Neuromuscular, Neurocutaneous, and spinal cord diseases

Question 1

What is pathophysiology of myasthenia gravis

Answer 1

Autoantibodies against nicotinic acetylcholine receptors at NMJ junction, fatigue through day, better with rest

Question 2

What is the most common and most common initial symptoms, and what can it be limited to in elderly ppl for myasthenia gravis

Answer 2

Extraocular eye muscles, with ptosis, diplopia, and blurred vision

Question 3

What goes weak and what is preserved in myasthenia gravis

Answer 3

Skeletal muscles weak, sensation and reflexes preserved

Question 4

How are limb muscles affected in myasthenia gravis

Answer 4

Proximal and Asymmetric

Question 5

Other symptoms of myasthenia gravis besides eye symptoms

Answer 5

Dysarthria, dysphagia, and generalized weakness

Question 6

What is myasthenia crisis and what percent of patients does it occur in?

Answer 6

An exacerbation of myasthenia gravis with respiratory muscles affected, requiring intubation15%

Question 7

Four diagnostic modalities of myasthenia gravis

Answer 7

1. ) Acetylcholine antibody test - specific, 20% beat it
2. ) EMG - shows decremental conduction of motor nerves
3. ) Edrophonium test - acetylcholine esterase inhibitor, improves symptoms but not used
4. ) CT to see if thymoma is present - 75% have abnormal histology, 15% have actual thymoma

Question 8

Treatment for myasthenia gravis (Five things)

Answer 8

1. ) AChE inhibitor - symptoms only - pyridostigmine
2. ) Thymectomy - symptoms and remission, do even when there is no thymoma
3. ) Immunosuppressive drugs - corticosteroids second line, azathioprine and cyclosporine third line
4. ) Plasmapharesis - removes antibodies, last resort
5. ) IV immunoglobulins - myasthenia crisis

Question 9

What is the forced vital capacity indication for intubation for patients with myasthenia gravis

Answer 9

Less than 15ml/kg, unless crisis, in which case do not wait

Question 10

Where are lambert-eaton’s autoantibodies directed towards

Answer 10

Presynaptic calcium channels

Question 11

Difference between symptoms of myasthenia gravis and lambert eaton

Answer 11

Lambert Eaton - improves with stimulation, hyporeflexia

Myasthenia Gravis - diminishes with stimulation, reflexes preserved

Question 12

What cancer is lambert-eaton associated with

Answer 12

Small cell lung cancer

Question 13

Gene mutation and result of duchenne’s mulscular dystrophy

Answer 13

X-linked recessive - no dystrophin, no inflammation

Question 14

Progression of muscular weakness in duchenne’s muscular dystrophy

Answer 14

Starts proximal and symmetric in children (pelvis girdle), progresses distally

Question 15

Two distinguishing features of duchenne’s muscular dystrophy

Answer 15

1. ) Gower’s maneuver - Patients use hands to get up

2. ) Enlarged calf muscles - first true hypertrophy, then pseudohypertrophy as fat replaces muscle

Question 16

Final complications of duchenne’s muscular dystrophy

Answer 16

Wheelchair bound, respiratory failure, and death in third decade

Question 17

What diagnostic lab is distinguished in duchenne’s, and what can you use to test for duchenne’s

Answer 17

Serum creatinine phosphokinase

Definitive: DNA testing

Question 18

What is the treatment used for duchenne’s muscular dystrophy

Answer 18

Prednisone - 5 years and older with declining motor skills

Surgery - fixes scoliosis, once wheelchair bound

Question 19

Similaries and differences for becker’s muscular dystrophy vs. duchenne’s muscular dystrophy

Answer 19

X-linked recessive too, less common, later onset and less severe because some dystrophin present

Question 20

What two other hereditary diseases can cause muscle weakness

Answer 20

Mitochondrial disorders: Ragged red muscle fibers

Glycogen storage diseases: Mcardle’s - muscle cramping after exercise because no glycogen phosphorylase

Question 21

What three things can exacerbate myasthenia gravis

Answer 21

1. ) Beta blockers
2. ) Antibiotics - aminoglycosides and tetracyclines
3. ) Antiarrhythmics - quinidine, procainamide, and lidocaine

Question 22

What are the genetics of neurofibromatosis type 1

Answer 22

Autosomal dominant

Question 23

What are the clinical features of neurofibromatosis type 1

Answer 23

1. ) Cafe au lait spots - pigmented spots
2. ) Neurofibromas - benign tumors of nerve sheath - treat by surgery
3. ) CNS tumors - gliomas, meningiomas
4. ) Axillary or inguinal freckling
5. ) Lisch nodules - iris hamartomas (dendritic melanocytes in iris)
6. ) Bony lesions

Question 24

What are the complications of neurofibromatosis type 1

Answer 24

1. ) Scoliosis
2. ) Pheochromocytoma
3. ) optic nerve glioma
4. ) Renal artery stenosis
5. ) Bone erosion

Question 25

What are the clinical features of neurofibromatosis type 2

Answer 25

1. ) Bilateral acoustic neuromas - classic 2. ) Multiple meningiomas 3. ) Cafe au lait spots 4. ) Neurofibromas 5. ) Cataracts

Question 26

What are the clinical features of tuberous sclerosis

Answer 26

1. ) Cognitive impairment 2. ) Epilepsy 3. ) Skin lesions (angiofibromas - papules with fibrous tissue, adenoma sebaceum)

Question 27

What are the complications of tuberous sclerosis

Answer 27

1. ) Retinal hamartoma - can lead to retinal detachment 2. ) Renal angiomyolipoma - could hemorrhage 3. ) Rhabdomyoma

Question 28

What is Sturge-Weber syndrome classic visible features

Answer 28

Facial vascular nevi (port wine stain), epilepsy, mental retardation

Question 29

What should you treat in sturge weber syndrome

Answer 29

Epilepsy

Question 30

What is the see pathologic feature of sturge-weber syndrome

Answer 30

Capillary angiomatoses of pia mater - knots of capillaries

Question 31

What are important features of von hippel-lindau disease

Answer 31

Cavernous hemangiomas of brain/brainstem, renal angiomas, and cysts in multiple organs

Question 32

What are two complications of von hippel lindau disease

Answer 32

1. ) Renal cell carcinoma | 2. )Pheochromocytoma (Think about close proximity of these)

Question 33

What is the pathophysiology of syringomyelia

Answer 33

Central cavitation of cervical cord, affecting anterior commissure (pain and temperature) at C8-T1

Question 34

What is the nerve progression of syringomyelia

Answer 34

1. ) Pain/temperature in upper extremities (C8-T1) 2. ) muscle weakness and atrophy (LMN's) 3. ) Hypothalamus tract - sympathetic - horners syndrome

Question 35

What is preserved in syringomyelia

Answer 35

Touch

Question 36

What imaging modality should you use to diagnose syringomyelia?

Answer 36

MRI, consult with neurosurgery

Question 37

What causes syringomyelia

Answer 37

Arnold chiari syndrome or trauma (including infection)

Question 38

What are causes of brown-sequard syndrome

Answer 38

Trauma, crush injury, tumors, abscesses

Question 39

What are the clinical features of brown-sequard syndrome?

Answer 39

``` Contralateral loss of pain and temperature Ipsilateral hemiparesis (corticospinal) Ipsilateral loss of position/vibration (dorsal columns) ```

Question 40

What is the pathophysiology of horners syndrome?

Answer 40

Cervical sympathetic nerves 1. ) Preganglionic - more workup required because central 2. ) Postganglionic - past superior cervical ganglion

Question 41

What are the clinical features of horners syndrome

Answer 41

Ptosis, miosis, anhidrosis (all ipsilateral) Levator palpebrae still intact

Question 42

Five causes of horners syndrome

Answer 42

1. ) Idiopathic (most cases) 2. ) Pancoast tumor 3. ) Internal carotid dissection 4. ) Brainstem stroke 5. ) Neck trauma

Question 43

What is the pathophysiology of poliomyelitis

Answer 43

Caused by poliovirus; anterior horn cells - LMNs affected

Question 44

What is affected and what is spared in poliomyelitis

Answer 44

Assymetric muscle weakness (legs more), normal sensation

Question 45

What two cranial nerves are affected by poliomyelitis

Answer 45

CN 9 and 10 - cardiovascular and respiratory problems

Question 46

Treatment or vaccination for poliomyelitis

Answer 46

Vaccination