Right Foot Drop

Chief Complaint: A 61 year-old male presents with 3 months of right foot drop.

DOMAIN A: DATA ACQUISITION

+ What are the relevant components of this patient’s history and physical examination, and why?

Relevant History:

  • How did this begin? Has it happened before?
  • Any history of trauma or injury?
  • Has he fallen?
  • Is the foot drop worsening?
  • Is there associated pain, numbness, or tingling? If so, where?
  • Is there weakness anywhere else?
  • Any other functional changes? E.g. bowel/bladder changes, balance problems.
  • Past medical/surgical history?
  • Family history?
  • Functional history?
  • Medications and allergies?
  • Social history? What is the patient’s work situation and environment? Is he able to perform his job duties safely and satisfactorily?
  • Has he sought care or had this problem evaluated by another doctor before?
  • What has he done to help treat the problem so far, if anything?

Relevant Physical Examination:

  • Vital signs
  • Inspection (gait, ?foot slap, ?too many toes sign, muscle atrophy, skin changes, bruising)
  • Manual muscle testing of bilateral lower extremities, and upper extremities if indicated by the history or remainder of physical examination
  • Sensory and reflex testing of bilateral lower extremities
  • Special testing: Tinel at tarsal tunnel and fibular head, straight leg raise, slump sit
 

DOMAIN B: PROBLEM SOLVING

The patient is a 61 year-old male accountant with a past medical history of hypertension, hyperlipidemia, and GERD. He takes amlodipine and atorvastatin for these conditions. He has been active for most of his adult life, and enjoys running in long distance races. He denies numbness, tingling, or bowel or bladder changes. He does feel like his grip strength is reduced and finds himself fumbling with his car keys more often than usual, occasionally dropping them. His foot drop has progressively worsened over the past 3-4 months. On exam, his right foot exhibits 3+/5 dorsiflexion strength and there is an audible foot slap when he walks. There is hyperreflexia in bilateral biceps, brachioradialis, and patellar reflexes. There is hand musculature atrophy bilaterally.

+ What is your differential diagnosis for the foot drop?

  • Anterior horn cell disease (ALS and its variants), cervical myelopathy/stenosis, cervical radiculopathy, lumbar radiculopathy, lumbar spinal stenosis, AIDP (Guillain-Barre Syndrome), CIDP, Charcot-Marie-Tooth (CMT) disease, postpolio syndrome, stroke

+ What type of workup would you arrange for this patient?

  • This patient demonstrates notable weakness and atrophy with upper motor neuron findings (hyperreflexia) in both upper and lower limbs, so an MRI of the brain and cervical spine is a reasonable place to start in working him up. Consideration could be given to MRI of thoracic and lumbar spine.
  • Depending on the results of the imaging, EMG/NCS of all 4 limbs would be considered.
 

DOMAIN C: PATIENT MANAGEMENT

+ What are your initial management recommendations for this patient?

  • Prescribing a right ankle-foot orthosis (AFO) would be appropriate for the patient’s safety and re-establishing proper gait mechanics. He may be prescribed an assistive device such as a cane as needed. Physical and occupational therapy prescriptions directed toward his functional rehabilitation are appropriate as well.
 

MRI of the brain and cervical spine reveal no significant stroke or cervical spine stenosis.

+ How would you proceed?

  • The MRI of the brain and cervical spine did not reveal any structural reason for the patient's weakness, so we need to keep searching to find out what is causing his symptoms. An EMG/nerve conduction study is an appropriate test at this point. I would educate and explain to the patient my rationale, and ensure that all questions are answered satisfactorily.
 
 

DOMAIN D: SYSTEMS-BASED PRACTICE

EMG/NCS reveals increased insertional activity, fibrillations and positive sharp waves, and polyphasic motor unit action potentials in bilateral tibialis anterior, medial hamstrings, rectus femoris, first dorsal interosseus of the hand, biceps brachii, and thoracic paraspinals.

+ What is your leading diagnosis and next step?

  • ALS (amyotrophic lateral sclerosis) and its variants, such as PLS. I would explain to the patient why a neurology referral is appropriate so that the patient can receive the most up-to-date medical treatment for his condition and possibly be enrolled in any clinical trials.
 

DOMAIN E: INTERPERSONAL AND COMMUNICATION SKILLS

The patient states, “I don’t understand, doctor. I’ve been active my whole life. There’s no reason my body should be weak like this. What is going on? Am I going to die or become crippled?”

+ How would you respond? This is our role-playing portion of the case. Pretend that I'm the patient.

  • The most important thing is to align yourself with the patient, counsel on the likely diagnosis and prognosis, and explain the treatment plan from your perspective going forward. Always ask if there are any questions or anything you can help explain before they leave the office. Always send a copy of your note to the patient’s primary care physician and neurologist so that all managing parties are on the same page.
  • A reasonable response would be, “I am so sorry that you are going through this. I can’t imagine how difficult this must be for you. I want you to know that I will be here for you every step of the way, starting with your rehabilitation. I am always here to help answer questions or clarify anything about your diagnosis. ALS is unfortunately your most likely diagnosis right now, and this disease most commonly leads to progressive disability and death over roughly 3 years. There are things we can do to maintain your function or slow down your functional loss, including bracing and submaximal exercise. I would also like to ask one of my neurologist colleagues to see you and offer you the most up-to-date treatments for ALS, including exploring if there are any clinical trials you might be able to participate in. This diagnosis is devastating to learn, and I would be more than happy to help you identify counseling services that might benefit you as you go through this process. I will send a copy of my office note today to your primary care physician as well as to your neurologist so that they are aware of our findings and plan. I would like to see you back in 6-8 weeks to see how you are doing with your rehabilitation needs. What other questions do you have for me today?”