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) 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) Multiple Sclerosis Chronic demyelination of CNS Characterized by remission / relapse CNS plaques formed by astrocytes Optic nerve often affected Gliosis CNS regeneration very limited in adults - Astrocytes form glial scar - Inhibits axonal regeneration - Oligodendroglia express protein that prevents axonal growth 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 Peripheral nerve regeneration Best when crushed (CT sheaths intact) Schwann cells very critical: - undergo mitosis - become phagocytic - Synth. growth factors / cytokines Phantom limb Neuroma! (Peripheral nerve fails to regen.) Treatment for parkinson's: Dopamine vs. L-dopa Blood-brain barrier - dopamine can't cross Klinefelter's syndrome XXY or XXXY (male) mild effects (extra X converted to barr bodies) 1^st Degree Burn Damage to superficial epidermis Stratum germinativum still viable Regenerates epidermis 2^nd Degree Burns Epidermis completely destroyed Remnants of glands/hair follicles in dermis Regenerates the epidermis 3^rd Degree Burns Destroys epidermis & dermis Skin grafts typically needed Hypovolemia / Shock - 15% body area (adults) - 10% body area (children) Basal Cell Carcinoma 70% of skin cancers Arise only in regions w/ sebaceous glands Age > 40, fair skin Eyelids / bridge of nose Seldom metastasize Squamous Cell Carcinoma 20% of skin cancers Epithelium replaced w/ pleomorphic cells Cells can penetrate dermis (late stage) 2-5% metastasize to regional LN Malignant Melanoma 2% of skin cancers Very metastatic - neural crest origin (migratory cells) - cells invade dermis (blood / lymph) Hyporeflexia / areflexia Indicates problem with spinal segment(s) being tested Hyperreflexia Indicates UMN problem Flexor withdrawal crossed extensor reflex Polysynaptic reflex - stimulus causes flexor withdrawal reflex - controlateral extensor neurons are fired Maintain balance / posture UMN injury Injury of corticospinal system Above decussation = contralateral paralysis of limbs Below decussation = ipsilateral paralysis below lesion Sensory Loss Injury to spinal cord Contralateral loss of pain / temperature Ipsilateral loss of fine touch / proprioception / vibration (Ipsilateral paralysis below lesion) T6 Hemisection Corticospinal Tract - ipsilateral paralysis Dorsal Column - ipsilateral loss fine touch / proprioception / vibration Anterolateral Column - Contralateral loss crude touch / temperature / pain BELOW T6! Most definitive index of meningitis PMN leukocytes in CSF Lumbar Puncture L4 or below Subarachnoid (thecal sac) Caudal Epidural - Outside of thecal sac (below S2) - Selective nerve block w/o affecting spinal cord Spinal Epidural Anesthetic placed in subarachnoid Loss of resistance passed ligamentum flavum Artery of Ademkiewicz Spinal cord supply (horiz. comp.) Arises on left @ T12 / L1 in 65% of people Damage to this artery can cause paralysis 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 Horner's Syndrome Injury to neurons / axons of superior cervical ganglia Sympathetics knocked-out / parasympathetics unopposed 1. Ptosis (drooping eyelid) 2. Miosis (small pupil) Hirschsprung's Disease Congenital aganglionic megacolon Failure of neural crest cells to migrate to distal colon 1:5000 births Affects males more (4:1) Achalasia Onset 25-60 y/o Loss of myenteric neurons (Auerbach's plexus) in lower esophagus Lower esophageal sphincter paralyzed in constriction Esophagus dilated 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 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) Most common cause of radiculopathies Vertebral disc herniations Neuropathies Caused by pathology affecting a peripheral nerve Sensory Dysfunction: - burning / tingling radiates in nerve distribution - involve adjacent dermatomes Motor Dysfunction: - cause paralysis Both radiculopathies & neuropathies can cause _________ - sensory loss (patterns are different) - atrophy - fasciculations 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 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 Breast Cancer Metastases > 75% lymph drainage via axillary nodes enlargement of axillary node indicates early metastases Risks of axillary LN excision? (metastatic breast cancer) - damage LTN - damage Thoracodorsal n. - can result in lymphedema of UE Winged Scapula - Protrusion / retraction of scapula - Inability to protract / rotate scapula - Inability to abduct UE > 90^o Caused by injury to LTN (innervates serratus anterior) LTN & lat. thoracic a. both run superficial to serratus anterior 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) 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) Loss of lateral pectoral nerve Partial denervation of pectoralis major m. (action: adduct / med. rotate UE) Pectoralis minor m. intact!!! (action: stabilize scapula) Erb's Palsy C5 (C6) brachial plexus injury This causes the limb to be...: - adducted - medially rotated - elbow extended (only if C6 is involved) - forearm pronated (waiter's tip) Klumpke's Palsy C7 / C8 (T1) brachial plexus injury - chiefly affect muscles of forearm / hand - Horner's Syndrome may accompany if T1 is involved 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 Wrist Drop Radial N. Injury (@ radial groove) - Triceps paresis (medial head) - Extensor muscle paralysis (wrist drop) 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) Common site of venipuncture? Careful not to go too far! Why? Median cubital vein (above biceps aponeurosis) (TAN) Biceps tendon, brachial a., median n. 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!!! Claw Hand Ulnar N. Injury - (commonly in cubital tunnel) Patient can't flex DIP of 4^th - 5^th 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! Dupuytren's Contracture Thickening of palmar fascia Surgery needed to free the fingers Carpal Tunnel Syndrome Compression of Median N. w/in tunnel Compartment Syndrome Bleeding in muscle compartment increases pressure. Causes decreased tissue perfusion (venous & arterial) distal to injury Surgical Emergency! (ischemia) Fasciotomy Anatomical center of gravity Anterior to S2 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) 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 Positive Trendelenburg Gait / Sign Gluteus medius muscle weakness causes pelvis to drop to contralateral side (superior gluteal n. injury) Riders Bones Ossification of adductor tendons chronic irritaion / inflamation Common Fibular N. Injury "Foot Drop" - inability to dorsiflex / evert foot Causes "toe drag" gait Most common nerve injury of the lower limb Varicose Veins Incompetent valves in LE veins Gravity takes over