract, Left
anhydrosis, ptosis
•Left-sided ataxia •Spinocerebellar
•Uvula deviated •CN10, Left
to right
46. Location Structure
•Side, Left •Sympathetic
tract, Left
•Side, Left •Spinocerebellar
•Medulla •CN10, Left
47. Location Structure
•Side, Left •Sympathetic
tract, Left
•Side, Left •Spinocerebellar
•Medulla •CN10, Left
Lateral medullary Posterior inferior
syndrome (L) cerebellar artery (L)
48. Assignment
In lateral medullary syndrome
(Wallenberg syndrome), there are
associated analgesia and
thermoanalgesia of the ipsilateral
face. Why? What brainstem
structure is affected?
49. Case Structure
10 y/o girl
with the ff symptoms
Left-sided weakness
Right eye deviates medially
Righ-sided facial weakness
50. Case Structure
10 y/o girl
with the ff symptoms
Left-sided weakness Motor (CS tract, R)
Right eye deviates medially
Righ-sided facial weakness
51. Case Structure
10 y/o girl
with the ff symptoms
Left-sided weakness Motor (CS tract, R)
Right eye deviates medially LR weakness, CN6 Right
Righ-sided facial weakness
52. Case Structure
10 y/o girl
with the ff symptoms
Left-sided weakness Motor (CS tract, R)
Right eye deviates medially LR weakness, CN6 Right
Righ-sided facial weakness CN7, Right
53. Location Structure
Motor (CS tract, R)
LR weakness, CN6 Right
CN7, Right
54. Location Structure
Medial structure Motor (CS tract, R)
LR weakness, CN6 Right
CN7, Right
55. Location Structure
Medial structure Motor (CS tract, R)
Pons LR weakness, CN6 Right
CN7, Right
56. Location Structure
Medial structure Motor (CS tract, R)
Pons LR weakness, CN6 Right
Pons CN7, Right
57. Location Structure
Medial structure Motor (CS tract, R)
Pons LR weakness, CN6 Right
Pons CN7, Right
Medial Pons Pons tumor
58. Location Structure
Medial structure Motor (CS tract, R)
Pons LR weakness, CN6 Right
Pons CN7, Right
Medial Pons Pons tumor
Millard-Gubler Syndrome
60. Case Structure
70 y/o male hypertensive
suddenly developed
Left-sided ipsilateral
ophthalmoplegia
Loss of pupilary light reflex, left
eye
Paralysis of right arm and leg
61. Case Structure
70 y/o male hypertensive
suddenly developed
Left-sided ipsilateral
ophthalmoplegia CN3, Left
Loss of pupilary light reflex, left
eye
Paralysis of right arm and leg
62. Case Structure
70 y/o male hypertensive
suddenly developed
Left-sided ipsilateral
ophthalmoplegia CN3, Left
Loss of pupilary light reflex, left
eye CN3, Left
Paralysis of right arm and leg
63. Case Structure
70 y/o male hypertensive
suddenly developed
Left-sided ipsilateral
ophthalmoplegia CN3, Left
Loss of pupilary light reflex, left
eye CN3, Left
Paralysis of right arm and leg Motor, CS tract, Left
64. Location Structure
CN3, Left
CN3, Left
Motor, CS tract, Left
65. Location Structure
Midbrain CN3, Left
CN3, Left
Motor, CS tract, Left
66. Location Structure
Midbrain CN3, Left
Midbrain CN3, Left
Motor, CS tract, Left
67. Location Structure
Midbrain CN3, Left
Midbrain CN3, Left
Medial, Left Motor, CS tract, Left
68. Location Structure
Midbrain CN3, Left
Midbrain CN3, Left
Medial, Left Motor, CS tract, Left
Medial Midbrain Weber’s Syndrome
69. Case Structure
70 y/o male hypertensive
suddenly developed
Left-sided ipsilateral
ophthalmoplegia
Right-sided propioception loss
Involuntary movement
70. Case Structure
70 y/o male hypertensive
suddenly developed
Left-sided ipsilateral
ophthalmoplegia CN3, Left
Right-sided propioception loss
Involuntary movement
71. Case Structure
70 y/o male hypertensive
suddenly developed
Left-sided ipsilateral
ophthalmoplegia CN3, Left
Right-sided propioception loss Medial Lemniscus, Left
Involuntary movement
72. Case Structure
70 y/o male hypertensive
suddenly developed
Left-sided ipsilateral
ophthalmoplegia CN3, Left
Right-sided propioception loss Medial Lemniscus, Left
Involuntary movement Red nucleus, Left
73. Location Structure
CN3, Left
Medial Lemniscus, Left
Red nucleus, Left
74. Location Structure
Midbrain, Left CN3, Left
Medial Lemniscus, Left
Red nucleus, Left
75. Location Structure
Midbrain, Left CN3, Left
Medial, Left Medial Lemniscus, Left
Red nucleus, Left
76. Location Structure
Midbrain, Left CN3, Left
Medial, Left Medial Lemniscus, Left
Medial, Left Red nucleus, Left
77. Location Structure
Midbrain, Left CN3, Left
Medial, Left Medial Lemniscus, Left
Medial, Left Red nucleus, Left
Medial Midbrain Benedikt’s Syndrome
