Neuro Flashcards
CN arising from spinal cord
CNXI (accessory nucleus found at C1-C4 spinal cord levels)
CN arising from the medulla oblongata
CN IX, X, XII
CN arising from pontomedullary junction
CN VI, VII, VIII
CN arising from pontocerebellar angle
CN VII and VIII
CN arising from the pons
CN V, VII
CN arising from midbrain
CN II, IV
CN arising from the posterior aspect of the midbrain
CN IV
CN arising from diencephalon
CN II
CN arising from telencephalon
CN I
Signs of Foster Kennedy Syndrome
olfactory groove meningioma, IL anosmia, IL optic atrophy, CL papilledema
CN sensory ganglia
TGIS9+10
Trigeminal (CNV), Geniculate (CNVII), inferior and cuperior ganglia (CN IX, X)
CN motor ganglia
COPS ciliary (CN III) Otic (CN IX) Pterygopalatine (CN VII) Submandibular (CN VII) Intramural (CN X)
Nerves traversing the jugular foramen
CN IX, X, XI
Nerves traversing the supraorbital fissure
CN III, IV, V1 (ophthalmic)
Nerves traversing cavernous sinus
CN III, IV, VI, V1 (opthalmic) and V2 (maxillary) + internal carotid plexus (sympathetic)
Nerve through foramen rotundum
CN V2 (maxillary)
Nerve through foramen ovale
CN V3, (mandibular)
Nerve through foramen magnum
CN XI + sympathetic plexus on vertebral artery
Nerves through internal auditory meatus
CN VII, VIII
nerves through stylomastoid foramen
CN VII
Brainstem Nuclei for CN III
oculomotor, Edinger-Westphal
Brainstem Nucleus for CN IV
Trochlear Nerve
What CN decussates before exiting the brainstem?
CN IV
Brainstem nuclei for CN V
chief sensory nucleus, mesencephalic, spinal trigeminal, trigeminal motor nucleus
Brainstem Nucleus for CN VI
Abducens
Brainstem Nucleus for CN VII
Facial, Superior Salivatory, Spinal Trigeminal, Solitary
Brainstem Nuclei for CN IX?
nucleus ambiguous, inferior salivatory, spinal trigeminal, solitary
Brainstem nuclei for CN X
Nucleus Ambiguis, dorsal vagal, spinal trigeminal, solitary
Nucleus for CN XI
acessory nucleus (cervical spinal cord)
Brainstem Nucleus for CN XII
Hypoglossal
two smooth muscles innervated by CN III
sphincter/constrictor pupillae + ciliary body
5 skeletal muscles innervated by CN III
levator palpebrae, superior rectus, medial rectus, inferior oblique, inferior rectus
Three components of the near triad
3 by III, convergence of eyes, pupilary constriction, contraction of ciliary muscle
muscle innervated by CN IV
superior oblique
action of muscle innervated by CN IV
intorsion, abduction and depression (turns pupil down and out)
Action to test muscle innervated by CN IV
Adduct and depress [in and then down]
Muscle innervated by CN VI
Lateral rectus
Signs of compressive injury to CN III
dilated pupil with normal eye movements
Aneurysm of what artery compresses CN III
Posterior Communicating Artery
Signs fo Diabetic Infarct in CN III
Oculomotor Palsy with normal pupil
Signs of Injury to CN IV
Diplopia worse walking down stairs; improves with head tilt to opposite side
Sign of injury to CN VI
diplopia with head tilt towards paralyzed muscle
Location of horizontal gaze center
pons
Location of vertical gaze center
midbrain
Signs of Argyll-Robertson pupil
pupil accomadate but doesn’t react (to light); tertiary syphilis; “prostitutes pupil”
Signs of internuclear ophthalmoplegia
injury to MLF (demyelination in MS): on leftward gaze, right eye does not adduct (convergence is still intact)
Structures injured in “one-and-a-half” syndrome
abducens nucleus and both MLF
Injury to right abducens nerve
IL CN VI palsy; cannot abduct eye
Injury to right abducens nucleus
ib rightward gaze, Right Eye does not ABduct, Left eye does not ADduct
Eye movement deficits in Right Medial Pontine Syndrome
On Rightwadr Gaze: Right eye does not ABduct, Left eye does not ADduct + on Leftward gaze Right eye does not ADduct
3 Causes of ptosis
CN III Palsy, Horner Syndrome, Myasthenia Gravis
Muscles innervated by CN V
temporalis, masseter, medial and lateral pterygoi, anterior digastric, tensor tympani, tensor veli palatinin, myelohyoid
Motor Signs with CN V injury
jaw closes to good side, atrophy of temporalis and masseter
Muscles innervated by CN VII
muscles of facial expression, poster digastric, stylohyoid, stapedius
Motor Signs with CN VII injury
Bell’s Palsy: complete facial paralysis, can’t smile or wrinkle forehead
Muscle Innervated by CN IX
Stylopharyngeus
Motor signs with CN IX injury
Dysphagia
Skeletal Muscles innervated by CN X
Levator veli palantini, palatoglossus, pharyngeal, laryngeal and esophageal
motor signs with CN X injury
dysphagia, hoarsenss, sagging palate, uvula deviated to opposite side
Muscles innervated by CN XI
Trapezius and SCM
Motor signs with CN XI injury
weakness shrugging shoulder, cannot abduct humerous beyond 90, weakness turning head to opposite side
Muscles innervated by CN XII
genioglossus, hyoglossus, styloglossus, intrinsic tongue muscles
Motor signs with CN XII injury
tongue deviates to side of lesion on protrusion, atrophy of tongue muscles
Skin innervated by CN V
V1 - forehead, upper eyelid and nose
V2 - cheek, lower eyelid, upper lip
V3 - jaw, lower lip
Skin innervated by CN VII, IX and X
small area around ear
What is Ramsay Hunt syndrome
Herpes infection in the geniculate ganglion = blisters in pinna
Signs of Ramsay Hunt Syndrome
IL facial paralysis, hyperacusis, loss of taste, herpes vesicles on external ear, canal
Viscera innervated by CN III
sphincter pupillae and ciliary muscle
Viscera innervated by CN VII
mucosa of nasal cavity, oral cavity, lacrimal, submandibular, sublingual glands
Viscera innervated by CN IX
parotid gland, mucosa of middle ear, mucosa of oropharynx
Viscera innervated by CN X
mucosa of larynx, pharynx, all viscera of foregut and midgut
CN/ganglia/nucleus for taste at the anterior 2/3 tongue
CN VII/ geniculate / solitary
General sensory innervation to anterior 2/3 tongue
CN V
CN/ganglia/nucleus for taste at posterior 1/3 tongue
CN IX/inferior ganglion of IX/ solitary
Signs of CN VII injury at the internal auditory meatus
IL complete facial paralysis, dry eye, dry mouth, hyperacusis, decreased taste on ant 2/3 of tongue (tinnitus/hearing loss if CN VIII affected)
Signs of CN VII injury in facial canal
IL complete facial paralysis, decreased taste on anterior 2/3 tongue
Signs of CN VII injury at the stylomastoid foramen
IL complete facial paralysis
Nerves for corneal reflex
In by CN V out by VII
Nerves for Pupillary Light Reflex
In by CN II, out by CN III
Nerves for Jaw Jerk
In by CN V, out by CN V
Nerves for Cough Reflex
In by CN X, out by CN X (also C3-T12 for diaphragm and intercostals)
Nerves for Gag Reflex
In by CN IX and out by CN X
Nerve most likely affected with aneurysm of Anterior Communicating/ACA
CN II
Nerve most likely affected with aneurysm of Posterior Communicating Artery
CN III
Nerve most likely affected with aneurysm at basilar bifurcation
CN III
Nerve most likely affected with aneurysm of ICA in cavernous sinus
CN VI
Nerves most likely affected with aneurysm of PICA
CN IX, X, XI, XII
What neurons (4 locations) are involved in discriminitive touch/proprioception/vibration pathway
posterior root ganglion, nucleus gracilis/cuneatus, VPL thalamus, postcentral gyrus
Where does the posterior column/medial lemniscus decussate?
rostral medulla (decussation of medial lemniscus as internal arcuate fibers)
Signs of injury to posterior columns in spinal cord
IL loss of discriminitive touch, proprioception and vibratory sense
Signs of injury to medial lemniscus
CL loss of discriminitive touch, proprioception and vibratory sense
What is Rombery test?
Test of Proprioceptive function, have patient stand upright with arms abducted eyes open and closed
3 sensory modalities that maintain stability of the trunk
vision, proprioception and vestibular
What is a positive Romberg test
a marked difference in the ability to maintain erect posture with eyes open and closed
What does a Romberg test look like in someone with cerebellar injury?
Patient cannot stand up even with eyes open
Neurons (4 locations) in pain/temperature pathway?
posterior root ganglia, posterior horn, VPL thalamus, postcentral gyrus
Where does the spinothalamic tract decussate?
Anteriori White Commissure, Spinal cord, at all levels
Deficits in Syringomyelia
BL dermatomal loss of pain and temperature (usually upper limbs)
Cause and signs of Dejerine-Roussy Syndrome
Extreme hypersensitivity to painful stimuli following posterior thalamic infarct
What is the function of lower motor neurons
innervate skeletal muscle
locatino of lower motor neurons
spinal cord + motor cranial nerve nuclei (III, IV, V, VI, VII, IX, X, XI, XII)
Location of upper motor neurons
cerebral cortex, red nuclear, reticular formation
Signs of injury to upper motor neuron
hemiparesis, increase muscle stretch reflexes (hyper-reflexia), spasiticty, clonus, +Babinski sign and Hoffman sign
Lower Motor Neuron (LMN) signs
paralysis, decreased muscular stretch reflexes (hyporeflexia), flaccid tone, atrophy
Motor tracts in the Posterior Limb of the internal capsule
Corticospinal (upper imb, lower limb)
What is spasticity?
a velocity-dependent increase in muscle tone (injury to UMNs)
What is rigidity?
A velocity-independent increase in muscle tone (damage to Basal Nuclei structures)
The corticospinal tract decussates at what level?
pyramidal decussation, caudal medulla
Motor tracts in the genu of the internal capsule
corticobulbar (to cranial nerve nuclei)
Signs of injury to the corticospinal tract in the right internal capsule
left UMN signs
Signs of injury to the corticospinal tract in the cervical spinal cord on the right
right, UMN signs
Signs of injury to the corticobulbar tract in the right internal capsule
Left, lower facial paralysis; tongue points away from lesion
Features of decorticate posture
UL flexed; LL extended
Location of lesion in decorticate posturing
rostral midbrain or thalamus (red nucleus intact)
Features of Decerebrate posturing
UL and LL extended
Location of lesion causing Decerebrate posturing
Midbrain - damage involving red nucleus or rubrospinal tract
Signs of Myopathy
Proximal Symmetric weakness, no sensory loss
What are the 2 most common causes of peripheral neuropathies?
Diabetes and Alcoholism
Signs of polyneuropathy
Stocking/Glove sensory loss
neurons in auditory pathway (at least 6)
Spiral ganglion, Cochlear Nucleus, Superior Olive, Inferior Colliculus, Medial Geniculate, Primary Auditory Cortex
Normal human frequency hearing range
20Hz to 20kHz –> decreases with age
Result of Rinne test in normal ear
air conduction > bone conduction
Result of Rinne test in Conductive Hearing Loss
Air Conduction < Bone Conduction
Result of Rinne test in Sensorineural Hearing Loss
Air Conduction > Bone Conduction
Weber in Normal Hearing
Localize to Midline
Weber test with Sensorineural hearing loss in Right Ear
Localize to the Left
Weber test with Conductive Hearing Loss in Right Ear
Localize to the RIght
Deficits with injury to CN VIII
IL deafness, dizziness, CL nystagmus