Case 20: Decreased sensation in extremities

Opening scenario

Shawn Perkins, a 42-year-old male; , comes to the physician's office because of an altered sensation in his legs and feet.

Vital signs

• Temperature: 97.7°F (36.5°C)
• Blood pressure: 110/80 mm Hg
• Heart rate: 64/min
• Respirations: 15/min

Examinee tasks

• Take a focused history.
• Perform a relevant physical examination (do not perform corneal reflex, breast, pelvic/genitourinary, or rectal examinations).
• Explain the preliminary differential diagnoses and initial workup plan to the patient.
• Write the patient notes after leaving the room.

Patient instructions

• When the examinee touches your legs below the knee with her/his fingers, say that you can only barely feel it.
• When the examinee pokes your legs below the knee with a sharp object, say that you can only barely feel it.
• When the examinee asks you if an object feels cold or warm, give a few incorrect answers.
• When the examinee moves your toe and asks you if it is pointing upward or downward, give him/her the wrong answer.
• When the examinee puts a vibrating tuning fork over your skin or joints below the knee, tell her/him that you cannot feel the vibration.
• When the examinee taps your ankle and knee with the reflex hammer, only slightly move your legs.
• When the examinee asks you to stand with both feet together, raise your arms, and close your eyes, start to lose your balance and sway back and forth.
• You are not aware of the meanings of medical terms (e.g., nerve conduction studies) and ask for clarification if the examinee uses them.
• Use the checklists below for history, physical examination, and communication and interpersonal skills.

Challenge: No challenging question from this patient. The examination and history are sufficiently challenging.

Hovering over or clicking on the speech bubbles in the lists below will reveal extra information about the adjacent term. However, clicking on links will cause you to navigate away from the current case, at which point your progress (i.e., your check marks) will be lost. If you do want more information on a subject, either open the link in a new tab or wait until you and your partner have finished the case and reviewed the check marks. Following the link to the patient note form or the abbreviation list will not interrupt your progress.

History of present illness

• Chief complaint
• I have a strange feeling in both of my legs below the knee and in both of my feet; . They tingle and I feel like ants are crawling all over my skin; . I noticed that it feels different when I stroke my shins or feet with my hand than before: I have the impression that I do not feel things as well as I used to.
• Onset
• It started 3 months ago.
• Constant/intermittent
• It always feels like this.
• Precipitating events
• None.
• Progression
• It is getting worse.
• Previous episodes
• Never.
• Alleviating factors
• None.
• Aggravating factors
• It is worse at night.
• Associated symptoms
• Sometimes it feels like my feet are on fire.
  • Location
  • Both of my feet, especially the soles.
  • Intensity (on a scale from 0–10)
  • Can be quite painful, I would say up to a 7. Most of the time it is not strong, though. Maybe a 2.
  • Quality
  • It is a burning pain.
  • Onset
  • 2 months ago.
  • Progression/constant/intermittent
  • Intermittent.
  • Previous episodes
  • Never.
  • Radiation
  • No.
  • Alleviating factors
  • None.
  • Aggravating factors
  • It is worse at night.

Burning feet syndrome typically occurs in alcoholic and diabetic polyneuropathy.

Review of systems specific to decreased sensation in the lower extremities

• Trauma
• No.
• Recent travel
• No.
• Edema
• No.
• Fever/chills
• No.
• Night sweats
• No.
• Fatigue
• Yes. I have been feeling tired for the past few months.
• Pain in joints
• No.
• Urinary problems
• None.
• Bowel problems
• None.
• Weight changes
• None.
• Recent infections
• None.
• Dizziness
• No.
• Blurry vision
• No.
• Muscular weakness anywhere
• When I walk, sometimes I get the feeling that I am not as strong as I used to be. Sometimes I get calf cramps.
  • Gait abnormalities
  • No.
• Change of sensation anywhere else
• Apart from my legs and feet, no.
• Erectile dysfunction
• No.
• Mood
• I have been feeling pretty decent lately.
• Forgetfulness
• Yes, I have the feeling that I have had problems remembering things in the past couple of weeks.

Past medical history, family history, social history

• Past medical history
• I have reflux. I had pancreatitis several times. My doc told me that I have chronic pancreatitis.
• Allergies
• None.
• Medications
• I have taken pantoprazole for 4 years or so.
• Hospitalizations
• I went to the hospital for my pancreatitis.
• Past surgical history
• None.
• Family history
• Both my parents had diabetes.
• Work
• I work in construction.
• Home
• I live alone.
• Alcohol
• I drink a few beers every day with my friends at the bar. And sometimes I like to drink vodka.
  • Exact amount
  • 4 beers daily. And 2 bottles of vodka per week.
  • Felt need to cut down on your drinking?
  • Yes, I have thought about cutting down.
  • Felt annoyed by people criticizing your drinking?
  • Yes, I got really annoyed when my ex-girlfriend criticized my drinking.
  • Felt guilty about drinking?
  • Yes, I felt guilty at times.
  • Felt the need to drink first thing in the morning?
  • In the past couple of weeks, I had a drink before noon several times.
• Recreational drugs
• No.
• Tobacco
• I have smoked a pack a day for 30 years.
• Diet
• I do not like cooking. I mostly eat toast with jam.

• Washed hands
• Used respectful draping
• Head, eyes, ears, nose, and throat examination
  • Inspection of the conjunctivae
  • Inspection of the sclera
  • Direct fundoscopy
• Cardiovascular examination
  • Auscultation of the heart
• Abdominal examination
  • Inspection of the abdomen
  • Auscultation of the abdomen
  • Percussion of the abdomen
  • Palpation of the abdomen
  • Palpation of the liver
  • Examination of shifting dullness
• Extremities
  • Inspection of the hands
  • Inspection of the lower extremities
  • Examination for pitting edema
  • Palpation of pedal pulses
  • Skin examination
• Neurologic examination
  • Examination of orientation to person, place, and time
  • Focused mental status examination
  • Focused examination of the cranial nerves
  • Focused examination of passive and active motion
  • Focused examination of sensation
    • Reduced light touch sensation, reduced pinprick sensation, reduced tactile discrimination of the skin below the knee; impaired proprioception; reduced sense of vibration
  • Focused examination of deep tendon reflexes
    • Reduced DTR in both lower extremities
  • Focused examination of gait
  • Rapid alternating movement test
  • Finger-to-nose test
  • Babinski sign
  • Romberg test
    • Positive

Patient interaction

• Examinee knocked on the door.
• Examinee introduced him- or herself and identified his/her role.
• Examinee correctly used the patient's name.
• Examinee asked open-ended questions.
• Examinee listened attentively (did not interrupt patient).
• Examinee showed interest in the patient as a person (i.e., appeared caring and showed respect).
• Examinee demonstrated ability to support patient's emotions (i.e., offered words of support, asked for clarification).
• Examinee discussed initial diagnostic impressions with the patient.
• Examinee explained management plan.
• Examinee used non-medical terms and provided reasons for planned steps in management.
• Examinee evaluated patient's agreement with next diagnostic steps.
• Examinee asked for concerns or questions.

Counseling and challenge

• Examinee offered counseling on alcohol abuse.
• Examinee offered counseling on smoking cessation.

Patient note

Differentials from the patient note

1. Vitamin B₁₂ deficiency: Patients with vitamin B₁₂ deficiency present with signs of symmetrical damage to large sensory fibers (decreased vibration sense, decreased proprioception, paresthesias, hyporeflexia), which are seen in this patient. This patient has a history of alcohol use disorder, chronic pancreatitis, a diet low in animal products, and prolonged intake of PPIs, which are all risk factors for vitamin B₁₂ deficiency. Although symptoms of small sensory fiber involvement (e.g., burning foot syndrome) are not typical for the condition, a positive Romberg sign, which suggests subacute combined degeneration of the spinal cord, and this patient's multiple risk factors for vitamin B₁₂ deficiency still make this the most likely differential diagnosis.
2. Alcoholic polyneuropathy: Patients with alcoholic polyneuropathy typically present with signs of symmetrical sensorimotor neuropathy starting in the distal extremities. Alcohol has a toxic effect on nerves and leads to thiamine deficiency. In a patient with a history of alcohol use disorder, formication (a burning sensation of the feet), muscle weakness, muscle cramps, and decreased DTRs all suggest alcoholic neuropathy. However, the condition does not usually damage the spinal cord, and affected individuals do not present with a positive Romberg sign, making it only the second most likely differential diagnosis here. The patient may also have a combination of both vitamin B₁₂ deficiency and alcoholic polyneuropathy, as both can occur in patients with alcohol use disorder.
3. Diabetic polyneuropathy: The features of diabetic polyneuropathy are similar to those of alcoholic polyneuropathy. However, as with alcoholic polyneuropathy, diabetic polyneuropathy is not associated with a positive Romberg sign. Additionally, while the patient has a family history of diabetes mellitus, he does not have a personal history of the disease. However, most patients with type 2 diabetes mellitus are asymptomatic and symptoms of complications may be the first clinical signs of disease.

Diagnostic studies from the patient note

• CBC: to assess for megaloblastic anemia in vitamin B₁₂ deficiency
• Vitamin B₁₂, folic acid, thiamine: to assess for vitamin B₁₂ deficiency. Since vitamin B₁₂ deficiency is often associated with folate deficiency, the patient should be evaluated for both. Thiamine plays an important role in the development of alcoholic polyneuropathy.
• Serum glucose, HbA1c: to assess for diabetes mellitus
• Nerve conduction studies: to assess nerve function and to help determine the type of neuropathy

Other differentials to consider

• Hereditary motor sensory neuropathies
• Mononeuritis multiplex
• Lead poisoning
• Uremia
• Guillain-Barré syndrome

Overview table of polyneuropathies