887 
But under such conditions the clonus generally is not quite as 
regular as in organic disorders, as is well known. The very short 
cloni, as in fig. 2, were only seen in organic diseases of the central 
nervous system. 
The complicated forms of deep reflexes, which are now to be 
considered, offer the peculiarity that after an initial simple twitch, 
the muscle does not entirely relax, but a state of hardening of the 
muscle substance persists for a longer or shorter time. This hardening 
may be caused in at least three different ways. 
Fig. 4 represents a record obtained in a patient with chorea 
minor and shows one of the changes described by Gorpon, Hey a. 0. 
as occurring in chorea minor. After the initial simple twitch we 
observe a second contraction which may be as high or even higher 
than the first. It begins either at the end of the simple twitch 
or even a little earlier. In this special case the second contraction 
showed the short duration of a single twitch, but I have also seen 
more tonic contractions in the same patient as well as in others 
with the same disease. The latency of this second contraction is of 
the order of 0.15—0.20 second and agrees with the latency for a 
central reaction on a stimulus applied to the peripheral organs of 
sense. As the probable seat of the lesions in chorea is the cerebrum, 
we must at least consider the possibility of a central reaction. It 
seems to me that this supposition is not entirely unfounded. I. even 
think it rather probable, that the deep reflexes are also, at least 
partially represented at a higher nervous level than the spinal cord, 
In peculiar circumstances, as in chorea minor, this cerebral part 
may sometimes appear. I think that this cerebral part of the reflex 
is answerable too for the so-called pseudo-kneejerk of Westranu, 
which in rare cases of tabes appears with a latency of about 0.2 second 
after tapping the knee-tendon or the skin above it. In more than 
a few cases of functional neurosis I have also seen reflexes as in 
fig. 4. I have never been able to record those reflexes, which as a 
matter of fact occurred only the first time that the knee-jerk was 
elicited; if the reflex was obtained a second time or at a later 
examination, the cerebral restraining impulse was sufficiently intense 
to prevent the action of the higher centrum. In chorea this restraining 
influence has entirely disappeared as well as the faculty of suppressing 
involuntary choreatic movements. 
Records closely resembling those of fig. 4 can be obtained some- 
times under totally different circumstances. Fig. 5 was recorded in 
a case of multiple sclerosis, the patient being nearly paralysed. He 
is just able to make a few slow movements with his extremely rigid 
