THE PLANTAR REFLEX - RePub

SUMMARY
This thesis describes a historical, clinical and electromyographic study of
the plantar reflex, with emphasis on:
- physiological relationships between the toe responses and the other
spinal reflexes that are evoked by plantar stimulation
- practical application of these associations to cases where the toe
response is equivocal
- pathophysiology of the pathological plantar response.
Chapter I gives a review of previous clinical studies. The plantar reflex
as such was not discovered by Babinski: many neurologists before his time
had noted flexion in ankle, knee and hip after stimulation of the sole. What
Babinski did discover was the diagnostic importance of the toe responses,
which had only been casually reported by others (in the Netherlands the
normal plantar reflex is erroneously connected with the name of von
Striimpell). Babinski assumed that the upgoing toe sign as well as the
normal downward response of the great toe were part of the flexion
synergy of the leg, but later studies left no doubt that this relationship
included only the pathological response: anatomical toe extensors are
flexor muscles in a physiological sense, and vice versa. However, the
synergistic background of the upgoing toe sign has become obscured by its
diagnostic weight. This neglect of physiology has in turn led to undue
emphasis on different methods of stimulation, and to exotic speculations
about the 'purpose' of the plantar reflex.
The notion that only an upgoing great toe plus fanning of the little toes
constitutes a full-fledged Babinski sign is proved to be a distortion of
history. Another popular dictum is that normal infants do not show a
Babinski sign - this is based either on misinterpretation of the plantar
grasp reflex or on the unwarranted assumption that the Babinski response
in adults is an isolated phenomenon.
The normal plantar response is a unisegmental reflex, not related to any
synergy.
Chapter II is devoted to a study of the variation and bias that occur in the
interpretation of equivocal plantar reflexes. Fifty neurologists from three
Dutch university hospitals were asked to judge a number of plantar
responses on film. The main part of the presentation only served to
disguise the fact that two films, both showing equivocal toe movements,
were presented twice at the same sitting. Variability was studied in thirty
neurologists who saw the films without additional information: they
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