Brainstem 2 Flashcards
A landmark for medial vs lateral blood supply of the upper medulla
Inferior Olivary Nucleus
Due to a deficit in the posterior inferior cerebela artery (PICA)
Lateral Medullary Syndrome (Wallenberg Syndrome)
In Wallenberge syndrome, we see contralateral body pain and temperature loss b/c of the lesion of the
Spinothalamic tract
In Wallenberge syndrome, we see IPSILATERAL face pain and temperature loss b/c of the lesion of the
Spinal Nucleus of V
In Wallenberge syndrome, we see IPSILATERAL hearing loss b/c of the lesion of the
Cochlear Nucleus
In Wallenberge syndrome, we see IPSILATERAL Horner’s syndrome b/c of lesion of
Descending Hypothalamic fibers
In Wallenberge syndrome, we see IPSILATERAL ataxia b/c of lesion of the
Inferior Cerebellar Peduncles
In Wallenberge syndrome, we see vertigo, nausea, vomiting, and nystagmus because of lesion of the
Vestibular nuclei
In Wallenberge syndrome, we see IPSILATERAL paralysis of larynx, pharynx, palate, dysarthria, dysphagia, and lack of gag reflex because of lesion of the
Nucleus Ambiguus (CNs IX and X)
In Wallenberge syndrome, we see taste loss because of lesion of the
Nucleus Solitarius
Medial Medullary syndrome is due to a deficit of the
Anterior Spinal Artery
In medial medullary syndrome, we see contralateral arm or leg weakness and spatic paralysis because of a lesion to the
Corticospinal tract
In medial medullary syndrome, we see CONTRALATERAL decreased position, tactile, and vibration sense because of a lesion of the
Medial Lemniscus
In medial medullary syndrome, we see IPSILATERAL flaccid paralysis of the tongue with deviation on protrusion to side of lesion because of lesion to
Hypoglossal nucleus and axons
In the Pons, the corticospinal tract is ALWAYS
Medial
In the pons, the STT and Descending hypothalamic fibers are ALWAYS
Lateral
In the Pons, shifts from medial to lateral
Medial Lemniscus
Has motor efferents for the muscles of facial expression, stapedius muscle, and part of digastric muscle
CN VII
Has preganglionic parasympathetic innervation for the lacrimal, sublingual, submandibular, and ALL of ther salivary glands EXCEPT for the parotid gland
CN VII
Nucleus of CN VII responsible for salivation and lacrimation
Superior Salivatory Nucleus (SSNu)
Nucleus of CN VII responsible for taste on anterior 2/3 of tongue
Rostral Solitary Nucleus
Unilateral facial weakness (of LMN type) acutely (overnight) with retroauricular pain and sometimes hyperacusis
Bell’s Palsy
Has motor innervation for th emuscles of mastication and tensor tympani
CN V
Provides touch and pain sensations for the nasal sinuses and inside of nose and mouth and cornea
CN V
CN V also provides pain from the
Supratentorial Dura Matter
Which division of CN V is responsible for the sensory innervation to the cornea and dura (anterior)?
V1 (opthalamic)
CN V2 (Maxillary) provides sensory for the
Upper teeth
Which division of CN V provides sensory innervation to the anterior 2/3 of the tongue and the lower teeth?
V3 (Mandibular Division)
The trigemino-thalamic pathway for pain and temperature from the face crosses at the
Medullary and pontine levels
Nucleus that extends from lower part of the pons, through the medulla, and to the upper cervical segment of the spinal cord (C2-C3)
-Pain and temperature from face
Spinal nucleus of V
Provides the ipsilateral impulses of pain, temperature, and some touch from the head, face, and neck
Spinal nucleus of V (Spinal trigeminal tract)
Spinal nucleus V also receives afferents from CNs
IX and X
The trigemino-lemniscal pathway for touch and pressure from the face crosses at
Pontine levels
The nucleus of CN V responsible for the impulses of touch and pressure sensation from the head and face
Main Sensory Nucleus of V (Trigemino-lemniscus pathway)
Unconscious proprioception and the afferent loop for the jaw jerk reflex are through the
Mesencephalic nucleus of V
Control the force of the bite (similar to the dorsal nucleus of Clarke)
-proprioceptive and impulse forces from the face
Mesencephalic nucleus of V
Nucleus of CN V for innervation of muscles of mastication and tensor tympani
Motor nucleus of V
CN V lesions are relatively
Uncommon
We will see chin deviation towards the paralyzed side due to pterygoid action when the jaw opens
CN V lesion
Facial sensation is normal, but there are recurrent episodes of brief severe pain lasting from seconds to a few minutes with
Trigeminal Neuralgia (V2-V3)
We also see loss of corneal/jaw reflex with
CN V lesion
A deficit of paramedian branches of the basilar artery
Medial Pontine Syndrome
What are two symptoms of medial pontine syndrome?
Contralateral arm or leg weakness (CST), and contralateral decreased position, tactile, and vibration sense (ML)
Due to a deficit in the anterior inferior cerebellar artery
Lateral Pontine Syndrome
Controls movement of the contralateral extremities
-Starts in upper brainstem and crossing occurs at upper brainstem
Rubrospinal tract
Travels with the LCST until it ends in the cervical spinal cord
Rubrospinal tract
Controls coordination of the head and eye movement
Tectospinal tracts
Starts in the superior colliculus of the midbrain and it is crossed
Tectospinal tract
Nucleus of CN III that provides motor innervation to the superior, inferior and medial rectal as well as the inferior oblique and levator palpebrae sup. muscles
Oculomotor Nucleus
Motor portion of CN III that controls sphincter pupillae and ciliary muscle
Edinger-Westphal nucleus
Ventral (medial) Midbrain syndrome (Weber) is a deficit of the
Posterior cerebral artery
In ventral (medial) Midbrain syndrome (Weber), we see contralateral arm of leg weakness and spastic paralysis because of lesion of the
Corticospinal tract
In ventral (medial) Midbrain syndrome (Weber), we see contralateral hemiparesis of the lower face because of lesion of the
Corticobulbar Tract
In ventral (medial) Midbrain syndrome (Weber), we see IPSILATERAL oculomotor palsy and ptosis because of lesion to
CN III axons and nuclei
Dorsal midbrain syndrome (Perinaud’s) is due to a
Pineal Tumor
In Dorsal midbrain syndrome (Perinaud’s), we see paralysis of upward gae and various pupillary abnormalities because of the lesion of
Superior colliculi and pretectal area
In Dorsal midbrain syndrome (Perinaud’s), we see noncommunicating hydrocephalus because of pressure on the
Cerebral aqueduct
The only nerve that enters on the dorsal side of the brainstem
Trochlear Nerve (CN IV)
