Dr. Neil Schwartz is a Stanford neurologist and the Program Director of Stanford’s Neurology Residency Program. Dr. Schwartz is an excellent teacher within the Stanford community and led this week’s Stanford 25 session on the neurology exam.
Take Home Points from Dr. Schwartz:
“Brain lesions, such as stroke, that affect the cortical-spinal tract:
— Have a particular pattern of weakness (so called pyramidal weakness). In the upper extremity, the extensors (deltoids, triceps, wrist extensors, finger extensors) are relatively weak while the flexors are relatively spared. In the lower extremity, the flexors (hip flex, knee flex, dorsiflex) are relatively weak while the extensors are relatively spared. This gives the commonly seen posture of a flexed arm, and a gait that requires circumduction to clear the ground in the swing phase b/c of foot drop.
— In general, result in distal muscle groups being more affected than proximal ones.
— Cause an increase in tone that is characterized by spasticity. This should be differentiated from rigidity (as seen in extra-pyramidal disorders like PD) and paratonia (as seen in severe dementia). Spasticity results in a velocity-dependent increase in tone.
— Cause an increase in reflexes that may include spread of the reflex, clonus, and/or the ability to elicit reflexes that are not always seen (pectoral, Hoffman’s, finger flexors, crossed adductor, etc).
— Can cause neurology’s most famous sign—the Babinski response. in fact, there are a number of maneuvers that can make the toe “go up”, but the important thing to know is that they are all indicative of pyramidal dysfunction somewhere within the CNS.
Regarding aphasia, confrontational naming, spontaneous speech, repetition, and following simple and complex commands should allow you to differentiate aphasias that are more expressive (i.e. anterior or Broca’s) vs. receptive (posterior or Wernicke’s). Recognize that rarely are aphasias purely one or the other.”