Quiz 1 Flashcards
What symptoms would be expected in a lesion of the cortex of the brain?
Aphasia
Apraxia
Find CN III-XII (IV not pictured) on this image:
What does rostral mean?
Towards the nose/beak
What is the embryological name for the brainstem?
What structure is pictured here? What part of the brainstem is it part of?
The tectum, which is part of the midbrain
What structure is pictured here? What view of the brainstem is being used?
The tectum, viewed in a midsaggital slice
What is immediately ventral to the tectum?
The cerebral aqueduct
What structure is pictured here? (HINT: it is part of the tectum)?
The quadrigeminal plate
What are the individual swellings of the quadrigeminal plate called? Into what two groups are they divided?
Colliculi
They are divided into two groups:
-Superior colliculi
-Inferior colliculi
What are the functions of the superior and inferior colliculi respectively?
Where is the choroid plexus found? What is its function?
What two ventricles are connected by the cerebral aqueduct?
What is the result of a blockage in the cerebral aqueduct?
What are two additional names for the cerebral aqueduct?
What area of the brain stem is the tegmentum?
Where is the red nucleus found in the brainstem? What landmark is found at the level of the red nucleus?
What is the main function of the red nucleus?
Assists in motor coordination as part of the extrapyramidal system
Where in the brainstem is the reticular formation found? What is its purpose?
Why is the substantia nigra great landmark for identifying the midbrain?
It is found from the rostral to the caudal levels of the midbrain
What are the two main functions of the substantia nigra? What major disease is associated with its degeneration?
What structure is pictured here?
What are two other names for the cerebral peduncle?
Where is the cerebral peduncle found on this cross-section?
Where can the corticospinal tract be found in the cerebral peduncle?
What side of the body do upper motor neurons traversing the corticospinal tract in the midrain end up innervating?
The contralateral side
What structure is pictured here? What structure is it just medial to?
It is just medial to the substantia nigra
What is the function of the spinothalamic tract?
From which side of the body does the spinothalamic tract relay pain and temperature sensation?
The contralateral side
What structure is seen here just anterior to the spinothalamic tract? (Sandwiched between the red nucleus and spinothalamic tract)
At what level of the spinal cord does vibration and proprioception in a peripheral neuron decussate to the contralateral side before ascending the DCML tract?
The Spinomedullary junction
Which two cranial nerves come off of the midbrain?
CN III (Oculomotor) and CN IV (Trochlear)
*CN III is medial, CN IV is lateral on the picture
Between which two arteries does the oculomotor nerve course?
On which side of the midbrain does CN IV exit?
*This can make it hard to find on gross anatomy
What are the three main elements of the midbrain’s functional significance?
What area of the brainstem is highlighted in this picture?
The pons
What structure is pictured here within the pons? What is its function?
At what level of the cortical spinal tract does decussation to the contralateral side of the body occur?
The pyramids (medulla)
What structure is highlighted in this picture? Is this an anterior or posterior view of the brainstem?
It is a posterior view of the brainstem
At what level of the brainstem is the 4th ventricle found?
The pons and upper medulla
What area of the pons is highlighted here?
What structure is highlighted here in the pons? What is its function?
How is it easiest to find the Spinothalamic (ALS) tract in the pons?
1) Find bulge of pons proper
2) Follow it to the side of the buldge
3) ALS tract will be between the side of the buldge and the middle cerebral peduncle
What structure is seen in the highlighted portion of the pons? What is its function?
What four cranial nerves are associated with the pons?
What three characteristics highlight the functional signifiance of the pons?
What are two major structures that can help to differentiate the pons in cross-section?
-4th ventricle AND middle cerebral peduncle
-pons proper (Uncle Bob’s belly)
What portion of the brainstem is seen here?
The medulla
What structure within the medulla is seen here?
What structure is seen in this cross-section of the medulla?
The pyramid
*It contains the corticospinal tract
Where does decussation of the corticospinal tract occur?
Towards the bottom of the pyramids at the spinomedullary junction
What structure is seen here, just lateral to the pyramids in the medulla?
The olives
What structure is seen in this medulla cross-section? What is contained in this structure?
What is this structure seen in the medulla?
The 4th ventricle
What structure is seen here in the medulla?
What is the structure seen lateral to the pyramids and just behind the olives in a cross section of the medulla?
The Spinothalamic (ALS) tract
What structure is found immediately dorsal to the pyramids of the medulla?
The DCML tract
Which four cranial nerves are associated with the medulla?
What are the three important characteristics of the functional signifiance of the medulla?
What are some ways to identify the medulla on cross-section?
-Pyramids
-Olivary nucleus
-4th ventricle
-“plummer’s crack”
What is the signifance of the sulcus limitans in development of the spinal cord?
It creates a division between the alar and basal plates, which will develop into sensory and motor nuclei, respectively
Differentiate the approximate locations of the following neuron tracts in the spinal cord:
-Somatic sensory
-Visceral sensory
-Visceral motor
-Somatic motor
What is the difference in motor and sensory orientation in the spinal cord versus the brainstem?
What are branchial motor nuclei? Why are they only found in the brainstem?
What are hearing and balance nuclei? Where are they found in the brainstem?
How are sensory and motor nuclei organized in the brainstem?
What is the signifiance of the vertical arrangement (North/South) of brainstem nuclei?
We find that nuclei types run in the same vertical tracts (i.e. somatic motor nuclei for CN III, VI and XII run in the same vertical tract) but all nuclei in a tract are NOT seen at all levels of brainstem
What are four questions that can be used to help identify the location of a CN nuclei?
What are the four somatic motor neurons? In what part of the brainstem are they found?
Where are the somatic motor nuclei found in the brainstem on the “East/West” axis (cross-sectional)?
What muscles are innervated by the oculomotor nucleus?
All extraocular muscles (except SO and LR)
What direction does the affected eye move if the oculomotor nerve is damaged? Why is this?
*Ptosis will also be present
At what level of the midbrain is the oculomotor nucleus?
The level of the superior colliculus
At what level of the midbrain is the trochlear nucleus found?
The inferior colliculus (caudal midbrain)
What is unique about the axon pathway of the trochlear nerve? Which eye will be affected if the right trochlear NUCLEUS (not nerve) is damaged? What is different about nerve damage?
The left SO will be affected
Trochlear nerve damage produces an ipsilateral deficit
What muscles does the trochlear nerve innervate?
How do we test the function of the superior oblique muscle?
What muscles are innervated by the abducens nerve?
Why would a patient get double vision when looking laterally to the side with an abducens NERVE (not nucleus) lesion?
Why does an injury to only one side of the abducens nucleus (right or left) result in an inability to look laterally to side of lesion with either eye?
In what part of the brainstem is the hypoglossal nucleus? What does it innervate?
What is the most important muscle innervated by the hypoglossal nerve?
To which side of the body does the tongue deviate if the hypoglossal nucleus/nerve is injured?
What are the four visceral motor neurons found in the brainstem? In which parts of the brainstem are they found?
Where are visceral motor neurons found in the brain stem with “East/West” distinction? I.e. where are they relative to the sulcus limitans?
What cranial nerve is the Edinger-Westphal nucleus associated with?
*Note that it follows the somatic motor pathway out of the midbrain
Where does the Edinger-Westphal nucleus synapse? What two muscles does it innervate? What are the actions of each muscle?
What happens to the lens of the eye when the Edinger-Westphal nucleus causes the ciliary muscles to contract?
Does seeing an object close up or from a distance require contraction of the ciliary muscles (relax susp ligaments and lens)?
Seeing an object up close requires more refraction from the lens, so contraction of the ciliary muscles is necessary for the accomodation
What symptom would be noticed in the event of damage to the Edinger-Westphal nucleus? (apart from blurry vision due to inability to execute lens accomodation)
*Note that the eye is also looking down an out, classic symptoms of oculomotor nucleus damage. This is because damage to the EW nucleus is often paired with damage to the OM nucleus
With what cranial nerve is the superior salivatory nucleus associated? What three glands are innervated by branches from this nucleus? What type of autonomic motor action is this?
What cranial nerve leaves the superior salivatory nucleus to innervate the salivary glands?
The chorda tympani branch of the Facial nerve (CN VII)
*Note the chorda tympani nerve hitchhikes along the lingual nerve (CN V-3) near the submandibular ganglion
What cranial nerve leaves the superior salivatory nucleus to innervate the nasopalatal glands and the lacrimal glands?
The greater petrosal branch of the Facial nerve (CN VII)
What are three symptoms that would be expected in the event of an injury to the superior salivatory nucleus of the pons?
In what part of the brainstem is the dorsal vagal nucleus found? What CN is it associated with? What organs is it responsible for ANS stimulation of?
It is found in the medulla
Why is there not many symptoms associated with injury to the dorsal vagal nucleus?
Most of the organs innervated (through the vagus nerve) have independent function, and some such as the heart, have dual innervation
Where is the inferior salivatory nucleus found in the brainstem? What CN is it associated with, and what is innervated? What can result from injury to the ISN?
*Found just posterior to the dorsal vagal nucleus
Injury can reduce the amount of saliva produced (note the parotid gland is only responsible for some of the saliva production)
What type of motor neuron is the trigeminal motor nucleus? In what part of the brainstem is it found? What cranial nerve is associated with it, and what muscles are innervated?
Branchial motor neuron
Found in the pons
Muscles of mastication include temporalis, masseter and pterygoids
Where is the chief-trigeminal nucleus located? What sensory information does it receive?
It is located just lateral (other side of sulcus limitans) to the trigeminal motor nucleus
Where is the spinal trigeminal nucleus located? What sensory information does it receive?
In what part of the brainstem is the facial motor nucleus found? What cranial nerve is it associated with? What is unique about the facial motor tract?
*It wraps around the abducens nucleus, so injury to the abducens nucleus/tract can also damage the facial motor tract
What can occur if the facial motor nucleus or tract is injured?
What is the signifiance of facial palsy with “sparing of the forehead”?
The forehead has dual innervation, so injury to the facial upper motor neuron (above the nucleus) will not cause palsy affecting the forehead (i.e. stroke)
Where in the brain is the nucleus ambiguus found? What muscles is it responsible for innervating? What CN is it associated with?
What are 3 significant clinical symptoms expected if there is an injury to the nucleus ambiguus?
What would be the expected effect of bilateral anterior cerebral artery lesions on sensory modalities such as pain & temperature as well as vibration and proprioception?
Bilateral ACA lesions would be expected to affect all sensory pathways mentioned.
If only some were affected (i.e. vibration & proprioception) that would be inconsistant with ischemia of the ACA arteries
Does Anterior Spinal Artery Syndrome (ASAS) occur from a CNS lesion, PNS lesion, both, or niether?
CNS lesion
What are the changes that spinal cord shock produces in neurological exam findings over time, such as with anterior spinal artery syndrome?
Acute lesions of spinal cord can produce:
1) Hypotonia
2) Hypo/a-reflexia
3) Absent Babinski signs
due to spinal cord shock.
From a few days to about 2 weeks later, shock can give way to UMN findings such as spasticity, hyperreflexia, and Babinski signs.
True/False: The DC/ML tract as well as the ALS tract (spinothalamic) are both supplied blood by the anterior spinal artery
False
DC/ML: posterior spinal arteries (set of arteries)
ALS: anterior spinal artery (single artery)
What tracts are most consistantly affected in anterior spinal artery syndrome (ASAS)? Why is this?
The ALS (spinothalamic) tract and the corticospinal tract
They are both supplied blood from the anterior spinal artery
What sensory/motor loss results from ASAS?
ALS tract- pain and temperature sensation
Corticospinal tract- motor
What are some common mechanisms for infarction of the anterior spinal artery?
1) Motor vehicle accidents
2) acute aortic aneurysm or dissection
3) peripheral vascular disease ischemia
4) sickle cell disease
5) polycythemia
What are classic signs and symptoms of ASA infarction?
Below level of lesion:
-Loss of motor function
-Loss of pain and T sensation
Retained:
-Proprioception and vibration
Autonomic dysfunction:
-Orthostatic hypotension
-Sexual dysfunction (i.e. priapism)
-Bowel and bladder dysfunction
-Areflexia
-flaccid internal/external sphincters
How can a diagnosis of suspected anterior spinal artery syndrome be confirmed?
Diffusion weighted imaging MRI sequence
This is a diffusion weighted MRI imaging of the thoracic spine to evaluate the liklihood of anterior spinal artery ischemia. What do the findings indicate?
1) Grainy appearance to a DWI MRI indicate ischemia in the sequence
2) Abnormal areas are white
Therefore this confirms the presence of ASAS
The T2 weighted-imaging can further corroborate the pattern seen in the DWI
What does apopleptic mean in context of stroke symptoms?
Apopleptic refers to thunderclap immediate onset, or abrupt onset of stroke symptoms
What are three major classifications of disorders that present with apoplexy?
1) Vascular (stroke)
2) Seizure (electrical)
3) Ion channel (channelopathies)
Why does a patient with lateral medullary syndrome not present with muscle weakness inferior to the face?
The corticospinal tracts are in anterior brainstem, and blood supply is not compromised there due to stroke
What are the two categories of disorders that produce ptosis?
CN III lesions:
-Ptosis
-Midriasis
-Eye looks down and out
Horner syndrome:
-Ptosis
-meiosis (small pupil)
-hemi-anhydrosis
*Note: Horner syndrome involves damage to sympathetic innervation of eyelid/eye, unlike somatic motor innervation such as CN III
What cranial nerves are involved in the gag reflex?
CN IX: Afferent sensory
CN X: Efferent motor
Why is tongue strength normal in lateral medullary syndrome?
The hypoglossal nucleus is located medial to the area of ischemic tissue
What can be indicated by incoordination and intention tremor seen in LMS?
Injury to the ipsilateral cerebellum
What causes the vertigo experienced by the patient in LMS?
Vestibular nuclei on affected side are lesioned, producing nystagmus, and the lesioned vestibular nuclei fire less frequently than non-lesioned.
This is interpreted as head rotation by the brain, but the visual input does not corroborate this, and the resulting discrepancy results in nausea.
Why is Wallenberg syndrome (LMS) often an overlooked diagnosis?
This stroke does not typically produce weakness.
Most patients and physicians equate stroke with weakness, usually unliateraly, but this is not often the case with LMS.
What is the triage plan for a patient presenting to the ER with Wallenberg syndrome?
Since the patient is having a stroke, they are eligable for tPA (tissue plasminogen activator)
What blood vessel is most likely lesioned to produce the ichemia seen in Lateral Medullary syndrome?
It is usually the posterior inferior cerebellar artery, however if the vertebral artery is lesioned it could produce a thromboembolism blocking the PICA
What are two other names for lateral medullary syndrome?
Wallenberg syndrome
Posterior inferior cerebellar artery syndrome
What is the name of and composition of this commissure of the spinal cord?
The anterior/ventral white commissure
It is composed of both
1) second order spinothalamic tract axons
2) local interneurons
What pathology can be seen in the region of the central canal of the spinal cord?
Expansion of the central canal secondary to syringomyelia
What could result from syringomyelia that could cause bilateral pain and thermal sensation loss in corresponding dermatomes?
Pressure from the cyst could impair/destroy the anterior white commissure, impairing the ALS tract where it normally dessicates
What is the somatotopic organization of the anterolateral system?
Sacral dermatomes are represented laterally and cervical dermatomes medially
What are two names for the area seen here in this section of spinal cord?
The dorsolateral fasciculus or Tract of Lissauer
What is the functional signifiance of the dorsolateral fasciculus (ToL)?
It contains axons involved in spinal reflexes and intersegmental integration
What two fasciculi are responsible for comprising the dorsal column (DCML tract)? What levels of the spinal cord are they found at?
Cuneate fasciculus- C1 to T6
Gracile fasciculus- T7 and below
What is the somatotropic representation of the dorsal columns of the spinal cord?
Medial to lateral:
Sacral -> Lumbar -> T -> C
Where are the cell bodies located for the circled axons?
The dorsal root ganglia
How can occlusion of the anterior spinal artery lead to slurred speech?
It supplies the hypoglossal axons passing through the medulla, in addition to the medial lemniscus and corticospinal tract
What is the frontal gaze center used for?
Saccadic eye movements- these are rapid eye movements used to bring a new object being viewed onto the fovea.
What patient symptoms are consistant with an affected frontal gaze center?
Difficulty with large amplitude eye movements to fix onto a new target
Which supranuclear gaze system is important for vergence; which is keeping an image on the fovea when the object is moved near to the face?
Occipital mesencephalic pathways
What is the function of the parietal-occipital gaze center?
To keep a moving image centered on the fovea (i.e. horse galloping or car driving)
In what situation is bone conduction greater than air conduction durinig a Rinne-Weber test?
Conductive hearing loss
In which ear will the tuning fork on the forehead (Rinne-Weber test) be lateralized to in neurosensory hearing loss?
The normal ear
Where do the cell bodies of upper motor neurons reside in the CNS?
The precentral gyrus (primary motor cortex) in the frontal lobe
What is another name for the primary excitative neurons of the corticospinal system?
A pyramidal cell
Which structure in the brain is the gatekeeper that prevents unwanted movements?
The thalamus
What brain structure is a consultant on movements that provides input to the thalamus?
The basal ganglia
What is the difference between the pyramidal and extra pyramidal tract in the brain?
The pyramidal tract refers to the primary UMN in the corticospinal tract
The extrapyramidal tract generally is referred to as the basal ganglia and its input to the thalamus BUT technically also includes the cerebellar-thalamus tract
Where are the supplementary motor area and posterior parietal cortex located in the cerebrum? What are their functions?
What is the corticobulbar tract? Where does it synapse?
Fibers connecting the motor cortex to terminate on the lower cranial nerve nuclei
It synapses on LMNs in the pons and medulla
What is the difference in innervation between corticobulbar tracts and corticospinal tracts?
What is unique about the temporal divison of CN VII (facial nerve)? In addition to contralateral UMN stimulation what other pathway innervates it?
Which branches of the facial nerve will be affected if there is a right sided lesion of the corticobulbar tract?
All the divisions of the facial nerve except for the temporal division will be affected
What three major brain areas are supplied blood from the middle cerebral artery?
1) Primary motor cortex
2) Broca’s area
3) Wenicke’s area
What important part of the primary motor cortex is supplied blood from the anterior cerebral artery?
What important part of the primary motor cortex is supplied blood from the middle cerebral artery?
Which parts of the brainstem are supplied blood by the basilar artery?
What two arteries are most notable for vascular supply to the motor cortex? Which parts of the motor homunculus are perfused by which artery?
What two arteries (artery systems) are responsible for perfusing the internal capsule? Which artery system perfuses which part?
What artery supplies blood to the cerebral peduncle?
What artery supplies blood to the pons?
What artery(ies) are responsible for perfusion to the pyramids of the medulla? For the lateral spinal cord?
What part of the spinal cord does the ASA not perfuse?
The dorsal columns (it basically covers everything else; pain, temp, motor function)
What is Man in the Barrel syndrome? What can cause it?
MIBS:
Weak
-Hips
-Shoulders
-Arms
Strong/normal
-Hands
-Legs
-Feet
It can be caused by bilateral watershed infarctations from hypo-perfusion of end arterioles from ACA & MCA
What is Locked In syndrome? What most commonly causes it? What part of gaze is spared? Why is consciousness usually preserved?
What is transverse myelitis? What are two notable types of causes? What diseases are examples of monophasic and polyphasic TM?
TM is inflammation of the spinal cord
Two notable causes are autoimmune and infectious etiologies
Monophasic: ADEM (acute disseminated encephalomyelitis)
Polyphasic: MS (multiple sclerosis)
What are the differences in power, tone and bulk between an UMN lesions and LMN lesion?
What are the differences in fasciculations, deep tendon reflexes (DTR), and Babinski sign between UMN and LMN lesions?
q
Through what part of the internal capsule does the corticobulbar tract pass?
The genu
Through what part of the internal capsule doors the cortico spinal tract and somatosensory tract pass through?
The posterior limb
What limb of the internal capsule is associated with the basal ganglia?
Anterior limb
Where in the brainstorm is the reticular formation found? What is its function?
It is found in the midbrain.
Its function is to maintain consciousness (i.e. lesions can produce coma)
What is opthalmoplegia?
Weakness or paralysis of the extraocular eye muscles (affecting one or more)
What disease is classically associated with opthalmoplegia, gait ataxia and encephalopathy? What is the cause of this disease?
Wernicke encephalopathy
It is caused by a thiamine (B1) deficiency
Why is administration of extra carbohydrates (such as IV dextrose) dangerous in a patient who has severe thiamine deficiency? What should be done before administering the IV dextrose?
Thiamine is used to metabolize carbohydrates, and administration of carbohydrates can worsen the deficiency. By further depleting the body and brain, the patient could be pushed into permanent injury, such as Korsakoff syndrome.
Pushing IV thiamine (cannot overload, as kidneys will excrete excess)
Besides the cerebellum, what other brain structure is most commonly affected by Wernicke encephalopathy?
The mamillary body (white arrows)
Mamillary body atrophy is the most common finding, although lesions can occur in other areas such as the oculomotor nuclei
What is the etiology of beriberi? What is beriberi?
It can be caused by thiamine (B1) deficiency
Beriberi can be DRY or WET
Dry: Symmetrical peripheral neuropathy of motor and sensory
Wet: Neuropathy + cardiac disease (cardiomyopathy, CHF, etc.; can present with tachcardia, peripheral edema and etc)
*Beriberi can be a weight loss surgery complication (thiamine is absorbed in jejunum and ileum primarily)
Symptoms of dermatitis, diarrhea and dementia are classically associated with what diseaes? What causes it?
Pellagra
It is secondary to niacin (B3) deficiency. It is fatal if untreated
What patient types are at risk for pellagra (broadly and specific to USA)?
Broadly, patients who are malnourished
In the USA it occurs most commonly in alcoholics who aren’t getting a balanced diet.
How is niacin deficiency diagnosed? How is it treated?
It is mainly clinically diagnosed, but supportive labs results include:
- low niacin, tryptophan (most helpful)
-anemia
-hypoproteinemia
-electrolyte imbalances
-abnormal LFTs
Tx is niacin supplementation
What are common SE of niacin supplementation? What are symptoms of toxicity?
Supplementation: flushing, nausea, vomiting, pruiritus, hives, constipation
Toxicity: More severe SE listed above, also niacin-induced myopathy
What type of neuropathy can be caused by pyridoxine (B6) toxicity?
Small fiber neuropathy (i.e. hyperesthesia, decreased distal pinprick sensation; intact motor and vibratory)
Is pyridoxine (B6) toxicity more often a result of dietary consumption or pill supplementation?
Pills
How is pyridoxine (B6) supplementation diagnosed?
A history of B6 supplementation accompanied by distal neuropathy should make you consider it on the differential
How is pyridoxine (B6) toxicity treated?
Stop supplementation
*100mg of B6/day is considered the risk for toxicity
What are symptoms of pyridoxine deficiency?
It is thought that in infants and small children it can cause seizures.
There is no reliable way to check B6 levels, so it is common practice to supplement children with intractable seizures with pyridoxine
What is an aphasia?
Partial or total loss of the ability to articulate ideas or comprehend spoken or written language
What is apraxia?
Loss of ability to carry out a skilled movement despite adequate understanding of the task and normal motor power
What is agnosia?
Inaiblity to recognize objects by use of the senses
What is anomia?
The inability to name objects or recognize written or spoken names of objects
What are four significant findings expected in a patient with cortically based dementia?
-Aphasia
-Apraxia
-Agnosia
-Anomia
What are the two classic elements of subcortical dementia?
1) Bradyphrenia
2) Basal ganglia associated movement disorders (rigidity, cogwheeling, tremor, bradykinesia)
What are 3 expected findings in a patient with subcortical dementia?
1) Bradyphrenia
2) Poor motivation
3) Poor attention
What two etiologies should be investigated in the event of enlarged brain ventricles in the absence of cortical atrophy?
1) Non-communicating hydrocephalus
2) Communicating hydrocephalus
How can ventricular dilation (i.e. hydrocephalus) cause urinary urgency?
In hydrocephalus, lateral horns of 3rd ventricle are disproportionately expanded, which exert pressure along the parafalcine area (medial frontal lobes).
The parafalcine area contains the motor homunculus for legs as well as 3 main centers for voluntary bowel and bladder control.
Important -stretching of this area can lead to the urinary urgency AND gait symptoms seen in patients
What is the etiology of normal pressure hydrocephalus (NPH)?
Loss of balance between CSF production and absorption
There is thought to be obstruction of CSF flow around brain convexities and insufficient absorption through arachnoid granulations of superior saggital sinus.
This is a communicating hydrocephalus
What clinical triad is classic of normal pressure hydrocephalus?
“Weird walking water”
-Dementia
-Gait impairment
-Urinary incontinence
What types of testing could confirm a suspicion of NPH?
CT or MRI- to demonstrate ventricular enlargement out of proportion to cortical atrophy
Spinal tap- to demonstrate normal pressure of CSF
*After high volume removal of CSF (40cc’s), short term improvement of symptoms (gait, urinary control, etc) could confirm dx
*CSF reaccumlates, which is why symptom improvement from high volume spinal tap is short-lived
What are the long-term treatments for NPH?
CSF diverting operation (to shunt CSF to relieve fluid build-up)
Candidates are typically those with less than 2 years of dementia and gait impairment, but the procedure works best when treated as early as possible
Can medications improve the symptoms of NPH?
The only symptoms that have been shown to be treatable are some medications for memory (memantine/Namenda, donepezil/Aricept) have been of some limited effect in reducing cognitive decline
Medications to treat elevated ICP have not been shown to be helpful
What is syringomyelia or syrinx?
A CSF-filled cyst in the spinal cord
What relationship does syrinx have with chiari malformation?
90% of idiopathic syringomelia have a Chiari I malformation (average age of presentation is 41)
What bacterium causes leprosy? In patients with what symptoms should leprosy be on the differential?
Leprosy is caused by the bacilli Mycobacterium leprae.
It should always be considered in patients with anesthetic nerves, hypertrophic nerves, hypopigmented macules, and in distal appendages.
Where does the second order neuron in the spinothalamic tract synapse in the brain?
In the VPL (ventral posterolateral nucleus) of the thalamus
What major artery is located in the membrane of the dura mater? What type of hematoma is most common secondary to its rupture?
The middle meningeal artery
An epidural hematoma
What type of hematoma is most probable if the bridging cerebral veins are ruptured?
A subdural hematoma
What region of the brainstem is surrounded by the tentorium cerebelli? Which cranial nerve is most vulnerable to compression of the brainstem into the tentorium?
The midbrain
CN III
What is dysautonomia?
An umbrella term of several medical conditions causing dysfunction of the autonomic nervous system?
Does dysautonomia cause a malfunction of the sympthathetic or parasympthetic nervous system?
Either or both
Name 5 common symptoms/signs of dysautonomia?
1) Xeropthalmia
2) Xerostoma
3) Abdominal fullness, gastroparesis
4) Piloerection
5) Orthostatic hypotension
There are many others such as myalgias, abnormal sweating, cardiac rythym irregularity
What is the name of the structure indicated by the arrow? What vessel supplies it?
The cingulate gyrus
It is supplied by the anterior cerebral artery
What is the function of the cingulate gyrus?
It is part of the LIMBIC system
It helps with emotion and behavioral processing as well as autonomic motor function
Are most humans right or left-brain dominant?
Left-brain dominant
What structure is indicated here? On which gyrus does it lie? What vessel supplies it?
The primary auditory cortex
It lies on the transverse temporal gyrus
It is supplied by the middle cerebral artery
Why do unilateral cerebral strokes cause unilateral deficits in motor, somatic sensation and vision but not in hearing?
Auditory information is sent to both hemispheres
What is the corpus callosum?
The primary commisural region of the brain. It consists of white matter tracts to connect the left and right hemispheres.
What primary cortical area is Broca’s area closest to?
The primary motor control for the face
What is the septum pellucidum?
The thin membrane that separates the two lateral ventricles
What white matter structure lines the superior edge of the lateral ventricles? What four sections is it divided into, and what cerebral lobes are they associated with?
The corpus callosum
Rostrum- frontal lobe
Genu- frontal lobe
Body- parietal
Splenium- temporal/occipital lobes
*the midbody can be referred to as the “body”
What gyrus sits just superior to the corpus callosum?
The cingulate gyrus
What white matter tract runs along the inferior edge of the lateral ventricles?
The fornix
What does the anterior commissure connect?
The two temporal lobes
What symptoms related to cranial nerve compression could occur in a pituitary adenoma?
Visual field defects (partial blindness)
Which CN nucleus is most likely to be compressed by a pineal tumor? What symptoms would be expected?
CN III nuclei, pupillary dilation
What language, motor and social developments are expected for a 2 month old baby?
*hunger
What language, motor and social developments are expected for a 4 month old baby?
What language, motor and social developments are expected for a 6 month old baby?
What language, motor and social developments are expected for a 9 month old baby?
What language, motor and social developments are expected for a 12 month old baby?
What language, motor and social developments are expected for a 18 month old baby?
What language, motor and social developments are expected for a 2 year old child?
What language, motor and social developments are expected for a 3 year old child?
What language, motor and social developments are expected for a 4 year old child?
What language, motor and social developments are expected for a 5 year old child?
What are Erikson’s 8 stages of psychosocial development and their respective ages?
Trust vs. Mistrust (0-18 months)
Autonomy vs. Shame and Doubt (18 months to 3 years)
Initiative vs. Guilt (3-5 years)
Industry vs. Inferiority (5-13 years)
Ego Identity vs. Role Confusion (13-20 years)
Intimacy vs. Isolation (20’s to 40’s)
Generativity vs. Stagnation (40’s to 60’s)
Integrity vs. Despair (late adulthood to 60’s and beyond)
What are the 4 stages of cognitive development put forth by Piaget, as well as the critical achievement of each stage?
Sensorimotor (0-2 years)
-Object permanence
Preoperations (2-7 years)
-Semiotic function
Concrete Operations (7-11 years)
-Conservation
Formal Operations (11+ years)
-Deductive reasoning (also inductive)
What is object permanence?
The ability to maintain a mental image of an object even if it is not present and visible
What is semiotic function?
The ability to use symbols to represent something else
What is conservation (in psychiatry)?
The ability to recognize that shpae of an object can change and the object still retain its identity
What is deductive reasoning? What is inductive reasoning?
DR- Applying general principles to specific situations
IR- Taking a hypothesis from something specific and generalizing it
At what age can normal stranger anxiety be observed in children?
About 8 months; they can be distressed by the presence of people other than caregivers
At what age can separation appear as a normal phenomenon?
About 18 months, related to not having achieved object permanence
What are the first 3 stages of Separation-Individuation as put forth by Mahler, and what is the age associated with each stage?
What are the 5 stages of grief as put forth by Kubler-Ross?
1) Denial
2) Anger
3) Bargaining
4) Depression
5) Acceptance
What are the last 3 stages of Separation-Individuation as put forth by Mahler, and what is the age associated with each stage?
What are the fiber type and conduction speed of both unmyelinated free nerve endings and myelinated nerve endings?
UM- C fibers, slow
M- A-delta, fast
Where are the primary sensory neuron cell bodies in the dorsal column located?
The dorsal root ganglia
What is the somatotropic organization of the DC tract?
Medial -> Lateral
Leg -> Arm
*Similar to PMC (leg -> arm/face)
Which fasciculi do the dorsal column neurons ascend at which spinal cord levels?
Cuneate fasciculus- C1-T6
Gracile fasciculus- T7-S5
Where are the secondary sensory neuron cell bodies of the DC tract located?
The caudal medulla
In what part of the brainstem do second order neurons of the DC tract form the medial lemniscus band?
The medulla
Where are the tertiary sensory neuron cell bodies of the DC/ML tract located? In which limb of the internal capsule to they travel to the postcentral gyrus?
The VPL nucleus of the thalamus
The posterior limb of the internal capsule
Which systems/tracts do mechanoreceptors and free nerve endings belong to, respectively?
What is the receptive field of a sensory neuron? Are all receptive field sizes roughly the same?
What do proprioceptors detect?
Does the DCML or the ALS pathway have fibers with a larger diameter? Which pathway conducts faster?
Which neuron in the DCML tract is responsible for decussation? At what level of the spinal cord/brainstem does this occur?
The 2nd order neuron
This occurs at the level of the medulla
Does the 2nd order sensory neuron in the DC tract ascend in the ipsilateral or contralateral medial lemniscus?
Contralateral
This is the point in the medulla at which decussation occurs
Describe how the somatotropic organization of the DCML tract changes from the medulla to the midbrain?
Where are the cell bodies of the first order neurons of the ALS tract found? Where do the second order neurons decussate?
The dorsal root ganglia
They decussate after ascending 1-3 spinal cord segments
What are the two main classes of nociceptive neurons?
After ALS axons enter the spinal column what tract do the use to ascend/descend 1-3 spinal cord segments?
Lissauer’s tract
What sensory deficits would be associted with expansion of the central syrinx?
The pressure on the anterior white commissure could cause dysfunction bilaterally (due to decussation) for the ALS pathways
What is sensory dissociation?
The idea that a focal lesion can disrupt fine touch and proprioception (CDML) but not pain and temperature (ALS) or vice versa
Besides the primary somatosensory cortex, what are four other notable locations the ALS projects to?
What occurs in descending modulation of pain?
Many brainstem areas receiving nociceptive input can modulate transmission of nociceptive information at spinal levels
Where do the 1st, 2nd, and 3rd order neuron cell bodies reside in the trigeminal tract? Where does the tract decussate?
What are the three main divisions for the trigeminal nucleus? Where is each located?
What is unique about the third order neuron pathway of the ALS tract vs the DCML tract?
The third order neurons of the ALS tract project to inthe insular cortex and anterior cingulate cortex in addition to the sensory cortex
How many neurons are used to reach their destination in sensory tracts versus motor tracts?
What signs or symptoms would be common in small fiber neuropathies versus large fiber neuropathies?
Name the body structures associated with the following dermatomes:
-C2
-C4
-C5
-C6
-C7
-C8
-T1
Name the body structures associated with the following dermatomes:
-T4
-T10
-L1
-L3
-L4
-L5
-S1
-S2
In what syndrome is sensory dissociation classically seen in a hemi-section of the spinal cord?
Brown-Sequard syndrome
In Brown-Sequard syndrome what are the expected findings:
-At the level of the lesion
-Ipsilateral and below
-Contralateral and below
What two systems are used for sensory transmission to the brain?
-Spinothalamic & DC/ML
-Trigeminal
What is graphesthesia?
The ability to tell handwriting on the skin purely by sensation of touch (i.e. drawing a number on the palm of the hand)
Agraphesthesia is the impariment of this ability
What is stereognosis?
The ability to perceive and recognize the form of an object purely by touch
Astereognosis is the impairment of this ability
What area of the brain do tests of graphesthesia and stereognosis test the function of?
The parietal lobe of the cortex
T/F: Romberg test is a test of cerebellar function (the ability to exercise motor control and fluidity when standing with the eyes closed)
FALSE
Romberg is NOT a test of cerebellar function, it is a test of proprioception through the dorsal column
What 9 classic sensory syndromes are important to understand for B&B exam 1 (as well as boards)?
What sensory information would be expected to be normal and which would be abnormal in small fiber neuropathy? Would it be unilateral or bilateral?
Normal
-vibration
-proprioception
-strength
-reflexes
Abnormal
-pain
-temperature
-autonomics
Bilateral and diffuse
What patient history finding in tandem with dermatomal hypersensitivity and vesicular eruption would be an indication of possible varicella zoster?
History of chicken pox
Superficial touch is extremely painful, though deep touch is not very bothersome
If the hypersensitivity/eruption is disseminated think about immunocompromisation
What are the two classic causes of dorsal column demyelination? Why is demyelination so problematic?
Syphilis and B12 deficiency
Demyelination leads to degeneration of the dorsal column
What symptoms/signs are similar between syphilis and B12 induced dorsal column demyelination? What symptoms/signs appear additionally in a B12 deficiency etiology?
Both
-Selective loss of vibration & proprioception
-Sensory ataxia: + Romberg
B12 deficiency- Corticospinal tract is also degenerating
-Spasticity (especially in the legs)
What sensory syndrome is likely to present with the following symptoms? What commonly precedes this presentation?
Syringomyelia or Syrinx
Neck trauma
What would be the expected presentation for a patient with a hemi-section (left side) at roughly T9-T11? What syndrome is this?
Brown Sequard Syndrome
What is the most common cause of Brown-Sequard syndrome?
An inflammatory demyelinating lesion due to multiple sclerosis
Trauma to the side of the spine is another common cause
What would be the expected presentation for Anterior Spinal Artery Syndrome? Why is it so much more severe than posterior spinal artery syndrome?
The anterior spinal artery perfuses the spinothalamic and corticospinal tracts; essentially all of the spinal cord except the dorsal column
Posterior spinal artery syndrome would only affect the dorsal column
Why is a diagnosis of Wallenburg syndrome often missed? What symptoms can be seen contralaterally versus ipsilaterally? Why are hoarseness and hiccoughs seen?
There are only sensory symptoms, and no motor impairments
Hoarseness and hiccoughs are seen due to the impairment of CN IX and X
What post-ischemic stroke syndrome classically produces a contralateral hemi-body burning pain, hypersensitivity to pain, and allodynia?
Thalamic pain syndrome
What are the three classic symptoms in a patient with Thalamic Pain syndrome? What does it commonly present after?
In peripheral neuropathy (i.e. due to prolonged hyperglycemia), would sensory or motor symptoms occur first? Which nerves tend to be affected first? Do DTRs attenuate or hyper-reflex? What distribution do symptoms occur in?
What illness that presents with xeropthalmia and xerostoma may also presesnt with a small fiber neuropathy?
Sjogren’s disease
What are 3 major clues that can raise suspicion for Rett syndrome?
1) Normal head circumference at birth that then flattens out on a growth chart
2) Stereotypic “hand wringing” or twisting
3) Normal development until about 6 months (sometimes later) followed by developmental regression
Also can involve severe intellectualy disability, seizures, loss of speech and other nonspecific symptoms
What key fact can differentiate Rett syndrome from ASD, Angelman syndrome or Cerebral palsy?
Rett syndrome presents with developmental REGRESSION, or in other words there is a period of normal development in early infancy
What causes Rett syndrome in 80% of women? Why is it mostly seen in females?
The cause of Rett syndrome in 80% of women is a mutation in the MECP2 gene on the X chromsome.
Rett syndrome is usually not compatible with life in boys (only 1 X chromosome)
Is Rett syndrome more often familial or sporadic?
99% of MECP2 mutations are sporadic
How is a diagnosis of Rett syndrome made?
History, review of development, and PE as well as genetic testing for MECP2 mutation
PE:
-microcephaly
-hand wringing movements
-severe intellectual disability
Is there any prenatal testing for Rett syndrome?
No
What are six significant comorbidities of Rett syndrome (there are more)?
Seizures can occuur in 90% of patients at some point of their life. Many patients are at risk for difficulty swallowing, cardiac arrythmias, breathing problems such as apnea or hyperventilation, scoliosis (up to 80%) and intellectual disability.
Are there any treatments for Rett syndrome?
No, but supportive care can be given to address individual issues or comorbidities
At what age is universal screening for autism performed in children? What is the name of the screening tool?
18 and 24 months of age
Modified Checklist for Autism in Toddlers Revised with Follow-up or M-CHAT-R/F
What are 3 diagnostic tools that can be used by specialists to diagnose autism?
Autism Diagnosis Observation Schedule (ADOS)
Childhood Autism Rating Scale (CARS)
Screening Tool for Autism in Toddlers & Young Children (STAT)
Since ASD has no core treatments or medications, what invervention is preferred?
Skill-based Intervention
1) Applied Behvaior Analysis (ABA)
2) Picture exchange communication (PECS)
3) Augmentative communication and visual supports
What is Autism Spectrum Disorder?
1) Impairment in social communication/interaction
2) Restricted, repetitive interests or behavior
What percentage of autism patients have regressive onset (language and/or social) in 2nd or 3rd year of life? What percentage have intellectual disability?
25% have regressive onset
33% have intellectual disability
Also there is increased risk of comorbid psychiatric disorders and medical conditions (especially GI related and sleep disturbances)
The disease previously identified as mental retardation has been instead identified as what?
Intellectual Disability disorder
What are the two types of functioning examined in the diagnosis of Intellectual Disability disorder?
What are the three domains of adaptive functioning (as used in diagnosis of IDD)?
What criteria must be met for a diagnosis of Intellectual Disability disorder?
What are the four most commonly administered IQ tests?
1) WISC (most common)
2) WAIS
3) Stanford-Binet
4) Leiter (non-verbal)
What are two tests used to measure adaptive functioning?
1) Vineland
2) Adaptive Behavior Assessment System (ABAS)
At what age are children tested for suspected IDD?
Note that adaptive testing can be done from birth but is most often tested with IQ concurrently
When should retesting IQ or adaptive functioning be done?
After significant life transitions or Medical issues that impact cognitive functioning (either after dx OR tx); essentially if there are reasons to expect a different result in a retest
What are two disease conditions that commonly present with intellectual disability?
1) Down syndrome
2) Fetal alcohol syndrome
What are notable characterstics (intellectual and physical) of children with fetal alcohol syndrome?
Characteristics:
-Growth deficiency
-Heart defects
-ID, learning disabilities
What percentage of ID is due to genetic, prenatal, perinatal, postnatal and unknown causes?
T/F: The less severe ID is the more likely it is to find an identifiable cause?
False, the oppsite
What is the standard of care testing to determine causes of ID?
Fragile X & SNP microarray
What part of the brainstem is shown here? What are the somatic, visceral, and branchial motor nuclei located in this level?
There is no branchial motor nuclei in the midbrain
What part of the brainstem is shown here? What are the somatic, visceral, and branchial motor nuclei located in this level?
What part of the brainstem is shown here? What are the somatic, visceral, and branchial motor nuclei located in this level?
Injury to the superior salivatory nucleus can lead to xerostoma, dry mucous membranes, and xeropthalmia. Injury to what other structure could produce impairment of the corneal reflex in addition to the previous findings?
Injur to the internal acoustic meatus
What brain structure connects the thalamus to the basal ganglia?
What important neural pathways/fibers traverse the respesctive parts of the internal capsule:
-Anterior limb
-Genu
-Posterior limb
What is the somatotopic organization of the internal capsule?
Basically, it is the reverse of the primary somatosensory cortex
Where is the cervicomedullary junction? What tract decussates at this level?
The pyramidal tracts (corticospinal)
IMPORTANT: 10% of corticospinal fibers do not decussate here
