Block 2 Diseases

Ulnar Canal Syndrome

Ulnar Canal Syndrome

Guyon Tunnel Syndrome

Injury to ulnar tunnel (nerve and artery)

Hypoesthesisa (medial 1.5 fingers)

Weakness causing clawing of 4 & 5 digits

Organophosphate Poisoning

Inactivates AChE→ increase acetylcholine → overstimulates nicotinic + muscarinic receptors

Muscle tremors

Increased sweating, saliva, tears

Decreased pupil size

Trauma to Medial Epicondyle

Produces paresthesia (numbness/tingling)

Decreased wrist Adduction and flexi on

Claw hand

Cannot make fist or flex 4/5 digit

Pure Autonomic Failure

decrease in sympathetic post-ganglionic neurons→ decrease in norepi

Hypotension

Bladder dysfunction

Decrease sweating

Pheochromocytoma

Neuroendocrine tumor

Diagnose from excess catecholamines

“Hypertension”

Sweating

Headache

Intermittent Schemia

Raynaud Syndrome (if idiopathic)

Arterial and arteriolar contraction

Aggravated by cold and emotional stress

Sympathetic nerves

Post-ganglionic sympathetic fibers

White fingers → loss of O2 → blue fingers → tingling/swelling/throbbing

Scaphoid

Most commonly fracture carpal bone

Fall on outstretched hand

Pain on lateral wrist with flexion and abduction

Dupuytren Contracture Palmar Fascia

Degeneration of longitudinal bands of palmar aponeurosis

Shorter and thicker aponeurosis and palmar fascia

Ring and pinky finger are most affected

Anterior Interosseus Syndrome

Median Nerve Injury

Okay sign is pinched instead of circular

Decreased flexion of IP joint in thumb and DIP of index finger

Referred pain

Cross talk by viscerosensory fibers and somatosensory input

Visceral problem (heart attack) is felt as pain in chest/left arm

Pronator Teres Syndrome

Nerve entrapment caused by Median Nerve compression at elbow by heads of pronator teres

After repeated allow movements

Cubical Tunnel Syndrome

Ulnar Nerve entrapment

Prior fracture/dislocation at elbow

Decreased sensation at pinky and ring finger

Slight claw hand

Supinator syndrome

PIN Syndrome

Posterior Interosseous Nerve

Pain and weakness in wrist/finger

NO sensory loss

Digital Synovial Sheath Infection

Inflammation of tendon and synovial sheath

Separate synovial sheath of 2/3 and 4 fingers

Median Nerve Palsy

Cannot flex DIP of index finger

Cannot flex 2/3 digit into fist

Synovial Cyst on Wrist

Contains clear mucinous fluid

Flexion can enlarge cyst and cause pain

Close to synovial sheath

Wrist drop

Lesion of radial nerve, loss of cutaneous sensation

Lesion of posterior interosseous nerve, NO loss of cutaneous sensation

Anatomical Snuff Box

Can assess fracture of trapezium and scaphoid

Contains radial artery and superficial branch of radial nerve and cephalic vein

Can find pulse of radial artery

Hyperhidrosis

Increased sweating on hands/feet

Treat with anticholinergics

Stretch Reflex

Important for testing spinal cord levels

Patellar knee jerk @ L4 → femoral nerve

AC Separations

Grade 1: strain AC ligament

Grade 2: rupture AC ligament

Grade 3: rupture AC + coracoclavicular ligament

Glenohumeral dislocations

90% anterior

Adhesive Capsulities

Frozen shoulder

Restricted active+ passive ROM

3 stages: freezing, frozen, thawing

Associated with hypothyroidism

Neurofibromatosis Type 1

Autosomal dominant

Mutation in cell cycle regulatory protein

Variable expression

Axillary freckling

Cafe au lait spots

Multiple neurofibromatosis

Lisch nodules in eyes

Marfan Syndrome

Autosomal dominant

Mutation in fibrillin gene (ECM and connective tissue)

Pleiotropy

Skeletal abnormalities

Long/thin limbs + fingers

Hyper mobile joints

Myopia + d

Hemophilia A & B

Gene defect in blood clotting factor VII (A) and IX (B)

Prolonged bleeding

Intracranial hemorrhage

Easy brushing

Hemoarthosis - bleeding in joints, swelling, loss of mobility

AIDS is most frequent cause of death

Factor replacement therapy via infusion

A-Thalassemia

Poor synthesis of alpha chain

Accumulation of b-globin tetra ears

• more soluble and less toxic than b-thalassemia

Entire gene deletion is most common

6 genotypes:

1. Normal (aa/aa)

2. Silent Carrier (-a/aa)

   1. Asymptomatic

   2. Normal RBC

3/4. A-Thalassemia trait (-a/aa), (—/aa)

Asymptomatic

Same as b-thalassemia minor

5. HbH disease (—/-a)

   1. Severe

   2. Same as b-thalassemia intermediate

6. Hydrops Fetalis (—/—)

   1. Fatal at birth

B-Thalassemia

Poor b-chain synthesis

Accumulation of a-chain tetramers

• very insoluble and more toxic than a-thalassemia

Increased death of RBC

Hemolytic anemia

Decreased hemoglobin

Excess alpha-globin

3 Major Types:

1. Thalassemia Minor (B/Bo)

   1. Asymptomatic or mild anemia

2. Thalassemia Major (Bo/Bo)

   1. Decreased b-globin or fully absent

   2. Increased RBC

   3. Enlarged liver and spleen

   4. Face and skull deformities

   5. Increased iron absorption

   6. Treat with iron chelation therapy

3. Thalassemia Intermedia (B+/B+), (B+/Bo)

   1. Varies between major and minor

Duchenne Muscular Dystrophy

Insertions or elections cause frameshift

NOT a factor of 3

X-linked (mutations usually inherited from mother)

Becker Muscular Dystrophy

Insertion to deletions cause frameshift

ARE factor of 3

Mild compared to DMD

Muscle atrophy

Fragile X Syndrome

Trinucleotide repeat expansion in 5’ NCR

Long face

Large mandible

Large everted ears

Marco-orchidism in males

Most common inherited cause of mental impairment

Most common known cause of autism

X-linked recessive- males

Ehlers Danlos Syndrome

Locus heterogeneity: same disease phenotype from mutations at different genes

Autosomal dominant: collagen gene mutation

Autosomal recessive: Lysyl hydroxylase mutation in ER

X-linked recessive: mutation in copper-binding protein reduces available Cu → decreases cross-linking via lysyl oxidase

Myotonic Dystrophy

Anticipation: most recent generation shows earlier onset + most severe symptoms

Increase in repeats = increase in disease severity and onset

Trinucleotide repeat in 3’NCR

Most common adult muscular dystrophy

creates RFLP after restriction digest

No PCR because repeat is too large

Cystic Fibrosis

Genetic mutation

Results in defective Cl ion channel

Improper folding and assembly of CFTR → degradation of Cl transport protein

Diagnostic hallmark is elevated Cl in sweat

Mucus accumulation in lungs

3 nucleotide deletion in CFTR gene → missing phenylalanine

Down Syndrome

Autosomal Trisomy

Trisomy 21

Most common genetic cause of cognitive impairment

Short stature

Decrease IQ

Flat profile

Slated eyes

Congenital heart defects

Increased risk of leukemia

High survival rate past age 30

Methemoglobinemia

Elevated methemoglobin in RBC

Low O2 affinity (deoxy form)

Autosomal recessive

Blood remains blue color when exposed to air

• Blood with lack of O2 will turn red when exposed to air

Acquired form: from oxidative stress (drugs, antibiotics, trimethoprim, anesthetics, nitrates)

Congenital form: deficiency NADH methemoglobin reductase, pyruvate kinase deficiency, treat with methylene blue: e- donor to reduce methemoglobin to normal hemoglobin (HbA with Fe)

Edwards Syndrome

Autosomal trisomy

Trisomy 18

Commonly death at birth

Prominent occiput

Smooth mouth and ears

Congenital heart

Internal organ defects

Clenched fists and overlapping fingers

Rocker bottom feet

PKU

Blood test for elevated phenylalanine and low tyrosine

Mutation in phenylalanine hydroxylase gene

Marker is added or lost restriction site

Blue Baby Syndrome

Babies more prone because elevated nitrate in water and food

No enzymes developed to protect against disease

Ellis Van Creveld Disease

Rare autosomal recessive

Genetic drift: finite population sizes

Polydactyl

Short limbed dwarfism

EVC gene

HIV

Exposure produces Ab against HIV

ELISA screening

2nd test with Western Blot

Immunoassay uses enzyme that recognizes HIV Ab after incubation

Patau Syndrome

Autosomal trisomy

Trisomy 13

Commonly death at birth

Oral-facial clefts

Small eyes

Polydactyl

Heart and organ defects

Sickle Cell Anemia

Mutation in b-globin gene

Creation of RFLP that is used for diagnosis

Southern blot: B-globin probe

PCR: MstII enzyme

ASO: probe for HbS

Klinefelter Syndrome

Sex chromosome aneuploidy

Long arms and legs

Breast development (gynecomastia)

Lower IQ

Turner syndrome

45, X

Short stature

Webbed neck

Lymphedema of ankles and wrists

Sterility

47, XYY Males

Sex chromosome aneuploidy

Essentially normal but tall

Mild social problems

47, XXX Females

Sex chromosome aneuploidy

Essentially normal

Increased schizophrenia problems

Avascular necrosis

Osteonecrosis

Bone tissue dies due to lack of blood supply

Usually in hip joint

Common after femoral neck fracture because damage of medial circumflex femoral artery + retinacular artery

Patellar Tendon Reflex

Tap on patellar ligament causes knee jerk

Tests femoral nerve and L2-L4 segments

Absence of reflex can be from any interruption to quad innervation

Piriformis Syndrome

Compressed sciatic nerve

Pain and numbness in butt and legs

• • sign is external rotation of foot

Femoral Neck Fracture

Due to osteoporosis or age

Shorter limb + laterally rotated

Can tear retinacular arteries

Trendelenburg Sign

Stand on 1 foot

• • if hip tilts down on lifted leg

Damage to superior gluteal nerve → glute medius + minimus

CANNOT abduct hip on standing leg

Intragluteal Injection

Always inject upper lateral quadrant

Avoids superior gluteal nerve and sciatic nerve

Arthritis

1. Rheumatoid

   1. Autoimmune inflammation narrows concentric joint space

   2. Worse after rest

   3. MCP, PIP, Hips, elbow, spine

2. Osteoarthritis

   1. Wear + tear narrows asymmetric joint space

   2. Worse after activity

      1. Hips, knees, DIP (herbenden’s nodes), PIP (Bouchard’s nodes)

Nursemaid’s elbow

Pain with arm supination

Arm is forcibly pulled by picking up child/swinging

Displaced annular ligament

Carpal Tunnel Syndrome

Median nerve entrapment

Tingling/pain of first 3.5 digits

Prayer test

De Quervain’s Tenosynovitis

Gamer’s Thumb

Pain/swelling at thumb

Tenosynovitis in Abductor Pollicis Longus + Extensor Pollicis Brevis

From repetitive hand motions + hormonal changes

• Finkelstein Test (passive + physician directed)

  • Eichhoff’s Test (active + patient directed)

Epicondylitis

1. Medial: pain with flexion → Golfer’s elbow

   1. Lateral: pain with extension → Tennis elbow

Swan-neck

Common in Rheumatoid Arthritis

Flexion of MCP + DIP

Extension of PIPB

Cystic Fibrosis

3’ nucleotide deletion in CFTR gene → missing phenyalanine

ASO probe

PCR for gene deletion

Autosomal Recessive

Down Syndrome

Trisomy 21

Most common genetic cause of mental incapacitation

Increased risk of leukemia or congenital heart defects

Edwards Syndrome

Trisomy 18

clenched fists + overlapping fingers

Rocker bottom feet

Ellis Van Creveld Disease

Rare Autosomal Recessive

Genetic Drift: finite population sizes

Polydactyl

Short limbed dwarfism

EVC gene

HIV

ELISA screening, 2nd test Western blot

Immunoassay uses enzyme that recognizes HIV Ab after incubation

Patau Syndrome

Trisomy 13

Oral Facial defects

Klinefelter Syndrome

47, XXY

long arms and legs

sterile and small testes

gynecomastia

Turner Syndrome

45, X

short stature

webbed neck

sterility

47, XYY

Males

essentially normal but tall

mild social problems

47, XXX

Females

essentially normal

increased schizophrenia problems

Venous Stasis

usually great saphenous vein

pooling of blood in lower leg

due to decreased activity/muscle contraction

can cause blood clots/thrombosis

Intragluteal Injection

always inject upper lateral quadrant

avoids superior gluteal nerve and sciatic nerve

Arthritis

1) Rheumatoid

Autoimmune inflammation narrows concentric joint space

Worse after rest

MCP, PIP, Hips, elbow, spine

2) Osteoarthritis

wear and tear narrows asymmetric joint space

worse after activity

hips, knees, DIP (herbenden’s), PIP (bouchard’s)

Nursemaid’s Elbow

pain with arm supination

arm is forcibly pulled by picking up child/swinging

displaced annular ligament

Carpal Tunnel Syndrome

median nerve entrapment

tingling/pain of first 3.5 digits

prayer test

Epicondylitis

1) Medial: pain with flexion → Golfer’s Elbow

2) Lateral: pain with extension → Tennis Elbow

Boutonniere

common in Rheumatoid Arthritis

Extension of MCP + DIP

Flexion of PIP

Results from rupture of extensor tendon