NSG Q&A Flashcards
Major branches of the ECA
SALFOPS Max
Superior thyroid, ascending pharyngeal, lingual, facial, occipital, posterior auricular, superficial temporal, maxillary artery
Classical clinical findings with an occlusion of the anterior choroidal artery
Hemiparesis, hemianesthesia, and hemianopsia
The PCA divides into what two terminal branches?
Parieto-occipital and calcarine arteries
What are Virchow-Robin spaces?
Potential spaces between the blood vessels and the arachnoid and pia layers within the brain and spinal cord
Which sinus courses within the attachment of the tentorium to the petrous ridge?
Superior petrosal sinus
Which large anastomotic vein joins the superior sagittal sinus?
The vein of Trolard (superior anastomotic vein)
Which large anastomotic vein joins the veins of the sylvian fissure with the transverse sinus?
The vein of Labbe
What is the venous angle as seen on a lateral view of a cerebral angiogram?
The angle is formed by the junction of the thalamostriate vein and the internal cerebral veins at the thalamic tubercle.
This area approximates the site of the foramen of Monro
What are the 3 main superficial cerebral veins?
Superior anastomotic vein of Trolard, inferior anastomotic vein of Labbe, superficial middle cerebral vein
Which artery is the most common cause of lateral medullary syndrome (Wallenberg’s)?
Most commonly due to occlusion of the ipsilateral vertebral artery.
This syndrome results from infarct in the region supplied by PICA, which is a branch of the vertebral artery
What is the arterial supply of the thalamus?
Branches of the PCOM arteries, and the perimesencephalic portion of the PCAs
What is the arterial supply of the lateral geniculate nucleus?
It has a dual supply.
Laterally, it receives supply from the anterior choroidal.
Medially, it receives supply from the lateral posterior choroidal
Which artery is most commonly involved in trigeminal neuralgia?
SCA
Which artery is most commonly involved in hemifacial spasm?
AICA
Which artery is most commonly involved in glossopharyngeal neuralgia?
PICA
What is the main arterial supply of the internal capsule?
The lateral lenticulostriate branches from the MCA, the medial striate artery from the ACA, and the direct branches from the ICA
Which vessel has the highest risk of injury in a Chiari decompression?
PICA
Which vessels supply the superior, middle, and inferior cerebellar peduncles?
The SCA, AICA, and PICA, respectively.
Where is the motor strip located in relation to the skull?
4-5.5 cm behind the coronal suture
What sutures make up the asterion?
The lambdoid, parietomastoid, and occipitomastoid sutures.
It is important to define the lower half of the junction of the transverse and sigmoid sinuses.
What are the compartments of the jugular foramen?
Pars venosa (posterolateral), which contains the sigmoid sinus, jugular bulb, CNs X and XI
Pars nervosa (anteromedial), which contains CN IX, and Jacobson’s nerve
What structure does CN VI go through to enter the cavernous sinus?
Dorello’s canal
What structures go through the internal acoustic meatus?
CN VII, CN VIII, and the labyrinthine artery
What structures pass through the annulus of Zinn?
The optic nerve, ophthalmic artery, oculomotor nerve, abducens nerve, and nasociliary nerve
The clivus is formed by which bones?
The occipital and the sphenoid bones
Which cranial nerve nuclei are positioned in the lateral recess near the foramen of Luschka?
The dorsal and ventral cochlear nuclei of CN VIII
What are the cirvumventricular organs?
Pineal gland, subforniceal organ, organum vasculosum of the lamina terminalis, median eminence of the hypothalamus, neurohypophyis, area postrema, and subcommissural organ
The atrium of the ventricle is deep to which cortical structure?
Supramarginal gyrus
Two pairs of small swellings can be seen in the floor of the 4th ventricle, the lateral and medial ridges. What do these structures represent?
The lateral ridges constitute the vagal trigone and indicate the location of the underlying dorsal motor nucleus of the vagus.
The medial ridges constitute the hypoglossal trigone and indicate the location of the underlying hypoglossal nucleus
Where in the brain are the cholinergic neurons found?
The basal nucleus of Meynert.
Abnormalities of this area have been found in patients with Alzheimer’s
Where are the NE-containing neurons found in the brain?
Locus ceruleus
Embryologic origin of the meninges?
The pia and arachnoid layers are formed from ectoderm while the dura is formed from mesoderm.
How much CSF is produced each day?
About 450 mL.
There is only about 150 mL of CSF in the body at any one time.
What separates the interpeduncular cistern from the chiastmatic cistern?
The Liliequist membrane which is an arachnoidal sheet extending from the dorsum sellae to the anterior edge of the mamillary bodies.
Which area of the hippocampus is most vulnerable to hypoxia?
CA1, also called Sommer’s sector.
The CA3 area is relatively resistant to hypoxia
What makes up the neostriatum?
The caudate and putamen
The gustatory area receives input from which nucleus?
The ipsilateral nucleus soliatarius
What deficit would result from a lesion of the right Meyer’s loop?
Left upper quadrantanopia
What clinical finding is seen when there is a lesion of the posterior part of the middle frontal gyrus?
Conjugate eye deviation toward the ipsilateral eye.
This is area 8, the cortical lateral conjugate gaze center.
Stimulation of this area results in eye deviation toward the contralateral side.
The hypothalamus receives fibers from the amygdala via which bundle?
Stria terminalis
Where in the internal capsule do the corticobulbar fibers run?
The genu of the internal capsule
Where in the internal capsule is the corticospinal tract located?
The posterior limb of the internal capsule
What is the main neurotransmitter of the corticothalamic tracts?
Glutamate
Where is the satiety center?
Medial hypothalamus.
Stimulation of this area results in decreased food intake.
Where is vasopressin synthesized?
In the supraoptic and paraventricular nuclei of the hypothalamus
Which part of the hypothalamus acts to lower the body temperature?
The anterior part.
Stimulation of this area causes dilatation of the blood vessels and sweating, which lower body temperature.
Where does the corticospinal tract originate?
The corticospinal tract originates from layer V of the cerebral cortex.
It passes through the corona radiata and posterior limb of the internal capsule.
This tract then runs in the cerebral peduncles and the pyramids of the medulla; it terminates at lamina VII in the spinal cord
What makes up the inferior parietal lobule?
The angular and supramarginal gyri.
The parietal lobe is divided into superior and inferior parietal lobules by the interparietal sulcus.
Damage to which part of the brain causes prosopagnosia?
The temporal association cortex.
Prosopagnosia is the inability to recognize familiar faces; it is caused by the impairment of pathways involved in visual processing
What makes up the inferior frontal gyrus?
The pars orbitalis, pars opercularis, and pars triangularis
Afferent fibers of the pupillary light reflex cross to the contralateral Edinger-Westfall nucleus via which structure?
The posterior commissure
Which cells give rise to the only output of the cerebellar cortex?
Purkinje cells - their signal is inhibitory
What are the middle and superior cerebellar peduncles also called?
Brachium pontis and brachium conjunctiva, respectivley
What is the other name for the inferior cerebellar peduncle?
Restiform body
What is the only afferent tract that runs through the superior cerebellar peduncle?
The ventral spinocerebellar tract.
What syndrome can be caused by a pineal region tumor?
Parinaud syndrome - this consists of upper gaze palsy, dissociated light near response, retraction nystagmus, and an absence of convergence
What is Weber syndrome?
CN III palsy with contralateral hemiparesis
This is due to an infarct in the medial midbrain
Where is the lesion located in Millard-Gubler syndrome?
At the base of the pons – this syndrome includes VII and VI nerve palsy and contralateral hemiplegia
What is the function of the red nucleus?
Maintains flexor muscle tone
Where is the vertical gaze center located?
The rostral interstitial nucleus on the MLF
Crossed nasal retinal visual fibers go to which layer(s) of the lateral geniculate nucleus (LGN)?
Layers 1, 4, and 6.
Fibers from the ipsilateral temporal hemiretina synapse in layers 2,3, and 5
Which trigeminal nucleus receives pain and temperature sensation from the face?
The spinal trigeminal nucleus.
This nucleus extends from the pons to C2 and merges caudally with the substantia gelatinosa.
This nucleus also receives input from CNs VII, IX and X
Which trigeminal nucleus receives proprioception from the face?
The mesencephalic nucleus
What does the lateral lemniscus carry?
The lateral lemniscus is the second order neuron of the auditory pathway.
It ascends in the brainstem to the inferior colliculus.
A lesion of the lateral lemniscus results in partial bilateral deafness
Which CN is most susceptible during CEA?
CN XII
What does hypoglossal nerve palsy suggest in the setting of a skull base tumor?
Hypoglossal nerve palsy may be a manifestation of tumor infiltration into the anterior portion of the ipsilateral occipital condyle
Where does the trochlear nerve decussate?
Within the superior medullary velum
What triggers a glossopharyngeal neuralgia “attack”?
Swallowing, talking, or chewing
What is Hering’s nerve?
A branch of CN IX that is the sensory limb of the carotid body.
When a chemoreceptor detects changes in blood O2 and CO2 concentration, Hering’s nerve is stimulated
What is the significance of an enlarged intervertebral foramen on radiography?
It may suggest a nerve root tumor
At what cervical level is the hyoid bone? Thyroid cartilage? Cricoid?
The hyoid bone is at the level of C3, the thyroid cartilage at C4-5, and the cricoid is opposite C6
Perioral tingling and numbness in syringobulbia is due to compression of which tract?
The spinal trigeminal tract
Which ligament is the primary restraint against atlantoaxial AP translation?
Transverse ligament
Where is the aortic bifurcation usually located?
At the mid body of L3
Loss of sensation over the webspace between the first and second toes is associated with what injury?
Injury to the deep peroneal nerve
What are the radiographic findings in acute transverse myelitis?
Radiographic findings are usually normal, possibly with increased T2 signal
What are some radiographic findings that can help distinguish infection from tumor in the spine?
A characteristic radiographic finding is that destruction of the disk space is highly suggestive of infection, whereas in general the tumor will affect primarily the body and will not cross the disk space
What is the unique feature of a far lateral disk herniation?
Unlike the usual disk herniation, a far lateral herniation impinges against the upper nerve root
Ex: a L4-5 far lateral disk herniation will produce a L4 nerve root radiculopathy
What is Spurling’s sign?
Radicular pain reproduced when the examiner exerts downward pressure on the vertex while tilting the head toward the symptomatic side.
This causes narrowing of the intervertebral foramen and reproduces the symptoms.
How dot he sympathetic fibers exit the spinal cord?
Via the ventral roots by way of the white rami communicantes
What are the symptoms of posterior interosseous neuropathy?
Finger extension weakness including the thumb with no wrist drop or sensory loss.
The posterior interosseous nerve may be entrapped at the arcade of Frohse, which is a fibrous band that the nerve goes through when it dives into the supinator muscle
Where is the site of entrapment of the suprascapular nerve?
Within the suprascapular notch beneath the transverse scapular ligament.
Entrapment results in atrophy of the infra- and supraspinatus muscles as well as deep, poorly localized shoulder pain.
This is due to the fact that this nerve carries sensation from the posterior joint capsule, but has no cutaneous representation.
Which nerve roots are usually affected in true neurogenic thoracic outlet syndrome?
The C8 and T1 nerve roots.
Thoracic outlet syndrome is most commonly due to a cervical rib or to an enlarged C7 transverse process.
What are the symptoms of anterior interosseous syndrome?
Weakness of flexion of distal phalanges of the thumb (flexor pollicis longus), index, and middle finger (flexor digitorum profundus 1 and 2).
This give the characteristic “pinch sign”.
There is no sensory loss as this is a pure motor branch of the median nerve.
What must be ruled out in a patient with wrist drop?
Lead poisoning
Where is the ligament of Struthers, what nerve may it compress, and what syndrome can compression of this nerve mimic?
The ligament of Struthers is present in a small percentage of the population and is found crossing the cubital fossa above the medial intermuscular septum.
In this area it may cause compression of the median nerve, which can mimic carpal tunnel syndrome.
In cases of median nerve compression by the ligament of Struthers, thenar numbness is more pronounced than in carpal tunnel syndrome (where the palmar cutaneous branch is spared).
Where is the arcade of Struthers, and what nerve may it compress?
The arcade of Struthers is located at the elbow near the medial head of the triceps.
It may compress the ulnar nerve at this location.
It is important in ulnar nerve transposition that the arcade of Struthers, when present, is released to prevent kinking of the ulnar nerve.
How does magnesium prevent excitotoxicity in brain injury?
Magnesium readily crosses the BBB and blocks various subtypes of calcium and NMDA channels.
What is the most abundant excitatory neurotransmitter in the brain?
Glutamate
What cellular elements compose the BBB?
Endothelial cells, astrocyte endfeet, and pericytes.
The capillary endothelial cells are connected together by tight junctions.
What happens to platelet function after SAH?
It is enhanced, leading to an increase in platelet aggregates in the cerebral microcirculation.
What happens to CBF immediately after a SAH?
It decreases.
It is thought that a disturbed balance between which peptide and molecule plays a major role in the development of vasospasm?
Endothelin-1 (vasoconstriction) and NO (vasodilatation)
What is deferoxamine?
An iron chelator.
Because ICH may result in iron toxicity to the brain, iron chelation may help to reduce brain damage in these cases.
What is S100B and how is it related to TBI?
S100B is a protein belonging to a multigenic family of low-molecular weight calcium-binding S100 proteins abundant in astrocytes.
After TBI, S100B protein is released by astrocytes - this protein may be neuroprotective and/or neurotrophic.
What is the (intracranial) Windkessel phenomenon?
The Windkessel phenomenon is the ability of the of the cerebral vasculature to expand and the ability of the CSF and venous blood to translocate to accommodate arterial pulsations and provide a smooth capillary flow in the brain.
What is the ischemic penumbra?
The term ischemic penumbra has been used to define a region in which CBF reduction has passed the threshold that leads to failure of electrical but not membrane function.
The neuron is functionally disturbed, but remains structurally intact.
What are the functions of transforming growth factor beta (TGF-B)?
TGF-B is a multifunctional polypeptide implicated in the regulation of various cellular processes including growth, differentiation, apoptosis, adhesion, and motility.
Abnormalities in the TGF-B signaling pathways are implicated in the development and progression of brain tumors.
What is the causative mutation in Crouzon syndrome?
Crouzon syndrome is caused by mutations in fibroblast growth factor receptor 2 (FGFR2) leading to constitutive activation of receptors in the absence of ligand binding.
This syndrome is characterized by premature fusion of the cranial sutures that leads to abnormal cranium shape, restricted brain growth, and increased ICP.
How does baclofen work?
Baclofen is an agonist of GABA; it reduces the release of presynaptic neurotransmitters in excitatory spinal pathways.
What is hypsarrhythmia?
A chaotic, high-amplitude, generalized EEG pattern characteristic of infantile spasms.
What is “subsidence” in relation to the aging spine?
Subsidence is the loss of vertebral column height that occurs normally with aging; it may also refer to the loss of graft height after surgery.
The use of dynamic plates allows normal subsidence to occur and may help bony fusion resulting in decreased incidence of construct failures.
What is the genetic defect in Gorlin syndrome?
Gorlin syndrome is an autosomal dominant disorder resulting from mutations in the patched (PTCH) gene that predisposes to neoplasias and widespread congenital malformations.
What is the composition of a PEEK cage?
Polyetheretherketone (PEEK) spacers have a modulus of elasticity close tot hat of cortical bone.
PEEK is a strong polymer that is able to withstand the compressive load of the vertebral column.
Its hollow center allows for packing of autologous bone.
What are common areas of leptomeningeal dissemination of tumors?
The most common areas of leptomeningeal dissemination of CNS tumors are the basilar cisterns, Sylvian fissures, and cauda equina, most likely because of both gravity and slower rate of CSF flow in these areas.
How does hypocalcemia lead to tetany?
When there is less calcium in the interstitial fluid, the Na opens sooner, so the membrane is more excitable.
In other words, hypocalcemia causes a lower threshold of membrane depolarization and action potential initiation.
How can hyperventilation induce seizures?
Hyperventilation causes a respiratory alkalosis, which increases the pH.
Increasing pH increases the membrane excitability and can induce seizures.
What are the two types of acetylcholine receptors?
Nicotinic - located in the neuromuscular junction and preganglionic endings of both sympathetic and parasympathetic fibers.
Muscarinic- found in all postganglionic parasympathetic endings and the postganglionic sympathetic endings of sweat glands.
What are the two main inhibitory neurotransmitters of the CNS?
GABA and glycine
What is hyperaglia?
This is increased sensitivity to pain (decreased pain threshold).
This can occur by either increased sensitivity of the receptors, by facilitation in the spinal cord, or thalamic lesions.
What is thalamic pain syndrome?
AKA Dejerine-Roussy syndrome.
This is usually due to a posteroventral thalamic stroke and its abnormal subsequent facilitation of the medial thalamic nucleus.
These patients usually have a contralateral hemianesthesia at first, with increased pain in that area in the following weeks to months.
What does a muscle spindle detect?
It detects length and velocity of change in the length of the muscle.
It is in parallel with the muscle fibers and is stimulated by stretching.
It increases firing with muscle stretch and decreases firing with muscle contraction.
What causes decerebrate posturing?
This is caused by a lesion between the pons and the midbrain.
This results in blockage of normal stimulation input to the medullary reticular formation from the red nucleus, basal ganglia, and cortex.
As a result, there is unopposed antigravity muscle tone that is stimulated by the lateral vestibular nucleus and pontine reticular nucleus.
What is the MOA of the nitrosoureas (BCNU, CCNU)?
These widely used chemotherapy agents in patients with malignant brain tumors are alkylating agents.
They alkylate DNA in multiple locations causing cross-links and often produce single or double stranded DNA breaks, which eventually lead to tumor cell death.
How does temozolamide work?
Temozolamide works by attaching a methyl group to the DNA base guanine.
This attachment prevents proper DNA replication and leads to cell death.
What is MGMT?
MGMT is a DNA repair enzyme that can remove the methyl group placed by temozolamide, thereby negating the cytotoxic effects of temozolamide.
Therefore, patients who express low levels of MGMT respond better to temozolamide.
What is the effect of sleep deprivation on the autonomic system?
Sleep deprivation increases sympathetic output and decreases parasympathetic output.
What is the Hering-Breuer inflation reflex?
This is a reflex that is stimulated by stretch receptors in the bronchi and bronchioles.
The afferent arm of the reflex is via the vagus nerve and inhibits the dorsal respiratory nucleus in the dorsal medulla to stop inspiration if the lungs are overly distended.
What causes vasogenic edema?
Vasogenic edema is caused by increased BBB permeability to proteins and macromolecules.
This type of edema is extracellular and is caused by vessel damage and inflammation.
What causes cytotoxic edema?
Cytotoxic edema is caused by an impaired Na/K pump as occurs in ischemia.
Water and electrolytes accumulate inside the cells.
It is an intracellular type of edema.
What are the visual field findings in patients with ischemic optic neuropathy?
Ischemic optic neuropathy is the most common cause of painless monocular blindness in the elderly.
This is caused by occlusion of the central retinal artery.
This causes an altitudinal field deficit.
What medications increase the level of Dilantin?
Cimetidine, coumadin, isoniazid, and sulfa drugs.
What is ideomotor apraxia?
This is the inability to perform a complex motor task despite the awareness of the task.
These patients can perform many complex tasks automatically, but cannot perform the same acts on command.
This condition is caused by a lesion of the supramarginal gyrus of the dominant parietal lobe.
What lesions can produce a head tilt?
CN IV palsy, anterior vermis lesion, tonsilar herniation.
In myasthenia, the head tilts back.
What is the term for the vermicular movement of the face in a patient with pontine demyelination?
Myokymia
What disorders can benefit from DBS of the ventral intermediate thalamic nucleus?
Essential tremor and parkinsonian tremor
What region of the internal capsule may be affected in a patient with dysarthria and clumsy-hand syndrome?
The genu
What do lesions of the bilateral hippocampi produce?
Recent memory impairment
What is the name of the area involved with cortical inhibition of bladder and bowel voiding that is damaged in NPH?
The paracentral lobule
If there is a problem with pupillary response, where is the lesion in relation to the lateral geniculate body?
Anterior to the lateral geniculate body
What are some causes of circumoral paresthesia?
Hypocalcemia, hyperventilation, syrignobulbia, and neurotoxin fish poisoning
What diseases may manifest as facial myokymia?
Intrinsic brainstem glioma or MS
What are the major signs and symptoms of lateral medullary infarction?
Vertigo, nausea, vomiting, intractable hiccups, diplopia, dysphagia, dysphonia, ipsilateral sensory loss of facial pain and temperature, ipsilateral Horner’s, contralateral pain and temperature loss of the limbs and trunk
What differentiates ptosis from CN III palsy from ptosis in Horner’s?
Horner syndrome ptosis is partial and disappears on looking up
What are conditions that may result in upgaze palsy?
Tumor on the quadrigeminal plate or pineal region (Parinaud syndrome), hydrocephalus or other causes of elevated ICP, Guillain-Barre, myasthenia, botulism, hypothyroidism
What is the diagnosis (until proven otherwise) of an adult patient who presents with recurrent meningitis without any other predisposing conditions?
CSF fistula.
Recurrent meningitis in an infant may be a manifestation of basal encephalocele.
A cherry red spot in the retina is seen in which conditions?
Tay-Sachs
Niemann-Pick
Pseudo-Hurler syndrome
Retinitis pigmentosa is seen in which conditions?
Friedreich ataxia
Refsum disease
Cockayne syndrome
Kern-Sayre syndrome
What is Melkersson-Rosenthal syndrome?
Triad of recurrent orofacial edema, recurrent CN VII palsy, and lingua plicata.
What is Ramsay-Hunt syndrome?
Herpes zoster oticus
Third most common cause of CN VII palsy
What is Heerfrodt syndrome?
Uveoparotid fever
CN VII palsy in sarcoidosis
Bilateral CN VII palsy is indicative of which disease?
Lyme disease
What is Millard-Gubler syndrome?
Ipsilateral CN VI and VII palsy and contralateral hemiparesis
What is Brissaud-Sicard syndrome?
Ipsilateral CN VII hemispasm and contralateral hemiparesis
What is Foville syndrome?
Ipsilateral CNs VI and VII involvement and horizontal gaze paralysis with contralateral hemiparesis
What is Panayiotopoulous syndrome?
Benign occipital lobe epilepsy in children
What is the most common side effect of mannitol?
Renal failure
What is the most common cause of SAH?
Head trauma
What is the most common cause of CSF leakage?
Head trauma
Having a skull fracture doubles the patient’s risk of CSF leak.
How can one differentiate if nasal drainage is CSF or nasal secretion?
The primary distinction is the glucose level.
Glucose is present in the CSF (at 50% of serum levels) and not present in nasal drainage.
Beta-2 transferrin can confirm the presence of CSF
What is the major cause of spontaneous intracranial hypotension?
Spontaneous CSF leaks.
Diffuse pachymeningeal enhancement on MRI is the most common finding.
What are the areas most prone to DAI after head trauma?
Corpus callosum and superior cerebellar peduncle.
What range of cerebral perfusion pressures are accommodated by cerebral autoregulation?
60-160 mmHg
CPP should be maintained above what number after a severe head injury?
70 mmHg
Where on the carotid artery is the most common location for a traumatic aneurysm?
Most traumatic aneurysms of the carotid artery are located on the segment between the proximal and distal dural rings.
They are pseudyaneurysms that may project medially into the sphenoid sinus.
They may present with the classic triad of head injury with basal skull fracture, unilateral visual loss, and epistaxis.
What are the prerequisites for a growing skull fracture?
- The skull fracture occurs in infancy or early childhood
- There is a dural tear at the time of the fracture
- There is brain injury at the time of the fracture with displacement of leptomeninges and possibly brain through the dural defect
- There is subsequent enlargement of the fracture to form a cranial defect
What are some cases where hyperemia of the brain can occur?
Head trauma, after CEA or stenting, and after excision of an AVM
What is the most common site of hypertensive cerebral hemorrhage?
Putamen
What are the signs and symptoms of Addisonian crisis?
Addisonian crisis is an adrenal insufficiency emergency with symptoms of mental status changes and muscle weakness.
Signs of postural hypotension, shock, hyponatremia, hyperkalemia, hypoglyecemia, and hyperthermia may be seen.
What is neurogenic pulmonary edema?
Neurogenic pulmonary edema is associated with SAH, head trauma, and seizure disorder.
It is caused by an increased capillary permeability in the lungs associated with an increased sympathetic discharge.
What is the name of a cystic tumor of the suprasellar region that arises from neuroectodermal remnants of Rathke pouch?
Craniopharyngioma
What preoperative medication can lessen general and cardiac risks in patients with a GH secreting tumor?
Somatostatin analogue
Which type of lesion can present with calcification in the sella area and erode through the posterior clinoids?
Craniopharyngioma
Erosion of the posterior clinoids may also occur from chronic increases in ICP.
What type of tumor can erode the internal acoustic meatus?
Acoustic schwannoma
What type of tumor can erode the petrous apex?
Trigeminal schwannoma
What type of tumor can erode the clivus?
Chordoma
What type of tumor can erode the sellar floor?
Large pituitary tumors
What type of tumor can erode the orbital foramen?
Optic nerve glioma
What type of tumor can erode the jugular foramen?
Glomus jugular tumor
What disease may produce generalized bone erosion? Generalized hyperostosis?
Multiple myeloma produces generalized bone erosion.
Paget disease usually results in generalized hyperostosis.
Meningiomas results in focal hyperostosis.
What is the most common extradural neoplasm involving the clivus?
Chordoma
What is the most common site of origin for chordomas?
Sacrum
What is the second most common site of origin for chordomas?
Clivus
Prophylactic cranial irradiation may be considered part of the standard treatment of patients with what disease?
Small cell lung carcinoma
Where are colloid cysts found?
The anterior roof of the 3rd ventricle
What is the most common intraorbital tumor found in adults?
Cavernous hemangioma.
These are benign, slow-growing vascular lesions.
They manifest as a painless, progressive proptotic eye.
What is the second most common type of intracranial schwannoma?
Trigeminal schwannoma
What is the most common presentation of a choroid plexus tumor?
Intracranial hypertension
What are the differences in location of a choroid plexus papilloma between an adult and a child?
Choroid plexus papillomas are rare benign tumors of the CNS that occur mostly in children.
These tumors are usually found in the left lateral ventricle in children and the 4th ventricle in adults.
What is the significance of elevated choline peaks and reduced NAA levels in spectroscopic evaluation of brain tumors?
Increased choline levels indicate increased membrane turnover.
NAA (which reflects neuronal integrity) is reduced in tumors.
What CSF tumor marker is positive in germinomas?
Placental alkaline phosphatase
Which pineal region tumor is most sensitive to radiation?
Germinoma
What serum marker should you look for in a patient with a pineal region tumor?
B-HCG and AFP because these neoplasms are of germ cell origin.
B-HCG is elevated in choriocarcinomas.
AFP is elevated in embryonal carcinomas and yolk sac tumors.
What are the 3 most common focal brain lesions in HIV?
Toxoplasmosis, primary lymphoma, and progressive multifocal leukoencephalopathy (PML)
What modality can distinguish primary lymphoma of HIV from other focal mass lesions associated with HIV?
A 18-FDG PET scan.
Lymphomas have a higher uptake than toxoplasmosis or PML.
What diagnostic test is recommended for a pediatric patient with a posterior fossa tumor?
MRI of the spine to rule out drop mets
What is Collin’s law?
Collin’s law (or rule) states that a congenital tumor may be considered cured if it does not recur within a period equal to the person’s age plus 9 months after surgery.
Where do meningiomas arise from?
Arachnoid cap cells present in the arachnoid granulations (convexity meningiomas) and in the arachnoid layers of the meninges (for non-convexity meningiomas)
How do meningiomas of the foramen magnum present?
Pyramidal weakness initially affecting the ipsilateral arm, followed by the ipsilateral leg, spreading to the contralateral limbs when the tumor enlarges.