Physical Diagnosis, M2 Course
James Campbell, M.D.
Rational Neurological Examination
Overview of classical examination
A) Cranial nerves (Bulbar function)B) Peripheral nervous system
1) Sensory (Touch, pain, vibration and position sense)
2) Motor (Tone, tremor, muscle mass, strength)
1) Deep tendon reflexes
2) Upper motor neuron signs (Babinski, Hoffman, abdominal reflexes)
D) Coordination (Finger-to-nose, heel-to-shin, rapid alternating movements, Romberg)
E) Gait and station, walking and locomotion
F) Extrapyramidal and frontal release (Rigidity, expressivity, glabellar, snout, grasp, palmo-mental)
G) Mental status (Speech, orientation, judgement, mood, affect, perception, knowledge, memory, recall, reasoning, complex activity, recognition, use of symbols)
Features of clinically useful examination strategies
A) Accuracy: requires a defining gold standard test (or outcome)
1) Reproducible or precise: two observers should come to same conclusion regarding state of the finding. The kappa statistic measures this parameter:
-1.0 complete disagreement
0.0 no better than chance
0.4 not too bad
0.6 getting pretty good
+1.0 perfect agreement
2) Valid: reports a finding which is useful in identifying the disease or target condition
a) Sensitivity - the fraction of patients with the condition that have a positive finding or test
b) Specificity - the fraction of patients without the condition that have a negative test
c) Predictive value of the positive test - fraction of patients with a test finding that actually have the condition. This depends on prevalence.
d) Likelihood ratio - odds of the condition in the presence (or absence) of the finding. Odds is the ratio of the probability of the condition divided by the probability of not nahving the conidition. The post-testing odds equals the pre-testing odds times the likelihood ratio.
0.10 strong negative predictor
1.0 has no predictive value
10 strong positive predictor
B) Clinical relevance
1) Studied in clinical settings comparable to "real life" with reasonable prevalence and spectrum of disease
2) Testing strategies are clinically reasonable: not time-consuming, understandable, acceptable to the patient and examiner, clear procedures with defined normals and abnormals, within the abilities of examiner and patient
Case #1 Dad Can't Walk
A 62 year old white male is brought to the ED at 9:00AM by his family because of new onset of weakness. He has a 40 pack year history of smoking and is being treated for hypertension and type II diabetes. His recent health has been good. His current medications include a shot of insulin each morning and lisinopril/hydrochlorothiazide 20/25mg. After breakfast this morning he was unable to arise from the toilet and fell, calling for help from his wife. She noticed he was not moving his leg or arm and called 911.
On examination his BP is 180/95, temp is 37.4C and pulse is regular at 105. Heart and lungs are normal. He has a bruit in the neck bilaterally. Neurologic examination is notable for loss of vision in the left upper portion of both visual fields. Otherwise extra-ocular movements are full and the remainder of the cranial nerves are normal. There is weakness documented in the left arm and leg with accompanying mild numbness. Achilles reflexes are diminished and symmetric, biceps is diminished on the left and normal on the right. There is a left sided plantar reflex. The patient appears somewhat sleepy but responds appropriately to questioning and follows commands. Mental status examination is unremarkable otherwise with normal speech, affect and cognitive function.
Case #2 Is Dad Getting the Alzheimer's?
A 72 year old white male is brought in for screening by his family because he is getting forgetful. They cite examples that include mislaying his tools, never remembering what his wife has just said, and coming back from the store without the milk. He has enjoyed reasonable health except for a TIA that he sustained last year. His workup including carotid dopplers and echocardiogram was negative. He is currently on two blood pressure medications and a cholesterol pill and pill counts suggest that he remembers to take his medication.
BP is 132/86. Physical examination including neurological screen is entirely negative. Mini-mental status testing score is 26.
Case #3 The Aching Wrist
A fifty year old white male comes to your clinic complaining of several months of wrist discomfort with numbness in the hand that occurs each morning on arising. This resolves over a couple of hours with minimal problems during the day except with heavy lifting or repetitive motion such as raking or house painting. He has fewer problems but has noted minor symptoms in the right hand as well. He reports weakness in the left thumb, especially with accompanying pain.
Physical examination shows localized numbness over the thumb and thenar prominence. Tinels sign is negative.
Case #4 Dad Has the Shakes
A 67 year old male comes to see you for his annual physical. He is under treatment for essential hypertension and elevated cholesterol. Review of systems is negative except a concern expressed regarding a trembling of both hands that occurs when fatigued. He is active and works out regularly with no unsteadiness or problems with activity. He asks if he is developing Parkinsons disease.
On examination mental status is normal and there is a fine symmetric tremor when hands are extended. He walks with a full gait and no difficulty heel-to-toe. Motor tone is normal without cog wheel rigidity. Glabellar sign is negative.