NBME (First Aid Content) Flashcards
A kind of learning where a natural response is elicited by a conditioned stimulus that was previously presented in conjunction with an unconditioned stimulus
Classical conditioning
Neurotransmitter changes in Alzheimer’s
Decreased ACh, increased glutamate
List an example of classical conditioning in PTSD
Something along the lines of flinching or ducking (natural response) in response to loud noises (learned stimulus) that were experienced in combat in the context of gunshots or explosions (unconditioned stimulus)
Learning in which an action is elicited because it produces a punishment or reward
Operant conditioning
Neurotransmitter changes in Parkinson disease
Decreased dopamine, increased ACh
List an example of negative reinforcement that might be used to convince a prisoner to speak in an interrogation situation
Remove the prisoner’s chains or other painful conditions every time that the prisoner speaks
A doctor notices that his patient reminds him of his younger brother - what is this called?
Countertransference
A teenager is angry at her sister, so she goes to kickboxing class to let out her anger. What is this called, and is it mature or immature?
Sublimation - mature ego defense
What are the four mature ego defenses?
Sublimation, Altruism, Suppression, Humor
A man feels guilty about his diet and his inability to lose weight, so he decides to donate to a charity to help people suffering from food insufficiency. What is this called, and is it mature or immature?
Altruism - mature ego defense
An 8-year-old has difficulty focusing and sitting still in school, and is fidgety and impulsive at home. His father says that he helps himself to sugary snacks even when he is told not to, and appears to not have good control over his impulses. He has been struggling in school, and has been sent to the office twice this month for acting out or acting impulsively. What diagnosis do you suspect, and how might you treat it?
Attention deficit hyperactivity disorder - onset before age 12, with hyperactivity, impulsivity, and/or inattention in multiple settings. Treat with stimulants (methylphenidate) and CBT, could also use atomoxetine, guanfacine, clonidine
Neurotransmitter changes in depression
Decreased norepinephrine, decreased 5-HT, decreased dopamine
Neurotransmitter changes in anxiety
Increased norepinephrine, decreased GABA, decreased 5-HT
Mid-line hand wringing is a key stereotyped behavior of which condition?
Rett Syndrome - X-linked dominant, seen almost exclusively in girls
Neurotransmitter changes in Huntington disease
Decreased GABA, decreased ACh, increased dopamine
Neurotransmitter changes in schizophrenia
Increased dopamine
A patient projects her feelings about her mother onto her psychiatrist - what is this called?
Transference
Decreased cognitive functioning without changes in level of consciousness, characterized by memory deficits, apraxia, aphasia, agnosia, behavior or personality changes, impaired judgment
Dementia
Treatment of delirium
Identify and treat underlying condition, use haloperidol as needed, use benzodiazepines for delirium tremens in alcohol withdrawal
List an example of how positive punishment and negative punishment might be used to teach a child not to throw food on the floor
Positive punishment: Say “No!” loudly every time the kid throws food
Negative punishment: Take away dessert every time the kid throws food on the floor
Herniation of the cerebellar vermis through the foramen magnum with aqueductal stenosis, leading to hydrocephalus
Chiari II malformation - often associated with lumbosacral meningomyelocele
Reversible causes of dementia-like symptoms
Hypothyroidism, depression, vitamin B12 deficiency, neurosyphilis
Distorted perception of reality characterized by delusions, hallucinations, and/or disorganized thinking
Psychosis
Hallucinations that can occur when waking up from sleep
Hypnopompic
How long do symptoms of schizophreniform disorder have to last in order to make a diagnosis?
1-6 months
Pain and popping sensation on internal rotation of tibia
Lateral meniscal tear
List an example of positive reinforcement that you might use to teach a child to be toilet trained
Child might receive a sticker or other small prize, or even just verbal praise, every time they successfully use the toilet
How long do symptoms of schizoaffective disorder have to last in order to make a diagnosis?
> 2 weeks
Fracture of this carpal bone in a fall on an outstretched hand can damage the ulnar nerve
Hook of the hamate
Patient with flattened deltoid, loss of shoulder abduction, loss of sensation in lateral arm
Axillary nerve injury - will also damage teres minor
Mental health complication of frequent cannabis use in teens
Schizophrenia and psychosis
Waxing and waning level of consciousness with acute onset, decreased attention span, decreased level of arousal, disorganized thinking, may have hallucinations, cognitive dysfunction
Delirium
First-line schizophrenia treatment
Atypical antipsychotics such as risperidone
Dislocation of this bone can cause carpal tunnel
Lunate
Nerve injury with fractured surgical neck of humerus
Axillary (C5-6)
Baker’s cyst location
Gastrocnemius-semimembranosus bursa, in the popliteal fossa
Positive symptoms of schizophrenia
Delusions, hallucinations, disorganized speech, disorganized or catatonic behavior (need at least one of the first 3 plus another or negative symptoms to make the diagnosis)
Pain after repetitive extension of elbow
Lateral epicondylitis - tennis elbow
Duration of symptoms necessary for classification as a manic episode
At least one week
Infant born with a tuft of hair at the L3 level of the mid-back. What is the disorder? If the mother had gotten an AFP test during pregnancy, what would the result have been?
Spina bifida occulta. Bony spinal canal didn’t close, but there is no herniation of the meninges or the spinal cord. SB occulta would have a normal maternal AFP, unlike the other two forms of spina bifida.
Widening of medial joint space of knee
MCL tear
A mother is folate-deficient and her infant is born with a neural tube closure defect on the lower mid-back. If the baby is diagnosed with a meningocele, what does that mean? What about a myelomeningocele?
Meningocele - meninges, but no neural tissue, herniated through the bony defect.
Myelomeningocele - meninges and neural tissue herniated through. This kid might not even have skin over the defect.
Hallucinations that can occur while going to sleep
Hypnagogic
4 bones that, when fractured, are probably at the highest risk of developing avascular necrosis
Femoral neck fracture; scaphoid fracture; navicular bone fracture, talus fracture
Agenesis of the cerebellar vermis with massive cystic enlargement of the 4th vesicle, such that it fills the posterior fossa, displacing the cerebellum and occipital nerve upwards
Dandy-Walker malformation. Often associated with non communicating hydrocephalus and spina bifida
Initial abduction of arm
Supraspinatus - suprascapular nerve
Widening of lateral joint space of knee
LCL tear
How long do symptoms of schizophrenia have to last in order to make a diagnosis?
> 6 months
Empty can test assesses this muscle
Supraspinatus
Pain after repetitive flexion of elbow
Medial epicondylitis - golfer’s elbow
Negative symptoms of schizophrenia
Flat affect, lack of volition, anhedonia, asociality, alogia
Most commonly fractured carpal bone, prone to avascular necrosis
Scaphoid bone
Loss of sensation of lateral forearm, loss of forearm flexion and supination
Musculocutaneous nerve injury, probably due to upper trunk compression
Duration of symptoms necessary for classification of a hypomanic episode
At least 4 consecutive days
Pain and popping sensation on external rotation of tibia
Medial meniscal tear
Pathophysiology and imaging of schizophrenia
Associated with increased dopamine, decreased dendritic branching, ventriculomegaly on brain imaging
Knee ligament extending from lateral femoral condyle to anterior tibia
ACL
Knee ligament extending from medial femoral condyle to posterior tibia
PCL
Pathologic finding elicited by valgus maneuver
MCL injury
Pathologic finding elicited by varus maneuver
LCL injury
Rotator cuff muscle that laterally rotates arm
Infraspinatus
Carpal bone immediately proximal to first metacarpal
Trapezium
Carpal bone immediately proximal to second metacarpal
Trapezoid
Carpal bone proximal to third metacarpal
Capitate
Carpal bone proximal to fourth and fifth metacarpals
Hamate
Radial nerve injury presentation
Wrist drop, decreased grip strength, loss of sensation on posterior arm/forearm and distal hand
Nerve injury causing wrist drop
Radial nerve
Nerve injury causing decreased grip strength
Radial nerve
Nerve injury causing thenar atrophy and inability to make a fist with first three fingers
Proximal Median nerve injury
Nerve injury causing inability to extend digits 4 and 5 in the hand
Distal Ulnar nerve injury
Nerve injury causing inability to extend digits 1-3 in the hand
Distal Median nerve injury
Nerve injury causing inability to make a fist with fingers 4 and 5
Proximal Ulnar nerve injury
Fracture of medial epicondyle of humerus
Proximal ulnar nerve injury -> inability to make a fist with fingers 4 and 5 (OK gesture)
Fractured hook of hamate
Distal ulnar nerve injury -> inability to extend digits 4/5 (ulnar claw)
Supracondylar fracture of humerus
Proximal median nerve injury -> can’t make a fist with first three fingers (Benediction hand)
Wrist laceration
Distal median nerve injury -> can’t extend digits 1-3 in the hand (median claw)
Superficial laceration of palm
Thenar atrophy -> inability to do opposition, flexion, or abduction of thumb, but no loss of sensation
Sensation to lateral half of dorsal hand (not counting digits 2 and 3)
Radial nerve
Wrist drop
Radial nerve injury
Midshaft fracture of humerus
Radial nerve injury
Using crutches that are inappropriately large
Radial nerve injury
Loss of abduction and adduction of fingers
Ulnar nerve injury - it innervates the interossei
Loss of sensation over hypothenar eminence
Ulnar nerve injury
Loss of forearm flexion and supination
Musculocutaneous nerve injury
Compression of the upper trunk of the brachial plexus
Musculocutaneous nerve injury -> loss of forearm flexion and supination, loss of sensation to lateral forearm
Arm hanging at side, medially rotated, extended, and pronated
Erb’s palsy - tear of upper trunk (C5-6), can occur in infants during delivery. Leads to deficits of deltoid and supraspinatus (loss of abduction), infraspinatus (loss of lateral rotation), biceps brachii (loss of flexion and supination)
Total claw hand
Klumpke palsy - tear of C8-T1/lower trunk, can occur with an upward force on a baby’s arm during delivery or due to upward forces in trauma. Leads to deficits of intrinsic hand muscles: lumbricals, interossei, thenar muscles, hypothenar muscles.
Atrophy of intrinsic hand muscles, and ischemia, pain, and edema in the affected arm
Thoracic outlet syndrome: compression of lower trunk and subclavian vessels. Will look the same as Klumpke’s palsy.
Patient with a claw hand and vascular insufficiency to that arm
Thoracic outlet syndrome
Winged scapula
Damage to long thoracic nerve, leading to serratus anterior deficit. Patient cannot abduct arm above horizontal position.
Function of lumbricals at MCP joints
flexion
Function of lumbricals at PIP and DIP joints
extension
Decreased sensation to medial thigh, decreased adduction at hip
Obturator nerve injury (L2-4 anterior division fibers)
Decreased thigh flexion at hip and leg extension
Femoral nerve injury (L2-4 posterior division fibers)
Inability to curl toes, loss of sensation on plantar foot, loss of inversion, loss of plantarflexion
Proximal injury to tibial nerve. Foot will appear everted and dorsiflexed at rest.
Inability to curl toes and loss of sensation to plantar foot, but inversion and plantarflexion are intact
Distal tibial nerve injury, probably due to tarsal tunnel syndrome
Fibular neck fracture resultant nerve injury
Common peroneal nerve injury
Foot drop with loss of eversion and dorsiflexion, loss of sensation on dorsum of foot
Common peroneal nerve injury
Nerve deficit from Baker cyst
Tibial nerve injury
Nerve deficit from compression of lateral leg
Common peroneal nerve injury
Trendelenburg sign
Pelvis tilts downward on one side. Lesion is CONTRALATERAL to the side of the hip that drops down, which is not the side the patient is standing on. Due to weakness of aBduction in the weight-bearing leg.
Superior gluteal nerve injury
Trendelenburg sign
Difficulty climbing stairs and rising from seated position, with loss of hip extension
Inferior gluteal nerve injury or problem with gluteus maximus
Site for IM injection in gluteal muscle in order to avoid nerve injury
Superior lateral gluteal quadrant
Direction that intervertebral discs generally herniate
Posterolaterally
Injury at disc level L3/4 affects what nerve?
L4
Injury at disc level L4/5 affects what nerve?
L5
Injury at disc level L5/S1 affects what nerve?
S1
Radiculopathy with weakness of knee extension and decreased patellar reflex
L4 radiculopathy
Radiculopathy with weakness of dorsiflexion, can’t walk on heels
L5 radiculopathy
Radiculopathy with weakness of plantarflexion, can’t walk on toes, decreased Achilles reflex
S1
Artery that runs with long thoracic nerve
Lateral thoracic artery
Artery that runs with axillary nerve
Posterior circumflex artery
Artery that runs with radial nerve
Deep brachial artery
Artery that runs with median nerve
Brachial artery
Artery that runs with tibial nerve
Popliteal artery in popliteal fossa -> posterior tibial artery posterior to the medial malleolus
Muscle fibers that do mostly oxidative phosphorylation
Type I - slow twitch red fibers with increased myoglobin and mitochondria
Muscle fibers that do mostly anaerobic glycolysis
Type II - fast twitch white fibers with less mitochondria and myoglobin
Bone formation of long and short bones
Endochondral ossification
Cartilagenous bone model then replaced with woven bone, which is then replaced with lamellar bone
Endochondral ossification
Woven bone
bone type that occurs in endochondral bone formation, after fractures
Bone formation of skull, flat bones
Woven bone formed directly without cartilage -> intermembranous ossification
Bone cell that differentiates from mesenchymal stem cells in periosteum
Osteoblast
Osteoblast function
Build bone by secreting collagen, manage bone signaling
Osteoclast function
Resorb bone by secreting H+
PTH function at low, intermittent levels
Builds bone
PTH function at overly high levels
Leads to bone catabolism/resorption
Hormone that inhibits apoptosis in osteoblasts and induces apoptosis in osteoclasts
Estrogen
FGFR3 mutation
Achondroplasia: failure of endochondral ossification due to inhibition of chondrocyte proliferation
Bone mineral density with a T score of less than or equal to -2.5
Osteoporosis
Osteoporosis prophylaxis
Weight-bearing exercise, calcium, vitamin D
Acute back pain, loss of height, kyphosis
Vertebral compression fracture
Treatment of osteoporosis
Bisphosphonates, teriparatide, SERMS, denosumab
Thickened and dense bones that are prone to fracture, with pancytopenia
Osteopetrosis (due to defective osteoclasts with mutations in carbonic anhydrase, etc)
Osteopenia in adults, with defective mineralization of osteoid
Osteomalacia
Defective mineralization of cartilagenous growth plates leading to epiphyseal widening and bow-legs
Rickets
Vitamin D, calcium, PTH, phosphate, and ALP levels in osteomalacia or rickets
Low vitamin D, low calcium, high PTH, low phosphate, high ALP
Most common site of osteonecrosis
Femoral head
Causes of osteonecrosis
Corticosteroids, alcoholism, sickle cell, trauma, the bends, idiopathic, Gaucher disease, slipped femoral epiphysis
Radiographs of osteonecrosis
Bone looks like there’s been a bite taken out of it
Serum calcium, phosphate, ALP, and PTH in primary hyperparathyroidism
Calcium high, phosphate low, ALP high, PTH high
Serum calcium, phosphate, ALP, and PTH in secondary hyperparathyroidism
Calcium low, phosphate high, ALP high, PTH high
Serum calcium, phosphate, and PTH in an excess of vitamin D (oversupplementation or granulomatous disease)
Calcium high, phosphate high, PTH low
Osteoarthritis or rheumatoid arthritis: mechanical wear and tear causes it
Osteoarthritis
Osteoarthritis or rheumatoid arthritis: autoimmune mechanism
Rheumatoid arthritis
Osteoarthritis or rheumatoid arthritis: risk factors include age, being female, obesity, trauma
Osteoarthritis
Osteoarthritis or rheumatoid arthritis: risk factors include being female, HLA-DR4, smoking, RF, CCP
Rheumatoid arthritis
Osteoarthritis or rheumatoid arthritis: pain in weight-bearing joints after use
Osteoarthritis
Osteoarthritis or rheumatoid arthritis: pain and morning stiffness/swelling get better with use
Rheumatoid arthritis
Osteoarthritis or rheumatoid arthritis: osteophytes, joint space narrowing, begins medially in knee, subchondral sclerosis, low WBCs in synovial fluid
Osteoarthritis
Osteoarthritis or rheumatoid arthritis: Erosions, cysts, high WBCs in synovial fluid
Rheumatoid arthritis
Treatment for osteoarthritis
Acetaminophen, NSAIDs, glucocorticoid injections
Joints most commonly involved in osteoarthritis
Knee, hip, DIPs, PIPs, first carpometacarpal joint
Joints most commonly involved in rheumatoid arthritis of the hand
MCP, PIP, wrist
Negatively birefringent, needle-shaped, yellow under parallel light crystals
Uric acid -> gout
Positively birefringent, rhomboid, blue under parallel light crystals
Calcium pyrophosphate
Common pathogens for septic arthritis
S. aureus, Streptococcus, N. gonorrhoeae
Purulent synovial fluid, WBC > 50,000
Septic arthritis
Gonococcal arthritis presentations
Septic arthritis (knee) or reactive arthritis (polyarthralgias, tenosynovitis, rash)
Pain and stiffness in shoulders and hips in an older woman, without weakness, with high ESR and CRP, that responds quickly to low-dose corticosteroids
Polymyalgia rheumatica (associated with giant cell arteritis)
Treatment for fibromyalgia
Exercise, therapy, TCAs, SNRIs
Endomysial inflammation with CD8+ T cells, progressive symmetric proximal weakness
Polymyositis
Perimysial inflammation and atrophy, CD4+ T cells, heliotrope rash, Gottron papules, symmetric proximal weakness
Dermatomyositis
A diagnosis of dermatomyositis suggests you should do what?
Work patient up for an occult malignancy
Autoantibodies to post-synaptic ACh receptor
Myasthenia gravis
Ptosis, diplopia, and weakness that worsens with muscle use
Myasthenia gravis
Treatment for myasthenia gravis
Pyridostigmine
Pyridostigmine MOA
Acetylcholinesterase inhibitor
Proximal muscle weakness with autonomic symptoms; improves with muscle use
Lambert-Eaton syndrome
Autoantibodies to pre-synaptic Ca++ channel lead to decreased ACh release
Lambert-Eaton syndrome
Muscles affected most in Lambert-Eaton
proximal large muscles
Muscles affected most in myasthenia gravis
Extraocular muscles
Malignancy associated with Lambert-Eaton syndrome
small cell lung cancer
Reversible cyclooxygenase inhibitor that is analgesic but not anti-inflammatory and is metabolized in the liver
Acetaminophen
Irreversible COX1 and COX2 inhibitor
Aspirin
COX2-selective NSAID used in osteoarthritis and rheumatoid arthritis
Celecoxib
Adverse effects of non-aspirin NSAIDs
Interstitial nephritis, gastric ulcer, renal ischemia
MOA of bisphosphonates
Pyrophosphate analogs that bind hydroxyapatite and inhibit osteoclasts
Side effects of bisphosphonates
Osteonecrosis of jaw, atypical stress fractures
MOA of teriparatide
Recombinant PTH analog that increases osteoblast activity
Preventative gout drugs
Allopurinol and Febuxostat (xanthine oxidase inhibitors)
Acute gout drugs
NSAIDs (naproxen, indomethacin), glucocorticoids, colchicine
Sensory and motor deficits in a child with meningomyelocele
At/below the level of the meningomyelocele
Neural cells derived from neuroectoderm
CNS neurons, ependymal cells/choroid plexus, oligodendrocytes, astrocytes
Neural cells derived from neural crest
PNS neurons, Schwann cells
Neural cells derived from mesoderm
Microglia
Two markers that are elevated in amniotic fluid in spina bifida
AFP, fetal acetylcholinesterase
Mutations in sonic hedgehog signaling pathway causing a failure of left and right hemispheres to separate
Holoprosencephaly
Syndromes with holoprosencephaly
Patau syndrome, fetal alcohol syndrome
Cranial nerves that sense taste
CN VII, IX, X
Cranial nerves sensing pain to the tongue
CN V3, IX, X
Cranial nerves providing motor innervation to the tongue
CN, X, XII
Wallerian degeneration
An injury to an axon causes it to degenerate distal to the injury, leading to axonal retraction proximally
Neural cell responsible for physical support and blood-brain barrier
Astrocytes
Neural cell that serves the function of a macrophage
Microglia
How does myelin affect conduction velocity?
Increases it
Cell that myelinates CNS
Oligodendrocytes
Cell that myelinates PNS
Schwann cells
How many axons can a Schwann cell myelinate?
Only 1
Cell type that may be injured in Guillain-Barre syndrome
Schwann cells
C-type free nerve endings
Slow, unmyelinated fibers that sense pain and temperature
Adelta type free nerve endings
Fast, myelinated fibers that sense pain and temperature
Large myelinated fibers that adapt quickly and sense light touch and position sense
Meissner corpuscles
Large myelinated fibers that adapt quickly and sense vibration and pressure
Pacinian corpuscles
Large myelinated fibers that adapt slowly and sense pressure, static touch (shapes, edges, etc), position sense
Merkel discs
Dendritic endins with a capsule that adapt slowly and sense pressure, objects moving along the surface of skin, and joint angle changes
Ruffini corpuscles
Inflammatory infiltrate is within this layer in Guillain-Barre syndrome
Endoneurium (at the level of single fibers)
This layer surrounding nerves must be rejoined in microsurgery for nerve or limb repair
Perineurium
This layer of tissue surrounds entire nerves - fascicles and microvasculature
Epineurium
Location of ACh synthesis
Basal nucleus of Meynert
Location of dopamine synthesis
Ventral tegmentum, SNpc (substantia nigra pars compacta)
Location of GABA synthesis
Nucleus accumbens
Location of norepinephrine synthesis
Locus coeruleus
Location of serotonin synthesis
Raphe nucleus
Disease states with decreased ACh
Alzheimer’s, Huntington’s disease
Disease states with increased ACh
Parkinson’s disease
Disease states with decreased dopamine
Depression, Parkinson’s disease
Disease states with increased dopamine
Schizophrenia, Huntington’s disease
Disease states with decreased GABA
Anxiety, Huntington’s disease
Disease states with increased norepinephrine
Anxiety
Disease states with decreased norepinephrine
Depression
Disease states with increased serotonin
Parkinson’s disease
Disease states with decreased serotonin
Anxiety, Depression
3 structures that form the blood-brain barrier
Tight junctions between capillary endothelial cells; basement membrane; astrocyte foot processes
Chemicals made by the hypothalamus
ADH, oxytocin
Paraventricular nucleus of hypothalamus
Makes oxytocin
Supraoptic nucleus of hypothalamus
Makes ADH
Where are ADH and oxytocin stored and released?
Posterior pituitary
Function of lateral area of hypothalamus
Sense of hunger. Stimulated by ghrelin, inhibited by leptin. If you destroy it, you starve yourself
Function of ventromedial hypothalamus
Sense of satiety. Stimulated by leptin. If you destroy it, you eat too much
Function of anterior hypothalamus
Cooling, parasympathetics
Function of posterior hypothalamus
Heating, sympathetic
Function of suprachiasmatic nucleus of hypothalamus
Circadian rhythm
What area of the brain controls extraocular movements in REM sleep?
PPRF (paramedian pontine reticular formation/conjugate gaze center) in the pons
Describe the trends in REM and NREM sleep throughout the night
You start by entering NREM sleep. REM sleep occurs every 90 minutes and its duration increases throughout the night.
How is melatonin release regulated?
Suprachiasmatic nucleus -> NE release -> acts on pineal gland -> melatonin release, all regulated by the circadian rhythm
Affects of alcohol, benzos, and barbiturates on sleep
Decreases REM sleep and delta wave sleep
EEG waveform when awake with eyes open
Beta waves - highest frequency, lowest amplitude
EEG waveform when awake with eyes closed
Alpha waves
EEG waveform when in NREM stage N1
Theta waves
EEG waveform in NREM stage N2
K complexes and sleep spindles
EEG waveform in NREM stage N3
Delta waves - lowest frequency, highest amplitude
EEG waveform in REM sleep
Beta waves - looks like when awake
Disorders of NREM sleep
Sleepwalking, night terrors, bedwetting
Characteristics of REM sleep
Loss of motor tone, increased use of O2 by brain, increased and variable pulse and blood pressure, this is when dreaming occurs
Describe the path of neurons passing through the ventral posterolateral nucleus of the thalamus
These are neurons from the spinothalamic (decussates 1-2 levels above SC input) and dorsal column tracts (dorsal columns decussate at the medial lemniscus). Carrying pain and temperature (spinothal) and pressure, touch, vibration, proprioception (dorsal columns). The neurons whose cell bodies are in the thalamus synapse in the primary somatosensory cortex.
Describe the path of neurons passing through the ventral posteromedial nucleus of the thalamus
These are trigeminal/taste sensation nuclei - face and taste - headed to the primary somatosensory cortex.
Describe the path of neurons passing through the lateral geniculate nucleus of the thalamus
These are inputs from CN II carrying vision, destined for the calcarine sulcus.
Describe the path of neurons passing through the medial geniculate nucleus of the thalamus
Inputs from the superior olive and inferior colliculus, containing information about hearing, destined for the auditory cortex.
Describe the path of neurons passing through the ventral lateral nucleus of the thalamus
These are neurons from the basal ganglia and the cerebellum carrying information about motor regulation and feedback, destined for the motor cortex.
5 Fs of the limbic system
Feeding, Fleeing, Fighting, Feeling, …Sex
Decreased activity of the nigrostriatial pathway
Extrapyramidal symptoms like dystonia, akasthisia, parkinsonism, tardive dyskinesia
Major dopaminergic pathway of brain
Nigrostriatial pathway
Primary therapeutic target of antipsychotic drugs
Mesolimbic dopaminergic pathway
Pathway whose dysfunction is responsible for “negative” symptoms
Decreased activity of mesocortical pathway
Pathway whose dysfunction is responsible for “positive” symptoms
Increased activity of mesolimbic pathway
Patient presentation of a left-sided lateral cerebellar lesion
Will fall toward the left (ipsilateral) due to impact on voluntary movement of extremities
Patient presentation of a medial or midline cerebellar lesion
Lesion involves vermis, other midline structures, and/or flocculonodular lobe, so patient will have a wide-based gait (truncal ataxia), nystagmus, head tilting, bilateral motor defects (axial and proximal limbs)
Input from the contralateral motor cortex to the cerebellum enters the cerebellum via:
middle cerebellar peduncle
Input from the spinocerebellar tracts enters the cerebellum via:
inferior cerebellar peduncle
Output via Purkinje cells -> deep nuclei of cerebellum -> contralateral cortex leaves cerebellum via:
superior cerebellar peduncle
Describe the excitatory pathway of the basal ganglia
Cortical inputs stimulate GABA release from striatum, inhibiting GABA release from GPI, which disinhibits the thalamus, leading to increased motion
Describe the inhibitory pathway of the basal ganglia
Cortical inputs stimulate the striatum to release GABA that disinhibits the subthalamic nucleus by inhibiting GPe, and since the subthalamic nucleus is disinhibited, that stimulates the GPi to inhibit movement
Dopamine binding to D1
stimulation of excitatory pathway
Dopamine binding to D2
inhibition of inhibitory pathway
Lesion of basal ganglia preventing the inhibitory pathway of the basal ganglia
Sudden jerky purposeless movements -> chorea, like in Huntington’s disease
Contralateral subthalamic nucleus lesion
Hemiballismus - half of body (arm and/or leg) undergoes sudden wild flailing because there is damage to the inhibitory pathway
Cerebellar dysfunction might produce this type of tremor
Intention tremor
Intention tremor
Slow, zigzag motion when trying to point at a target (like in nose-finger test)
Sudden, brief, uncontrolled muscle contraction
Myoclonus
Tremor seen in Parkinson’s disease
Resting tremor - uncontrolled movement of distal appendages
Dysfunction to this basal ganglia function occurs in Parkinson’s disease
Dysfunction of excitatory pathway, due to lack of dopamine production in the SNlc
Intracellular eosinophilic inclusions composed of alpha-synuclein in neurons
Lewy bodies, seen in Parkinson’s disease and Lewy Body Dementia
Disorder with depigmentation of substantia nigra pars compacta and Lewy bodies
Parkinson disease
Presentation of Parkinson disease
Tremor at rest, rigidity (cogwheel sign), akinesia/bradykinesia, postural instability, shuffling gait
Trinucleotide repeat (CAG) disorder on chromosome 4 that is autosomal dominant
Huntington disease
Part of the brain impacted in Huntington disease
Caudate nucleus - loses ACh and GABA production, and has increased dopamine, leading to lack of the inhibitory pathway of the basal ganglia
Pathology on autopsy or imaging in Huntington disease
Atrophy of caudate and putamen, hydrocephalus ex vacuo
Patient with choreiform movements, aggression, depression, and dementia
Huntington disease
Cause of neuronal death in Huntington disease
NMDAR binding and glutamate excitotoxicity
Nonfluent aphasia with intact comprehension, impaired repetition
Broca’s aphasia
Fluent aphasia with impaired comprehension, impaired repetition
Wernicke’s aphasia
“It… hard… … talk”
Broca’s aphasia
“I want to elevator because talk blue”
Wernicke’s aphasia
Lesion location in Broca’s aphasia
inferior frontal gyrus of frontal lobe
Lesion location in Wernicke’s aphasia
superior temporal gyrus of temporal lobe
Fluent aphasia with intact comprehension but impaired repetition
Conduction aphasia
Lesion location in conduction aphasia
Arcuate fasciculus
Nonfluent aphasia with impaired comprehension and impaired repetition
Global aphasia - affects arcuate fasciculus, Broca’s area, and Wernicke’s area
Nonfluent aphasia with intact comprehension and intact repetition
Transcortical motor aphasia
Lesion location in transcortical motor aphasia
Frontal lobe around Broca’s area, but not Broca’s area itself
Fluent aphasia with impaired comprehension but intact repetition
Transcortical sensory aphasia
Lesion location in transcortical sensory aphasia
Temporal lobe around Wernicke’s area, but not Wernicke’s area itself
Nonfluent aphasia with impaired comprehension but intact repetition
Transcortical mixed aphasia
HSV encephalitis may cause disinhibited behavior as a result of damage to this structure
Amygdala
Lesion to frontal lobe
Disinhibition, defects in concentration/orientation/judgment
Lesion to nondominant (usually R) parietal cortex
Hemispatial neglect syndrome
Lesion to dominant parietal cortex
Agraphia, acalculia, finger agnosia
Lesion to reticular activating system in the midbrain
Coma - reduced levels of arousal and wakefulness
Confusion, ophthalmoplegia, truncal ataxia, memory loss, personality changes
Wernicke-Korsakoff syndrome - associated with thiamine deficiency and excessive alcohol use
How can you accidentally induce Wernicke encephalopathy?
Giving glucose without thiamine to a patient who is thiamine deficient (like a long-term alcoholic)
Lesion to mamillary bodies
Wernicke-Korsakoff syndrome
Lesion to cerebellar hemisphere
Intention tremor, limb ataxia, loss of balance, defects are ipsilateral to the lesion
Lesion to cerebellar vermis
Truncal ataxia and dysarthria, other central body defects
Lesion to subthalamic nucleus
Contralateral hemiballismus
Lesion to hippocampus
Anterograde amnesia
Lesion to paramedian pontine reticular formation
Eyes look away from the side of the lesion
Lesion to frontal eye fields
Eyes look toward the lesion
Normally, pressure of which gas drives cerebral perfusion?
PCO2
Consequence of decreased BP or increased ICP
Decreased cerebral perfusion pressure
Equation for Cerebral Perfusion Pressure
CPP = MAP - ICP
CPP = 0
Brain death - no cerebral perfusion
How to treat acute cerebral edema that’s unresponsive to other interventions
Therapeutic hyperventilation to decrease PCO2 -> vasoconstriction -> cerebral blood flow decreases -> ICP decreases
Severe hypotension can damage which areas of the brain first?
Watershed areas between the territories supplied by the cerebral arteries
Anteromedial surface of brain supplied by:
Anterior cerebral artery
Lateral surface of brain supplied by:
Middle cerebral artery
Posterior and inferior surface of brain supplied by:
Posterior cerebral artery
A stroke producing aphasia is likely where?
MCA, in dominant hemisphere. Temporal lobe if fluent aphasia (Wernicke), frontal lobe if nonfluent aphasia (Broca)
An MCA stroke in the non-dominant hemisphere could produce what finding, in addition to contralateral paralysis and sensory loss?
Hemineglect
A stroke producing contralateral paralysis/sensory loss of the face and upper limb is likely where?
MCA
A stroke producing contralateral paralysis/sensory loss of the lower limb is likely where?
ACA
A stroke producing contralateral paralysis/sensory loss of the face and body without cortical signs (neglect, aphasia, visual field loss) is likely where?
Lenticulostriate artery
A pure motor stroke would impact what area?
Internal capsule - lacunar infarct
A stroke with contralateral hemianopia would be due to which vessel?
PCA
A stroke with “locked-in syndrome” - conscious, but with vertical eye movement and blinking, and with quadriplegia and paralysis of most of the face, would be due to which vessel?
Basilar artery
A stroke with facial droop, decreased lacrimation and salivation, decreased taste would likely be due to which vessel?
Anterior inferior cerebellar artery - facial nucleus effects are specific to AICA
A stroke with dysphagia and hoarseness, as well as ipsilateral Horner syndrome, and decreased pain and temperature of ipsilateral face and contralateral body, would be from which vessel?
Posterior inferior cerebellar artery - nucleus ambiguus effects are specific to PICA
Contralateral paralysis and decreased contralateral proprioception, with a tongue deviating ipsilaterally, would be due to a stroke in which vessel?
Anterior spinal artery
Location of a berry aneurysm
Bifurcations in the circle of Willis, most commonly where anterior communicating artery and ACA join
“Worst headache of my life” in a patient with ADPKD or Ehler-Danlos
Berry aneurysm rupture causing subarachnoid hemorrhage
An aneurysm of the ACA might compress which structures?
Optic chiasm, causing visual acuity defects and bitemporal hemianopia
An aneurysm of the PCA might compress which structures?
CN III - blown pupil (mydriasis), with ptosis, and eye pointing down and out. This is an ipsilateral CN III palsy.
Lentiform area of hyperdensity on CT that does not cross suture lines
Epidural hematoma
Rupture of this artery most commonly causes epidural hematoma
Middle meningeal
Rupture of these vessels causes subdural hematoma
Bridging veins
Intracranial hemorrhage in shaken babies
Subdural hematoma
Crescent hemorrhage crossing suture lines
Subdural hematoma
Brain distortion that occurs in subdural hematoma
Midline shift
Rupture of what can cause a subarachnoid hemorrhage?
AV malformation, or aneurysm
“Worst headache of my life”
Subarachnoid hemorrhage
Star-shaped hyperdensity on CT near midline
Subarachnoid hemorrhage due to bursting of a saccular aneurysm
Hemorrhagic stroke that can result from systemic hypertension
Intraparenchymal hemorrhage
Areas that are typically affected by intraparenchymal hemorrhage
Basal ganglia, internal capsule; can be lobar
Area of brain most vulnerable to hypoxia
Hippocampus
Imaging procedure with a stroke
Noncontrast CT to exclude hemorrhage must be done before tPA can be given
Conditions under which you can give tPA
Within 3 hours of onset of the stroke, no hemorrhage, no substantial risk of hemorrhage
Ways to reduce risk of ischemic stroke
Antithrombotic medications (aspirin, clopidogrel), control blood pressure and blood sugars and lipids, treat conditions like afib that increase risk
Headache, seizures, focal neurologic deficits in a patient with factor V Leiden disease
May have venous sinus thrombosis
Main location of CSF return to venous circulation
Arachnoid granulations in the superior sagittal sinus
Cells that make CSF
Ependymal cells of choroid plexus
Interventricular foramen, aka foramen of Monro
Connections between lateral ventricles and third ventricle
Cerebral aqueduct, aka Sylvian aqueduct
Connection between 3rd and 4th ventricles
Foramina of Lushcka and Foramen of Magendie
Connections between the 4th ventricle and subarachnoid space (Luschka is lateral, Magendie is medial)
Increased ICP with no apparent cause on imaging in a woman of childbearing age
Pseudotumor cerebri (aka idiopathic intracranial hypertension)
Papilledema and increased opening pressure on LP
Pseudotumor cerebri
What does a lumbar puncture accomplish in pseudotumor cerebri?
Reveals the increased opening pressure, provides headache relief, may be able to treat it
RFs for pseudotumor cerebri
Female of childbearing age, vitamin A excess, danazol, tetracycline
Headache, diplopia with CN VI palsy, papilledema, no change in mental status
Increased ICP… Could be pseudotumor cerebri
Treatment for pseudotumor cerebri
Weight loss, acetazolamide, topiramate, shunt placement, repeat lumbar puncture
Mechanism of communicating hydrocephalus
Less CSF absorption by arachnoid granulations leads to increased ICP, papilledema, herniation. Can occur with arachnoid scarring after meningitis.
Urinary incontinence, ataxia (magnetic gait - feet stuck to floor), and cognitive dysfunction in an elderly patient with CSF pressure normal/occasionally elevated
Normal pressure hydrocephalus. Ventricles are expanded, distorting the corona radiata
Structural blockage of CSF within the ventricular system
Noncommunicating hydrocephalus
Vertebral level at which the spinal cord ends
L1-L2
Vertebral level to which the subarachnoid space extends
S2
Vertebral levels for lumbar puncture
L3/4 or L4/5
Voluntary motor tract in the lateral part of the spinal cord
Lateral corticospinal tract (sacral most outside radially, cervical most medial)
Voluntary motor tract in the anterior part of the spinal cord
Anterior corticospinal tract
Ascending fibers for pressure, vibration, touch, and proprioception
Dorsal columns - fasciculus gracilis and cuneatus
Ascending tracts for pain and temperature
Lateral spinothalamic tract
Ascending tract for crude touch and pressure
Anterior spinothalamic tract
Sympathetic neurons in the spinal cord
Lateral horn, T1-L2
Where do the dorsal column fibers decussate?
Medial lemniscus
Where do the dorsal column and spinothalamic neurons synapse in the thalamus?
VPL
Where do the spinothalamic tract fibers decussate?
At anterior commissary
Nerve endings whose sensations are transmitted in spinothalamic tract
Free nerve endings -Adelta and C fibers
Where do descending fibers of the lateral corticospinal tract decussate?
Decussate on of the pyramids
Weakness, atrophy, fasciculations, hyporeflexia, negative Babinski sign, flaccid paralysis
LMN signs
Weakness, hyperreflexia, increased muscle tone, positive Babinski, spastic paralysis
UMN signs
What kind of clinical signs would occur with a lesion that only affects the anterior horn bilaterally?
Affects LMNs only, so LMN signs -> floppy, fasciculations, hypotonia, hyporeflexia, atrophy, etc.
Where does spinal cord damage occur in polio?
Anterior horn, bilaterally
Where does spinal cord damage occur in ALS?
Lateral corticospinal tracts and anterior horn
What kind of deficits are present in ALS?
UMN defects due to lesions in lateral corticospinal tract
LMN defects due to lesions in anterior horn
Treatment for ALS
Riluzole - not curative
Asymmetric limb weakness, especially hands and feet, fasciculations, and progressive atrophy over time due to a defect in superoxide dismutase 1
ALS
Complete occlusion of the anterior spinal artery would damage which tracts?
Everything except for the dorsal columns: pressure, vibration, touch, and conscious proprioception would be preserved at levels above and below the lesion, but everything else would be impaired.
Tertiary syphilis can cause what spinal cord lesion?
Tabes dorsalis - demyelination of dorsal columns and dorsal nerve roots, leading to sensory ataxia due to impaired proprioception, and sensory defects for all kinds of sensory fibers at the level of the lesion.
Charcot joints, shooting pain, abnormal pupils, no deep tendon reflexes, positive Romberg test
Tabes dorsalis
What kind of a lesion is caused in syringomyelia?
Central lesion of the spinal cord damaging the anterior commissure, leading to bilateral loss of pain and temperature at the level of the lesion
What kind of a lesion is present in vitamin B12 deficiency?
Subacute combined degeneration - demyelination of spina cerebellar, lateral corticospinal, and dorsal column tracts. Patients have impaired position and vibration sense, paresthesias, and ataxic gait.
What kind of a lesion is present in Brown-Sequard syndrome?
Hemisection of the spinal cord - ipsilateral UMN signs below the level of lesion due to loss of corticospinal tracts, ipsilateral loss of tactile/vibration/proprioception sense below the level of lesion due to loss of dorsal columns, contralateral loss of pain and temperature below the lesion due to spinothalamic tract loss, ipsilateral loss of all sensation as well as presence of LMN signs at the level of the lesion itself.
Brown-Sequard syndrome above T1 may produce what additional finding?
Ipsilateral Horner syndrome due to damage to oculosympathetic pathway
Biceps reflex
C5 nerve root
Triceps reflex
C7 nerve root
Patellar reflex
L4 nerve root
Achilles’ tendon reflex
S1 nerve root
Function of superior colliculi
Conjugate vertical gaze center
Function of inferior colliculi
Auditory signal integration
Cranial nerves that are purely sensory
I, II, VIII
Cranial nerves that are purely motor
III, IV, VI, XI, XII
Cranial nerves that have both motor and sensory components
V, VII, IX, X
Function of solitary nucleus
Viscerosensory info (taste, baroreceptors, etc) to VII, IX, X
Function of nucleus ambiguus
Motor innervation of pharynx, larynx, upper esophagus (IX, X, XI)
Corneal reflex
Afferent V1, efferent VII
Lacrimation reflex
Afferent V1, efferent VII
Pupillary light reflex
Afferent II, efferent III
Gag reflex
Afferent IX, efferent X
Cranial nerve lesion causing jaw to deviate to the right
CN V motor on the right side, jaw will deviate TOWARD the lesion
Cranial nerve lesion causing uvula to deviate to the right
CN X lesion on the left; uvula will deviate away because the weakened side collapses
Cranial nerve lesion causing weakness when turning head to the left, and shoulder droop on the right
CN XI lesion on the right side
Cranial nerve lesion causing tongue to deviate toward the right
CN XII lesion on the right side
Contralateral paralysis of lower muscles of facial expression, sparing the forehead
Upper motor neuron lesion of CN VII, due to destruction of motor cortex or the connection between the motor cortex and the facial nucleus in the pons. Forehead is spared because it is bilaterally innervated by CN VII UMNs.
Ipsilateral paralysis of upper and lower muscles of facial expression with loss of taste sensation to anterior tongue.
Lower motor neuron lesion of CN VII, due to destruction of the facial nucleus or CN VII anywhere along its course.
Idiopathic CN VII LMN lesion
Bell’s palsy (treat with corticosteroids and acyclovir)
Structures that pass through the cavernous sinus
CN III, IV, VI, V1, V2, internal carotid artery
Nerve most susceptible to injury in cavernous sinus syndrome
CN VI
How does the outer ear transfer sound waves?
Vibration of tympanic membrane
How does the middle ear transfer sound?
Ossicles conduct and amplify the sound
How does the inner ear conduct sound?
Basilar membrane in the cochlea vibrates due to the sound waves, and the vibrations are transduced via hair cells into signaling along CN VII.
Area of the cochlea that best hears low-frequency sounds
At the apex, near the helicotrema
Area of the cochlea that best hears high-frequency sounds
At the base of the cochlea
Abnormal Rinne test (increased conduction through the bone), and abnormal Weber test localizing sound to the affected ear
Conductive hearing loss
Normal Rinne test, and Weber test localizes to the unaffected ear
Sensorineural hearing loss
Where is aqueous humor produced?
Nonpigmented epithelium on ciliary body
Factors that decrease aqueous humor production
Beta blockers, alpha-2 agonists, carbonic anhydrase inhibitors
How does aqueous humor leave the anterior chamber?
Through the angle of the anterior chamber, either by passing through the trabecular mesh work or by draining into the urea and sclera
Light is focused behind the retina due to an eye that is too short along the AP axis
Hyperopia (farsighted)
Light is focused in front of the retina, due to an eye that is too long in the AP direction
Myopia (nearsightedness)
Abnormal curvature of cornea causing different refractive power at different axes
Astigmatism
Age-related impairment in accommodation due to decreased lens elasticity
Presbyopia
Ciliary flush, sudden painful vision loss, halos, nausea and vomiting, rock-hard eye
Acute angle closure glaucoma
Itchy red eyes bilaterally with clear discharge
Allergic conjunctivitis
Red eye with purulent discharge
Bacterial conjunctivitis, treat with ABX
Virus most responsible for viral conjunctivitis
Adenovirus
Swollen preauricular LNs, sparse mucous discharge, and red eye
Viral conjunctivitis - self-resolving
Accumulation of pus in anterior chamber
Hypopyon
Hypopyon and/or conjunctival redness in patients with a history of systemic inflammatory disorders (think HLA-B27)
Uveitis/iritis
Slowly progressive metamorphopsia and eventual loss of central vision
Age-related macular degeneration
Rapid loss of vision due to bleeding beneath choroidal neovascularization
Wet macular degeneration - treat with anti-VEGF injections
Retinal hemorrhages and macular edema in a diabetic patient
Nonproliferative diabetic retinopathy - treat with blood sugar control
Neovascularization and chronic retinal hypoxia in a diabetic patient
Proliferative diabetic retinopathy
Compression from hypertension or retinal artery atherosclerosis leads to retinal hemorrhage and venous engorgement with edema
Central retinal venous occlusion
Separation of the photoreceptor layer of the retina from the outermost pigmented epithelium leading to vision loss, appearing as crinkling of retinal tissue on fundoscopic exam
Retinal detachment - often preceded by posterior vitreous detachment (flashes and floaters)
Treatment of flashes/floaters/curtain
Emergent retinal detachment - Urgent ophtho surgery referral
Acute painless monocular vision loss with a cloudy pale retina and a cherry-red spot at the fovea
Central retinal artery occlusion
Marcus Gunn pupil
Afferent pupillary defect from optic nerve damage or retinal injury
Conditions associated with Horner syndrome
Lesions of spinal cord above T1 - Pancoast tumor, Brown-Sequard syndrome, etc
down and out gaze
CN III damage
blown pupil
Damage to parasympathetics running on outside of cranial nerve III
Eye moving upward with contralateral gaze, head tilt toward the side of the lesion (or compensatory head tilt in opposite direction)
CN IV damage
Medially directed eye that cannot abduct
CN VI damage
Medial longitudinal fasciculus
Allows for crosstalk between CN VI and III to coordinate eyes to move in the same horizontal direction. Is highly myelinated.
Horizontal gaze palsy where the ipsilateral lateral rectus is activated, but the contralateral medial rectus is not, leading to nystagmus in the abducting eye, with normal convergence.
Internuclear ophthalmoplegia
ApoE2 association with Alzheimer’s
Decreases risk
ApoE4 association with Alzheimer’s
Increases risk
Risk factors for Alzheimer’s
Down syndrome, APP, presenilin-1, presenilin-2
Dementia with widespread cortical atrophy, decreased ACh, and senile plaques in grey matter with beta amyloid extracellularly and neurofibrillary tangles (tau protein) intracellularly
Alzheimer’s disease
Early onset changes in personality or behavior or aphasia with degeneration of frontotemporal lobe
Frontotemporal dementia
Dementia and hallucinations followed by Parkinsonian features
Lewy body dementia
Histological finding in Lewy body dementia
Intracellular Lewy bodies, made of alpha-synuclein, in the cortex
Multiple cortical and/or subcortical infarcts on MRI or CT over an extended period of time, with dementia symptoms that have a step-wise progression
Vascular dementia
Charcot triad of MS
Scanning speech, intention tremor/incontinence/internuclear ophthalmoplegia, nystagmus
CSF findings in multiple sclerosis
Increased IgG and myelin basic protein, with oligoclonal bands
Things that are diagnostic of multiple sclerosis
MRI is gold standard; oligoclonal bands are diagnostic
Destruction of Schwann cells leads to inflammation and demyelination of peripheral nerves and motor fibers, leading to symmetric ascending muscle weakness/paralysis, maybe with autonomic dysfunction
Acute inflammatory demyelinating polyradiculoneuropathy (Guillain-Barre syndrome)
Tx for Guillain-Barre syndrome
Plasmapheresis, IVIG
Autosomal dominant motor and sensory neuropathy associated with foot deformities
Charcot-Marie-Tooth disease
Acute unilateral headache, 15 min-3 hours in a repetitive pattern, with excruciating periorbital pain, lacrimation, and rhinorrhea, and maybe Horner syndrome
Cluster headache
Bilateral headache lasting around 4-6 hours, with steady constant pain, no photophobia, and no aura
Tension headache
Unilateral headache lasting 4-72 hours, with pulsating pain, nausea, photophobia, phonophobia, may have aura
Migraine headache
Type of headache due to release of substance P, calcitonin gene-related peptide, vasoactive peptides (or due to irritation of CN V, meninges, or vasculature)
Migraine
Acute treatment of cluster headache
Supplemental O2 and sumatriptan
Acute treatment of tension headache
Analgesics, NSAIDs, acetaminophen, can use amitriptyline for chronic pain
Acute treatment of migraine headache
NSAIDs, fluids, triptans, dihydroergotamine
Cluster headache prophylaxis
Verapamil
Migraine headache prophylaxis
Lifestyle changes, beta blockers, calcium channel blockers, amitriptyline, topiramate, valproate
Positional or central vertigo: delayed horizontal nystagmus on positional testing
Peripheral vertigo
Positional or central vertigo: directional change of nystagmus, skew deviation, diplopia, dysmetria
Central vertigo
Most common type of highly malignant brain tumor
Glioblastoma multiforme (grade IV astrocytoma)
Typically benign brain tumor arising from arachnoid cells that is often asymptomatic or may present with seizures or focal neurologic deficits
Meningioma
Highly malignant cerebellar tumor in children that is a form of primitive neuroectodermal tumor
Medulloblastoma
Childhood supratentorial tumor derived from remnants of Rathke pouch that can cause bitemporal hemianopia
Craniopharyngioma
Ependymal cell tumor found in the 4th ventricle that can cause hydrocephalus and has a poor prognosis
Ependymoma
Prognosis for a pilocytic astrocytoma in children
Good prognosis
Consequence of cingulate/subfalcine herniation under the falx cerebri
Can compress ACA
Consequence of transtentorial (central) herniation
Caudal displacement of brainstem -> rupture of basilar artery branches -> usually fatal
Consequences of uncal herniation
Compression of CN III (blown pupil with down-and-out gaze), ipsilateral PCA compression leading to contralateral homonymous hemianopia, contralateral compression of crus cerebri leading to ipsilateral paresis
MOA of opioids
Agonists at opioid receptors modulate synaptic transmission -> lead to opening of K channels and closing of Ca channels to decrease synaptic transmission -> decrease release of ACh, NE, 5HT, glutamate
MOA of tramadol
very weak opioid agonist, inhibits 5HT and norepinephrine reuptake
Risks associated with tramadol
Decrease seizure threshold, serotonin syndrome
What side effects of opioids do people not develop tolerance to?
Miosis and constipation
MOA of benzodiazepines
Facilitate GABA-A action by increased frequency of Cl- channel opening
Benzo used for status epilepticus
Lorazepam, Diazepam
Drug to treat benzodiazepine overdose
Flumenazil
Drug that can treat malignant hyperthermia
Dantrolene - ryanodine receptor antagonist
Drugs for Parkinson disease
Ergot (bromocriptine) or non-ergot (pramipexole, ropinirole) - dopamine agonists
Increased dopamine release and decreased dopamine reuptake: amantadine
Levodopa/carbidopa: levodopa is converted to dopamine in the CNS, and carbidopa prevents it from being coverted to dopamine in the periphery by inhibiting DOPA decarboxylase
Alzheimer’s drugs
Memantine (NMDA receptor antagonist), donepezil or rivastigmine or galantamine (AChE inhibitors)
Drug that can be used for Huntington disease
Haloperidol - D2 receptor antagonist
MOA of sumatriptan
5HT1B/1D agonist
Symptoms of alcohol withdrawal
Severe withdrawal can cause autonomic hyperactivity and delirium tremens - treat with benzos emergently
Side effects of lithium
Tremor, nephrogenic diabetes insipidus, hypothyroidism, teratogenicity
