Neuromuscular Diseases

Question 1

Muscular Dystrophy

Answer 1

Hereditary
Painless degeneration and atrophy of skeletal muscles

Hyperkalemia with Sux
May be susceptible to MH

Question 2

What is the most common and most severe muscular dystrophy?

Answer 2

Duchenne’s Muscular Dystrophy

Question 3

Duchenne’s Muscular Dystrophy

Answer 3

X-linked recessive
Diagnosed in early childhood

TLC and RV are decreased
Recurrent pulmonary infections
Risk for aspiration
Myocardial dysfunction

Hyperkalemia with Sux
May be susceptible to MH

Question 4

Multiple Sclerosis

Answer 4

Random and multiple sites of demyelination of corticospinal tract neurons in the brain and spinal cord - EXCLUSIVE of the peripheral neurons
Autoimmune

Question 5

What are the s/s of multiple sclerosis?

Answer 5

Visual disturbances
Ataxia
Limb paresthesia and weakness
Spastic paresis of skeletal muscles 
Exacerbations and remission

Question 6

Management of Anesthesia: Multiple Sclerosis

Answer 6

Identify exacerbations 
Supplement steroids 
Avoid marked temp changes 
Subarachnoid block is questionable ???
Not concerned about aspiration risk 
Hyperkalemia with Sux

Question 7

Myasthenia Gravis

Answer 7

Chronic autoimmune disease involving the NMJ
Decrease in Ach receptors
Weakness and rapid exhaustion of skeletal muscles with repetitive use

Question 8

What are the s/s of myasthenia gravis?

Answer 8

Ptosis and diplopia
Weakness of pharyngeal and laryngeal muscles
Asymmetric extremity skeletal muscle weakness and atrophy
Cardiomyopathy
Hypothyroidism

Question 9

What are the most common initial symptoms of myasthenia gravis?

Answer 9

Ptosis and diplopia

Question 10

What is the treatment for myasthenia gravis?

Answer 10

Anticholinesterase drugs - pyridostigmine 
Steroids
Cyclosporine 
Plasmapheresis 
Thymectomy 

*These patients may come in with cholinergic crisis

Question 11

Anesthesia Management: Myasthenia Gravis

Answer 11

Expect altered response to MR - resistant to Sux, sensitive to NDMR
Tracheal intubation w/o MR - aspiration risk

Question 12

Parkinson’s Disease

Answer 12

Degenerative disease of the CNS
Loss of dopaminergic fibers in the basal ganglia
*Dopamine is an inhibitory NT acting on the extrapyramidal motor system
These patients have more Ach and less dopamine

Question 13

What are the s/s of Parkinson’s Disease?

Answer 13

Skeletal muscle rigidity
Resting tremor
Diaphragmatic spasms
Mental depression

Question 14

Treatment for Parkinson’s Disease

Answer 14

Increase concentration of dopamine! 
Levodopa - combines with decarboxylase inhibitor 
Anticholinergic drugs
Antihistamine drugs 
Continue meds perioperatively

Question 15

What drugs should you avoid in the patient with Parkinson’s?

Answer 15

Avoid drugs with antidopaminergic effects

Droperidol, possibly opioids, Reglan

Question 16

What is the most common type of scoliosis?

Answer 16

Idiopathic scoliosis

Question 17

Describe the respiratory changes with thoracic scoliosis.

Answer 17

Restrictive pattern
Decreased - VC (60-80% of predicted), TLC, IRV, FRC, IC, ERV
*RV may be normal, FEV1/FVC is normal

Question 18

What would the ABG of patient with thoracic scoliosis look like.

Answer 18

Arterial hypoxemia and desaturation

PaCO2 and pH normal

Question 19

What is the most common cardiovascular system change in the patient with severe scoliosis?

Answer 19

MVP

*May develop pulmonary HTN…leading to RHF

Question 20

Considerations for scoliosis correction surgery.

Answer 20

Prepare for blood loss
Deliberate hypotension w/o compromising spinal cord BF
Strict parameters for extubation - VC > 10 mL/kg, TV > 3 mL/kg, RR < 30, Neg insp. force > -30
Complications - pneumo, atelectasis, pleural effusion, hemothorax, neurologic injury

Question 21

Eaton-Lambert Syndrome

Answer 21

Antibodies to presynaptic Ca channels

Sensitive to Sux and NDMRs

Question 22

What is the opposite of Parkinson’s disease?

Answer 22

Huntington’s disease - plenty of dopamine, not enough Ach

Autosomal dominant degenerative disease of the CNS

Question 23

Alzheimer’s Disease

Answer 23

Cerebral atrophy especially in hippocampus and temporal lobes
Ach makes memories, GABA throws memories out

Tx- anticholinesterases (Tacrine, Donepezil)

Avoid scopolamine, benadryl, and versed