Intro to Differential Diagnosis

Question 1

*Describe the diagnosis processes

Answer 1

1) Pattern recognition
2) Hypothetico deductive
- Hypothesis generation
3) Algorithm
4) Exhaustive
5) Logical reasoning

Question 2

*Components of illness scripts

Answer 2

• Pathophysiology: what causes the disease
• Epidemiology: who commonly gets this disease
• Time course: how long it’s been going on
• Symptoms & signs
• Diagnosis: results of testing
• Treatment: how would you treat this disease

Question 3

*Differences between diagnosis informed care and medical screening

Answer 3

Diagnosis: uses directed questions & focused physical examination tests in a hypothesis-driven manner
Medical Screening: general systems review with the goal to assess for risk factors that may impact patients’ overall well-being

Question 4

*Classification system of red flag screening

Answer 4

I = suggests serious pathology outside of MSK disorder, possible immediate intervention by a specialist
II =further patient questioning & adoption of selected examination methods
III = common, require further physical examination, likely to alter treatment

Question 5

*Procedures to improve diagnostic accuracy (possible causes)

Answer 5

• TIM VaDeTuCoNe
• Trauma
• Inflammation: aseptic or septic
• Metabolic condition
• Vascular: arterial, venous, or lymphatic
• Degenerative
• Tumor: malignant primary, malignant metastatic, or benign
• Congenital
• Neurogenic/Psychogenic

Question 6

Examples of a medical diagnosis

Answer 6

• stroke
• fracture
• foot pain

Question 7

Examples of a PT diagnosis

Answer 7

• impaired gait
• generalized weakness
• decreased force production
• impaired AROM
• pain
• decreased strength

Question 8

What is a diagnosis

Answer 8

• Process + product of a clinical investigation related to the pathology underlying a patient/client’s signs & symptoms resulting in a label
• investigation + label = diagnosis

Question 9

What are some goals of a diagnosis

Answer 9

• (Primary) determine whether PT services are indicated for the patient’s condition
• identify the target disorder

Question 10

Diagnosis limitations

Answer 10

• cause of condition may not be determined
• label may not be descriptive
• specificity of labeling depends on information & experience

Question 11

4 possible options for is the suspected diagnosis within scope of practice

Answer 11

• Emergency referral: as a guide, on the same day
• Urgent referral: as a guide, within 5 days
• Watchful waiting: close surveillance while undergoing tx as required while allowing time to pass before medical intervention “treat and refer”, safety netting
• Appropriate referral: diagnosis is within scope of practice, evaluate and treat

Question 12

Define safety netting

Answer 12

• management strategy used for people who may present with possible serious pathology
• strategies should include advice on which signs & symptoms to look out for, which action to take, & the time frame within which that action needs to be taken

Question 13

*Describe performing diagnosis informed care

Answer 13

• PT interprets the diagnosis to determine appropriate intervention & prognosis
• MUST prioritize the most important aspects of disablement to address in pain
• most interventions have an indirect effect on pathology
• requires PT to determine cause/effect between pathology & functioning

Question 14

Limitations of diagnosis informed care

Answer 14

• the label alone is insufficient to guide PTs
• most PT referrals indicate: shoulder, knee, hip, back pain
• essentialist approach relates to mechanism
• “treat the patient, not the diagnosis!”

Question 15

Define essentialism

Answer 15

• treatment of the cause/source is more effective than treating individual signs & symptoms
• mechanism is not always directly responsible for impairment in functioning

Question 16

Where to start in thinking about a diagnosis

Answer 16

• Formal processes decrease error
• Start with the question: What disease is causing my patient/client’s dysfunction?

Question 17

Define backward and forward reasoning

Answer 17

• Backward: make hypothesis and test it (novice)
• Forward: pattern recognition (expert)

Question 18

Common age pattern for biceps tendonitis

Answer 18

• common in 18-35 y/o involved in sports

Question 19

Pattern recognition foundations

Answer 19

• Frequency: how common is the condition in that age group
• Variability: inferences about entire population based on small subset patients
• Causation: whether the person has a disease or not
• Prototype: comparing a disease found in one patient to another with similar characteristics
• Location: remote (referred) or local (palpation/over anatomy)

Question 20

Types of follow up questions to help differentiate/eliminate as many diseases as possible

Answer 20

• Key feature: specific to a disorder & not others
• Rejecting feature: if present then it is not the disorder & probably something else
• Non-differentiating feature: common to several disorders (narrowing of possibilities)
• Differentiating feature: specific to one or two disorders (further narrowing of possibilities)

Question 21

Difference between medical screening and red flag screening

Answer 21

Medical: involves an algorithmic process of systems based health review and focuses on the search for “Red Flags”
Red Flags: lack diagnostic accuracy to predict intended conditions and interpretation is often context-dependent requiring a deeper level of processing

Question 22

Red flags cluster for malignancy

Answer 22

• > 50 y/o
• failure of conservative management
• unexplained weight loss
• history of cancer
• sensitivity of 100% for identifying a malignancy

Question 23

Examples of immediate medical attention (I) red flags

Answer 23

• blood in sputum (coughed up substance)
• loss of consciousness/altered mental status
• neurological deficit not explained by monoradiculopathy
• bowel/bladder changes
• patterns of symptoms not compatible with mechanical pain
• pulsatile abdominal masses

Question 24

Examples of require further physical tests & differential analysis (II) red flags

Answer 24

• abnormal reflexes
• bilateral or unilateral radiculopathy/paresthesia
• unexplained referred pain
• unexplained significant upper/lower limb weakness

Question 25

Examples of subjective questioning/examination procedures (III) red flags

Answer 25

- >50 y/o, clonus, fever, elevated ESR, gait deficit - Hx of disorder with infection/hemorrhage - Hx of metabolic bone disorder - Hx of cancer - impairment precipitated by recent trauma - long term corticosteroid use - long term workers compensation - non-healing wounds/sores - recent unexplained weight loss - writhing pain

Question 26

Diagnostic process for differential diagnosis/imaging

Answer 26

- Identify patient's chief concern & determine any communication barriers - Identify any red flags through medical screening - Create a sign/symptom timeline & appreciate anatomy - Create diagnostic hypotheses considering all possible forms of remote & local pathology - Ask specific questions to rule specific conditions as less likely - Perform tests to differentiate among remaining diagnostic hypotheses - Decide on a diagnostic impression - Determine appropriate plan of care (referral types)

Question 27

Risk factors for cardiovascular issues

Answer 27

- (+)Age: men ≥45, women ≥55 - (+)Family Hx: MI, coronary revascularization, or sudden death <55 in father or <65 in mother - (+)Cigarette Smoking: current smoker or quit within previous 6 mo - (+)Sedentary Lifestyle: <30 min of moderate intensity exercise at least 3 days per week for at least 3 mo - (+)Obesity: BMI ≥30 or waist >102 cm/40 in for men, waist >88 cm/35 in for women - (+)Dyslipidemia: LDL ≥130 or HDL <40, total >200 - (+)Pre-diabetes: fasting glucose ≥100 but <126, 2 hr oral test ≥140 but <200 - (-)High HDL Cholesterol: ≥60