General Flashcards
Long-term use of proton pump inhibitors to decrease gastric acid production is associated with which of the following serum deficiencies?
B12 (Cyanocobalamin)
How does PTH therapy work in patients with osteoporosis?
Activation of osteoblasts function via PTH/PTHrP type 1 receptors
Parkinsonism is seen most commonly following toxic exposure to which of the following agents?
manganese
can also be produced by carbon disulfide, carbon monoxide, cyanide, MPTP, and organic solvents
antiemetics including metoclopramide and prochlorperazine have significant antidopaminergic activity and can cause drug-induced Parkinsonism.
What type of drug is Phenoxybenzamine?
Phenoxybenzamine is an alpha-adrenergic blocker. Propranolol is a beta-adrenergic blocker. Clonidine is an alpha agonist. Albuterol is a beta agonist. Dobutamine is a beta and alpha agonist
The medication most commonly used for management of Ménière disease is an antagonist of which of the following receptor types?
One of the most common drugs used to treat Menieres disease is betahistine which is an antagonist of histamine H3 receptors.
The other main class of drugs used to treat Menieres disease are diuretics. The most common diuretics used to treat Menieres disease are thiazides with or without potassium-sparing diuretics such as hydrochlorothiazide/triamterene or spironolactone as well as the carbonic anhydrase inhibitor acetazolamide as a second-line therapy.
intravenous tissue plasminogen activator (tPA) be administered no later than how long after the onset of acute ischemic stroke?
Initial studies demonstrated benefit for intravenous tPA given 0-3 hours after stroke onset. A later publication demonstrated utility of tPA up to 4.5 hours after stroke onset.
Numerous mechanical thrombectomy trials for patients with large vessel occlusion acute ischemic strokes have demonstrated efficacy in both “early” and “late” windows, expanding the indication for this intervention to 24 hours.
Which of the following is the correct spinal cord location for percutaneous cervical cordotomy on a patient with unilateral cancer pain?
Percutaneous cordotomy targets the contralateral spinothalamic tract in patients with unilateral somatic pain, primarily cancer related pain.
First order spinal nerve axons enter the ipsilateral dorsal root, before they terminate in the dorsal horn. Second order axons then travel across the anterior white commissure and ascend via the spinothalamic tract, where they are arranged somatotopically.
This is an excellent procedure for the treatment of cancer pain located at or below the C5 dermatomal level for patients with limited life expectancy.
A patient who takes vitamin supplements reports headaches, diplopia, and diffuse myalgias. Examination shows papilledema and dry, scaly skin. The patient is most likely consuming an excess of which vitamin?
The clinical scenario best describes a patient with chronic vitamin A toxicity.
Vitamin C toxicity can lead to GI symptoms, fatigue, and nephrolithiasis due to increased calcium oxalate formation.
Vitamin E toxicity is rare but can cause increased risk of bleeding and coagulopathy as high doses may alter Vitamin K metabolism.
Niacin and Pyridoxine are B vitamins which can be associated with facial flushing and sensory peripheral neuropathy when taken in excess, respectively.
Inheritance pattern of Duchenne’s muscular dystrophy and myotonic distrophy?
Duchenne’s muscular dystrophy is transmitted in an X-linked fashion. Myotonic dystrophy is transmitted in an autosomal dominant fashion.
What characteristic imaging finding on MRI would best differentiate neuromyelitis optica from multiple sclerosis?
A longitudinally-extensive spinal cord lesion is most consistent with neuromyelitis optica (NMO) and is helpful in differentiating it from multiple sclerosis. NMO, or Devic disease, once thought to be a form of multiple sclerosis, is associated with bilateral optic neuritis, longitudinally-extensive transverse myelitis, and antibodies to the aquaporin 4 water channel.
Diagnosis of NMO require optic neuritis, myelitis, and two of the following: a longitudinally extensive spinal cord lesion on MRI (extending 3 or more segments), brain MRI not initially meeting criteria for MS, or NMO-IgG seropositivity
Which T-scores defines osteoporosis?
T-score is defined as a standard deviation measurement resulting from a bone density test.
The World Health Organization (WHO) defines osteoporosis as having a T-score lower than -2.5. Osteopenia is defined as a T-score between -1 and -2.5.
Definition and drugs associated with causing RCVS:
Reversible cerebral vasoconstrictive syndrome (RCVS) is a clinical syndrome characterized by acute thunderclap headache, emesis and nausea
due to a transient disturbance in the control of cerebrovascular tone
segmental vasoconstriction on angiography and reversibility of the lesion
triggered by vasoactive substances, including SSRI such as sertraline, or cocaine
occur post partum or after exposure to adrenergic or serotonergic drugs.
uniphasic course, and vary from pure cephalalgic forms to rare catastrophic forms associated with hemorrhagic and ischemic strokes, brain edema, and death.
nimodipine seems to reduce thunderclap headaches within 48 hr of administration, but has no proven effect on hemorrhagic and ischemic complications.
Kearns-Sayre syndrome: inheritance, lab abnormalities, and symptoms?
AD
Ptosis, pigmentary retinopathy, ophthalmoplegia that can progress to deafness and CM
affected enzyme is mitochondrial DNA non maternally inherited
Increased serum pyruvate, spongy brain
progressive external ophthalmoplegia, retinitis pigmentosa, and cardiac conduction defects
refsums disease: inheritance, lab abnormalities, and symptoms?
AR
affected enzyme is phytanic acid oxidase
symmetric lower extremity peripheral neuropathy, retinitis pigmentosa, hearing loss, cardiomyopathy
hurler disease: inheritance, deficiency, lab tests, and symptoms?
AR alpha-L-iduronidase
increased urine dermatan, zebra bodies
MR, gargoyl face, thick meninges, spinal cord compression, corneal opacities, conduction deafness, cardiac disease
Behcets disease: vessel involved, pathology, clincal picture, treatment
small vessels (venules)
arterial occulsion, aneurysm, thrombophlebitis
mostly in males and present with: meningo-encephalitis, brain stem edema, confusion, oro-gential ulcers, uveitis, ulerative colitis, erythema nodosum, polyarthritis
tx: steroids
What is tetrodotoxin?
voltage gated sodium channel blocker
what is tetraethylammonium (TEA)?
voltage gated K channel is inhibitor
what is the conduction velocity in large, myelinated fibers?
as high as 120m/s
Where is ACh found? what inhibits acetylcholinesterase?
nucleus basalis of meynert, motor cortex, skeletal muscle, preganglionic autonomic nerves (N), postganglionic parasympathetic nerves (M), and postganglionic sympathetic nerves supplying sweat glands (M)
M= muscarinic, G protein coupled receptors, blocked by pertussis toxin, atropine, scopalamine. Stimulated by bethanacol, carbacole, pilocarbine
all others are nicotinic, blocked by hexamethonium, succinocholine, tubocurare
AChE inhibited by neostigmine, physostigmine, endophronium…
Where are dopamine and NE found? What is the tyrosine to dopamine/NE pathway? What is the rate limiting step?
NE: pontine locus ceruleus and postganglionic sympathetic nerve fibers
dopamine: substansia nigra, ventral tegmental area, and arcuate nucleus of hypothalamus
both breakdown to VMA and HMA, respectively
In pathway, tyrosine hydroxylase is the rate limiting step
dopamine cannot cross BBB, only L-dopa
NE is synthesized in vesicles
Which are the inhibitory neurotransmitters? Where are they found?
dopamine
glycine (found in the spinal cord; renshaw cells)
GABA: found in the cortex, basal ganglia, cerebellum (purkinje cells) and spinal cord
serotonin-found in brainstem nuclei (median raphe nuclei) that project to the hypothalamus and spinal cord (dorsal horns). It acts to inhibit pain pathways, induces sleep, and affects mood. used by pineal gland to produce melatonin
Pathway of the spinothalamic tract:
carries sensory information through delta type A fibers (to thalamus for pain) and C fibers (slow pain fibers to reticular formation and periaqueductal grey.
sensory fiber ascends lissaurs tract and synapses on laminae 1,4,5 and 6
Fibers ascend in the anterior (i.e., ipsilateral) and lateral (i.e., contralateral, due to crossing of fibers in the anterior commissure, within three levels) spinothalamic tracts to the ventroposterolateral (VPL; body), ventroposteromedial (VPM; face), and posterior thalamic nuclei for touch and temperature sensations; then synapse in the somatosensory cortex
Fibers also relay impulses in the spinoreticular tract to the intralaminar thalamic nucleus for pain.
Can also synapse in the reticular formation, tectum, and periaqueductal gray for pain throuch c fibers
TLDR: spinothalamic tract –> medial/trigeminal lemniscus –> VPL.VPM/posterior thalamus –> S1
Six layers of neurons in the sensory cortex:
Layers 1 (most superficial; molecular layer) and 2 (association fibers; external granular layer) receive diffuse, nonspecific input from the lower brain and may control the excitability of a region.
Layers 3 (cortico-cortical association that connect one temporal lobe to the other and commissural fibers; external pyramidal layer/pyramidal cells) relay axons to other cortical areas
Layer 4 (internal granular layer) of each column does not interact with the other columns, whereas other layers do. Afferent fibers arrive in layer 4 and either spread up or down a column. Receives thalamocortical input and is enlarged in SENSORY cortices. forms external band of baillarger and white line of gennari
Layers 5 (internal pyramidal layer) and 6 (projection fibers; fusiform layer) disperse axons to distant parts of the nervous system. Layer 5 is larger and connects to the brainstem, basal ganglia, and spinal cord and is enlarged in MOTOR cortices, whereas layer 6 is smaller and connects to the thalamus.
Pyramidal cells are chief cortical efferents; stellate or granule cells are the main interneurons and are much more numerous.
pathway of the posterior column to the cortex:
Axons enter the spinal cord and divide into a medial branch that travels up the dorsal column (25% of fibers), and a lateral branch (75% of fibers) with multiple synapses in the dorsal horn for reflexes
Second-order neurons are located in the medulla, within the medially situated nuclei gracilis and laterally situated nuclei cuneatus
Arcuate fibers cross to form the medial lemniscus (ML), joining fibers from the main sensory nucleus of the trigeminal nerve (V) and the upper spinal nucleus of V to terminate in the thalamic VPL (body) and VPM (face).
The ventrobasal complex (VPL, VPM, and the posterior thalamic nucleus) sends fibers to the cortical somatosensory areas S1 and S2. A somatotopic organization exists with the lower limbs represented medially in the spinal cord, laterally in the thalamus, and medially again in the cortex
How do we sense proprioception (receptors) and what is the pathway?
The muscle spindles, Pacinian corpuscles, Ruffini’s end organs, and Golgi’s tendon organs of the extremities
Lower limb proprioception is conveyed within the lateral column from Clarke’s column neurons (rexed lamina 7) through the ipsilateral dorsal spinocerebellar tract to the cerebellum (through inferior cerebellar peduncle)(i.e., not in the posterior columns)
Upper extremity proprioception is conveyed through the posterior columns in the fasciculus cuneatus prior to synapsing onto the accessory cuneate nucleus in the caudal medulla, before being relayed to the cerebellum via the cuneocerebellar tract
Somatic association areas (Brodmann’s areas 5, 7):
located behind S1 and above S2
Receives input from S1, ventrobasal thalamus (VPL, VPM, posterior thalamic nucleus), visual cortex, and auditory cortex
Stimulation elicits complex body sensations
A lesion in this region results in amorphosynthesis (i.e., the inability to recognize or detect objects sensed contralaterally) and astereognosia
contributes to 2-point discrimination (1 mm in the finger, 30–70 mm in the back)
Pain pathway mediators are:
bradykinin, 5-hydroxytryptamine (5-HT; serotonin), histamine, K+, acids, acetylcholine (Ach), and proteolytic enzymes all activate pain receptors. Prostaglandins enhance pain receptor sensitivity, but do not themselves excite these receptors
Thalamic pain (Dejerine–Roussy) syndrome
usually due to a posteroventral thalamic stroke causing ataxia and contralateral hemianesthesia, which in subsequent weeks to months is characterized by not only a return of crude sensation but also increased pain and affective, unpleasant feelings. It may be caused by facilitation of the medial thalamic nucleus with increased transmission of reticular formation pain.
What structures are involved in memory?
dorsomedial thalamus, hippocampus, temporal cortex, ascending reticular activating system (ARAS), and neocortex
What is the memory pathway from the hippocampus?
hippocampus → precommissural fornix → septal gray → diagonal band of Broca → the amygdala
Characteristic pathologic findings for alzheimers disease are the following:
Neuronal loss and atrophy associated with generalized cortical atrophy—more pronounced in temporal and parietal lobes.
Neurofibrillary tangles—intraneuronal inclusion: Paired helical filaments formed by hyperphosphorylation of microtubule-associated protein tau.
Senile plaques: extracellular:
- Comprised of amyloid β peptides, proteolytic product of amyloid precursor protein (APP) located on chromosome 21;
- Average 50 μm in size;
- Overexpression is seen in Down’s syndrome and has symptoms of this disease by age 40 years;
- ApoE4 mutation leads to excessive accumulation of amyloid.
Hirano’s bodies: eosinophilic intracellular aggregates of actin and associated proteins in neurons.
histology of picks disease?
Pick’s bodies (intracellular inclusions of tau protein) and Pick’s cells (swollen neurons) are specific.
symptoms of wernicke’s encephalopathy?
ataxia and nystagmus.
Korsakoff’s psychosis with anterograde and retrograde amnesia and confabulation
pathology of lewy body dementia:
Typified by α-synuclein cytoplasmic inclusions referred to as Lewy’s bodies.
Loss of both ACh- and dopamine-producing neurons
symptoms of bilateral frontal lesions:
impaired gait and incontinence (lack of warning), pseudobulbar palsy (degeneration of corticobulbar pathways to cranial nerve [CN] V, VII, X, XI, and XII nuclei with sparing of III, IV, and VI).
A lesion in the supplemental motor cortex produces:
involuntary grasping (it normally inhibits this reflexive activity)
A lesion in area 6 (premotor area, anterior to motor cortex area 4) produces and what are the sensory inputs to area 6?:
spasticity by increased stretch reflexes.
Inputs are VL and SMA
A lesion in area 4 produces:
hypotonia and weakness of the contralateral distal limb, but no spasticity.
Uncinate fasciculus connects the:
anterior temporal lobe to the orbitofrontal gyrus
Arcuate fasciculus connects:
Wernicke’s to Broca’s area
Anterior commissure and middle corpus callosum connect the:
two temporal lobes
Definition: Kluver–Bucy syndrome—from bilateral amygdala injury.
Absence of emotional response, compulsion to explore all objects visually, tactilely, and orally; hypersexuality and visual agnosia.
Pleasure concentrated in which nucleus?
nucleus accumbens and septal nuclei
Stimulation of the globus pallidus (GP) can produce:
an experience of joy
Guilt, anxiety, and paranoia may be associated with the:
orbitofrontal cortex
What is the role and connections in the amygdala?
plays a role in emotion and fear; interconnected with olfactory system (afferent) and hypothalamus (efferent)
What causes pathological laughing or crying? What paths control movement?
injury to bilateral corticobulbar tracts from stroke, MS, or ALS
Three paths control the pontomedullary facial movements involved with laughing and crying:
The voluntary pathway involves the corticobulbar tract in the genu of the internal capsule (posterior).
The involuntary pathway is anterior to the genu of the internal capsule.
Damage to the anterior path causes unilateral decreased movement with emotion. Damage to the posterior path causes unilateral increased movement with emotion.
Erections and orgasms can be produced by stimulation of:
thalamic medial dorsal nucleus, medial forebrain bundle, and septal nuclei
Definition: stria medullaris
connects septal area, hypothalamus, olfactory area, and anterior thalamus –> habenula
Definition: Medial forebrain bundle
Connects septal area, hypothalamus, basal olfactory areas, hippocampus/subiculum → midbrain, pons, and medulla
Definition: Diagonal band of broca
connects septal nuclei –> amygdala
Definition: lamina terminalis
closed rostral end of the neural tube (formed by anterior neuropore that closes at embryonic day 24)
Definition: Golgi’s tendon organs—
encapsulated receptors with bundles of tendon fibers passing through them, located at the muscle–tendon junction
detects the tension within 10 to 15 contained muscle fibers.
afferent signal is mediated from type Ib fibers to interneurons that decrease α motor neuron output. The reflex is not monosynaptic. It prevents muscle tearing and serves to equalize forces in the muscle, such that tense fibers are allowed to relax.
Defintion: Myotatic (muscle stretch) reflex—
When a muscle is stretched, impulses travel from the spindle’s type Ia fibers to the α motor neuron; this induces contraction via a monosynaptic reflex. A damping mechanism smooths contractions from multiple sources to produce fluid (i.e., not jerky) movement.
area 6: consists of…, location, input, projections
premotor cortex (lateral) and SMA (medial)
input from VL and SMA to PMC
input from VL, area 4, and S1 to SMA
Majority of projections are to 4, 5, 7, and premotor cortex with subcortical efferents to thalamus (VL, VA, MD)
S2: location in the cortex, input
by the supramarginal gyrus
input from VPL/VPM, S1
What are the different areas of S1? What results from a lesion to area 2?
3, 1, 2
lesion to area 2 results in asteriognosis
Taste pathway: cranial nerves, nuclei, innervation
CN 7, 9, 10 –> nucleus of the solitary tract –> VPM thalamus –> gustatory cortex in area 43
Primary visual cortex: location, important cell layer, vascular supply?
area 17 in the cuneus through the calcarine fissure
has a large layer 4 called the white band of gennari
occipital pole is location of macula. Main blood supply is PCA but has redundant supply from MCA. PCA strokes have macular sparing due to the MCA
Primary auditory cortex: location, input, representation, where is sound localized?
area 41, 42, 22 in the mid/posterior superior temporal gyrus
input from medial geniculate body
has bilateral representation
sound localized in the trapezoid body
Thalamic nuclei: Anterior nucleus- input, projection, tract involvement?`
input from mammillary bodies (mammillothalamic tract)
projects to cingulate gyrus and anterior limb of internal capsule
involved in memory/learning (limbic system)
Motor thalamic nuclei: Projections and input
VA: input GPi and SNr. projects to frontal eye fields: area 8, PMC, SMA
VL: input SNr, GPi, and deep cerebellar nuclei. projects to SMA and primary motor cortex
aka as Voa
motor nuclei are found anterior to sensory. Important when targeting thalamus for DBS
Pallidothalamic fibers: pathway
consists of ansa lenticularis and lenticular fasciculus
projects to VA, VL, and IL (aka Voa)
sensory thalamic nuclei: inputs and projections
VPL: input medial lemniscus and anterior spinothalamic tract. projects to S1
VPM: input from trigeminothalamic tract and gustatory (from nucleus of the solitary tract). project to S1 and area 43
collectively aka Vc
pulvinar: input and projections
input: occipital cortex and superior colliculus
projections: primary and secondary visual cortex (17, 18, and 19)
How many layers are in the cerebellar cortex? what cells are in each?
three layers (MPG):
Molecular layer: made up of basket cells (inhibitory via gaba; contacts purkinje cell bodies) and stellate cells (inhibitory via GABA; contacts purkinje dendrites)
purkinje cell layer: only output from cerebellar cortex. inhibitory via GABA to deep nuclei and vestibular nuclei. Stimulated by parallel fibers (from granule cells). Also receives climbing fibers from inferior olive (most excitatory cell in CNS; glutamate)
granular layer: contains granule cells which are the only excitatory cells in cortex (via glutamate; axons ascend to molecular layer to form parallel fibers) and golgi type II cells (inhibitory via GABA; dendrites contact parallel fibers, axons in glomeruli). contain glomeruli which are made up of granule cell dendrites, mossy fibers (from brain stem nuclei and spinal cord; excitatory), and golgi cell axons.
What are the deep cerebellar nuclei?
fastigial, dentate, emboliform, globose
emboliform and globose together = interposed
input mostly from purkinje cells (inhibitory) and mossy and climbing fibers (excitatory)
**All output is excitatory except for inhibitory to inferior olive
what is the cerebellar output and input? What is the dentorubrothalamic tract?
input (afferents) mostly from inferior (restiform and juxtarestiform bodies; juxtarestiform carries primary and secondary vestibulocerebellar fibers) and middle peduncles
output through superior peduncle via dentorubrothalamic tract
purkinje cells –> dentate nucleus –> superior cerebellar peduncle (site of decussation) –> some to contralateral red nucleus and others to VL and VPL –> cortex –> internal capsule via corticospinal tract or rubrospinal tract–> decussation in medulla –> spinal cord
since there are two decussation sites, damage to right dentate nucleus will cause ipsilateral body effects
What is cerebellar learning?
What are the three types of axonal transport? Which proteins are involved and their speed? Inhibitors?
Fast anterograde: Kinesin and ATP. >400m/day. disrupted by vincristine and cholcecine
slow anterograde: dynamin (GTP) or actin/myosin. 0.2-0.4m/day
retrograde: Dynein and ATP. >400m/day. used by rabies and tetanus to enter CNS.
All travel on microtubules
What increases an action potential? What decreases the velocity of an action potential?
Increased with axonal diameter and transmembrane resistance (myelin)
decreased with increasing internal resistance and increased membrane capacitance
Where is serotonin found? What is the precursor and rate limiting step?
raphe nucleus
made from tryptophan. tryptophan hydroxylase is the rate limiting step
Main neurotransmitter in the spine? inhibitors? syndromes caused by mutations?
glycine
blocked by strychnine and tetanus
mutations causes familial startle syndrome and stiff man syndrome
What is the triangle of guillon and molleret?
triangle formed by dentate nucleus, red nucleus, and inferior olive nucleus
Right red nucleus –> right inferior olive –>inferior cerebellar peduncle –> Left dentate nucleus –> superior cerebellar peduncle –>right red nucleus
damage (usually vascular) to this triangle –> hypertrophy of inferior olive nucleus and intermittent firing causing pallito-mycolus and ocular clonus. Eye movement persist even through sleep
Symptoms of wallenburg syndrome?
Ipsilateral: horners, decreased pain and temperature in the face, ataxia
contralateral: decreased pain and temperature in the body
multiple cranial neuropathy syndrome and CN involved: Garcin
progressive, unilateral pan-cranial neuropathy
multiple cranial neuropathy syndrome and CN involved: Collet-Sicard
9, 10, 11, 12
multiple cranial neuropathy syndrome and CN involved: Villaret
9, 10, 11, 12, sympathetic, +/- 7
multiple cranial neuropathy syndrome and CN involved: Tapia
7, 10, 12, +/- sympathetic
What are the different waves during BAER monitoring?
Spike and dome waves with different frequencies and their type of seizure:
1-2 hz: lennox-gastaut syndrome
3 hz: petit mal (PM) and absence
4-6 hz: juvenile myoclonic eplilepsy
conditions on which 2 hz triphasic waves are seen:
hepatic, renal, pulmonary encephalopathies, and hydrocephalus
Optic nerve fibers have their cell of origin from:
Ganglion cells
Gum hyperplasia, hirsutism, ataxia, thrombocytopenia, and SJS can all occur with which AED?
Phenytoin
Which drug can be complicated by cyanide toxicity?
Sodium nitroprusside
Which receptor transmits vibration sense?
Pacinian corpuscle
Canavans disease: inheritance, deficiency, clinical picture?
AR
N-acetyl-aspartoacylase
MR, macrocephaly, blindness
Which drug has no beta-2 agonist effect?
Phenylephrine
Neimann Pick disease: deficiency and clinical picture?
Sphingomyelinase
Cherry red spot in macula, hepatosplenomegaly, MR
What is a DNA repair disorder characterized by CNS and peripheral nerve demyelination, cataract, and dwarfism?
Cockaynes syndrome
Zellwegers syndrome: inheritance, clinical syndrome
AR
Decreased liver peroxisomes, long chain fatty acid accumulation, and a cerebro-hepato-renal syndrome
which disease has polyostotic fibrous dysplasia?
McCune-Albright Syndrome
Which disease features bilateral basal ganglia hypodensities?
Hallervorden-Spatz disease
Which disease is characterized by bilateral basal ganglia calcifications?
Fahrs disease
The superior longitudinal fasciculus connects the:
frontal lobe to parietal and occipital
The inferior longitudinal fasciculus connects the:
temporal lobe to occipital
special visceral afferents fibers of the facial nerve: supply, through which nerve, nucleus in brainstem
transmit taste sensation from the anterior 2/3 of the tongue.
travel through the chorda tympani n.
They reach the tongue through the lingual branch of the mandibular division of the trigeminal n.
They synapse in the cranial part of the nucleus of tractus solitarius.
middle part glossopharyngeal n, caudal part vagus
Nuclei of CN3, type of efferents, and their targets:
Edinger–Westphal nucleus provides parasympathetic (general visceral efferent)
The general somatic efferents arise from the central nucleus supplying levator palpebrae superioris bilaterally
medial nucleus supplying contralateral superior rectus
lateral nucleus supplying ipsilateral inferior rectus, inferior oblique and medial rectus
general visceral efferent fibers of the glossopharyngeal nerve arise from and travel/synapse through to supply the:
inferior salivary nucleus, travel through the lesser petrosal n, synapse in the otic ganglion, then supply the parotid gland through the auriculotemporal n
Fabrys disease: inheritance, deficiency, clinical picture?
X-linked recessive
α-galactosidase A deficiency
ceramide (sphingosine + long-chain fatty acid) accumulation in tissues, corneal opacities, cerebrovascular occlusions, CAD, kidney insufficiency, skin angiokeratomas, and weakness from peripheral neuropathy
Mitochondrial myopathies? two types
inherited through maternal mitochondria include MELAS, MERRF, MNGIE, Luft’s, and Leigh’s diseases
Kearns–Sayre is a defect in mitochondrial DNA not maternally inherited.
Pelizaeus–Merzbacher disease: inheritance, deficiency, clinical picture?
X-linked recessive
defect in synthesis of proteolipid lipoprotein
mental retardation with cerebellar involvement, ataxia, nystagmus, spasticity, and tigroid pattern on MRI
CN affected with Tolosa–Hunt (painful ophthalmoplegia):
III, IV, V1, VI, periorbital pain
Wilsons disease: inheritance, deficiency, clinical picture?
AD-13
Hepatolenticular degeneration, Kayser–Fleischer ring in cornea
Opalski cells, Alzheimer II astrocytes, decreased serum Cu and ceruloplasmin, increased urinary Cu. Serum free (unbound) Cu can be elevated. deposits in lentiform nucleus
Menkes kinky hair disease: inheritance, deficiency, clinical picture?
XR
decreased copper absorption from GI
diffuse loss of neurons
MR, colorless brittle hair, Sz, intracranial aneurysm, tortuous abdominal viscera
Definition: Bunina bodies
intracytoplasmic inclusions found in ALS
Definition: one and a half syndrome`
bilateral internuclear ophthalmoplegia resulting in bilateral failure of adduction, as well as VI nerve palsy on one side resulting in failure of abduction of that eye only
caused by bilateral lesion of medial longitudinal fasciculus, plus unilateral VI nerve palsy
Causes include brain stem ischemia or demyelination.
Defintion: Benedikt’s syndrome
midbrain stroke syndrome involving the third cranial n causing ipsilateral IIIrd n palsy and red nucleus causing contralateral ataxia
Defintion: Weber’s syndrome
involves ipsilateral IIIrd n palsy and contralateral hemiplegia (corticospinal tract)
Gauchers disease: inheritance, deficiency, clinical picture?
Autosomal recessive
Glucocerebrosidase deficiency
Wrinkled tissue-paper appearing cells
Hepatosplenomegaly, lungs, anemia, thrombocytopenia, Ashkenasi Jews
Best treatment to PREVENT sickle cell crisis?
hydroxyurea increases fetal hemoglobin and decreases platelets and leukocytes, thereby reducing the frequency of sickling and need for blood transfusions after acute crisis
What causes neuronal depolarization? (which ion effect)
sodium influx
repolarization is caused by sodium channel closure (inner inactivation gate) and potassium efflux
What are the characteristic EEG waves during each sleep and awake cycles?
stage 1: low voltage alpha waves
stage 2: K complexes and sleep spindles
stage 3: some delta waves and K complexes
stage 4: delta waves more than 50%
REM: beta waves
awake quiet: alpha waves
awake alert: beta waves
During ACUTE sickle cell crisis, what is the best treatment to prevent strokes?
exchange transfusions by reducing level of HgbS by taking out the patients own blood and transfusing with donor blood
blood transfusions can be done too but exchange is best
vision occurs when metarhodopsin 2 activates:
G protein
what daily intervention decreases the risk of strokes in sickle cell patients:
adequate hydration
treatment of pseudomonas infection leads to renal failure from ATN. Which is the likely abx?
aminoglycoside (ex. tobramycin)
will also cause deafness
Patient with sickle cell disease has stroke and recovers well. What test should they get annually?
TCDs
if abnormal can get exchange transfusion
Which are the vitamin K dependent clotting factors?
II (prothrombin), VII, IX, X, protein C, and protein S
which neurotransmitter receptor is associated with calcium influx and cell death?
glutamate
it is an NMDA receptor and is both voltage- and ligand-gated
which type of nerve fiber transmits prickling pain and temperature (cold)?
3
type 4 (C) transmits burning pain and temp (hot and cold) sensation
What are the different broadmann areas of the somatosensory cortex and what do they sense?
3a: muscle and tendon stretch
3b: skin receptors (slow and rapid adapting)
1: rapid adapting skin (fine touch)
2: pressure and joint positon
which rexed lamina transmits second order neurons for fast pain transmission?
I (marginal zone)
II (substantia gelatinosa) transmits slow burning pain
how is light sensed in the retina?
light converts retinal rhodopsin –> metarhodopsin 2 –> activates G protein -> stimulates phosphodiesterase –> converts cGMP to 5’GMP –> sodium channels close –> hyperpolarization and graded electric conduction
In the retina, which cells provide lateral inhibition to increase contrast in phototransduction?
horizontal cells transmit signals horizontally and inhibit laterally
which optic pathway projection transmits to the basal brain for behavioral functions?
VENTRAL LGB (magnocellular layers 1 and 2)
both ventral and dorsal (parvocellular layers 3-6 project to the primary visual cortex (area 17)
The suprachiasmatic nucleus is part of which pathway and what is the function?
optic pathway
regulates circadian rhythm
The pretectal nucleus is part of which pathway and what is the function?
optic pathway
pupillary reflex
The superior colliculus is part of which pathway and what is the function?
optic pathway
conjugate eye movements
which muscle in the ear is involved in a reflex that protects the cochlea by attenuating load sounds?
stapedius (supplied by 7) and tensor tympani (supplied by 5)
What is another name for the superior and inferior cerebellar peduncles? what do they transmit?
restiform body
info to cerebellum from the spinal cord rather than the cortex
How does info from the cortex transmit to the cerebellum?
cortex –> ipsilateral pontine nuclei –> contralateral middle cerebellar peduncle –> cerebellum
What does the cerebellar uncinate fasciculus connect and through which peduncle? What about the juxtarestiform body?
connects the fastigial nuclei to the contralateral vestibular nuclei and travels around the superior cerebellar peduncle, while the juxtarestiform body connects the fastigial nuclei to the ipsilateral vestibular nuclei and travels in the inferior cerebellar peduncle
What does test sensitivity measure?
Sensitivity marks how often the test is positive when the patient has the disease
What does test specificity measure?
Specificity indicates how often the test is negative when the disease is absent
What hormones are produced by the posterior pituitary gland and from which nucleus?
ADH (vasopressin) is synthesized in the supra-optic nucleus, while oxytocin is predominantly synthesized in the paraventricular nucleus
The collateral sulcus separates the:
Fusiform gyrus from the parahippocampal gyrus
Location, projections, and neurotransmitter of renshaw cells?
rexed lamina VII and VIII
provide recurrent inhibition to the α-motor neuron
release glycine, which opens chloride channels
Which vasculitides affects large and medium-sized vessels and causes interstitial keratitis, menieres, hearing loss, and cavernous sinus thrombosis?
Cogans syndrome
