Flash card review
What is the origin and branches of the mengingohypophyseal trunk?
Origin: usually arises from the posterior aspect of the central third of the posterior bend of the ICA at the level of the dorsum sella.
Branches: tentorial artery (Bernasconi and Cassinari), the dorsal meningeal artery, and the inferior hypophyseal artery.
Alpha motor neurons are most commonly found in which Rexed lamina?
Rexed lamina IX, which is located in the ventral motor areas of the gray matter.
Fibers in layer 1 (Rexed lamina)
Marginal zone, fast pain (A-delta) and temperature fibers.
Fibers in layer 2 (Rexed lamina)
Substantia gelatinosa, slow pain (C fibers)
Fibers in layer 4 (Rexed lamina)
Nucleus propius, interneurons to thalamus
Fibers in layer 7 (Rexed lamina)
Contains the zona intermedia
Fibers in layer 9 (Rexed lamina)
Alpha and gamma motor neurons
The dentate nucleus receives its blood supply from the:
SCA (also supplies the other deep cerebellar nuclei and SCP)
What is the location of the nucleus accumbens?
The nucleus accumbens is located in the rostral and basal forebrain at the point where the head of the caudate meets the putamen.
What is the line of Gennari?
Subcortical white matter tract in the occipital lobe that carries visual fibers.
Vascular territory of the anterior choroidal artery?
AchA supplies the optic tract and the inferior portion of the posterior limb of the internal capsule
Vascular territory of the ophthalmic artery?
The ophthalmic artery supplies the retina via the central retinal artery and the dura mater of the planumsphenoidale via the ethmoidal branches.
Distal to the brainstem, how many segments does the facial nerve have?
The facial nerve consists of five segments: cisternal, meatal, labyrinthine, tympanic, and mastoid.
Winging of the scapula may result from injury to what 3 nerves and their corresponding muscles?
- Long thoracic nerve - serratus anterior.
- Dorsal scapular nerve - rhomboid.
- Spinal accessory - trapezius.
What is innervated by the dorsal scapular nerve?
Purely motor which supplies the levator scapule and the major and minor rhomboids.
What are the boundaries of the thoracic inlet?
Base: 1st rib.
Anterior: Scalenus anticus.
Posterior: Scalenus medius.
Injury to the radial nerve proximal to the elbow results in what?
- Paralysis of brachioradialis.
- Complete wrist drop.
- Digital extensor paralysis.
- Sensory deficit over dorsum of the radial side of the hand.
What ligament forms the boundary of the cubital tunnel floor?
Ulnar collateral ligament.
What ligament forms the boundary of the cubital tunnel roof?
The roof of the cubital tunnel is the arcuate ligament (aka Osborne’s ligament) connecting the two heads of the flexor carpi ulnaris between the medial epicondyle and the olecranon.
What 3 sites along the median nerve are potential points of compression?
- Between the two heads of the pronator teres.
- Beneath the lacertus fibrosus (bicipital aponeurosis).
- Beneath the tendinous origin of the flexor digitorum superficialis.
Lordosis in the cervical spine approximates:
The normal cervical spine approximately 14.4 degrees of lordosis from C2 to C7.
Arterial supply to the pituitary?
Most pituitary arterial flow is from both the inferior hypophyseal artery (from the meningohypophyseal artery) and the superior hypophyseal artery (from the supraclinoid ICA).
What does the transverse crest separate?
The transverse crest separates the facial nerve and superior vestibular nerve from the cochlear and inferior vestibular nerve.
What does Bill’s bar separate?
Bill’s bar separates the facial nerve from the superior vestibular nerve.
What are the branches off the ICA?
CV MICO SPAAM
- Caroticotympanic artery.
- Vidian artery.
- Meningohypophyseal trunk (posterior trunk) - 3 main branches (tentorial artery of Bernasconi and Casinari, inferior hypophyseal artery, and dorsal meningeal trunk).
- Inferior cavernous sinus artery - lateral trunk.
- Capsular artery of McConnel - medial trunk.
- Ophthalmic branch.
- Superior hypophyseal artery.
- PCOM.
- Anterior choroidal.
- ACA.
- MCA.
What are the branches off the ECA?
SALFOPS I-max
- Superior thyroid.
- Ascending pharyngeal.
- Lingual.
- Facial.
- Occipital.
- Posterior auricular.
- Superficial temporal.
- Internal maxillary artery.
Describe the central artery of Percheron.
The central artery of Percheron arises from the first segment of the PCA and gives rise to bilateral medial thalamic perforators. Occlusion results in bilateral paramedian thalamic infarctions.
These patients typically present with weakness, vestibuloocular and ophthalmoplegic abnormalities. Visual fields remain intact.
What are the borders of Kawase’s triangle?
Anteromedial boundary is formed by the lateral edge of the trigeminal nerve.
Anterolateral boundary is formed by the greater superficial petrosal nerve.
Posterior boundary is formed by the internal auditory canal or a line connecting the hiatus fallopii to the dural ostium of Meckel’s cave.
What are the borders of Trautmann’s triangle?
Located in the posterior fossa.
Medial to the sigmoid sinus.
Superior to the jugular bulb.
Inferior to the superior petrosal sinus.
What are the borders of Macewen’s triangle?
External auditory meatus, inferior temporal line, and the suprameatal line (spine of Henle).
What are the borders of Glasscock’s triangle?
Line from the foramen spinosum to the facial hiatus, the greater superficial petrosal nerve and the mandibular nerve.
What is the most common location for dural AV malformations?
The region of the transverse sigmoid sinus junction accounts for the majority of dural AV malformations (around 63%).
The superior sagittal sinus is a relatively uncommon location (only about 7%).
Borden classification: type 1 dural AV fistulas.
No venous sinus outflow restriction and drain only through sinuses in an anterograde fashion.
Borden classification: type 2 dural AV fistulas.
Some degree of venous restriction that causes some anterograde or retrograde flow and subarachnoid venous drainage.
Borden classification: type 3 dural AV fistulas.
Drain only through subarachnoid veins.
Which cranial nerve(s) pass through the anteromedial pars nervosa?
NERVOUS NINE.
CN IX is located in the anteromedial pars nervosa.
Which cranial nerve(s) pass through the posterolateral pars venosa?
CNs X and XI pass through the posterolateral pars venosa.
Major neurotransmitter in the substantia nigra?
Dopamine
Major neurotransmitter in the dorsal raphe nucleus?
Serotonin
Major neurotransmitter in the locus ceruleus?
Norepinephrine
Major neurotransmitter in the basal nucleus of Meynert?
ACh
Major neurotransmitter in Golgi type II interneurons, substantia innominata?
GABA
Afferent limb of the pupillary reflex?
CN II
Afferent limb of the corneal and tearing reflex?
CN V1
Afferent limb of the gag reflex?
CN IX
Afferent limb of the cough reflex?
CN X
Afferent impulses from the carotid baroreceptor are transmitted primarily to which nucleus?
Afferent impulses from the carotid body are transmitted through the inferior ganglion (petrosal ganglion) to the nucleus tractus solitarius and paramedian nucleus then to nucleus ambiguus and dorsal motor nucleus of CN X for regulation of the heart.
Function of the dorsal motor nucleus of CN X?
The dorsal motor nucleus of CN X provides parasympathetic input to the vagus nerve to the thorax and abdominal viscera up to the splenic flexure of the colon.
Damage to the superior laryngeal nerve causes?
Low tone of voice.
Damage to the recurrent laryngeal nerve causes?
Hoarseness.
The average total brain H20 content is?
Bewteen 70-80%.
What maintains flexor tone?
The rubrospinal tract maintains flexor tone. The red nucleus has input from both cerebral cortices and the contralateral cerebellar interposed nuclei (globse and emboliform).
Output is to rexed laminas V,VI, and VII to inhibit extensor activity.
Neurotransmitters of Renshaw cells?
Glycine.
Principle visceral nucleus of the brainstem?
The nucleus solitarius receives afferent visceral information from the heart, lungs, GI tract, as well as for taste.
What are the circumventricular organs?
POSS MAN
Pineal gland. Organum vasculosum of the lamina terminalis. Subforniceal organ. Subcommissural organ. Median eminence of the hypothalamus. Area postrema. Neurohypophysis.
Neural tube closure initiates at the:
During neurulation (post ovulation day 21) the neural crest starts to close at the caudal rhombencephalon and form the neural tube.
Complete neural tube closure generally occurs by 18 weeks gestation.
Schwann cells are derived from?
Neural crest cells.
Neural crest cells also give rise to ganglion satellite cells, most of the neurons of the peripheral nervous system, melanocytes, and part of the cranial mesenchyme.
During gastrulation the formation of the notochordal process begins with cells invaginating through:
Hensen’s node (primitive node) is the regional thickening of cells anterior to the primitive streak, through which gastrulating cells migrate anteriorly to form tissues in the future head and neck.
The metopic suture generally ossifies during the:
Second year of life.
The coronal suture is usually obliterated and ossifies around:
24 years of age.
The resting membrane potential is determined mainly by what ion?
Potassium.
Neurotransmitter that is found in a postganglionic sympathetic nerve terminal?
ACh and NE.
Hexamethonium blocks what receptor?
Hexamethonium is a nicotinic ACh receptor antagonist, acts by preventing ACh from binding to the cholinergic receptor.
Anterograde transport is mediated by what protein?
Kinesins.
Retrograde transport is mediated by what protein?
Dynein.
Describe the difference in the BBB in the choroid plexus compared to elsewhere.
In the choroid plexus, the BBB is primarily epithelial.
This is in contrast to the endothelial BBB that exists elsewhere.
What is the rate limiting enzyme in dopamine synthesis?
Tyrosine hydroxylase is the rate limiting enzyme for the synthesis of dopamine from tyrosine.
It is an oxidase that converts tyrosine to L-DOPA.
What neurotransmitter(s) is synthesized within synaptic vesicles?
Norepinephrine is the only neurotransmitter synthesized within synaptic vesicles.
NE is the neurotransmitter of most POST-ganglionic sympathetic neurons and also in the locus ceruleus.
What is the second messenger of all norepinephrine receptors?
All NE receptors are metabotropic receptors that use G proteins and the second messenger cAMP.
What is the rate limiting enzyme in serotonin synthesis?
Tryptophan hyrdroxylase is the rate limiting enzyme for serotonin synthesis.
Serotonergic neurons are located primarily in the raphe nuclei.
What is the mechanism of action of the cholera toxin?
Activates Gs.
What is the mechanism of action of the pertussis toxin?
Inactivates Gi.
What is the mechanism of action of lithium?
Activates Gs.
What is the mechanism of action of the tetanus toxin?
Inhibits glycine and GABA release.
What neurotransmitter is released by Renshaw cells?
Renshaw cells are inhibitory interneurons in the spinal cord.
They release glycine.
Description of Meissner capsules.
Rapidly adaptive, touch receptors.
Description of Merkel receptors.
Slowly adaptive, touch and pressure receptors.
Description of free nerve endings.
Pain receptors.
Description of Ruffini corpuscles.
Rapidly adaptive, vibration receptors.
Description of Pacinian corpuscles.
Slowly adaptive, heavy pressure receptors.
What are some potential complications of intrathecal baclofen pump overdose?
Moderate complications include hallucinations, seizure, confusion and psychotic behavior.
Severe complications include respiratory depression, coma and hypotension.
What percentage of acute SCI are associated with cervical spine fractures?
39%.
What percentage of thoracic spine injuries result in concurrent spinal cord injury?
10%.
Lundberg ‘A’ waves are a result of what?
The brain’s normal compensatory response to an increase in cerebrovascular volume secondary to dilation of vasculature.
What type of edema predominates in the early stages of TBI?
In the earliest stages of acute head injury, cytotoxic edema is the major factor responsible for intracranial hypertension.
Cytotoxic edema occurs minutes to hours after injury and is the manifestation of cellular swelling.
Vasogenic edema occurs hours to days after acute head injury and is the result of extracellular fluid permeating the disrupted endothelial lining in the brain’s capillary network.
What medical treatment options are most effective for essential tremor?
Alcohol, primidone, beta-blockers.
What is the mechanism of action of Botox?
Toxin enters the nerve terminal via endocytosis, interacts with SNARE proteins, and inhibits the vesicular release of ACh at the neuromuscular junction.
What signs/symptoms are seen in cardiogenic shock?
Increased HR, decrease in CO, decrease in SVR.
Cardiac index less than 1.8L/min/m2.
Pulmonary capillary wedge pressure greater than 18mmHg.
What organism is most likely to cause meningitis following traumatic skull fracture?
Streptococcus pneumoniae is responsible for 50-70% of all cases of meningitis occurring after traumatic skull fracture.
Describe Hallervorden-Spatz syndrome.
Involves the deposition of iron especially in the globus pallidus and retina.
Presents with dystonia, rigidity, and neurobehavioral changes.
Pathogenesis of Dandy-Walker malformation.
Malformation associated with hypoplasia of the vermis, pseudocystic 4th ventricle, upward displacement of the tentorium, torcula and lateral sinuses, and AP enlargement of the posterior fossa.
Common locations for arachnoid cysts.
Sylvian fissure (54%), CPA (17.5%), parasellar or convexity (15% each).
Galassi’s classification for Sylvian fissure arachnoid cysts: type 1.
Temporal tip, biconvex shape, communicates with subarachnoid space.
Galassi’s classification for Sylvian fissure arachnoid cysts: type 2.
Quadrilateral shape, moderate mass effect, delayed uptake of iodine contrast after cisternography.
Galassi’s classification for Sylvian fissure arachnoid cysts: type 3.
Large, rounded, severe compression with shift, no communication with subarachnoid space.
Describe a primary vein of Galen malformation.
Rare form of embryonic AV shunt located in the midline in the choroidal fissure.
It consists of multiple feeding arteries, principally the anterior and posterior choroidal arteries and the ACA, draining directly into an enlarged venous pouch.
Describe a secondary vein of Galen malformation.
Deep midline true AV malformation that drain selectively into the great vein of Galen thereby causing distention and enlargement of the vein.
These malformations result from persistent adjacent dural and parenchymal AV shunts, which lead to secondary dilation of a normally developed vein of Galen.
Mneumonic for MRI appearance of hemoglobin by stages.
Acute, subacute, chronic.
T1 - George Washington Bridge (gray, white, black).
T2 - oreo cookie (black, white, black).
Describe the arterial pathophysiology of chronic HTN.
Serum proteins accumulate in the basement membrane and cause collagen deposition, hyalinization of the media, atrophy of the muscularis layer, vessel dilatation or stenosis, and fatty macrophage accumulation occurs commonly (lipohyalinosis).
Common sites for hypertensive intraparenchymal hemorrhage.
Putamen (60%), thalamus (20%), pons (10%), cerebellum (5%), and subcortical (2%).
Ocular manifestation of putamen hemorrhages.
Eyes deviate toward the lesion.
Ocular manifestation of thalamic hemorrhages.
Persistent downgaze.
Ocular manifestation of cerebellar hemorrhages.
Eyes deviate away from the lesion.
Ocular manifestation of pontine hemorrhages.
Fixed, pinpoint pupils.
What is the most common site of origin for juvenile angiofibromas?
Posterior nasopharynx.
The fossa of Rosenmuller is a well established site of origin of angiofibromas.
Describe cavernous angiomas.
Benign tumors commonly present with seizures, hemorrhage, and stroke.
Angiographically occult.
Hamartomatous vascular anomalies characterized by densely packed and grossly enlarged immature capillaries without intervening neural tissue.
Mnemonic for sellar/parasellar masses.
TACHMOS.
Teratoma, adenoma/aneurysm, craniopharyngioma, hypothalamic glioma/hamartoma, mets, optic glioma, sarcoid.
Tumors associated with gelastic seizures.
Hypothalamic hamartomas.
Most common location of central neurocytomas.
About 3/4 occur in the lateral ventricles along the septum pellucidum with the foramen of Monro.
Other 1/4 occur in the 3rd ventricle.
Immunohistochemistry stain that is positive in central neurocytomas.
Synaptophysin.
Describe age and common location for pleomorphic xanthoastrocytomas.
Mainly affects children and young adults, and is most commonly found in the temporal lobe.
Describe age and common location for desmoplastic infantile gangliogliomas.
They occur before 18 months. Typically present as massive frontal cystic lesions.
Most common presentation of mesial temporal sclerosis.
Complex partial seizures.
DWI and ADC signals in arterial occlusion and ischemia.
Hyperintense on DWI, hypointense on ADC.
DWI and ADC signals in venous occlusion and thrombosis.
Hypointense on DWI, hyperintense on ADC.
DDx for solitary lytic lesions in the skull.
Metastatic lesion, myeloma, fibrous dysplasia, TB, trauma, histiocytosis X, osteomyelitis, leptomeningeal cyst, and epidermoid/dermoid.
Appearance of eosinophilic granuloma in the skull.
Lytic lesion with well delineated non-sclerotic margins and beveled edges.
Most common tumor of pineal recess?
Germinoma.
What tumor can be followed with B-HCG levels?
Choriocarcinoma.
What tumor can be followed by APF levels?
Endodermal sinus tumor.
What tumor can be followed by CEA levels?
Teratomas.
What are the 3 distinct anatomic locations of brainstem gliomas?
- Pontine (diffuse intrinsic 50%).
- Tectal (exophytic, 20%).
- Cervicomedullary (focal 20, 10%).
Damage to the upper motor neuron pathway for CN VII causes…
Weakness in the CONTRALATERAL lower face.
“Forehead sparing” is due to the bilateral innervation of the superior face.
Damage to the lower motor neuron pathway for CN VII causes…
Weakness in the entire IPSILATERAL face.
Cerebellar proprioception is under what control?
The cerebellum is responsible for UNCONSCIOUS proprioception.
It receives input from the dorsal nucleus of Clark (Rexed’s layer 7). This info travels through the ipsilateral dorsal spinocerebellar tract.
What system is responsible for conscious proprioception?
The dorsal column-MLF system.
Function of the superior olive.
The superior olivary nucleus’ primary input is derived from the bushy cells of bilateral anterior ventral cochlear nuclei. This input occurs primarily via the ventral acoustic stria. Its output is to the lateral lemnisci.
The superior olivary nucleus is the first point where binaural input is combined.
Wave forms in brainstem auditory evoked responses.
Wave 1 - auditory nerve. Wave 2 - cochlear nuclei (pons). Wave 3 - superior olivary complex. Wave 4 - lateral lemniscus. Wave 5 - inferior colliculus. Wave 6 - medial geniculate nucleus. Wave 7 - auditory radiations (cortex).
What system is monitored via somatosensory evoked potentials?
Dorsal column system.
Erb’s point for somatosensory evoked potentials.
N9 (supraclavicular region).
What tract regulates extensor tone?
The lateral vestibulospinal tract regulates extensor tone through the lateral vestibular nucleus.
The vestibulospinal tract arises from the lateral vestibular nucleus (i.e. Deiter’s nucleus) and descends bilaterally in the anterior part of the lateral funiculus.
What tract regulates flexor tone?
Flexor activity is regulated by the rubrospinal tract from the red nucleus.
The rubrospinal tract arises from magnocellular neurons in the red nucleus and crosses at the ventral tegmental decussation. Stimulation of the red nucleus leads to excitation of contralateral flexor alpha motor neurons and inhibition of extensor alpha motor neurons.
The predominant neurotransmitter of the pedunculopontine nucleus is?
Acetylcholine.
Function of the pedunculopontine nucleus?
One of the main components of the reticular activating system.
Functions include arousal, attention, learning, reward, and locomotion. Also implicated in the generation and maintenance of REM sleep.
Nimodipine blocks what calcium channel?
L-type.
What level should be measured to check for acromegaly?
Elevated IGF-1 levels almost always suggest acromegaly.
Treatment of the rhythmic involuntary movements seen in chorea?
Decreasing dopaminergic tone.
What is the most common endocrinologic abnormality associated with lymphocytic hypophysitis?
Low ACTH secretion.
Dopamine secretion is stimulated by what?
Thyroid releasing hormone, prolactin, and vasoactive intestinal peptide (VIP).
What symptom/sign is not found in variant CJD but is found in sporadic CJD?
Periodic sharp wave complexes on EEG.
What scan can be used when deciding whether Horner’s syndrome is congenital?
Family albumin tomography (FAT Scan).
Lack of sensory loss, presence of a “pinch sign” and hand weakness is characteristic of what?
Anterior interosseus syndrome.
Anomic aphasia.
Characterized by the inability to recall proper names and names of objects.
Conduction aphasia.
Characterized by relatively impaired repetition of speech, accompanied by some difficulty in naming and some comprehension impairment.
Transcortical sensory aphasia.
Comprehension is impaired, output is fluent and may even include jargon, and repetition is relatively good.
Transcortical motor aphasia.
Comprehension and repetition are very good, but spontaneous speech output is impaired.
Definition of echolalia.
The near mandatory tendency to repeat what has just been said by another person.
Definition of palilalia.
Repetition of the last word.
Definition of logoclonia.
Repetition of the last syllable.
Definition of logorhea.
Meaningless outpouring of words.
Definition of phatosomia.
Persistent “medicine-like” smell present even in the absence of a stimulus.
It is typically seen after head injury.
Definition of cacosmia.
Imagining of unpleasant odors, particularly putrefactive odors.
Definition of parosmia.
Distortion of the sense of smell, as in smelling odors that are absent.
Symptoms of Millard-Gubler syndrome.
Abducens and facial nerve paralysis as well as contralateral hemiplegia of the extremities.
It involves unilateral damage to the inferior pons, commonly by pontine infarction or hemorrhage.
Difference between akathisia and tardive dyskinesia.
Akathisia is a subjective disorder characterized by a desire to be in constant motion resulting in an inability to sit still and a compulsion to move. It develops early in treatment (days). It is reversible and can be treated with benztropine and trihexyphenidyl.
Tardive dyskinesia is an involuntary disorder characterized by repetitive purposeless movements which typically involve the buccolingual masticatory areas. Presents weeks to months after treatment and is usually irreversible.
Tardive dyskinesia is caused by blockage of what receptor?
Dopamine.
What are risk factors for pseudotumor cerebri?
- Plump females.
- Tetracycline.
- Cyclosporine.
- Steroid withdrawal.
Describe PML.
PML is a subacute demyelinating disease of the CNS caused by the JC virus.
Progressive FND is the clinical hallmark.
Extremity weakness and disturbance of speech are the most common symptoms.
Describe cavernous malformations.
May be inherited or sporadic and consist of variable sized sinusoids or cavernous spaces between capillaries.
Unlike AVMs and capillary telangiectasias, they have NO intervening brain tissue between the vascular spaces.
When can fibrillations be seen on EMG after nerve transection?
10-25 days after axon death.
In neuropathic disorders the motor unit potentials on EMG would most likely show what?
Motor unit potentials in neuropathic disorders are polyphasic and show prolonged duration.
In myopathic disorders the motor unit potentials on EMG would most likely show what?
Motor unit potentials in myopathic disorders show large numbers of fibers with early recruitment and decreased amplitude.
Can be polyphasic (secondary to reinnervation).
Common location of aneurysms arising from PCOM?
Aneurysms almost always arise from the superior medial aspect of the PCOM.
What part of the cord is most resistant to traumatic injury?
Lateral spinal cord.
This explains why some trauma patients have sacral sparing, since the sacral fibers are more laterally located and are relatively protected by the pedicles.
Definition of isthmic spondylolisthesis.
Fracture of the pars interarticularis (2 subtypes, A and B).
What is a type IIA isthmic spondylolisthesis?
Stress fractures of the pars interarticularis.
What is a type IIB isthmic spondylolisthesis?
Also occurs from micro-fractures of the pars, however in contrast to type IIA, the pars remain intact but stretched out as the fractures fill in with new bone.
An elongated pars interarticularis would cause greater stress possibly resulting in further microfractures of the pars and thus repeating the process.
What is Morquio’s disease?
Autosomal recessive deficiency of N-acetylgalactosamine-6-sulfatase causing a build up of keratin sulfate.
Patients usually have normal intelligence, dwarfism, disabling kyphosis, platyspondyly (universal vertreba plana), anterior breaks of vertebrae/bullet shaped and a “wine glass” pelvis.
What does the anterior interosseous nerve innervate?
Flexor digitorum profundus 1 and 2, flexor pollicis longus, and pronator quadratus.
NO sensory.
What is the etiology of Froment’s sign?
Weakness of the adductor pollicis.
What is Wartenberg’s sign?
One of the earliest signs of ulnar nerve entrapment.
It is the result of weakness of the third palmar interosseous muscle which leads to an abducted posture of the pinky.
How does injury to the common peroneal nerve possibly present?
Weakness and atrophy of foot dorsifelxion, weakness and atrophy of foot eversion, sensory deficit over anterolateral foreleg and dorsum of foot.
What is the main factor in planning management for vein of Galen malformations?
Age of presentation.
Initial treatment is conservative. Embolization of a neonate is high risk and they should be treated medically (for cardiac failure) until 5-6 months of age.
What conditions are associated with vein of Galen malformations?
Atrial septal defects, patent ductus arteriosis, and pseudo-aortic coarctation.
What is the incidence of intracranial cerebral aneurysms in patients less than 19 years of age?
0.6-0.7%.
ICA bifurcation aneurysms are the most common site for aneurysms in the 16-20 year old group.
Compression fractures of the vertebral body are considered unstable if there is loss of vertebral height of?
> 50%.
What suture is affected in trigonocephaly?
Metopic
What suture is affected in scaphocephaly?
Sagittal
What suture is affected in posterior plagiocephaly?
Lambdoid
What suture is affected in anterior plagiocephaly?
Coronal
What sutures is affected in anterior brachycephaly?
Bicoronal
What sutures are affected in posterior brachycephaly?
Bilambdoid
What sutures are affected in scaphocephaly?
Sagittal and metopic
What sutures are affected in turribrachycephaly?
Bicoronal, sagittal and metopic.
Definition of coupling in consideration to the lumbar spine?
Coupling is the 3-D movement (vertebral rotations and translations in 3 dimensions) by the spine to maintain alignment.
Indications for correction of lumbar scoliotic deformity?
Progression of deformity, severe spinal or radicular pain, segmental instability, and neurologic deficits.
What is bobble head doll syndrome?
Associated with to-and-fro head oscillation in patients with suprasellar arachnoid cysts.
The head movements are accompanied by macrocephaly, ocular disturbances, psychomotor retardation, and sometimes endocrine dysfunction.
What is the choroidal type of vein of Galen malformation?
There are multiple shunts communicating with the anterior dilatation of the median prosencephalic vein.
What is the mural type of vein of Galen malformation?
AV shunt is in the wall of the dilated vein.
Describe the Magerl technique for placement of lateral mass screws.
Technique for placement of lateral mass screws BELOW C2.
Starting point is 1 mm medial and 1-2mm cephalad to the center of the lateral mass and the screw angles aiming 25 degrees laterally and 30 degrees cephalad.
For C1 lateral mass screws, the two starting points are:
- Midpoint between the medial edge of the foramen transversarium and the medial surface of the lateral mass.
- Point on the lateral mass just below the C1 posterior arch.
The screw angle should be 10 degrees medial and aimed at the anterior arch of C1.
Proper entry point when placing an odontoid screw?
At the inferior endplate of C2 in the midline, anteriorly.
What vessel can lead to major bleeding from the posterior nasal cavity during a transsphenoidal hypophysectomy?
Internal maxillary artery.
The approach to the middle third ventricle with the least risk to surrounding venous structures would be opening via the?
Tenia fornices.
What structure can be lesioned during stereotactic surgery for the treatment of essential tremor?
Ventral intermediate nucleus.
What region of the brain releases endogenous opioids upon stimulation?
Periaqueductal gray in the midbrain.
Where would the corpus callosum need to be incised in order to be directly above the foramen of Monro?
2.5 cm behind the genu.
Rod strength is proportional to what?
Diameter^3.
The strength of a screw is proportional to what?
Inside diameter^3.
How can you tell the difference between hemangioblastoma and pilocytic astrocytoma pre-operatively?
Angiography of hemangioblastoma will show a hypervascular lesion with intense and prolonged early enhancement of the mural nodule associated with dilated feeding vessels.
What is the target for DBS when treating dyskinesia?
Subthalamic nucleus.
What is the target for DBS when treating essential tremor?
Ventral intermediate (ViM) nucleus.
What is the target for DBS when treating dystonia?
Globus pallidus.
What is the order of structures traversed when doing DBS?
Thalamus, zona incerta, subthalamic nucleus, substantia nigra.
When doing DBS of the subthalamic nucleus, going posterolateral will cause what?
Dysesthesias.
When doing DBS, going anterolateral will cause what?
Tetonic muscular contraction.
When doing DBS, going dorsally will cause what?
Decrease in tremor.
When doing DBS, going medially will cause what?
Double vision, changes in pupils.
Which symptom of Parkinson’s is most improved by pallidal stimulation?
Dyskinesia can be reduced by stimulation at both globus pallidus internus (GPi) and subthalamic nucleus (89% vs 62%).
During DBS, stimulation of what structure generally improves bradykinesia of Parkinsons?
Bradykinesia tends to improve more with STN than GPi stimulation.
What structural geometrical ratio is favorable for aneurysm coiling?
High fundus to neck ratio are good candidates for coiling.
What is the percentage of hemorrhage recurrence in a ruptured cerebral aneurysm?
The rehemorrhage risk for a ruptured cerebral aneurysm is actually highest immediately post-rupture.
There is a 20% risk at 2 weeks, 50% at 6 months, and 3% per year after that.
What is the rate of rupture for an unruptured aneurysm > 10mm?
1-2% per year.
What is the rate of rupture for an unruptured aneurysm < 10mm?
0.05% per year.
What are the rates of angiographic and symptomatic vasospasm after SAH?
Angiographic vasospasm occurs in 30-70% of patients.
Symptomatic vasospasm occurs in 20-30% of patients.
What is the peak time for vasospasm after SAH?
The peak time to vasospasm is between 4-14 days.
What two vessels may be injured during temporal lobectomy and amygdalohippocampectomy?
P2 segment of PCA and the anterior choroidal.
What approach is preferred for a large tumor in the posterior horn of the lateral ventricle?
Parieto-occipital transcortical approach.
What is a common complication of L5-S1 ALIF in men?
Retrograde ejaculation is seen in 0.5-6% of men undergoing L5-S1 ALIF.
Combining orbitozygomatic extension with frontosphenotemporal craniotomy allows for treatment of what?
High basilar apex aneurysms.
What is the presentation of a grade 0 Hunt/Hess?
Unruptured aneurysm.
What is the presentation of a grade 1 Hunt/Hess?
Asymptomatic or minimal headache and slight nuchal rigidity.
What is the presentation of a grade 1A Hunt/Hess?
No acute meningeal or brain reaction, but with fixed neurologic deficit.
What is the presentation of a grade 2 Hunt/Hess?
Moderate to severe headache, nuchal rigidity, no neurologic deficit other than cranial nerve palsy.
What is the presentation of a grade 3 Hunt/Hess?
Drowsiness, confusion, or mild focal deficit.
What is the presentation of a grade 4 Hunt/Hess?
Stupor, moderate to severe hemiparesis, possible early decerebrate rigidity, and vegetative disturbances.
What is the presentation of a grade 5 Hunt/Hess?
Deep coma, decerebrate rigidity, and moribund appearance.
Treatment options for symptomatic carotid stenosis based off NASCET criteria?
- Low grade stenosis (< 50% by NASCET criteria): medical therapy (antiplatelet agents and risk factor control).
- Moderate grade stenosis (50-69%): consider patient’s risk factor profile and comorbidities.
- High grade stenosis (70-99%): CEA plus antiplatelet therapy and risk factor control/prevention.
Treatment options for asymptomatic carotid stenosis based off NASCET criteria?
> 60% stenosis: if surgical complications exceed 3%, CEA would be harmful to patient.
What are some risk factors for the development of cerebral aneurysms?
Age < 50, female, HTN, smoking and genetic predisposition.
What is the minimum platelet count for a patient undergoing a craniotomy?
50,000.
What are indications for dorsal root entry zone lesions?
DREZ is most appropriate for pain following brachial plexus and lumbosacral plexus avulsion.
Target for DBS when treating Parkinson’s disease?
Subthalamic nucleus.
Target for DBS when treating dystonia?
Globus pallidus pars interna.
Target for DBS when treating tremor?
Ventrointermediate nucleus (ViM).
What potential sites can be lesioned to treat essential tremor?
- Corticospinal tract.
- Cerebral cortex.
- Zona incerta.
- Subthalamic nucleus.
- Cerebello-ventrointermedial thalamic tract fibers.
During a subtemporal intradural transtentorial approach, which CN is protected by transecting the tentorium 1-2 cm posterior to its entry into the dural margin?
One of the key steps of the subtemporal transtentorial approach is dissection of the trochlear nerve from the edge of the tentorium.
What pathological process is seen in variant CJD?
- Kuru plaques in the cerebellum.
Hirano bodies can be seen in what disease?
- Alzheimer’s disease.
Hirano bodies are rod-shaped eosion inclusions.
What protein is responsible for the formation of Lewy bodies?
- Alpha-synuclein.
Lewy bodies are seen in Parkinson’s disease and diffuse Lewy body disease.
What percentage of Huntington’s patients have a psychiatric disorder?
- 95%.
These symptoms (most commonly depression, mania or psychosis) worsen with the progression of the disease.
What is the inheritance pattern of DYT1 hereditary dystonia?
The DYT1 gene (which maps to chromosome 9q34) is responsible for most cases of early-onset torsion dystonia in both Askenazic Jews and non-Jewish families.
This disease is inherited in an autosomal dominant mode with reduced penetrance.
What two levels of the cervical spine are most likely to show signs of degeneration?
The two most common levels to exhibit degenerative changes are C5-6 followed by C6-7.
What cord syndrome has the worst prognosis?
Anterior cord syndrome has the worse prognosis of all cord syndromes.
What is Crowe’s sign?
Multiple freckles in the axillary or inguinal region seen in neurofibromatosis patients.
What conditions can cause atrophy of type 1 muscle fibers?
- Myotonic dystrophy.
2. Congenital myopathy.
What conditions can cause atrophy of type 2 muscle fibers?
- Steroids.
- Myasthenia.
- Denervation.
- Muscle disuse.
- Paraneoplastic syndrome.
What is Foix-Alajouanine syndrome?
- Foix-Alajouanine syndrome refers to the necrotizing myelopathy that follows acute thrombosis of a spinal AV malformation.
- Most commonly affects the lower thoracic and/or lumbosacral levels.
Classic features of transverse myelitis?
- Weakness of the arms and legs.
- Pain.
- Sensory alteration.
- Bowel and bladder dysfunction.
Classic CT findings of osteoid osteoma?
- Lytic lesion with sclerotic margin and a centrally calcified nidus.
- Classically lumbar neural arch.
Malignancies associated with NF1?
- Optic gliomas.
- Brainstem gliomas.
- Malignant peripheral nerve sheath tumors.
- Pheochromocytoma.
- Leukemia.
Before what does a cerebral insult need to occur to cause cerebral palsy?
- 2 years.
What are the 4 main types of cerebral palsy?
- Ataxic - voluntary movements are jerky, balance is lost.
- Athetoid - continual muscle movements prevent or severely interfere with voluntary movements.
- Hypotonic - muscles are limp, cannot contract.
- Spastic - muscles are stiff, some body parts are paralyzed.
Which type is the most common form of cerebral palsy?
- Most common is the spastic type, which involves the continuous contraction of muscle groups.
- The spastic type affects the corticospinal tract.
What is the most common presentation of cerebral palsy in preterm infants?
- Diplegia is a condition that affects movement of both lower limbs.
- This occurs due to the selective hypoxic/ischemic vulnerability of the periventricular germinal matrix.
What is the most common presentation of cerebral palsy in full term infants?
- Quadriplegia.
What is the most common pattern of inheritance for familial forms of craniosynostosis?
- Autosomal dominant.
What chromosome is affected with turribrachycephaly?
- Chromsome 7p.
2. Turribrachycephaly is a short and wide skull, may be pointed at the top.
What chromosome is affected with Kleeblattschadel?
- Chromosome 15q.
- Kleeblattschadel is a cloverleaf shaped skull as a result of fusion of all sutures except for the metopic and squamosal sutures.
Patients with vein of Galen malformations are classified based on what?
Age.
- Neonates - present in extremis with severe CHF.
- Infants - present with seizures or hydrocephalus.
- Older children and young adults - headaches or signs and symptoms of SAH.
What are the 3 proposed theories of arachnoid cyst development?
- Active CSF secretion from cyst membrane.
- Osmotic gradient from a higher protein content within the cyst fluid.
- One way ball-valve mechanism.
What are the 4 main factors that are suggestive of an underlying intraspinal anomaly in scoliosis patients?
- Curve to the left.
- Age younger than 11.
- Rapidly progressive curve.
- Angle > 50-55 degrees.
What is Currarino’s triad?
Autosomal dominant, congenital malformation that consists of the triad of:
- Sacral defect (scimitar sacrum - crescentic bony defect and malsegmentation).
- Anorectal malformation (anal stenosis, anal extopia, and imperforate anus).
- Presacral anomaly (anterior meningocele, teratoma, or cyst).
What is the incidence of Dandy-Walker malformation?
- 1 in every 25,000-30,000 births.
Characteristic features of Dandy-Walker malformation?
- Cystic dilatation of the 4th ventricle.
- Hypoplasia of the cerebellar vermis.
- Hydrocephalus.
- Large posterior fossa.
What is the most common associated CNS abnormality with Dandy-Walker malformation?
- Agenesis of the corpus callosum.
Description and treatment of type I Hangman’s fracture?
- Translation < 3mm, stable.
2. Tx: collar or halo.
Description and treatment of type II Hangman’s fracture?
- Translation > 3mm, flexion-distraction injury, unstable.
2. Tx: reduction with halo vest 12-16 weeks, if poor result then surgery with plating.
Description and treatment of type IIA Hangman’s fracture?
- Angulation < 11 degrees, ALL intact, unstable.
2. Tx: treated conservatively with traction or a halo/vest or C2 transpedicular screws.
Description and treatment of type III Hangman’s fracture?
- “Jumped facets” of C2 or C3, unstable.
- Tx: surgical reduction with wiring, possible C2 transpedicular screws or treated conservatively with traction or a halo/vest.
Most common malignant brain tumor of childhood?
- Medulloblastoma.
What layer do medulloblastomas arise from?
- Thought to arise from the external granular cell layer of the cerebellum.
Histopathological features of medulloblastomas?
- Homer-Wright rosettes - radially arranged nuclei surrounding central fibrillary material.
What are Homer-Wright rosettes?
- Radially arranged nuclei surrounding central fibrillary material.
- These are seen in medulloblastomas and neuroblastoma.
What are Flexner-Wintersteiner rosettes?
- Cuboidal or short columnar cells arranged around a central lumen.
- These are seen in medulloblastomas, retinoblastoma, and pineoblastoma.
What is Mollaret’s meningitis?
- Aseptic meningitis caused by rupture of epidermoids.
What is the diagnostic criteria of benign perimesencephalic SAH?
- The epicenter of the hemorrhage is immediately anterior to the midbrain.
- Extension of blood to the posterior part of the interhemispheric fissure is permissible.
- There may be an extension of blood to the basal part of the Sylvian fissure.
- Absence of frank amounts of intraventricular blood.
- Absence of intracerebral hematoma.
Meningiomas stain positive for what two substances?
- Vimentin and epithelial membrane antigen (EMA).
What is lymphocytic hypophysitis?
- Rare, autoimmune inflammatory lesion of the pituitary gland that commonly affects young women whom are in the late pregnancy or postpartum period.
- Overall mortality rate is 8% with most women dying of adrenal insufficiency.
What layers of the hippocampus are most susceptible to hypoxic injury?
- CA1 (Sommer’s sector) and CA4.
What layers of the cortex are most susceptible to hypoxic injury?
- Watershed area - parieto-occipital layers 3, 5 and 6.
What structures of the basal ganglia are most susceptible to hypoxic injury?
- Caudate and putamen.
What cells of the cerebellum are most susceptible to hypoxic injury?
- Purkinje cells.
What layer of the hippocampus is most resistant to hypoxic injury?
- CA2.
What is the most common location for a ruptured intracranial aneurysm?
- ACOM (30%), followed by PCOM (20%), and then the MCA (13%).
What is the 5 year cumulative risk of rupture of an aneurysm < 7mm in the anterior circulation, in patients with NO SAH?
0%.
What is the 5 year cumulative risk of rupture of an aneurysm < 7mm in the anterior circulation, in patients with previous SAH?
1.5%.
What is the 5 year cumulative risk of rupture of an aneurysm < 7mm in the posterior circulation, in patients with previous SAH?
3.4%
What is the 5 year cumulative risk of rupture of an aneurysm < 7mm in the posterior circulation, in patients with NO SAH?
2.5%.
What is the rebleed rate after SAH during the first 24 hours?
4%.
What is the daily rebleed rate after SAH from day 2-14?
1%.
What is the total bleed rate after SAH from day 2-14?
17%.
What is the most common location for an unruptured aneurysm to be found?
MCA.
What are the rates of re-bleeding after aneurysmal SAH in the first 24 hours? Up to 2 weeks? Within the first year after a SAH?
- 4% in the first 24 hours.
- 1.0-1.5% per day - days 2-14.
- 50% at 6 months, then 3% per year.
What is the major cause of adult-onset hemiballism?
- Cerebrovascular disease.
- Hemiballismus is usually caused by a focal destructive lesion of the contralateral subthalamic nucleus or its connections with the GP.
What condition can manganeses toxicity present similar to?
- Manganese toxicity is associated with Parkinson-like symptoms.
Hypertrophic peripheral nerves are most commonly seen in what condition?
Leprosy.
What are the 3 cardinal histopathological features of PML?
- Demyelination.
- Enlarged nuclei of oligodendrocytes.
- Bizarre astrocytes.
What is the inheritance pattern in Sturge-Weber syndrome?
- Non-genetic, sporadic.
What is the most common genetic alteration seen in meningiomas?
- Most commonly (60% of sporadic cases) - loss of the NF-2 gene on chromosome 22q.
What percentage does the brain receive of CO, blood’s O2, and blood glucose?
- Receives 15% of CO.
- 20% of blood’s O2.
- 15% of blood glucose.
What are the effects of cingulate herniation?
- Compression of the ACA.
What are the effects of uncal herniation?
- Compression of the midbrain - coma, dilated pupil.
What are the effects of central herniation?
- Compression of the thalamus and midbrain - coma.
What are the effects of tonsillar herniation?
- Compression of the medulla - cardiorespiratory arrest
What are the 4 typical histopathological features of GBM?
- Nuclear pleomorphism.
- Endothelial hyperplasia.
- Mitotic activity (MIB-1, Ki-67).
- Central necrosis surrounded by viable tumor nuclei giving appearance of palisading which is called pseudopalisading.
Necrosis is found in GBM but NOT AA.
What is Waterhouse-Friderichsen syndrome?
- Massive, usually bilateral, hemorrhage into the adrenal glands that is caused by fulminant meningococcemia.
- Septic shock, vasomotor collapse, and DIC occur.
What is the most common cause of encephalitis in epidemics?
- Arbovirus (think mosquitos).
What is the most common cause of sporadic encephalitis?
- HSV-1.
What is the most common cause of encephalitis in the immunocomprised population?
- HIV, CMV, papovavirus.
What is the most common location for an intracranial malignant nerve sheath tumor?
- Trigeminal nerve.
What histopathological staining is present in gangliogliomas?
- Ganglioglioma is negative for epithelial membrane antigen, vimentin (positive in meningioma), and transthyretin (choroid plexus papilloma), but is positive for synaptophysin (neuronal origin) and GFAP.
Most common genetic alteration of oligodendrogliomas?
- Loss of heterozygosity of chromosome 1p and 19q is common and suggestive of a good response to chemotherapy.
Common chemo regimen for oligodendrogliomas?
- Procarbazine, lomustine (CCNU) and vincristine (PCV therapy) for anaplastic oligodendroglioma.
Where do juvenile nasopharyngeal angiofibromas usually form?
- Juvenile nasopharyngeal angiofibromas usually arise in the fossa of Rosenmuller and commonly present with recurrent epistaxis in a young individual.
What tissue are chordomas from?
- Chordomas arise from the remnants of the notochord.
What has a better prognosis between chordoma and chondrosarcoma?
- Chondrosarcoma has a better prognosis when compared to chordoma.
What two stains are positive in meningiomas?
- Vimentin and epithelial membrane antigen (EMA).
Microscopic features of Schwannomas?
- Verocay bodies, which are anuclear regions that are adjacent pallisading spindle-shaped cells found in Antoni A areas.
- Antoni A areas contain compact fusiform cells in a reticulin/collagen matrix with fascicles of cells in many planes which give the appearance of “schools of fish”.
- Antoni B areas contain round cells in a loose spongy appearance.
What stain can be used to differentiate schwannomas from meningiomas?
- S100 is markedly positive in schwannomas which help to distinguish them from meningiomas.
What tissue are schwannomas derive from?
- Neural crest cells.
What hormones are basophils in the pituitary?
- TSH, FSH, LH, ACTH.
What hormones are acidophils in the pituitary?
- PRL, GH.
How can you distinguish epidermoids from arachnoid cysts of DWI?
- Epidermoid tumors are hyperintense on DWI.
2. Arachnoid cysts are hypointense on DWI.
What cells are paragangliomas derived from?
- Paragangliomas (aka chemodectomas) arise from the glomus cells (special chemoreceptors located along blood vessels that have a role in regulating blood pressure and blood flow) and are derived from the embryonic neural crest.
What are the 4 types of paragangliomas?
- Carotid body - arise from the carotid bifurcation.
- Glomus jugulare - arise from the superior vagal ganglion.
- Glomus tympanicum - arise from the auricular branch of the vagus nerve.
- Glomus intravagagle - arise from the inferior vagal ganglion.
Pontine hemorrhages cause what pupillary finding?
- Fixed, pinpoint pupils.
What is the hemorrhagic risk per year for AVMs?
- 2-4% per year.
Cowdry type A inclusion bodies can be seen in what conditions?
- Herpes simplex and CMV.
What are Cowdry type A inclusion bodies?
- Intranuclear eosinophilic inclusions with a surrounding halo.
- They can be found in neurons, astrocytes and oligodendrocytes.
Type 1 fiber atrophy can be seen in what conditions?
- Muscle diseases including myotonic dystrophy, congenital myopathy.
Type 2 fiber atrophy can be seen in what conditions?
- Neurogenic or muscle diseases including denervation, disuse, myasthenia, steroids and paraneoplastic syndromes.
Type 1 fiber hypertrophy can be seen in what condition?
- Wernig-Hoffman disease.
Type 2 fiber hypertrophy can be seen in what condition?
- Congenita fiber-type disproportion.
What are the histopathologic findings of HIV encephalitis?
- Diagnosed by microglial nodules in the white and subcortical gray matter with focal demyelination.
- There are multinucleated giant cells that are unique to HIV encephalitis.
What is onion bulb formation and what conditions can it be seen in?
- Onion bulb formation occurs after repeated cycles of demyelination and remyelination, resulting in a thick layer of abnormal myelin around the peripheral axons.
- This can be seen in Charcot-Marie-Tooth and Refsum’s disease.
What condition can cause calcification of the basal ganglia?
- Fahr’s disease.
What condition can have Opalski cells?
- Wilson disease.
What is ulegyria?
- “Mushroom-like” atrophic gyri are due to anoxic-ischemic injury to the infant brain.
- Because of the unique vascular supply to the gyri in the newborn (greater perfusion of the apices of the gyri than to the cortex at the depth of sulci) hypoxia causes tissue loss greater in the depth of the sulci (intrasulcal atrophy) mostly in parieto-occipital regions.
What is the most frequent inherited ataxia?
- Friedreich’s ataxia.
What is the presentation of Friedreich’s ataxia?
- Ataxia, foot deformity (pes cavus), scoliosis, cardiomyopathy, blindness, deafness, and diabetes.
What are the genetic alterations in Friedreich’s ataxia?
- GAA trinucleotide repeats.
2. Frataxin gene on chromosome 9q which encodes a mitochondrial matrix protein.
What are the pathological features of Friedreich’s ataxia?
- Loss of sensory ganglion cells, dorsal nuclei (Clarke’s columns - sends fibers to dorsal spinocerebellar tract), and dentate nuclei, posterior columns (deprives the cerebellum of sensory input for coordination), spinocerebellar tracts, lateral corticospinal tracts.
What is the grading system for germinal matrix hemorrhages?
Grade 1 - confined GMH.
Grade 2 - IVH without hydrocephalus.
Grade 3 - IVH with hydrocephalus.
Grade 4 - IPH.
What is adrenoleukodystrophy?
- X-linked recessive disease due to deficiency in peroxisomal lipid oxidation.
What is the pathology in adrenoleukodystrophy?
- Accumulation of long chain fatty acids, cavitation of the parieto-occipital white matter, U-fiber sparing.
What are some causes of cerebellar degeneration?
- Phenytoin.
- Paraneoplastic syndrome.
- Down syndrome.
- Freidreich’s ataxia.
- Alcohol.
What are the genetics and symptoms of phenylketonuria?
- Autosomal recessive on chromosome 12.
- Deficiency in phenylalanine hydroxylase.
- Musty odor, MR in utero.
- Limiting the intake of phenylalanine (meat, chicken, fish, cheese, dairy) will decrease MR.
What are the genetics and symptoms of homocysteinuria?
- Autosomal recessive.
- Deficiency in methionine metabolism.
- Symptoms include MR, stroke, lens dislocation, arachnodactyly (spider fingers). Physically similar to Marfan’s but increased homocysteine in the CSF, blood and urine.
What are the genetics and symptoms of maple syrup urine disease?
- Autosome recessive.
- Decreased branched-chain amino acid metabolism.
- Usually death within 4 weeks.
What enzyme is deficient in Niemann-Pick’s disease?
- Sphingomyelinase.
What enzyme is deficient in Gaucher’s disease?
- Glucocerebrosidase.
What enzyme is deficient in PKU?
- Phenylalanine hydroxylase.
What gene is altered in Niemann-Pick’s disease?
- SMPD1.
What are the symptoms of Niemann-Pick’s?
- Cherry red macula (50%).
- Hepatosplenomegaly.
- Supranuclear paresis of vertical gaze.
- Normal head size.
What substance accumulates in Tay-Sachs disease?
- GM2 gangliosides.
What are the genetics, deficiency and symptoms of Gaucher’s disease?
- Autosomal recessive.
- Deficiency in glucocerebrosidase.
- Accumulation of glucocerebrosidases (during late childhood) in the liver, spleen, and lungs, hypersplenism with anemia and thrombocytopenia.
What do the cells look like in Gaucher disease?
- Wrinkled tissue paper appearance.
What are the genetics, deficiency and symptoms of Fabry’s disease?
- X-linked recessive.
- Deficiency in alpha-galactosidase with accumulation of ceramides.
- Symptoms include HTN, renal failure, MI or stroke (MI or stroke usually occur in the 6th decade).
What are the genetics, deficiency and symptoms of Tay Sachs disease?
- Autosomal recessive (predilection for Ashkenazi Jews).
- Deficiency of hexosaminidase A with accumulation of GM2 gangliosides.
- Symptoms: death usually occurs 6 months to 4 years of age, cherry red macula, macrocephaly without visceromegaly.
What is the pathology of Tay Sachs?
- Accumulation of GM2 gangliosides in the gray matter.
What are the genetics, deficiency and symptoms of Sandhoff’s disease?
- Autosomal recessive.
- Deficiency in hexosaminidase A and B.
- Symptoms: startle reaction, early blindness, progressive mental and motor retardation, doll-like face, cherry red macula, and macrocephaly.
Similar picture to Tay-Sachs disease but Sandhoff’s has visceral storage in the liver, spleen, kidney and heart.
What are the genetics, deficiency and symptoms of GM1 gangliosidosis?
- Autosomal recessive (onset three months of age).
- Deficiency in acid beta-galactosidase.
- Symptoms: CNS and visceral involvement with cherry red macula, bone abnormalities, contractures, dysmorphic face, and hepatosplenomeagly.
What are the genetics, deficiency and symptoms of Hurler syndrome?
- Autosomal recessive.
- Deficiency in alpha-L-iduronidase.
- Symptoms: Gargoyle face, MR, corneal opacities, conduction deafness, skeletal abnormalities, thick meninges, enlarged neurons.
What is the pathology of Hurler syndrome?
- Accumulation of mucopolysaccharides.
2. Zebra bodies - accumulation of stored gangliosides in lysosomes of the gray matter.
What are the genetics, deficiency, and symptoms of Scheie’s syndrome?
- Autosomal recessive.
- Deficiency in alpha-L-iduronidase.
- Symptoms: spinal cord compression from thickened dura, glaucoma, corneal opacities, carpal tunnel syndrome.
Milder form of Hurler’s disease with NO MR.
What are the genetics, deficiency, and symptoms of Hunter’s syndrome?
- X-linked recessive.
- Iduronate sulfatase.
- Symptoms: urine contains heparain and dermatan sulfate, skin pebbling, peripheral nerve entrapments.
What are the genetics, deficiency, and symptoms of Sanfilippo’s syndrome?
- Autosomal recessive.
- Multiple enzymes.
- Symptoms: urine contains heparin, MR, mild corneal clouding, and mild skeletal abnormalities.
What are the genetics, deficiency, and symptoms of Morquios syndrome?
- Autosomal recessive.
- Deficiency in galactose 6-sulfate and beta-galactosidase.
- Symptoms: severe skeletal abnormalities (short pedicles) with ligamentous laxities, odontoid hypoplasia, thick cervical dura, dwarfism, and osteoporosis.
What are the genetics, deficiency and symptoms of Maroteaux-Lamy syndrome?
- Autosomal recessive.
- Deficiency in arylsulfatase B.
- Symptoms: urine contains dermatan sulfate, may be compressive myelopathy and hepatosplenomegaly but NO mental retardation.
What are the genetics, deficiency, and symptoms of Sly’s syndrome?
- Autosomal recessive.
- Deficiency in beta-glucuronidase.
- Symptoms: joint stiffness, odontoid dysplasia, urine contains dermatan sulfate, heparin sulfate and chondroitin sulfate.
What are the genetics, deficiency, and symptoms of Krabbe’s disease?
- Autosomal recessive.
- Deficiency in galactocerebroside beta galactosidase.
- Symptoms: sparing of subcortical U-fibers, psychomotor delay, and microcephaly.
What is the pathology of Krabbe’s disease?
- Globoid cells with psychosine accumulation and accumulation of galactocerebroside from myelin sheaths in lysosomes.
What are the genetics, deficiency, and symptoms of metachromatic leukodystrophy?
- Autosomal recessive on chromosome 22.
- Deficiency in arylsulfatase A.
- Symptoms: psychomotor deterioration, degeneration of PNS myelin, kidney, liver and spleen damage.
What is the pathology of metachromatic leukodystrophy?
- Accumulation of sulfatides in lysosomes, sparing of subcortical U-fibers, degeneration of CNS.
What are the genetics, deficiency, and symptoms of adrenoleukodystrophy?
- X-linked recessive.
- Deficiency in lipid oxidation in peroxisomes.
- Symptoms: adrenal insufficiency, bronze skin, behavioral and intellectual deterioration, visual, auditory and motor decline.
What gene is altered in adrenoleukodystrophy?
- The gene (ABCD1 or “ATP binding cassette) codes for a protein that transfers fatty acids into peroxisomes, where the fatty acids undergo beta-oxidation.
A dysfunctional gene leads to the accumulation of very long chain fatty acids.
What is the pathological characteristic of adrenoleukodystrophy?
- Accumulation of long chain fatty acids, cavitation of the parieto-occipital white matter.
What are the genetics, deficiency, and symptoms of Pelizaeous Merzbacher disease?
- X-linked recessive.
- Defective synthesis of proteolipid apoprotein myelin basic protein needed for oligodendrocyte differenation and survival.
- Symptoms: abnormal eye movements, spasticity, ataxia, and MR.
Pelizaeous-Merzbacher disease is the only leukodystrophy with 100% incidence of nystagmus.
What is the pathological characteristics of Pelizaeous-Merzbacer disease?
- Tigroid pattern on MRI, atrophic brain with demyelination that spares perivascular white matter.
What are the genetics, deficiency, and symptoms of Canavan disease?
- Autosomal recessive.
- Deficiency in N-acetyl-aspartoacylase.
- Symptoms: macrocephaly, psychomotor regression, blindness and spasticity.
What is the pathological characteristic of Canavan disease?
- Spongy white matter degeneration with vacuoles that affect subcortical U-fibers.
What are the genetics and symptoms of Alexander’s leukodystrophy?
- Sporadic inheritance with no clear genetic transmission.
2. Symptoms: macrocephaly, mitochondrial dysfunction, psychomotor retardation and seizures.
What is the pathological characteristic of Alexander’s disease?
- Frontal lobe mainly affected with white matter demyelination and Rosenthal fibers form periventricular, perivascular, and subpial.
What are the genetics, deficiency, and symptoms of Menkes kinky hair disease?
- X-linked recessive.
- Deficiency in copper absorption in the GI tract with secondary deficiency in copper-dependent mitochondrial enzymes.
- Symptoms: brittle, twisted and colorless secondary hair growth, seizures, and MR.
What is the pathological characteristic of Menkes disease?
- Loss of neurons, tortuous vessels, and metaphyseal spurring.
Menkes disease is the opposite of Wilsons disease.
What are the genetics, deficiency, and symptoms of Leigh’s disease (aka subacute necrotizing encephalomyeloathy - SNEM)?
- Autosomal recessive or X-linked.
- Deficiency in mitochondrial cytochrome C oxidase.
- Symptoms: decreased muscle tone and head control, seizures, myoclonus, ophthalmoplegia, respiratory and swallowing problems.
What is the pathological characterstics of Leigh’s disease?
- Bilateral symmetric spongiform degeneration and necrosis of midbrain, pons, thalamus and hypothalamus.
What are the genetics and symptoms of Lowe syndrome?
- X-linked recessive, OCRL gene.
2. Symptoms: bilateral cataracts, large eyes, nystagmus, psychomotor retardation, death by renal failure.
What are the genetics, deficiency, and symptoms of ataxia telangiectasia?
- Autosomal recessive.
- Defective DNA repair (ATM gene on Chr11q22-23).
- Symptoms: CNS degeneration, ataxia, dysarthria, ophthalmoplegia, and decreased antibodies.
- Death occurs by 20 years from infection or lymphoma.
What are the genetics, deficiency, and symptoms of Lesch-Nyhan syndrome (aka Kelley-Seegmiller syndrome)?
- X-linked recessive.
- Deficiency in hypoxanthine guanine phosphoribosyltransfersae (HGPRT) enzyme with accumulation of uric acid.
- Symptoms: MR, gout, hyperuremia, self mutilation and choreoathetosis.
What is the pathological characteristic of Lesch-Nyhan syndrome?
- Tophaceous gout - nodular masses of uric acid crystals (tophi) are deposited in different soft tissues of the body.
What are the 4 peroxisome biogenesis disorders?
- Zellweger syndrome - most severe.
- Refsum disease - mildest.
- Neonatal adrenoleukodystrophy.
- Rhizomelic chondrodysplasia.
What are the genetics, deficiency, and symptoms of Zellweger syndrome?
- Autosomal recessive.
- Decreased degradative proteins in peroxisomes and secondary accumulation of very long chain fatty acids.
- Symptoms: high levels of iron and copper build up in blood and tissue and cause an enlarged liver; facial deformities such as high forehead, underdeveloped eyebrow ridges, and deformed ear lobes; neurological abnormalities such as MR and seizures. Infants lack tone.
What is the pathological characteristics of Zellweger syndrome?
- Cortical dysgenesis with white matter degeneration and hepatorenal dysfunction.
- Very long chain fatty acids are generally found in the CNS and peroxisomes of these cells can not import the necessary degradative proteins for beta-oxidation to occur.
- Decreased phytanic acid intake is recommended.
What are the genetic alterations seen in Friedreich’s ataxia?
- Autosomal recessive on chromosome 9 (codes for the Frataxin protein - it has been shown to be connected with the removal of iron from the cytoplasm surrounding the mitochondria, and in the absence of frataxin, iron builds up and causes free radical damage).
Symptoms of Friedreich’s ataxia?
- Ataxia.
2. Associated with cardiomyopathy and diabetes.
Pathological characteristics of Friedreich’s ataxia?
- Sparing of motor neurons with degeneration of axons and myelin in the posterior columns and corticospinal tracts.
- Effects are also seen in the spinocerebellar tracts, cerebellum, inferior olive and brainstem nuclei (CNs VIII, X, XII).
What are the X-linked metabolic diseases?
- Fabry’s.
- Hunter’s.
- Pelezius-Merzbacher.
- Adrenoleukodystrophy.
- Lesch-Nyhan.
- Lowe’s.
- Menke’s kinky hair.
What diseases can cause stroke in the pediatric population?
- Homocysteinuria.
2. Fabry’s disease.
What inheritance pattern is seen in Wohlfart-Kugelberg-Welander disease?
- Autosomal dominant.
What diseases elicit Parkinson’s symptoms in adolescents?
- Wilson’s disease.
2. Hallervorden-Spatz.
What diseases affect mitochondrial DNA?
- Kearns-Sayre syndrome.
- Leber’s hereditary optic atrophy.
- Leigh’s subacute encephalopathy.
- Luft’s disease.
- MELAS.
- MERRF.
Name 2 disorders of tau protein?
- Pick’s disease.
2. Progressive supranuclear palsy.
Name 2 disorders of alpha-synuclein?
- Parkinson.
2. Diffuse Lewy body disease.
Name 3 trinucleotide repeat disorders?
- Huntington’s.
- Spinocerebellar ataxias.
- Friedreich’s ataxia.
What is a type A trigeminal schwannoma (Jefferson classification)?
- Type A: arising mainly from the gasserian ganglion and the middle temporal fossa.
What is a type B trigeminal schwannoma (Jefferson classification)?
- Type B: arising from the trigeminal nerve and mainly the posterior cranial fossa.
What is a type C trigeminal schwannoma (Jefferson classification)?
- Type C: dumbell-shaped (both middle and posterior cranial fossa).
What percentage of meningiomas are progesterone receptor positive? Estrogen receptor positive?
- 70% of meningiomas are progesterone receptor positive.
2. Less than 10% of meningiomas are estrogen receptor positive.
What is Froin’s syndrome?
- Froin’s syndrome is an isolated pocket of CSF resulting from blockage of CSF flow in the spine, most commonly caused by spinal cord masses and spinal meningitis.
- This can be identified on LP by increased protein (very high), normal CSF cell count, and xanthochromic CSF.
What is the most common intracranial vessel pathology seen in Ehlers-Danols and Marfan’s?
- Dissection.
What is the Simpson grading scale?
- Prognosticates meningioma recurrence post resection.
What are the grades in the Simpson grading scale?
- Grade I: complete tumor resection with dural resection and abnormal bone removal - 9% recurrence rate.
- Grade 2: complete tumor resection with coagulation of dura - 19% recurrence rate.
- Grade 3: complete tumor resection without dural or bone treatment - 29% recurrence rate.
- Grade 4: subtotal removal of tumor - 39% recurrence rate.
- Grade 5: simple decompression - 89% recurrence rate.
What percentage of patients with bilateral jumped facets have complete SCI?
- 2/3rds.
Destruction of the ventromedial hypothalamic nucleus results in what?
- Overeating (hyperphagia) and severe obesity.
Destruction of the posterolateral hypothalamic nucleus results in what?
- Aphagia and starvation.
What genetic alterations are associated with an unfavorable prognosis for meningiomas?
- Deletions in 1p and 14q are associated with transformation to atypical (WHO grade III) and malignant meningioma.
