Muscle Weakness ; Lecture

Question 1

Muscle weakness due to _________ disease is typically proximal, while weakness from _________ disease is distal.

Answer 1

muscle; nerve.

Question 2

True/False: Bulbar involvement is characteristic of Myasthenia Gravis (MG).

Answer 2

True.

Question 3

What are the key anatomical structures involved in motor function?

Answer 3

Motor cortex.
Medulla/spinal cord.
Anterior horn cell.
Motor neuron.
Neuromuscular junction (NMJ).
Muscle.

Question 4

Myasthenia Gravis primarily affects the _________, while Duchenne Muscular Dystrophy involves the _________.

Answer 4

neuromuscular junction; muscle.

Question 5

True/False: Stroke, multiple sclerosis (MS), and tumors can affect the motor cortex and spinal cord.

Answer 5

True.

Question 6

What key aspects should be assessed in the history of a patient with muscle weakness?

Answer 6

Onset (sudden vs gradual).
Distribution (proximal vs distal, symmetrical vs asymmetrical).
Variability (fixed vs progressive).
Associated sensory features (e.g., tingling, numbness).

Question 7

Symmetrical weakness suggests _________ causes, while asymmetrical weakness often indicates _________ or inflammatory causes.

Answer 7

genetic or metabolic; vasculitic.

Question 8

Which toxins can cause peripheral neuropathy?

Answer 8

Alcohol, nitrous oxide, chemotherapy, amiodarone, and lead.

Question 9

What are the most common causes of peripheral neuropathy?

Answer 9

Diabetes.
Alcohol.
Idiopathic causes (20%+).

Question 10

Peripheral neuropathies can affect _________, _________, or both, and may involve _________, myelin, or both.

Answer 10

motor nerves; sensory nerves; axons.

Question 11

What are the hallmark features of Myasthenia Gravis?

Answer 11

Fatigueable weakness.
Proximal limb involvement.
Ptosis and diplopia.
Bulbar symptoms (speech, swallowing).
Risk of respiratory failure.

Question 11

True/False: Chronic peripheral neuropathies are usually length-dependent, starting in the legs.

Answer 11

True.

Question 12

Myasthenia Gravis is associated with _________ dysfunction, including thymic hyperplasia and _________.

Answer 12

thymus; thymoma.

Question 13

True/False: EMG with repetitive stimulation is more sensitive than antibody tests for diagnosing MG.

Answer 13

True.

Question 14

How is MG treated?

Answer 14

Acetylcholine esterase inhibitors (e.g., pyridostigmine).
Immunosuppressants (steroids, azathioprine).
Thymectomy if thymoma is present.
Monitoring forced vital capacity (FVC).

Question 15

_________ myopathy and _________ myopathy are common drug-induced muscle disorders.

Answer 15

Steroid; statin.

Question 16

True/False: Mitochondrial disorders may involve eye movement abnormalities and are associated with muscle disorders.

Answer 16

True.

Question 17

What tests are critical for evaluating neuropathy?

Answer 17

History and examination.
Nerve conduction studies (NCS).
EMG.
CSF study.
Neuropathy and vasculitic screens.

Question 18

A neuropathy screen includes _________, _________, and _________.

Answer 18

FBC; glucose; B12/folate levels.

Question 19

How is myopathy investigated?

Answer 19

Creatine kinase (CK).
EMG.
Muscle MRI.
Genetic testing.
Biopsy.

Question 20

A 50-year-old landlady reports tingling in her fingers and feet with clumsiness and frequent falls. What is the likely diagnosis?

Answer 20

Diabetic peripheral neuropathy.

Question 21

A 45-year-old reporter has numbness over the lateral two digits of the left hand. Phalen’s test is positive. What is the diagnosis?

Answer 21

Carpal tunnel syndrome

Question 22

In a myasthenic crisis, _________ and _________ functions should be closely monitored.

Answer 22

respiratory; bulbar.

Question 23

What are the key management strategies for neuromuscular diseases?

Answer 23

Multidisciplinary team (MDT) involvement.
Address breathing and swallowing issues.
Treat underlying causes.
Provide supportive care (e.g., physiotherapy, OT).

Question 24

_________ and _________ are critical red flags in neuromuscular emergencies.

Answer 24

Sudden respiratory distress; progressive bulbar dysfunction.

Question 25

True/False: Proximal muscle weakness typically involves difficulty with stairs, chairs, and hair grooming.

Answer 25

True