Sensibility, the knee-jerk, and plantar phenomena are normal.
Later the affected muscles become exquisitely tender, and then atrophy, while the knee-jerk or other reflex is lost.
The deep reflexes may also be altered, the knee-jerk being frequently absent on the affected side.
In some subjects the larger dose, 45 cubic centimeters, practically abolished the knee-jerk.
The presence or absence of the knee-jerk may be a most significant symptom to the physician.