STEP1_Neuro Flashcards
____________ arise from chromaffin cells in the adrenal medulla, which is derived from neural crest cells.
Pheochromocytomas
Neurocutaneous disorders (phakomatoses) are characterized by involvement of structures derived from what embryonic layer?
the embryonic ectoderm (central nervous system, skin, and eyes).
What disease/finding in a young child is highly suspicious (nearly 100% specific) for tuberous sclerosis?
cardiac rhabdomyoma
What degenerative ocular disease is commonly misdiagnosed as Parkinson’s?
Parkinson disease can sometimes be confused with progressive supranuclear palsy.
Progressive supranuclear palsy usually presents as an isolated vertical gaze palsy, followed by paresis of other ocular movements, and signs and symptoms of Parkinsonism (ie, tremor, bradykinesia, rigidity, and postural instability).
What drug combo decreases dopamine breakdown in pt. with parkinsons diz?
Selegiline (MAO-inhibitor) + COMT inhibitor (e.g. entacapone or tolcapone) leads to decreased dopamine breakdown. Entacapone is a peripheral COMT inhibitor while tolcapone is a central and peripheral COMT inhibitor.
What drugs can be used to treat Parkinson disease leading to decreased tremor and rigidity?
Antimuscarinics like Benztropine can also be used to treat Parkinson disease leading to decreased tremor and rigidity (mnemonic: Park your Mercedes-Benz).
Neuroblastoma is the most common tumor of the adrenal medulla in children, and it frequently results from amplification of what?
N-myc oncogene.
Do oligodendrogliomas contain Psammoma bodies?
NO!!!
Where do oligodendrogliomas tend to occur and what do oligodendrogliomas look like on histology?
Cerebral Hemisphere of middle aged people; may present with siezures Sx.
Histo: large, round nuclei with a clear lao of cytoplasm “FRIED EGG” cells.
What are psammoma bodies?
lamellated mineral deposits formed via calcification of whorled clusters of cells found inside the tumor.
Psammoma bodies are associated with what neoplasms?
meningioma, papillary adenocarcinoma of the thyroid, ovarian serous papillary cystadenocarcinoma, and mesothelioma (mnemonic: PSaMMoma (Papillary [thyroid], Serous [ovary], Meningioma, Mesothelioma).
What are Meningiomas, the 2nd most common type of primary brain tumor? Where are they located?
Meningiomas arise from arachnoid cells external to the brain.
frequently occur in the convexities of cerebral hemispheres and in the parasagittal regions.
What findings are ~w/ Neurofibromatosis type 1 (NF-1)?
A helpful mnemonic for the NF1 is: CAFE SPOT:
Café-au-lait spots Axillary freckling (and inguinal) Fibroma Eye) lisch nodule Scoliosis or other skeletal abnormality Pheochromocytoma OT optic tumor (glioma).
A defect in excision of thymidine dimers is the cause of _______________, an autosomal-recessive disorder that predisposes individuals to melanomas and basal and squamous cell carcinomas. Because of the inability to repair ultraviolet-induced DNA damage, deleterious mutations lead to frequent skin malignancies.
xeroderma pigmentosum
Medial longitudinal fasciculus syndrome is characteristic of _____________. It leads to palsy of the ipsilateral medial rectus.
multiple sclerosis
Medial longitudinal fasciculus syndrome is characteristic of multiple sclerosis. It leads to palsy of the ______________.
ipsilateral medial rectus.
Dissection or thrombosis of the posterior inferior cerebellar artery classically results in _____________________.
lateral medullary syndrome.
Manifestations include ipsilateral Horner syndrome, absent pain and temperature sensation on the ipsilateral face and contralateral body, and ataxia.
_____________ is a manifestation of a lesion to the nondominant parietal lobe of the cerebral cortex
Hemineglect
Deviation of the tongue indicates damage to the __________ nucleus
hypoglossal
What are periodic acid–Schiff-positive cytoplasmic inclusions that are remnants of autophagic vacuoles called?
What disease process are they associated with?
Bunina bodies
ALS
These are found in the neurons of patients with amyotrophic lateral sclerosis, not the muscle. This image of a neuron containing Bunina bodies was produced using ubiquitin immunohistocemistry.
What neuromuscular disease will show small angulated muscle fibers on muscle biopsy?
ALSA
muscle biopsy specimen (like that shown here) would reveal muscular atrophy due to lack of neuronal input. Atrophy is defined as a decrease in preexisting cell mass; atrophy with severe fatty replacement.
What is the func. of the golgi tendon organs?
Muscle preconception
Group B streptococci is one of the leading causes of newborn meningitis. After an episode of meningitis has resolved, meningeal scarring can occur as a complication.
What can result from this?
Communicating (non-obstructive) hydrocephalus.
d/t decrease absorption of CSF by the arachnoid villi
What is the MOA of a drug that is used to improve cognitive measures in pt. with Alzheimer’s?
donepezil (a cholinesterase inhibitor/indirect cholinomimetic) improves cognitive measures by upregulating acetylcholine activity. Donepezil, however, does not alter the course of the disease.
The ____1____ nerve arises from S2–S4 of the sacral plexus and innervates the structures of the ___________2___________.
- pudendal
2. perineum, including sensation of the genitalia
What are the Motor functions of the pudendal nerve?
voluntary urinary and fecal continence, and contraction of pelvic and urogenital diaphragms to support pelvic viscera.
What are the motor and sensory innervation of the Ulnar nerve?
the ulnar nerve innervates the hypothenar muscles, two of the lumbrical muscles, and all of the interosseous muscles; also, it gives off two sensory branches: (1) the palmar cutaneous branch and (2) the dorsal cutaneous branch, which supplies the skin over the hypothenar eminence, and the dorsal ulnar aspect of the hand, respectively.
Left inferior frontal gyrus = ?
Broca’s area (BA 44)
Left Superior temporal gyrus = ?
Weernicke’s area (BA 22)
What makes up the BBB?
Complex of:
endothelial cells
pericytes
astrocyte foot processes
Proximal portion of the basilar membrane is responsible for hearing what frequency of sound?
HIGH!
thinnest and least compliant part of the basilar membrane.
Resting Tremor + bradykinesia (slow movements) == ?
Parkinsons
Parkinson disease is associated with increased muscle tone, cogwheel rigidity, and postural instability. It is a movement disorder caused by the degeneration of the pars compacta region of the substantia nigra, resulting in decreased dopaminergic stimulation of the direct excitatory pathway of the basal ganglia.
accumulation of α-synuclein deposits leading to cytoplasmic inclusions (Lewy bodies) are often seen in pathologic specimens from patients with what disease?
Parkinsons
history of menstrual irregularities, cold intolerance, and constipation suggests multiple endocrine disorders that can be attributed to dysfunction of the anterior pituitary, is ~w/ what ophthalmic issue?
Bitemporal Hemianopia
d/t compression of the optic chiasm
What are the physical manifestations of cerebellar lesions?
including loss of coordination (ataxia), hypotonia, intention tremor, and instability (patients feel they are going to fall toward the side of their lesion)
What disease involves inflammation and demyelination of peripheral nerves.
Guillain-Barré syndrome (GBS)
GBS also has been associated with systemic diseases such as Hodgkin lymphoma, systemic lupus erythematosus, sarcoidosis, Lyme disease, and infection with Epstein-Barr virus, cytomegalovirus, herpes simplex virus, and HIV.
MS is ~w/ what HLA?
HLA-DR2
What is a S/Sx that is seen in the early stages of MS?
Sudden vision loss
MRI demonstrating periventricular white matter lesions (plaques) & alevated oligoclonal bands in the cerebrospinal fluid are highly suggestive of what?
MS
Are Fasciculations ~w/ UMN or LMN?
LMN
Weakness, atrophy, fasciculations, decrease reflexes, decrease muscle tone and faccid paralysis = ?
LMN lesion
Protein aggregates and neuronal death in the caudate nucleus = ?
Huntingtons
CAG
Gerstmann syndrome is a neurologic disorder characterized by four primary symptoms:
(1) Writing disability exhibited as inability to write known as agraphia
(2) Lack of understanding the rules for calculation or arithmetic known as acalculia
(3) Inability to identify fingers known as finger agnosia
(4) Inability to distinguish right from left is termed right-left disorientation
damage to the lateral forearm suggests injury to the ___________ nerve
musculocutaneous;
also will have an absent biceps reflex (C5)
What sign is associated with internal malignancies such as colorectal, stomach, liver, or pancreatic cancers.
Leser-Trélat sign
what are the skin manifestation of Gastric cancer?
Skin manifestations of gastric cancer include acanthosis nigricans and Leser-Trélat sign, which is the sudden eruption of multiple seborrheic keratoses
___________ is characterized by physical restlessness, difficulty sitting still, and a compelling need to move.
Akathisia
Drug-induced parkinsonism manifests as?
tremor, bradykinesia, and cogwheel rigidity.
The superior laryngeal artery accompanies the internal branch of what nerve in the larynx?
superior laryngeal nerve
A lesion of this nerve can lead to loss of sensation in the laryngeal mucosa above the vocal folds and loss of the cough reflex.
Pt. is unable to look up, but the rest of the eye movements are normal. Compression of what structure is responsible?
Superior colliculus; this is Parinaud syndrome
What can lead to defects in vertical gaze, near-light dissociation, and noncommunicating hydrocephalus because of compression of the cerebral aqueduct.
Parinaud syndrome
Parinaud syndrome is caused by a lesion in what?
dorsal midbrain.
____________ cells give rise to neuroglial cells including astrocytes and oligodendrocytes.
Neuroectoderm
what cells do schwann cells and pigment cells come from?
NCC
What nerve is a branch of the vagus nerve that innervates all of the intrinsic laryngeal muscles except the cricothyroid muscle?
The recurrent laryngeal
The recurrent laryngeal nerve is a branch of the vagus nerve that innervates all of the intrinsic laryngeal muscles except the __________ muscle.
cricothyroid
The cricothyroid muscle is innervated by what?
the external branch of the superior laryngeal nerve.
the external branch of the superior laryngeal nerve innervates what muscle?
cricothyroid muscle
What is the MCC eye tumor of childhood?
Retinoblastoma;
caused by mutations in RB1 gene on chromosome 13q
mmc eye tumor in peds that looks to reveals small, round, primitive-appearing blue cells; may have rosettes.
Retinoblastoma
Familial retinoblastoma: bilateral eye tumors, associated with what other tumor?
osteosarcoma
The pituitary can be approached transnasally via the _________ sinus for hypophysectomy.
sphenoid
What are the 4 functions of the CN3?
CN3 = Oculomotor nerve
- Constricts pupil (sphincter pupillae)
- Accommodates (focus for near vision; ciliary muscle)
- Innervates extraocular muscles (medial rectus, superior rectus, inferior rectus, inferior oblique). Adduction (looking toward the nose, medial rectus) is the most important function.
- Raises eyelid (levator palpebrae)
Oculomotor lesions can result in: (5)
Oculomotor lesions can result in:
I- nability to adduct the eye (leading to horizontal diplopia)
- Mydriasis
- Ptosis
- Inability to constrict the eye
- Loss of accommodation
What type of seizure typically presents as staring blankly into space for a few seconds?
Absence seizure typically presents as staring blankly into space for a few seconds.
What brain structure is sensitive to anoxic injury and can be selectively affected, leading to a deficit in the ability to form new memories?
Hippocampus; involved in the formation of new memories.
The caudate and putamen together are called what?
~w/ what disease?
Striatum or neo-striatum
HUNTINGTONS
Facial nerve (CN VII) lesion leads to what defects? (6)
Facial nerve (CN VII) lesion:
- Paralysis of muscles of facial expression (including the orbicularis oculi)
- Hyperacusis (caused by paralysis of the stapedius muscle)
- Loss of taste from the anterior two-thirds of the tongue
- Loss of corneal reflex (efferent limb)
- Deficits in salivation (submandibular and sublingual glands)
- Lacrimal gland dysfunction
In unilateral (left) facial paralysis due to a lesion of the facial nerve (CN VII; Bell’s palsy).
Lower motor neuron lesions of CN VII affect what?
Upper motor neuron lesions causes what?
Lower motor neuron lesions of CN VII affect the entire ipsilateral half of the face and
upper motor neuron lesions cause contralateral symptoms that spare the forehead,
The median nerve of the arms/hands, passes thru what forearm muscle?
Pronator teres
The musculocutaneous nerve passes thru what forearm muscle?
Coracobrachialis
The ulnar nerve passes thru what forearm muscle?
Flexor carpi ulnaris
The radial nerve passes thru what forearm muscle?
Supinator
What nerve emerges from the interpeduncular fossa of the midbrain and then passes between the superior cerebellar artery and the posterior cerebral artery immediately lateral to the basilar artery.
The oculomotor nerve (CN III)
The oculomotor nerve (CN III) emerges from the interpeduncular fossa of the midbrain and then passes between what arteries?
superior cerebellar artery and the posterior cerebral artery immediately lateral to the basilar artery.
Compression of CN III by an adjacent aneurysm can result in the inability to do what?
adduct that eye
Craniopharyngioma is from what embryological structure?
Rathke’s pouch;
tumors cells look like cells of tooth enamel, b/c of similar embryo.
Symptoms due to encroachment on pituitary stalk or optic chiasm
What is visual agnosia?
You can see objects, but you CANNOT recognize or tell what they are.
What lesion is ~w/ visual agnosia?
lesions in the Temporo-Occipital association cortex (the “what” pathway/ Ventral Pathway)
What brain pathway analyzes spatial relationships between objects, between the body and visual stimuli, and motion?
The dorsal pathway, or the “where” pathway projects to parieto-occipital association cortex
(cortex that bridges the occipital and parietal lobes)
Where does CNV2 exit?
Foramen Rotundum
A useful mnemonic for the foramina through which the branches of the trigeminal nerve leave the skull is “SRO”—or “Standing Room Only”—for V1 to V3:
Superior orbital fissure—V1
Foramen Rotundum—V2
Foramen Ovale—V3
HSV-1 can remain latent in what part of the nervous system?
Trigeminal Ganglion
What does bacterial abscesses in the brain look like on CT?
Ring-Enhancing!!
Bacterial abscesses in the brain do NOT present with nuchal rigidity.
What is the mcc of crain abscesses in peds?
recurrent episodes of otitis media
A astrocytic tumor that grows from the walls of the lateral ventricles, and contains the large ganglioid cells is called?
Sub-ependymal Giant Cells Astrocytoma.
It is pathognomonic of tuberous sclerosis, which is caused by mutations of the TSC1 or TSC2 genes
The following are ~w/ what disease?
- Autosomal dominant
- Facial lesions (adenoma sebaceum)
- Hypopigmented “ash-leaf” spots on the skin
- Multiple hamartomas, including cortical tubers
- Renal angiomyolipomas
- Cardiac rhabdomyomas
- Astrocytomas
- Subependymal giant cell astrocytoma
Tuberous sclerosis:
Bilateral Schwannomas of the 8th cranial nerve is ~w/ what ?
NF2
small, pigmented, nodular lesions of a hamartomatous nature that are present in patients who have ???
neurofibromatosis type 1; there are called Lisch Nodules.
Other features of NF1 include café-au-lait spots, axillary freckling, neurofibromas, scoliosis, pheochromocytoma, and optic gliomas.
The follwoing is ~w/…
- Hemandtioblastoma
- Renal cell carcinomas
- pheochromocytomas
VHL; chr. 3 [AD]
Café-au-lait spots (choice A) are pigmented macules of the skin found in both types of neurofibromatosis.; and can also be seen in what other syndrome?
McCune-Albright syndrome
The chemoreceptor trigger zone (CTZ), which causes vomiting, is located in the __________ on the floor of the fourth ventricle.
area postrema
The ___________ zone, which causes vomiting, is located in the area postrema on the floor of the fourth ventricle.
chemoreceptor trigger zone (CTZ)
The chemoreceptor trigger zone (CTZ), which causes vomiting, is located in the area postrema on the floor of the ____________.
fourth ventricle
___________ lies just lateral to the floor of the rostral part of the fourth ventricle. Cells in this nucleus synthesize norepinephrine, and involved in the control of cortical activation (arousal).
Locus coeruleus
Locus coeruleus lies just lateral to the floor of the rostral part of the fourth ventricle. Cells in this nucleus synthesize __________ , and involved in the control of cortical activation (arousal).
norepinephrine
The floor of the third ventricle contains the ________________ , with temperature regulation, feeding centers, pituitary control, and other regulatory functions, but has no significant role in vomiting.
hypothalamus
Corneal reflex:
Afferent limb: ?
Efferent limb: ?
Corneal reflex:
Afferent limb of the corneal blink reflex is by ipsilateral CN V.
Efferent limb of the corneal blink reflex is by bilateral CN VII.
Adduction of the left eye is controlled by the _________ nerve via the action of the medial rectus.
oculomotor nerve (CN III)
Adduction of the left eye is controlled by the oculomotor nerve (CN III) via the action of the _______ muscle.
medial rectus m.
Sensory innervation to the anterior half of the external ear canal is supplied by the __________ nerve, which also supplies the facial surface of the upper part of the auricle.
auriculotemporal nerve of the Mandibular br. of the Trigeminal nerve.
CNV_3
Loss of knee flexion, foot dorsiflexion, and weak extension of the thigh == what nerve?
Sciatic n.
Sensory Loss= posterior thigh, leg, and foot
Loss of ABduction of the limb; Trendelenburg gait == what nerve?
Superior Gluteal nerve.
Weakness of hip extension and lateral rotation of the thigh = what nerve?
INFERIOR gluteal n.
A useful mnemonic for Patau syndrome is M1CRoCePHaly:
Mental retardation, 13 chromosome, Cardiac defects, Renal defects, Cleft lip & palate, Polydactyly, Holoprosencephaly.
________________ is a form of neural tube defect, associated with folate deficiency, and is characterized by complete failure of higher brain structures to develop.
Anencephaly
What is lissencephaly?
is a forebrain anomaly, characterized by the absence of cortical gyri. Grossly, the fetal cortex has a smooth surface and lacks the normal gyri.
Various motor and sensory deficits separated in space and time == ?
MS; unmistakable appearance of well-demarcated areas of demyelination of the white matter.
Shine light in Marcus Gunn pupil ⇒ pupils do not constrict fully
Shine light in normal eye ⇒ pupils constrict fully
Shine light in affected pupil again ⇒ ??
apparent dilation of both pupils because the stimulus carried by the optic nerve (CN II) of the affected eye is weaker than the normal eye.
pathologic features in the brain include microglial nodules, with multinucleated giant cells is ~w/ what?
HIV encephalitis
round intracytoplasmic neuronal inclusions that contain alpha-synuclein in the substantia nigra and neocortex ==?
Lewy bodies.
What etiologic agent is a negative-sense single-stranded RNA virus transmitted to humans by animal bite and what is the classic histo?
Rabies. Elongated intracytoplasmic neuronal inclusions (Negri bodies)