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Most common form of primary CNS tumor in adults?
Intermediate filaments expressed by the tumor cells?
Astrocytoma 80-90% of glial tumors
Glial fibrillary acid protein (GFAP)
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What is the prognosis of astrocytoma? Why?
8-10 months survival
- - Become more anaplastic w/ time
- - Non-capsulated (difficult to resect)
- - Spread to other parts of CNS via CSF
- (seldom metastasize outside the CNS)
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Multiple Sclerosis
- Chronic demyelination of CNS
- Characterized by remission / relapse
- CNS plaques formed by astrocytes
- Optic nerve often affected
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Gliosis
- CNS regeneration very limited in adults
- - Astrocytes form glial scar
- - Inhibits axonal regeneration
- - Oligodendroglia express protein that prevents axonal growth
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Guillan-Barre Syndrome
- Acute inflammatory polyradiculoneuropathy
- Affects PNS myelin only
- Usually bilateral, symmetrical, motor weakness
- Evidence of T-cells, plasma cells and macrophages around axons
- Severe cases can lead to death
- Most cases resolve in 2-4 weeks
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Peripheral nerve regeneration
- Best when crushed (CT sheaths intact)
- Schwann cells very critical:
- - undergo mitosis
- - become phagocytic
- - Synth. growth factors / cytokines
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Phantom limb
- Neuroma!
- (Peripheral nerve fails to regen.)
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Treatment for parkinson's:
Dopamine vs. L-dopa
- Blood-brain barrier- dopamine can't cross
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Klinefelter's syndrome
- XXY or XXXY (male)
- mild effects
- (extra X converted to barr bodies)
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1st Degree Burn
- Damage to superficial epidermis
- Stratum germinativum still viable
- Regenerates epidermis
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2nd Degree Burns
- Epidermis completely destroyed
- Remnants of glands/hair follicles in dermis
- Regenerates the epidermis
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3rd Degree Burns
- Destroys epidermis & dermis
- Skin grafts typically needed
- Hypovolemia / Shock
- - 15% body area (adults)
- - 10% body area (children)
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Basal Cell Carcinoma
- 70% of skin cancers
- Arise only in regions w/ sebaceous glands
- Age > 40, fair skin
- Eyelids / bridge of nose
- Seldom metastasize
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Squamous Cell Carcinoma
- 20% of skin cancers
- Epithelium replaced w/ pleomorphic cells
- Cells can penetrate dermis (late stage)
- 2-5% metastasize to regional LN
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Malignant Melanoma
- 2% of skin cancers
- Very metastatic
- - neural crest origin (migratory cells)
- - cells invade dermis (blood / lymph)
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Hyporeflexia / areflexia
Indicates problem with spinal segment(s) being tested
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Hyperreflexia
Indicates UMN problem
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Flexor withdrawal crossed extensor reflex
- Polysynaptic reflex
- - stimulus causes flexor withdrawal reflex
- - controlateral extensor neurons are fired
- Maintain balance / posture
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UMN injury
- Injury of corticospinal systemAbove decussation = contralateral paralysis of limbs
- Below decussation = ipsilateral paralysis below lesion
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Sensory Loss
- Injury to spinal cordContralateral loss of pain / temperature
- Ipsilateral loss of fine touch / proprioception / vibration
(Ipsilateral paralysis below lesion)
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T6 Hemisection
- Corticospinal Tract- ipsilateral paralysis
- Dorsal Column- ipsilateral loss fine touch / proprioception / vibration
- Anterolateral Column- Contralateral loss crude touch / temperature / pain
BELOW T6!
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Most definitive index of meningitis
PMN leukocytes in CSF
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Lumbar Puncture
- L4 or below
- Subarachnoid (thecal sac)
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Caudal Epidural
- - Outside of thecal sac (below S2)
- - Selective nerve block w/o affecting spinal cord
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Spinal Epidural
- Anesthetic placed in subarachnoid
- Loss of resistance passed ligamentum flavum
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Artery of Ademkiewicz
- Spinal cord supply (horiz. comp.)
- Arises on left @ T12 / L1 in 65% of people
- Damage to this artery can cause paralysis
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Metastases via Batson's Plexus
- - Epidural plexus that drains spinal cord
- - Veins do NOT have valves
- - Increased intra-abd. pressure can cause reflux of blood into plexus
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Horner's Syndrome
- Injury to neurons / axons of superior cervical ganglia
- Sympathetics knocked-out / parasympathetics unopposed
- 1. Ptosis (drooping eyelid)
- 2. Miosis (small pupil)
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Hirschsprung's Disease
Congenital aganglionic megacolon
Failure of neural crest cells to migrate to distal colon
- 1:5000 births
- Affects males more (4:1)
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Achalasia
- Onset 25-60 y/o
- Loss of myenteric neurons (Auerbach's plexus) in lower esophagus
- Lower esophageal sphincter paralyzed in constriction
- Esophagus dilated
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Referred Pain
Visceral pain afferents enter spinal cord with somatic afferents
All pain fibers run w/ sympathetic system and enter spinal cord at the same segment that gives rise to preganglionic efferents
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Radiculopathy
- Caused by injury of nerve root / spinal nerve
- Sensory Dysfunction:- posterior (dorsal root) injury
- - deficit pattern is dermatomal
- - burning / tingling radiates in dermatome
- Motor Dysfunction:
- - anterior (ventral root) injury
- - may cause paresis (weakness)
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Most common cause of radiculopathies
Vertebral disc herniations
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Neuropathies
- Caused by pathology affecting a peripheral nerve
- Sensory Dysfunction:
- - burning / tingling radiates in nerve distribution
- - involve adjacent dermatomes
- Motor Dysfunction:
- - cause paralysis
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Both radiculopathies & neuropathies can cause _________
- - sensory loss (patterns are different)
- - atrophy
- - fasciculations
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40 y/o M feels sharp pain in left side of neck / weakness in LUE. ER exam shows loss of sensation over lateral aspect of left shoulder / weakness on abduction of LUE / elbow flexion. Cannot retract left scapula. LUE adduction against resistance is normal.
Where is injury? Likely cause? Diagnosis?
- - C5 spinal nerve
- - C4/5 IV disc herniation
- - C5 radiculopathy
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20 y/o M stabbed / knife blade penetrated the man’s right coracobrachialis. ER exam showed complete inability to flex right elbow or supinate right hand. He had a complete loss of sensation over lateral aspect of forearm.
Where is injury? Likely cause? Diagnosis?
- - musculocutaneous nerve
- - transection of n. as it passes thru coracobrachialis m.
- - traumatic musculocutaneous neuropathy
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Breast Cancer Metastases
- > 75% lymph drainage via axillary nodes
- enlargement of axillary node indicates early metastases
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Risks of axillary LN excision?
(metastatic breast cancer)
- - damage LTN
- - damage Thoracodorsal n.
- - can result in lymphedema of UE
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Winged Scapula
- - Protrusion / retraction of scapula
- - Inability to protract / rotate scapula
- - Inability to abduct UE > 90o
- Caused by injury to LTN (innervates serratus anterior)
- LTN & lat. thoracic a. both run superficial to serratus anterior
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Loss of lateral & medial pectoral nerves
- Total denervation of pectoralis major m.
(action: adduct / med. rotate UE)
- Total denervation of pectoralis minor m.
- (action: stabilize scapula)
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Loss of medial pectoral nerve
- Partial denervation of pectoralis major m.
- (action: adduct / med. rotate UE)
- Total denervation of pectoralis minor m.
- (action: stabilize scapula)
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Loss of lateral pectoral nerve
- Partial denervation of pectoralis major m.
- (action: adduct / med. rotate UE)
- Pectoralis minor m. intact!!!
- (action: stabilize scapula)
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Erb's Palsy
- C5 (C6) brachial plexus injuryThis causes the limb to be...:
- - adducted
- - medially rotated
- - elbow extended (only if C6 is involved)
- - forearm pronated (waiter's tip)
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Klumpke's Palsy
- C7 / C8 (T1) brachial plexus injury- chiefly affect muscles of forearm / hand
- - Horner's Syndrome may accompany if T1 is involved
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Klumpke's Palsy w/ Horner's Syndrome
- C7 - T1 brachial plexus injury
- Horner's is only present if T1 is involved
Ptosis / Miosis caused by damage of T1 White Communicating Ramus
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Wrist Drop
- Radial N. Injury (@ radial groove)- Triceps paresis (medial head)
- - Extensor muscle paralysis (wrist drop)
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Significance of venous drainage in upper limb
2 routes: deep (paired) / superficial (unpaired)
- Unpaired (superficial) drainage begins in dorsum of hands (dorsal venous network)
- Paired (deep) drainage begins in the palm of hand (deep veins)
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Common site of venipuncture? Careful not to go too far! Why?
Median cubital vein (above biceps aponeurosis)
(TAN) Biceps tendon, brachial a., median n.
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Pronator (Teres) Syndrome
- Median N. Injury (entering forearm between heads of pronator teres)- loss of DIP & PIP flexion (digits 1-3)
- - "hand of benediction"
Ulnar n. to lateral half of FDP still works!!!
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Claw Hand
- Ulnar N. Injury - (commonly in cubital tunnel)
- Patient can't flex DIP of 4th - 5th digits (FDP medial half)Also, wrist adduction impaired (FCU); wrist abducts when trying to flex
If trauma is in distal forearm, most intrinsic hand muscles will be denervated!
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Dupuytren's Contracture
- Thickening of palmar fascia
- Surgery needed to free the fingers
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Carpal Tunnel Syndrome
Compression of Median N. w/in tunnel
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Compartment Syndrome
- Bleeding in muscle compartment increases pressure.
- Causes decreased tissue perfusion (venous & arterial) distal to injury
- Surgical Emergency! (ischemia)
- Fasciotomy
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Anatomical center of gravity
Anterior to S2
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Significance of venous drainage in lower limb
2 routes: Superficial vs. Deep
Superficial veins in subcutaneous tissue (superficial fascia)
Deep veins accompany arteries below the deep fascia (fascia lata & crural fascia)
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Osgood-Sclatter's Disease
- Disruption of the epiphyseal plate at the tibial tuberosity in adolescence.
- May cause inflammation of the tuberosity and chronic recurring pain, especially in young athletes
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Positive Trendelenburg Gait / Sign
- Gluteus medius muscle weakness causes pelvis to drop to contralateral side
- (superior gluteal n. injury)
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Riders Bones
- Ossification of adductor tendons
- chronic irritaion / inflamation
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Common Fibular N. Injury
- "Foot Drop" - inability to dorsiflex / evert foot
- Causes "toe drag" gait
Most common nerve injury of the lower limb
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Varicose Veins
Incompetent valves in LE veins
Gravity takes over
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