All highlighted content Flashcards
Studying for final
What can cause neural tube defects?
Lack of folic acid during pregnancy
What does the brainstem do?
Control bodily functions needed for survival ex/ **respirations, BP, HR
Lesions in what two areas cause lethargy and coma?
Upper pons and midbrain
If a patient comes in complaining of the “worst headache of my life” with sudden onset, what might be their diagnosis?
Subarachnoid hemorrhage
1) What can be described as a “balloon like outpouching” of a vessel?
2) How are these connected to the vessel?
3) What part of this “balloon” structure can rupture?
1) Berry Aneurysms
2) Typically connected to the vessel by a stalk
3) The dome can rupture.
List 3 risk factors for the rupture of aneurysms
HTN (hypertension), cigarette smoking, alcohol consumption,
What is typically caused by rupture of bridging veins?
Subdural hematoma
All information passed between what two things passes through the brainstem?
Between cerebral hemispheres and the spinal cord
What is cauda equina syndrome?
Impaired function of nerve roots below L-1, L-2
1) What are 4 potential causes of cauda equina syndrome?
2) Why does it need to be treated quickly?
1) Compression from disk herniation, tumors, trauma, epidural abscess
2) To avoid permanent effects
About_____ of fibers in corticospinal tract cross over to control movement of opposite side of body
85%
About 85% of fibers from what tract cross over to control movement of the opposite side of the body?
Corticospinal tract
What do lesions in cerebellum cause?
Movement disorders
What can cause movement disorders?
Lesions in cerebellum or basal ganglia
1) What causes hypokinetic movement disorders? Name one.
2) The same thing causes hyperkinetic movement disorders; name one
1) Lesions in the basal ganglia; Parkinsonism (slow and rigid)
2) Huntington’s disease (“dancelike” involuntary movements)
True or false: Hypokinetic and hyperkinetic movement disorders have the same cause
True
Name 8 things controlled by the hypothalamus
1) Autonomic
2) Neuroendocrine
3) Limbic and other circuits
4) Body temp
5) Hunger
6) Thirst
7) Fatigue
8) Sleep
What controls sleep?
The hypothalamus
What controls neuroendocrine functions?
Hypothalamus
What two arteries supply all blood to the brain? What part does each supply?
1) Internal carotid arteries; supply anterior
2) Vertebral arteries; supply posterior
What two arteries join to form the basilar artery at the circle of willis?
Vertebral arteries
What is the brain’s drainage system for blood?
Internal jugular vein
The ring at the base of the brain is called what?
Circle of Willis
If a patient has a gaze toward the side of the lesion, what kind of stroke may they have had?
MCA (middle cerebral artery)
What causes a watershed zone?
When the blood supply to 2 adjacent cerebral arteries is compromised
What are two causes of two adjacent cerebral arteries being compromised? [and thus causing watershed infarction]
1) Sudden occlusion of the internal carotid or
2) A drop in BP in setting of carotid stenosis
What are the 3 main somatosensory and motor pathways? List what each does
1) Lateral corticospinal tract: Motor
2) Anterolateral columns: Sensory; pain, temperature & crude touch
3) Posterolateral columns: Sensory; vibration, fine touch, proprioception
1) Where is the primary motor cortex?
2) Where is the primary somatosensory cortex?
1) Primary motor = precentral
2) Primary somatosensory = postcentral
1) What is the most important descending motor pathway of the nervous system?
2) What does it do?
1) Lateral corticospinal tract
2) Controls the movement of extremities
1) What forms the anterior spinal artery?
2) What supplies most of the cord?
3) What forms the posterior spinal artery?
1) Vertebral arteries
2) Anterior spinal artery
3) Vertebral arteries
Where is venous return for the spinal cord?
Epidural space
Where does pyramidal decussation occur?
At medulla/spinal cord junction
Where does the corticospinal tract go?
Posterior limb
Is the ANS afferent, efferent, or both?
Only efferent pathways
What are the two ANS divisions?
Sympathetic and parasympathetic divisions
1) What do sympathetic neurons release to end organs?
2) What about parasympathetic?
1) Sympathetic: norepinephrine to the end organs
2) Parasympathetic: acetylcholine
What 3 things control the ANS?
Hypothalamus, brainstem nuclei, and the amygdala
What are the 3 long tracts of the spinal cord?
1) Posterior column-medial leminiscal system
2) Anterolateral systems
3) Corticospinal tract
1) What does the Posterior column-medial leminiscal pathway convey?
2) Where does it decussate?
1) Proprioception, vibration sense, and fine touch
2) In lower medulla
What pathway’s nerves cross over at the same level?
Anterolateral pathway **
What can vitamin B12 deficiency affect in the CNS?
Posterior cord
Anterior cord syndrome damage causes what?
Loss of pain and temperature sensation below the level of the lesion
**anterior spinal artery infarct is a common cause
What are the 4 dermatomes we need to know?
T4 – nipple line
T10 – umbilicus
C6 – thumb (6 shooter)
S5 - perianal
What is the biggest cause of radiculopathy?
Diabetes
1) What can cauda equina syndrome cause?
2) What can this then cause?
1) Saddle anesthesia (sensory loss in S2-5, numbness in inguinal area)
2) Bladder disfunction, constipation, fecal incontinence and loss of erections
Almost all pathways projecting into the cerebral cortex, relay through the thalamus; which one doesn’t?
Olfactory
1) What supply anterior hemispheres?
2) What about posterior hemispheres?
3) What forms the basilar artery?
4) What forms the Circle of Willis?
1) Internal carotid arteries
2) Vertebral arteries
3) Vertebral arteries
4) The anterior and posterior blood supplies form the anastomotic ring
1) What come off the aorta?
2) What does the common carotid arteries split into?
3) List the arteries that supply the cerebral hemispheres
1) Common carotid arteries
2) Internal and external carotid arteries
3) Anterior, middle and posterior cerebral arteries (ACA, MCA, PCA)
What are the anterior and middle cerebral arteries (ACA & MCA)?
The termination of the internal carotids
What supply the Wernicke’s and Broca’s areas?
Middle cerebral artery
What supply the basal ganglia and the internal capsule?
Branches of the MCA
What can cause lacunar infarctions?
HTN
What are watershed infarcts?
2 adjacent cerebral arteries are compromised
What is the watershed?
The region in-between the 2 adjacent compromised vessels
1) What type of stroke is caused by lack of adequate blood supply to the brain for long enough to cause cell death?
2) What can cause it?
1) Ischemic stroke
2) Can be caused by embolus or thrombus
1) What links the anterior cerebral arteries together?
2) What do the posterior communicating arteries do? Be specific
1) The anterior communicating artery
2) Link anterior and posterior circulations; specifically they join the internal carotids and the posterior cerebrals
1) Where does the anterior cerebral artery (ACA) go?
2) What does it supply?
1) Travels forward, splits into 2 main branches, then turns back over the corpus collosum
2) The cortex on the anterior medial surface of the brain from frontal to anterior parietal lobe.
-Includes the medial sensorimotor cortex.
1) Where does the middle cerebral artery (MCA) go?
2) What does it supply?
1) Enters Sylvian Fissure and then splits into 2-4 main branches, which form loops.
2) The cortex above and below the Sylvian Fissure; including the lateral temporal lobe and parts of the parietal lobe.
-Also includes thalamus and posterior limb of the internal capsule
1) Where does the posterior cerebral artery (PCA) go?
2) What does it supply?
1) Curves back off the basilar artery
2) Through its many branches supplies: the inferior and medial temporal lobes and the medial occipital cortex.
1) What artery supplies the medial sensorimotor cortex?
2) What supplies the the inferior and medial temporal lobes?
3) What supplies the lateral temporal lobes?
1) ACA
2) PCA
3) MCA
1) What supplies blood to the thalamus and posterior limb of the internal capsule?
2) What could a lacunar infarction in this area cause?
1) Small branches of the MCA
2) Contralateral hemiparesis
1) What is lacunar infarct syndrome?
2) What is it characterized by?
3) Give examples
1) The clinical manifestations of a lacunar infarct
2) Pure motor hemiparesis.
3) Contra/Unilateral face, arm and leg weakness.
-Location ex/posterior limb of internal capsule.
1) What strokes are most common, MCA, ACA, or PCA?
2) What is its unique symptom?
1) MCA
2) Patients often have a gaze toward the side of the lesion
What two things can watershed infarctions cause?
1) Sudden occlusion of the internal carotid
2) Drop in BP in setting of carotid stenosis
1) How long does a TIA last?
2) Give 4 common causes
1) <24 hours (usually closer to 10 minutes)
2) Migraines, seizures, arrhythmias and hypoglycemia
_____% of patients with TIAs with have a stroke within ___ months and most of those within the next _____ hours
10%; 3 months; 48 hours
What is leading cause of significant disability?
Strokes
1) What are the two main types of strokes?
2) What type of stroke is caused by a thrombus or embolus?
1) Ischemic and hemorrhagic
2) Ischemic
What is the biggest difference between a thrombus and embolus?
1) Embolus: travels
2) Thrombus: doesn’t travel
1) What type of stroke is usually caused by an embolus: large vessel, or small vessel?
2) What are small vessel strokes also called?
1) Large vessel
2) Lacunar infarcts
1) What are emboli most often made of?
2) Where do they commonly come from?
1) Most often blood clots.
2) The heart
Define dissection [in the context of strokes]
Tear on the inner surface of an artery
1) What do cortical signs come from?
2) What are they?
1) Lobar strokes
2) Aphasia, neglect, homonymous visual field defects, apraxia, hemiparesis, and sensory loss
What sometimes causes headaches with ischemic strokes?
Innervation of the blood vessels and meninges
What is usually the cause of strokes in younger patients?
Dissection/trauma
What do the internal jugular veins do?
Drain the dural sinuses (which is where the veins that drain the brain go)
A tumor on the pituitary can press on the optic chiasm and cause what kind of field defects?
Bilateral temporal (aka bitemporal hemianopia)
A tumor on the what part of the brain can press on the optic chiasm?
Pituitary
How would you describe the orientation of the image on the retina?
Inverted and reversed
Information from the lower visual field is projected on the ___________ retina
upper
Why are images reversed on the retina?
The right visual field projects onto the left retina (and vice versa) of each eye
Why are images inverted on the retina?
Information from the upper visual field is projected onto the lower retina, and vice versa
The central fixation point for each eye is what?
The fovea
Where do fibers that carry visual information cross?
Optic chiasm
True or false: There is a total crossing of fibers in the optic chiasm
False; it’s a partial crossing of fibers
Lesions anterior to the [optic] chiasm produce what kind of visual field defects?
monocular
Lesions of the optic chiasm produce what kind of visual field defects?
bilateral lateral
The medial (nasal) fibers from both eyes do what in the optic chiasm?
Cross over
The optic tract wraps around the midbrain, then to where?
The lateral geniculate nuclei (LGN) of the thalamus
Where does the optic tract go after the optic chiasm?
The LGN of the thalamus
What can result in bitemporal hemianopia from compression of the optic chiasm?
Pituitary adenomas
Why do pituitary adenomas cause the visual effect they do?
They press on the optic chiasm, compressing the medial fibers, which convey the outer half of vision for both eyes
What is the superior colliculus important in?
Directing visual attention and eye movements towards visual stimuli
1) The superior colliculus and pretectal areas project where for visual attention?
2) How?
1) To the brainstem and association cortex
2) Via relays in other thalamic nuclei
What are the functions of the other thalamic nuclei that project the superior colliculus to the brainstem?
Visual attention/orientation/discrimination/perception (i.e. help us direct our attention to something seen or heard)
What do the neurons of the LGN participate in? (3 things)
Motion, spatial awareness, and color vision.
What fans out over a wide area to form the optic radiations?
The superior colliculi
What pathway is likely defective if color vision isn’t working?
The LGN
Central __________________ occlusion can cause infarction of the entire retina
retinal artery
Define Amaurosis Fugax
Transient occlusion of the retinal artery
1) What causes Amaurosis Fugax?
2) What is a common cause of that?
1) Emboli [occluding the retinal artery]
2) Ipsilateral carotid artery stenosis
If a patient describes having the visual of a window shade going up or down in one eye, what might they be having?
Amaurosis Fugax
What are the two main symptoms of Amaurosis Fugax?
1) A “window shade going up or down” on ONE eye
2) Loss of vision in one eye for roughly 10 min.
What can Amaurosis Fugax be a signal of?
Impending retinal or cerebral infarct.
1) What is optic neuritis?
2) What does it cause?
1) A demyelinating disorder of the optic nerve related to MS
2) Eye pain with movement (among other things) of one eye
_____ or more of patients with a clinically isolated episode of optic neuritis will eventually develop MS
50%
If a patient complains of pain in one eye that’s worse with movement, what may they have?
Optic neuritis
What is the vestibular system? What does it do?
Sensory system that senses balance and spatial orientation coordinating movement with balance
What are the two parts of the labyrinth of the inner ear?
1) Bony labyrinth
2) Membranous labyrinth.
The bony labyrinth is filled with ________ called ______
fluid; perilymph
1) What makes up the membranous labyrinth?
2) Where is it?
3) What is the membranous labyrinth filled with?
1) The cochlear duct, utricle, saccule and semicircular canals
2) Suspended in the perilymph.
3) Filled with endolymph.
The maculae consist of ___________ called ________ sitting in a gelatinous layer where mechanoreceptor hair cells are embedded
calcified crystals; otoliths
Primary vestibular neurons in the vestibular ganglia convey information about what?
Angular and linear acceleration
1) The lateral vestibular nucleus gives rise to what?
2) What two things is this important in?
1) The lateral vestibulospinal tract
2) Maintaining balance and extensor tone.
1) Where is the MVT (medial vestibulospinal tract) found?
2) What is it important in?
1) Extends only to the cervical spine
2) Important in controlling head and neck position
What is an important job of the medial longitudinal fasciculus (MLF)?
Conjugates the gaze
Define vertigo
Spinning sensation
1) Most vertigo cases are caused by what?
2) What is a less common cause of vertigo?
1) Peripheral disorders involving the inner ear (usually benign.)
2) Central disorders of the brainstem or cerebellum are less common (usually urgent.)
Dix-Hallpike testing can help differentiate between what?
Central or peripheral causes of vertigo
1) What does the Dix-Hallpike test look like if the patient has peripheral lesions of the inner ear?
2) What does the nystagmus look like?
1) 2-5 second delay [in vertigo and nystagmus]
2) The nystagmus is horizontal or rotary and does not change directions
1) What does the Dix-Hallpike test look like if the patient has central lesions of the inner ear?
2) What does the nystagmus look like?
3) Is there adaptation if it’s repeated?
1) Nystagmus and vertigo may begin immediately in supine position
2) Vertical nystagmus, nystagmus that changes directions while the patient is in the same position or prominent nystagmus in the absence of vertigo are only seen with central lesions.
3) No adaptation
1) What is the most common cause of vertigo?
2) How long does it last?
3) When does it happen?
1) Benign paroxysmal positional vertigo (BPPV)
2) Brief episodes of vertigo lasting for a few seconds
3) Occur with change of position
1) With Benign paroxysmal positional vertigo (BPPV), what helps the dizziness?
2) What is usually the cause?
1) If the patient remains still, the dizziness usually abates.
2) Otolithic debris in the semicircular canals
1) What characterizes Meniere’s disease?
2) What is the etiology?
1) Recurrent episodes of vertigo with progressive hearing loss and tinnitus
2) Excess fluid (and pressure in endolymphatic system)
1) Besides Meniere’s, what can cause cause hearing loss and tinnitus with associated dizziness?
2) How is it different? (3 things)
1) Acoustic neuroma
2) Causes unsteadiness, it’s not true vertigo, and does not have discrete episodes.
Name two common causes of central vertigo
1) Vertebrobasilar ischemia or infarct
2) Small hemorrhage in cerebellum or brainstem
What can gentamicin cause?
Bilateral vestibular dysfunction (and dizziness)
1) What is the second most common cause of vertigo?
2) What is its suspected origin?
3) Who does it affect?
4) Is hearing impaired?
1) Vestibular neuritis
2) Viral origin
3) 30 to 50 years of age; men and women are affected equally
4) Not impaired
What are the 3 angular axes that semicircular canals use to detect angular acceleration?
1) Anterior
2) Posterior
3) Horizontal (lateral)
Name 3 essential roles of the vestibular nuclei
1) Adjustment of posture
2) Muscle tone
3) Eye position in response to movements of the head in space.
Where are vestibular nuclei found?
Brainstem
Semicircular canals convey information about ______ acceleration, while otolith organs convey information about ________ acceleration.
Angular; linear
What tract is important in maintaining balance and extensor tone, and extends the entire length of the spinal cord?
Lateral vestibulospinal tract
What nuclei contribute to the medial vestibulospinal tract, that is important in controlling head and neck position and extends only to the cervical spine?
Medial vestibulospinal nucleus and Inferior vestibulospinal nucleus
What part of the vestibular system conjugates the gaze?
Medial longitudinal fasciculus (MLF)
Name a positive sign that could mean that a patient possibly has a problem outside of their vestibular system
Orthostatic hypotension
An adaptable horizontal or rotary nystagmus is indicative of what?
Peripheral lesions of the inner ear
In which vestibular condition does a change in position cause vertigo due to otolithic debris in the semicircular canals?
Benign paroxysmal positional vertigo
A patient complaining of a full feeling in the ear, ringing of the ears and hearing loss over time that accompanies recurrent episodes of vertigo. What would be your diagnosis?
Meniere’s disease
True or false: acoustic neuromas cause true vertigo
False
Vestibular neuritis is the ____most common cause of vertigo while Benign paroxysmal positional vertigo is the ____ most common cause of vertigo.
2nd; 1st
Name 2 common causes of central vertigo
1) Vertebrobasilar ischemia or infarct
2) Small hemorrhage in cerebellum or brainstem
Gentamicin is ototoxic and causes ____________ vestibular dysfunction
bilateral
What is the vestibular system? What does it do?
Sensory system that senses balance and spatial orientation coordinating movement with balance
What are the two parts of the labyrinth of the inner ear?
1) Bony labyrinth
2) Membranous labyrinth.
The bony labyrinth is filled with ________ called ______
fluid; perilymph
1) What makes up the membranous labyrinth?
2) Where is it?
3) What is the membranous labyrinth filled with?
1) The cochlear duct, utricle, saccule and semicircular canals
2) Suspended in the perilymph.
3) Filled with endolymph.
The maculae consist of ___________ called ________ sitting in a gelatinous layer where mechanoreceptor hair cells are embedded
calcified crystals; otoliths
Primary vestibular neurons in the vestibular ganglia convey information about what?
Angular and linear acceleration
1) The lateral vestibular nucleus gives rise to what?
2) What two things is this important in?
1) The lateral vestibulospinal tract
2) Maintaining balance and extensor tone.
1) Where is the MVT (medial vestibulospinal tract) found?
2) What is it important in?
1) Extends only to the cervical spine
2) Important in controlling head and neck position
What is an important job of the medial longitudinal fasciculus (MLF)?
Conjugates the gaze
Define vertigo
Spinning sensation
1) Most vertigo cases are caused by what?
2) What is a less common cause of vertigo?
1) Peripheral disorders involving the inner ear (usually benign.)
2) Central disorders of the brainstem or cerebellum are less common (usually urgent.)
Dix-Hallpike testing can help differentiate between what?
Central or peripheral causes of vertigo
1) What does the Dix-Hallpike test look like if the patient has peripheral lesions of the inner ear?
2) What does the nystagmus look like?
1) 2-5 second delay [in vertigo and nystagmus]
2) The nystagmus is horizontal or rotary and does not change directions
1) What does the Dix-Hallpike test look like if the patient has central lesions of the inner ear?
2) What does the nystagmus look like?
3) Is there adaptation if it’s repeated?
1) Nystagmus and vertigo may begin immediately in supine position
2) Vertical nystagmus, nystagmus that changes directions while the patient is in the same position or prominent nystagmus in the absence of vertigo are only seen with central lesions.
3) No adaptation
1) What is the most common cause of vertigo?
2) How long does it last?
3) When does it happen?
1) Benign paroxysmal positional vertigo (BPPV)
2) Brief episodes of vertigo lasting for a few seconds
3) Occur with change of position
1) With Benign paroxysmal positional vertigo (BPPV), what helps the dizziness?
2) What is usually the cause?
1) If the patient remains still, the dizziness usually abates.
2) Otolithic debris in the semicircular canals
1) What characterizes Meniere’s disease?
2) What is the etiology?
1) Recurrent episodes of vertigo with progressive hearing loss and tinnitus
2) Excess fluid (and pressure in endolymphatic system)
1) Besides Meniere’s, what can cause cause hearing loss and tinnitus with associated dizziness?
2) How is it different? (3 things)
1) Acoustic neuroma
2) Causes unsteadiness, it’s not true vertigo, and does not have discrete episodes.
Name two common causes of central vertigo
1) Vertebrobasilar ischemia or infarct
2) Small hemorrhage in cerebellum or brainstem
What can gentamicin cause?
Bilateral vestibular dysfunction (and dizziness)
1) What is the second most common cause of vertigo?
2) What is its suspected origin?
3) Who does it affect?
4) Is hearing impaired?
1) Vestibular neuritis
2) Viral origin
3) 30 to 50 years of age; men and women are affected equally
4) Not impaired
What are the 3 angular axes that semicircular canals use to detect angular acceleration?
1) Anterior
2) Posterior
3) Horizontal (lateral)
Name 3 essential roles of the vestibular nuclei
1) Adjustment of posture
2) Muscle tone
3) Eye position in response to movements of the head in space.
Where are vestibular nuclei found?
Brainstem
Semicircular canals convey information about ______ acceleration, while otolith organs convey information about ________ acceleration.
Angular; linear
What tract is important in maintaining balance and extensor tone, and extends the entire length of the spinal cord?
Lateral vestibulospinal tract
What nuclei contribute to the medial vestibulospinal tract, that is important in controlling head and neck position and extends only to the cervical spine?
Medial vestibulospinal nucleus and Inferior vestibulospinal nucleus
What part of the vestibular system conjugates the gaze?
Medial longitudinal fasciculus (MLF)
Name a positive sign that could mean that a patient possibly has a problem outside of their vestibular system
Orthostatic hypotension
An adaptable horizontal or rotary nystagmus is indicative of what?
Peripheral lesions of the inner ear
In which vestibular condition does a change in position cause vertigo due to otolithic debris in the semicircular canals?
Benign paroxysmal positional vertigo
A patient complaining of a full feeling in the ear, ringing of the ears and hearing loss over time that accompanies recurrent episodes of vertigo. What would be your diagnosis?
Meniere’s disease
True or false: acoustic neuromas cause true vertigo
False
Vestibular neuritis is the ____most common cause of vertigo while Benign paroxysmal positional vertigo is the ____ most common cause of vertigo.
2nd; 1st
Name 2 common causes of central vertigo
1) Vertebrobasilar ischemia or infarct
2) Small hemorrhage in cerebellum or brainstem
Gentamicin is ototoxic and causes ____________ vestibular dysfunction
bilateral
Name 3 potential causes of diplopia
1) Thyroid disease
2) Myasthenia gravis (NMJ disorder)
3) CN 3, 4, or 6 disorders or their brainstem nuclei
Name 2 symptoms of CN III Palsy
1) Eye may be in “down and out” position at rest.
2) Pupil is dilated and unresponsive to light
(could have also said that eye will only move in abduction, depression and intorsion)
Trochlear nerve palsy would cause what?
Vertical diplopia
What is the most commonly affected CN in head trauma?
Trochlear (CN4)
Why is CN VI Abducens Nerve Palsy very medically significant?
Can be an early warning sign of elevated ICP
A lesion in what nerve would cause “blown pupils”?
CN3
Name and define the 3 symptoms of Horner’s syndrome
1) Ptosis: drooping upper eyelid
2) Miosis: decreased pupillary size
3) Anhidrosis: decreased sweating in the face and neck of the ipsilateral side
1) Are pontine pupils non-reactive to light, or reactive?
2) What structure is affected to cause this?
1) Reactive
2) Pons (large lesion)
Pharmacological Miosis is what?
Bilateral pinpoint pupils (caused by Rx or illegal drugs)
Name 3 functions of the superior colliculi
1) Visual attention
2) Perception
3) Discrimination
Olfactory nerves send signals back to what part of the brain that associates smell to memories and emotions?
Amygdala
In what directions do the trochlear nerve make the eye rotate?
Down and medial
In what direction does the abducens nerve make the eye rotate?
Abduction (aka moving laterally)
What cranial nerve supplies sensory to the anterior ⅔ of the tongue?
CN 5
A 40 year old male patient presents with recurrent episodes of brief, left sided jaw and cheekbone pain that last seconds to minutes. The episodes usually are set off by them shaving their face for work in the morning.
1) What would be your most likely diagnosis?
2) Where would you expect there to be a lesion?
1) Tic Douloureux
2) Left branch of V2/V3 trigeminal nerve (ispilateral)
What nerve supplies motor to the mandible and the anterior portion of the external ear?
CN 5
Ototoxic drugs, meningitis, and exposure to loud sound are most likely to cause what kind of hearing loss?
Sensorineural
List 4 symptoms of acoustic neuroma
1) Unsteadiness
2) Facial pain
3) Tinnitus
4) Unilateral hearing loss
_____ innervates the posterior ⅓ of the tongue while _______ innervates the anterior ⅔ of the tongue for sensory receptors
CN 9, CN 5 (CN 7 does anterior taste)
True or false: All laryngeal muscles and the cricothyroid are ONLY controlled by the recurrent and superior laryngeal nerves
True
What two muscles are innervated by CN 11 ?
Sternocleidomastoid and trapezius
A lesion of CN 11 would cause ipsilateral shoulder shrug weakness and weakness of the head turning ______ the lesion
Away
Unilateral vocal cord paralysis and hoarseness after surgery to the neck indicates what?
Injury to the recurrent laryngeal nerve
What two bumps are found on the dorsal surface of the midbrain?
The superior and inferior colliculi.
Where does the 4th ventricle end?
At the entry of the spinal cord
What cranial nerve arises from the spinal cord?
CNXI (11)
1) The olfactory nerve (CN1) connects to what?
2) What do the olfactory nerves run through?
1) The forebrain
2) Olfactory tracts
Define anosmia
Loss of sense of smell
Where do the optic nerves terminate?
LGN of the thalamus
What 3 nerves control the extraocular muscles?
CN III (3, oculomotor) ,CNIV (4, trochlear), CNVI (6, abducens)
1) What does CNV (trigeminal) nerve supply?
2) What part of the tongue does it supply sensory innervation to?
1) Sensory innervation to the face
2) Anterior 2/3 of tongue
1) What is Trigeminal Neuralgia (tic doulouruex)? Include what nerves it affects
2) Even though its cause is unknown, what do we think causes it?
3) Do the nerve fibers involved cross over? What is the implication of this?
1) Recurrent episodes of brief pain, that last seconds to minutes; V2/V3
2) Demyelination
3) Do not cross over, so lesions cause ipsilateral deficits
1) What is the main function of the facial nerve (CN7/ VII)?
2) What else does it do?
1) Controls muscles of facial expression (motor)
2) Sensation of the external ear
1) Define conductive hearing loss (HL)
2) Define sensorineural hearing loss
1) Conductive HL: abnormalities of the external auditory canal or middle ear [causing HL]
2) Sensorineural HL: disorders of the cochlea or CN VIII [causing HL]
1) What is the most common facial nerve (CNVII) disorder?
2) What can it cause? (3 main things)
3) What would it look like on a neuro exam or imaging?
1) Bell’s palsy
2) Unilateral facial weakness, ear pain, and loss of taste
3) Typically normal (besides symptoms above)
Recurrent episodes of Bell’s Palsy warrant what?
An extensive work up to rule out tumors, infiltrating diseases, Lyme’s disease sarcoid, and HIV.
What is the function of the vestibulocochlear nerve (CN8)?
Hearing and vestibular sensation
1) What is the most common tumor of the inner ear?
2) Is hearing loss unilateral or bilateral?
3) What nerve can it affect, and what can happen when it does?
1) Acoustic Neuroma
2) Almost always unilateral.
3) CNVIII; causes facial pain and sensory loss
What nerve controls taste from posterior 1/3 of tongue?
Glossopharyngeal nerve (CN9)
What are the two main functions of the vagus nerve (CN10)?
Swallowing and gag reflex
Name 2 branches of the vagus nerve and what they control
Recurrent and superior laryngeal nerves control all laryngeal muscles and the cricothyroid
1) What is the main function of the spinal accessory nerve (CN11)?
2) What kind of weakness could a lesion of it cause?
1) Motor to sternomastoid and trapezius muscles
2) Weakness of head turning AWAY from the lesion
1) What is the function of the hypoglossal nerve (CN12)?
2) What kind of weakness could a lesion of it cause?
1) Motor to tongue
2) Weakness of the tongue that points TOWARDS the side of lesion when protruding
1) What is Glossopharyngeal Neuralgia similar to?
2) When can injury to the recurrent laryngeal nerve occur?
3) What would an injury to the recurrent laryngeal nerve cause?
1) Trigeminal Neuralgia (except in CN 9 distribution)
2) During surgeries of the neck
3) Unilateral vocal cord paralysis and hoarseness
What is aspiration pneumonia and what is it a common cause of?
Pneumonia caused by impaired swallowing, is a common cause of death in the elderly
1) What does a lesion of CN X (vagus) cause the soft palate and uvula to do?
2) What is the stage curtain sign?
1) The soft palate and uvula will deviate towards the normal side
3) Soft palate on the abnormal side hangs low
1) Descending sympathetic pathway runs through what?
2) What does damage to this cause?
1) Runs through lateral brainstem
2) Horner’s Syndrome
What are the 4 main groups of things found in the brainstem?
1) Cranial nerve nuclei and related structures
2) Long tracts
3) Cerebellar circuitry
4) Reticular formation and related structures
In Locked-In-Syndrome:
1) Motor function is ________
2) Sensation and cognition are ________
3) What two tracts are affected?
1) Absent
2) Intact
3) Corticospinal and corticobulbar
True or false: Locked-In-Syndrome is a type of coma
False; they’re different
1) What is the end goal of the rostral end of the reticular formation?
2) What is the end goal of the caudal end of the reticular formation?
1) The rostral end functions to maintain an alert conscious state.
2) Carry out motor reflex and autonomic functions
List and define the 3 processes that control the levels of consciousness
1) Alertness: normal functioning of the brainstem and arousal circuits
2) Attention: same circuits as above plus the frontoparietal association cortex
3) Awareness: a combination of multiple higher order systems from different regions of the brain into a summary of mental activity that can be remembered at a later time
What activates the 5 arousal systems that maintain normal consciousness?
Reticular formation and related structures that receive input from sensory pathways
Numerous regions of the ___________ project to the reticular formation so that _______________________ can lead to an increased level of alertness through this system.
association cortex; cognitive processes and emotions
1) Is glutamate excitatory or inhibitory?
2) What does GABA promote?
1) Excitatory
2) Deep sleep
1) What NT causes muscle contraction?
2) What disorder involves this NT?
1) Acetylcholine
2) Myasthenia gravis
What does dopamine cause and act on?
Causes feelings or pleasure, satisfaction and motivation. Works on reward center.
What is an NT used in sympathetic response?
Norepinephrine
What NT functions in attention?
Norepinephrine
Which NT is sometimes referred to as the “feel good” chemical?
Serotonin
What is histamine used to regulate?
Alertness and wakefulness
Most histamine in the body is found outside of the CNS in __________ playing a role in _______________________________
mast cells; immune responses and allergic reactions
1) Histamine outside the CNS is found where?
2) What does it play a role in here?
1) In mast cells
2) Immune responses and allergic reactions
If the __________________ is spared, consciousness is typically spared
reticular formation
1) Unarousable, unconsciousness with closed eyes has to last how long to be considered a coma?
2) What is it a dysfunction of?
1) > 1 hour
2) Upper brainstem reticular formation
What is a very important thing to include in an exam of a patient in a coma?
Check their pupils
Define dissociative state. What neurologically is wrong?
Non-responsiveness (but not unconscious) from severe emotional trauma, neuro exam is normal
Patients with Akinetic Mutism, Catatonia display what?
Profound deficits in response to initiation
Define brain death
Based on clinical exam: no evidence of forebrain or brainstem function; no sleep-wake cycles
What does the Pre-Botzinger Complex of the medulla do?
Pacemaker for respirations
What do the Phrenic nerve efferents do?
Control diaphragm during inspiration
What can lesions in the medulla lead to?
Respiratory arrest and death
1) Where is the nucleus solitarius?
2) What is it? Where does it get input from?
1) In the medulla
2) Cardiorespiratory nucleus (controls heart rate and BP); receives inputs from baroreceptors in carotid body and aortic arch via CNs 9 and 10
What type of lesions typically cause uncoordinated movements called ataxia?
Cerebellar
What do the inferior vermis and flocculonodular lobes of the cerebellum do?
1) Regulate balance (proximal trunk muscle control)
2) Interact with vestibular circuitry (vestibulo-ocular control)
What do the anterior lobes of the cerebellum do?
Responsible for proprioception
What do the intermediate cerebellar regions do?
Control distal limbs
What do the lateral cerebellar hemispheres do?
Motor planning of distal extremities
Deficits in coordination occur ___________ to the lesions of the cerebellum
ipsilateral
What do medial cerebellar lesions do?
Affect the trunk muscles bilaterally
The cerebellum is attached to the ____________ and ________________ by 3 ________________.
dorsal pons and rostral medulla; peduncles
Name 2 things vermis or flocculonodular cerebellar lobe lesions affect
1) Unsteady gait
2) Trunk control
Where are the cerebellar tonsils found?
Inferior surface
What connect the cerebellum to the brainstem?
The peduncles: superior, middle and inferior
What are the conditions for something to be a coma
1) Unarousable (even with sternum rub, smelling salts, etc)
2) Unconsciousness with closed eyes
3) For greater than 1 hour
What 3 things should you give via IV to a patient in a coma?
Thiamine, glucose and naloxone
Melatonin is produced by what? In what pattern?
Pineal gland; circadian pattern
What condition does a patient appear fully awake, but not respond?
Akinetic Mutism, Catatonia
What state is caused by emotional trauma and accompanies a normal neuro exam?
Dissociative
What is required to declare brain death?
Clinical exam
What type of unconscious state involves sleep-wake cycles and other responses or reflexes?
Vegetative state
Aneurysm of posterior communicating artery can cause what?
CNIII palsy
During the pupillary light reflex, after the fibers synapse at the superior colliculus, where do they go? What does this contain?
Edinger–Westphal nuclei; contain preganglionic parasympathetic neurons
Where is the Pre-Botzinger Complex?
In the medulla
1) Heart rate and BP are controlled by what?
2) What does this place receive input from?
1) Nucleus solitarius (of medulla)
2) Baroreceptors in carotid body and Aortic arch (via CNs 9 and 10)
What controls the proximal trunk?
Vermis
1) What part of the cerebellum does proprioception?
2) What does motor planning of distal extremities?
1) Anterior lobes
2) Lateral cerebellar hemispheres
Name 1 thing in the medulla
Respiratory pacemaker
True or false: the 4th ventricle is found in the brainstem
False; stops at the brainstem
What is the role of the reticular formation?
Coordinating vital functions
What 3 nerves play a role in mediating vestibulo-ocular reflexes?
CNs 3,4, and 6
Damage to the descending sympathetic pathway that runs through the lateral brainstem can cause what symptoms?
Ptosis, miosis, anhidrosis
What is formed by the fronto-parietal association cortex with the arousal circuits in the upper brainstem?
Consciousness system
Which condition causes an autoimmune antibody block of acetylcholine receptors on skeletal muscle?
Myasthenia gravis
Having too much of what neurotransmitter would be a finding in schizophrenia?
Dopamine
Having too little of what neurotransmitter would cause depression, inattentive/ ADD?
Norepinephrine
What area of the brainstem is thought to contain sleep promoting regions?
Medulla’s Reticular formation
Upper brainstem reticular formation dysfunction can cause what?
Coma
Akinetic Mutism/catatonia may improve a deficit in response to initiation by what?
Dopamine agonist
How does a vegetative state differentiate from brain death?
1) Can have sleep wake cycles
2) Possible brainstem reflexes
3) May make sounds
An aneurysm of the posterior communicating artery most commonly causes what?
CN 3 palsy
Where are preganglionic parasympathetic neurons of the optic tract located?
Edinger-Westphal nuclei
A patient who is in what kind of coma would have small but light responsive pupils bilaterally?
Pontine lesion
Which area of the brainstem is involved in controlling heart rate and BP and receives inputs from baroreceptors in the carotid body and aortic arch via CN IX and X?
Nucleus solitarius
What gives rise to many branches that supply the brainstem and cerebellum?
Vertebrobasilar system
What is the most medial functional portion of the cerebellum called?
Vermis
What area of the cerebellum is responsible for regulating balance and vestibulo-ocular control?
Inferior vermis and flocculonodular nodes
1) What function is the anterior lobes of the cerebellum responsible for?
2) What function is the intermediate cerebellar region of the cerebellum responsible for?
3) What function is the lateral cerebellar hemispheres of the cerebellum responsible for?
1) Proprioception
2) Control of distal limbs
3) Motor planning of distal extremities
1) Deficits in coordination occur _______ to cerebellar lesions, while medial lesions affect the trunk muscles __________.
2) A lesion where would cause unsteady gait, trunk control, posture, and balance?
1) Ipsilaterally, bilaterally
2) Vermis/Flocculonodular nodes
What gland is the “master gland”?
Pituitary gland
The hypothalamus is _______________ to the optic chiasm
posterior
What is the master clock of circadian rhythms?
Suprachiasmatic nucleus (of hypothalamus)
What systems do the hypothalamus and pituitary link?
Neural and endocrine systems
List the 4 systems the hypothalamus controls to maintain homeostasis
1) Homeostatic mechanisms
2) Endocrine control
3) Autonomic control
4) Limbic mechanisms
The limbic-hypothalamic interconnections play an important role in what?
Emotional influences on autonomic pathways
What is the regulator of circadian rhythms?
The suprachiasmatic nucleus
True or false: the hypothalamus controls or partially controls both hunger and thirst
True
Lesions in the part of the hypothalamus that controls appetite can cause what?
Weight loss/obesity
Lesions in the part of the hypothalamus that controls thirst can do what?
Decrease water intake
Oxytocin, a hormone released by the hypothalamus and released by the posterior pituitary, can do what?
Increase nurturing behaviors.
What organ is involved in hyperthermia? Why?
Hypothalamus; detects increased body temperature and can dissipate heat
What does the posterior hypothalamus do?
Conserves heat
The limbic cortex forms what? What two things does it surround?
A ring–like limbic lobe surrounding the corpus collosum and upper brainstem
1) What system of the brain goes from the forebrain to the brainstem?
2) Where are most parts of this system?
1) The limbic system
2) Most are hidden in the medial hemispheres
What are the 4 main categories of limbic system functions?
1) Homeostatic functions including autonomic and neuroendocrine control
2) Olfaction
3) Memory
4) Emotions and drives
HOME
What part of the brain is important in memory functions?
Hippocampus
1) Where is the amygdala?
2) What does it function in?
1) Tip of the hippocampus.
2) Emotional, autonomic, and neuroendocrine circuits of the limbic system
Smell contributes to the detection of what two things?
Odors and taste
Some fibers of the olfactory tract go somewhere other than the olfactory cortex; where do they go?
Amygdala
What are the two jobs of the hippocampus?
1) Memory
2) Creates context [for past/future events]
What are the two critical areas for memory formation?
1) Medial temporal lobe memory area
2) Forebrain
1) What does the medial temporal lobe memory area contain?
2) What does the forebrain contain that’s related to memory?
1) Hippocampus
2) Thalamus and hypothalamus’s nuclei
Today, patients with refractory temporal lobe epilepsy can be cured with what?
Unilateral medial temporal lobe resection.
1) Define declarative memory
2) Define nondeclarative memory
1) Explicit memory; involves conscious recall of facts or experiences.
2) Implicit memory; learning of habits, skills or other acquired behaviors.
What two things come from the posterior pituitary?
Oxytocin and vasopressin
Where does ACTH come from?
Anterior pituitary
Where is the hypothalamus? What does it make up?
Under the thalamus; third ventricle ‘s inferior portion
What contains axons whose cell bodies are located in the hypothalamus?
Posterior pituitary
The hypothalamus is the central regulator of what?
Homeostasis
1) What can the hypothalamus detect?
2) What does it activate?
3) What can lesions cause because of this?
4) What does the posterior hypothalamus do?
1) Increased body temperature and
2) Mechanisms to dissipate heat,
3) Hyperthermia
4) Conserves heat.
What is memory loss like in concussion?
Usually reversible memory loss, except for a few hours around the injury
Can infarcts/ischemia cause memory loss? When?
They can, especially when bilateral medial temporal lobes are affected.
1) What cause of memory loss could be due to a cardiac arrest?
2) Is memory loss permanent? What structure is involved?
1) Global cerebral anoxia
2) Memory loss is usually permanent; the hippocampus is very vulnerable to anoxic injury
Seizures can cause what?
Memory loss
1) Where is the amygdala?
2) What two things does it play a big role in?
1) Tip of the hippocampus
2) Emotions and drives.
What structure is important in attaching emotions to stimuli?
Amygdala
1) What 3 structures being abnormal can cause schizophrenia?
2) What NT is can also cause it, and what can improve symptoms?
1) Limbic system, frontal lobes, and thalamus.
2) An abnormality in dopamine, therefore symptoms can improve with antidopaminergic agents
What two things cause anxiety?
1) Excessive activity in the amygdala
2) Failure of control by the frontal cortex
What 3 NTs can be markedly imbalanced in bipolar depression/ mania?
Serotonin, norepinephrine and dopamine
List 4 causes of memory loss
1) Concussion
2) Infarcts/ischemia
3) Global cerebral anoxia
4) Seizures
Which two areas does the hypothalamus receive inputs from?
Amygdala and regions of the limbic cortex
What receives inputs from retinal ganglion cells about whether it is day or night?
Suprachiasmatic nucleus
What two structures does the limbic system surround?
Corpus callosum and upper brainstem
What regulates emotions, affection, memory, drives, and homeostasis?
Limbic system
What C-shaped structure is buried in the medial temporal lobe and is important in memory functions?
Hippocampus
What functions in emotional, autonomic, and neuroendocrine circuits of the limbic system?
Amygdala
The medial temporal lobe memory area contains the ________, while the forebrain which contains nuclei of _________ and __________ that are critical for memory formation.
hippocampus; thalamus and hypothalamus
What can cause memory loss especially when bilateral medial temporal lobes are affected?
Infarct/ischemia
What area of the brain plays a big role in emotions and drives, is an active participant in all four limbic functions, and attaches emotions to stimuli?
Amygdala
What clinical disease is caused by abnormalities in the limbic system, frontal lobe, and thalamus?
Schizophrenia
What clinical disease is marked by an excessive rate of activity in the amygdala and the failure of control by the frontal cortex?
Anxiety
What hormone causes increased production of corticosteroids?
ACTH
What hormones increase production of testosterone, estrogen, and progesterone?
FSH and LH
What hormone functions in milk letdown?
Oxytocin
What hormone functions in milk production?
PRL
What is ADH also called?
Vasopressin
Connections through the corpus callosum allow the ________________ hemisphere to participate in the language processing network and it is important in ____________ and __________ of our speech.
non-dominant; emotion and tone of our speech.
1) What hemisphere is specialized for language and execution of motor tasks?
2) What hemisphere is more important for the consciousness system (alertness, attention and awareness)
1) The dominant hemisphere
2) Non-dominant hemisphere
Attention and alertness are mediated by what?
Brainstem + frontoparietal networks interacting
Brainstem + frontoparietal networks mediate what two things?
Attention and alertness
The right hemisphere is more important for ______________ mechanisms
attentional
1) Hemineglect syndrome occurs with infarct or other acute lesion of the _____________
2) What can this included?
1) right parietal lobe
2) Neglect for 1/2 of one’s body (and other things)
Do bilateral or unilateral medial temporal lobe lesions typically cause amnesia?
Bilateral
What lesions do not usually produce severe amnesia?
Unilateral lesions
Define transient global amnesia
Patients develop retrograde and anterograde amnesia with no obvious cause or associated deficits
1) In early Alzheimer’s Disease what memory loss is prominent?
2) What does this disease preferentially affect?
1) For recent events
2) The hippocampal, temporal and forebrain structures.
Define infantile amnesia and what may cause it
The inability of adults to recall years 0-3 of their lives (thought to be because the CNS is still maturing)
What is age related memory change?
Gradual decline in memory function over decades
1) Define anterograde amnesia
2) Define retrograde amnesia
2) Deficit of forming new memories
2) Deficit of memories prior to the brain injury
What memories depend on medial temporal lobe? Which do not?
Recent depend on it; remote memories do not
Which area of the brain is the most dominant area in most people?
Left hemisphere
Broca’s area communicates with what?
Prefrontal cortex
Which of the following are restraint functions of the frontal lobes?:
Judgment
Inhibiting socially inappropriate responses
Self-governance
Perseverance
All
Which two areas of the brain help mediate attention and alertness?
Frontoparietal and brainstem
Which area of the brain is more important in attentional mechanisms for most people?
Right hemisphere
Lesions the right hemisphere of the brain would have more prominent and long lasting deficits in ______________ than the contralateral side
attention
What condition is seen with infarct or other acute lesions of the right parietal lobe?
Hemineglect syndrome
A patient with a history of migraines presents with temporary retrograde and anterograde amnesia with no obvious cause or associated deficit. They keep asking you the same questions over and over with no recollection of just having asked it. The patient has a full recovery, except for just a few hours before and after this episode. What would be your most likely diagnosis?
Transient global amnesia
