A 77-year-old female patient presents with increasing muscle weakness and numbness in both lower legs over the last week.She presents using crutches and with her daughter for walking assistance.Patient had influenza 3 weeks ago and was treated with amantadine.The patient denies recent trauma.Current medications include beta blocker and ACE inhibitor.Denies use of tobacco or alcohol.On physical examination,the patient is alert and oriented x 3,afebrile,pulse 66,resps 16/min,BP 110/70.Neck: no JVD,no thyromegaly,no bruits over carotid arteries.Heart: regular rate and rhythm,no murmurs.Lungs are clear to auscultation.Abdomen is non-tender with no organomegaly.Extremities: Skin is pink,cool to touch,and intact bilaterally.Hand grip strength: 5/5 bilaterally.Biceps DTR +2/4 bilaterally.Left and right quadriceps muscle strength 4/5.Patella reflex: 1/4 bilaterally.Achilles reflex: 1/4 bilaterally.Ankle strength: R + 3/5 and L + 3/5.Sensation to pinprick and cotton ball intact in face and upper extremities and bilaterally equal.Sensation to pinprick and cotton ball decreased in feet bilaterally.Dorsalis pedis pulses +1/4 bilaterally.Negative Homan's and Babinski's sign.The following disorder(s)should be high priority in the differential diagnosis:
A) Amyotrophic lateral sclerosis
B) Guillain-Barré syndrome
C) Polymyositis
D) Multiple sclerosis
