spinal cord and brainstem syndromes Flashcards
A man presents with double vision and left sided weakness. On exam, his right eye is deviated down and out. His right eye will not move medially and ptosis is present. He is weak on the left side, arm and leg. He cannot walk or lift his left arm. What is this syndrome called? Where is the lesion localized?
The eye being deviated down and out, and not being able to move medial = oculomotor nerve problem.
This is Weber Syndrome.
Since the oculomotor nerve is in the midbrain and the man has muscular weakness on the contralateral side, the lesion must be in the right ventral midbrain.
A man presents with double vision and left sided weakness. On exam, his right eye will not abduct. His diplopia worsens when he looks to the right, but is better when he looks to the left. He is weak on the left side, arm and leg. He cannot walk or lift his left arm. What is the name of this syndrome? Where is the lesion located?
He has a problem with his right abducens nerve and motor function on the left side of his body. Since there are crossed signs, this must be a lesion in the brainstem.
Raymond Syndrome.
Lesion is in the right ventral pons
Man presents with a flat right nasolabial fold. He cannot move the corner of his right mouth. He is drooling from the right side of this mouth. His speech is slurred. He is weak on the left side, arm and leg and he cannot walk or lift his left arm. What is this syndrome called? Where is the lesion?
Problem with the right facial nerve and descending motor nerves. Thus, it must be a brainstem lesion in the right pons.
This is called Millard Gubler Syndrome
Other symptoms would be hyperacusis (loss of stapedius muscle), impaired direct and consensual corneal reflex (CN VII mediates efferent arc of corneal reflex), inability to wrinkle brow or elevate the eyebrow
Woman presents with slurred speech, imbalance, and numbness. On exam, her speech is dysarthric and she’s drooling. Her gag reflex is diminished on the right. Her right face is numb to pain and temperature. Her left body is numb to pain and temperature. She is imbalanced and clumsy
The slurred speech and diminished gag reflex mean there is a problem with CN IX, X and XI, which are located in the medulla. Since pain and temp go through the spinalthalamic tract located posteriorly/dorsally, the lesion must be in the right dorsal medulla. the limb clumsiness is ataxia from the cerebellar connections which are affected by the lesion.
This is called Wallenberg syndrome or Lateral medullary syndrome
Man presents with slurred speech and left sided weakness. On exam, his speech is dysarthric with a lingual quality. Tongue protrudes to the right and cannot move to the left. His left side is weak, both arm and leg. What is this syndrome called? Where is the lesion?
Crossed signs (right tongue weakness, left body weakness) suggest brainstem location. Motor signs suggest anterior location/involvement of corticospinal tract. Since the hypoglossal nerve is in the medulla, the lesion is in the right ventral medulla.
Jackson syndrome
Which cranial nerves have their nuclei in the midbrain? pons? medulla?
midbrain - CN III
Pons - CN V and VII
medulla - CN IX, X, XI, XII
Where are motor fibers in the brainstem?
Where are sensory fibers in the brainstem?
Anterior brainstem has descending motor pathways
Posterior brainstem has ascending sensory pathways
What are the common causes of a central cord injury?
What gets damage in a central cord injury? What clinical findings does this lead to?
Common causes - syringomyelia, hyperextension of the cervical spine (MVA), cervical compression
There is damage to the middle of the cord, including the anterior white commisure through which the spinothalamic tract decussates. This leads to a cape-like sensory loss/suspended sensory loss of pain and temperature but preserved sensation and motor function.
Classic example is a person who tell you “I brned my fingers without feeling it.”
What is the cause of Brown-Sequard syndrome?
What are the clinical findings of Brown-Sequard?
Brown-Sequard is caused by hemisection of the spinal cord, most often due to trauma.
Below the lesion - ipsilateral UMN deficits, ipsilateral deficits in motor function and sensation, contralateral deficits in pain and temperature
At the level of the lesion - ipsilateral LMN deficits, ipsilateral loss of all sensation
Normal bowel and bladder because they are bilaterally innervated
