Video 9 Brainstem Lesions

Question 1

What causes and what are the symptoms of Weber syndrome?

Answer 1

Midbrain infarction resulting from occlusion of the paramedian branches of the posterior cerebral artery:

• Cerebral peduncle lesion results in Contralateral spastic paralysis (AKA Contralateral hemiparesis).
• Oculomotor nerve (CN III) palsy results in Ipsilateral ptosis, pupillary dilation, and lateral strabismus (eye looks down and out).

Question 2

Which possible causes results in Locked-in syndrome?

Answer 2

Lesion in superior pons, Basilar artery strokes, hyponatremia corrected too quickly, leading to central pontine myelinolysis.

Question 3

Patient whose hyponatremia was corrected too quick and develops quadriplegia, what is the name of this syndrome?

Answer 3

Locked-in syndrome

Question 4

Which are the symptoms of the locked syndrome?

Answer 4

Preserved consciousness and blinking, quadriplegia, loss of voluntary facial, mouth, and tongue movements.

Question 5

What is the cause of medial inferior pontine syndrome?

Answer 5

Caused by occlusion of a paramedian branch of the basilar artery resulting in unilateral infarct of medial aspect of inferior pons.

Question 6

What are the symptoms of medial inferior pontine syndrome?

Answer 6

Contralateral spastic hemiparesis, Contralateral loss of light touch/vibratory/kin esthetic sensation, Paralysis of gaze to side of lesion, Ipsilateral paralysis of lateral rectus muscle, Note that pain and temperature sensation are persevered.

Question 7

Damage to which areas causes medial inferior pontine syndrome symptoms?

Answer 7

1)Contralateral spastic hemiparesis (corticospinal tract damaged).
2)Contralateral loss of light touch/vibratory/skin esthetic sensation (medial Lemniscus damage).
3)Paralysis of gaze to side of lesion (damage to pontine gaze center: PPRF and abductees nucleus).
4)Ipsilateral paralysis of lateral rectus muscle (damage to abducens nerve fiber).
Note that pain and temperature sensation are persevered.

Question 8

What is the cause of lateral inferior pontine syndrome?

Answer 8

Caused by occlusion of one of the anterior inferior cerebellar artery (AICA) resulting in unilateral infarct of lateral aspect of inferior pons (AKA anterior inferior cerebellar artery syndrome).

Question 9

What are the symptoms of lateral inferior pontine syndrome?

Answer 9

1) Ipsilateral facial nerve paralysis.
2) Ipsilateral loss of taste from anterior 2/3 of tongue.
3) Nystagmus, vertigo, nausea/vomiting.
4) Ipsilateral limb and gait ataxia.
5) Ipsilateral loss of pain and temperature sensation from the face.
6) Ipsilateral Horner syndrome.

Question 10

Damage to which areas causes lateral inferior pontine syndrome symptoms?1)Ipsilateral facial nerve paralysis.

2) Ipsilateral loss of taste from anterior 2/3 of tongue.
3) Nystagmus, vertigo, nausea/vomiting.
4) Ipsilateral limb and gait ataxia.
5) Ipsilateral loss of pain and temperature sensation from the face.
6) Ipsilateral Horner syndrome.

Answer 10

1) Facial nucleus and nerve fiber damage.
2) Solitary nucleus and nerve fibers.
3) Vestibular nucleus and nerve fiber damage.
4) Damage to middle and inferior cerebellar peduncles
5) Spinal trigeminal nucleus and nerve fiber damage.
6) Damage to descending sympathetic tract.

Question 11

What is the cause of superior /Rostral pontine syndrome?

Answer 11

It is an occlusion of one of the Anterior Inferior Cerebellar Artery (AICA) arteries in the superior/Rostral pons.

Question 12

What are the symptoms of the lateral superior pontine syndrome?

Answer 12

1) Ipsilateral loss of light touch and vibration sensation from face.
2) Ipsilateral jaw weakness and deviation of jaw toward side of lesion.
3) Contralateral loss of pain and temperature sensation from body.

Question 13

Damage to which areas causes the lateral superior pontine syndrome symptoms?

1) Ipsilateral loss of light touch and vibration sensation from face.
2) Ipsilateral jaw weakness and deviation of jaw toward side of lesion.
3) Contralateral loss of pain and temperature sensation from body.

Answer 13

1) Main sensory trigeminal nucleus and fiber damage.
2) Trigeminal motor nucleus and nerve fiber damage.
3) Damage to Spinothalamic tract.

Question 14

What is the hallmark sign of a general brainstem lesion?

Answer 14

Alternating syndromes: with long tract symptoms on one side (I.e., hemiparalysis) and cranial nerve symptoms on the other.

Question 15

What causes medial medullary syndrome?

Answer 15

Caused by occlusion of a paramedian branch of anterior spinal artery (from vertebral artery) resulting in unilateral infarct of medial portion of Rostral medulla (AKA anterior spinal artery syndrome).

Question 16

What are the symptoms of medial medullary syndrome?

Answer 16

1) Contralateral spastic hemiparesis.
2) Contralateral tactile and kin esthetic defects.
3) Tongue deviates toward side of the lesion.
4) Note that pain and temperature sensation are preserved.

Question 17

Damage to which areas causes medial medullary syndrome symptoms?

Answer 17

1) Contralateral spastic hemiparesis (pyramid/corticospinal tract damage).
2) Contralateral tactile and kin esthetic defects (medial Lemniscus damage).
3) Tongue deviates toward side of the lesion (hypoglossal nucleus/nerve damage).
4) Note that pain and temperature sensation are preserved.

Question 18

What are the causes of lateral medullary syndrome (AKA Wallenberg syndrome)?

Answer 18

Caused by occlusion of one of the posterior inferior cerebellar arteries (PICA) resulting in unilateral infarct of lateral portion of Rostral medulla (AKA posterior inferior cerebellar artery syndrome).

Question 19

What are the symptoms of Wallenberg syndrome?

Answer 19

1) Loss of pain and temperature over Contralateral body.
2) Loss of pain and temperature over Ipsilateral face.
3) Hoarseness, difficulty swallowing, loss of gag reflex.
4) Ipsilateral Horner syndrome.
5) Vertigo, nystagmus, nausea/vomiting.
6) Ipsilateral cerebellar deficits (I.e., ataxia a, past pointing).

Question 20

Damage to which areas causes the symptoms of the Wallenberg syndrome?

1) Loss of pain and temperature over Contralateral body.
2) Loss of pain and temperature over Ipsilateral face.
3) Hoarseness, difficulty swallowing, loss of gag reflex.
4) Ipsilateral Horner syndrome.
5) Vertigo, nystagmus, nausea/vomiting.
6) Ipsilateral cerebellar deficits (I.e., ataxia a, past pointing).

Answer 20

1) Spinothalamic tract damage.
2) Trigeminothalamic tract damage.
3) Nucleus ambiguus: glossopharyngeal and vagus damage.
4) Descending sympathetic tract.
5) Vestibular nuclei damage.
6) Inferior cerebellar peduncle damage.

Question 21

What are the causes of inter nuclear ophtalmoplegia (AKA MLF syndrome)?

Answer 21

Younger patients (under 50): Multiple Sclerosis.
Older patients (over 50): Stroke.

Question 22

What are the signs of Weber syndrome?

Answer 22

Contralateral spastic paralysis or hemiparesis, CN III palsy (eye looks down and out), Ptosis.

Question 23

What is the signs of Wallenberg syndrome?

Answer 23

1) Contralateral loss of pain and temperature sensation on the body.
2) Ipsilateral loss of pain and temperature on the face.
3) Hoarse voice, difficulty swallowing, loss of gag reflex.
4) Ipsilateral Horner syndrome.
5) Vertigo, nystagmus, nausea/vomiting.
6) Ipsilateral cerebellar defects.

Question 24

A patient cannot abduct her left eye on lateral gaze and convergence is normal. She also is having a difficulty smiling. In what part of the CNS is there lesion?

Answer 24

Lesion of PONS

Question 25

A lesion of what artery can cause a locked-in syndrome?

Answer 25

Basilar artery.