Volume 1

Textbook of nervous diseases for physicians and students / Translated by Alexander Bruce.

  • Oppenheim, Hermann.
Date:
1911
Catalogue details

Licence: Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)

Credit: Textbook of nervous diseases for physicians and students / Translated by Alexander Bruce. Source: Wellcome Collection.

Provider: This material has been provided by UCL Library Services. The original may be consulted at UCL (University College London)

    36/644 (page 7)
    Exaggeration of muscular tonus (stiffness, rigidity or spastic condition of the muscles) can be recognised, secondly, from exaggeration of the tendon phenomena. On account of the close, though not absolute and constant, relation of the tendon phenomena to the muscle tonus, it is advisable to examine them directly after examination of the passive mobility of the limb. Examination of the Tendon Phenomena—By this symptom, which Westphal1 and Erb 2 described, independently of each other, in 1875, we understand muscular contractions which are induced by a mechanical stimulation of a tendon. The most important of these is the knee jerk (also called the patellar phenomena or reflex). This is always present in healthy persons, and its absence has great diagnostic singificance. Erb regards this symptom as a simple reflex. Westphal held that the knee jerk depends on a direct excitation of the muscle which is maintained in a state of tonus through reflex influences. Results of later investigation favour the reflex-theory (Sternberg, Jendnissik, Scheven and others). Recently several writers have given their support to Westphal's view (Muskens, Sherrington). In order to produce the knee jerk, the following method is the best : the leg of the patient, who lies on his back, is bared, placed at an obtuse angle and supported b}* the left hand of the examiner at the popliteal space, the heel resting on the bed. The right hand first feels for the patellar tendon, if it does not at once stand out distinctly, and then gives it a sharp tap with the percussion hammer. The thigh should first be watched to ascertain whether the extensor cruris muscle becomes tense. The effect of this tension is, when it is sufficiently strong, an extension of the leg. But it is advisable to place less weight on this factor (as it does not alwa}-s appear) than on the muscular contraction. This should not be confused with a simple vibration of the skin and muscle substance, which is directly communicated to them from the tendon. If the tap on the tendon has not elicited the contraction, then we should discover whether there is not an active or unconscious voluntary muscular tension. This will be rapidly recognised if the supported leg does not fall back to the bed immediately on the supporting hand being taken away. Relaxation of the tension should then be induced according to the rules given above, the examination being modified by allowing the patient to cross one leg over the other. If this has not the desired effect, then Jendrassik's method ma}' be used : the patient is asked to fold his hands and at a word to make a forcible effort as if to pull them asunder, without, however, really doing so. At that moment the tendon is tapped. If this does not succeed in eliciting the knee jerk then we should examine the patient in a sitting position, which is best done if he sits on a table and allows his legs to hang free. It has also been proposed that during examination of the knee jerks other stimulations should be applied, such as the prick of a needle, the throwing of a bright light on the retina. These act not only by distracting the attention of the patient, but apparently also by increasing the nerve conduction. It is further recommended that the patient should breathe deeply, read aloud, etc., during the examination I have, however, always been able to dispense with these and similar procedures. 1 A. j. P., Bd. iv. and Bd. v. 2 A. j. P., Bd. v. See also specially the monograph of Sternberg, Die Sehnenrellexe. etc., Leipzig u. Wien, 1893 ; also Scheven, A. f. d. g. Phys., 117.