OBSTETRICAL PARALYSES From the large category of paralyses caused by injury to the new born during parturition, there are classified under the title obstetrical paralyses, only those confined to the upper extremity and due to injury of the brachial plexus. Its symptom-complex is identical with plexus paralysis in the adult and it deserves special consideration only on account of its etiology and the regularity of the nervous symptoms following the birth-trauma. Duchenne accurately described the disease and Erb elucidated its nature. Subsequent- authors have only substan tiated the results of the studies and observations of the above named and have broadened and deepened our knowledge of the clinical mani festations and pathogenesis of the disease.
Symptoms.—Inactivity is noticed in the diseased arm immediately after birth. Whereas the healthy extremity, especially shortly after birth, shows a rather marked rigidity of its musculature and whereas the child executes various more or less extensive movements, with it, the diseased arm hangs relaxed, and it is impossible, by pricking the skin to elicit active lifting of the arm at the shoulder or flexion of the elbow. The shoulder hangs somewhat lower than the unaffected one this is less marked in very recent cases than in older ones. The upper arm is rotated inwards and the forearm pronated so that the palm of the hand is turned more or less outwards. The movements of the scapula are either not interfered with at all or else only slightly. Supination in the elbow-joint is always absent; the \vrist-joint seems either free from involvement or else extension is limited, flexion remaining possible. The finger-joints as a rule are free from disturbances although rarely they suffer limitation in flexion. The sensibility is either undisturbed or there may be disturbances of sensation in the distribution of the musculocutaneous and more rarely the axillary nerve (Oppenheim); even with very extensive paralyses, the sensibility on the inner surface of the arm remains normal (Klumpke). Tests of the electrical reactions in the newborn give, in general, results of but little practical value, since the irritability is physiologically less as compared with older chil dren and adults, and the contractions themselves, physiologically, tardy and vermiform (C. Solt mann and A. Westphal). The reaction of degeneration and other similar reactions are not to be employed in the same sense as in the adult. The form of the disease described as the
type, by Duchenne and Erb, is the most frequent, occurring according to Stransky in SO per cent. of all cases. The disease depends upon a pe culiar combination of muscle-palsies which is manifest in all these cases and the rationale of the occurrence of which was rightly recognized by Erb. The following muscles are involved: deltoid (lifter of the arm), biceps (flexor of the forearm), infraspinatus (external rotator of arm) supinator longus (flexor, possibly supinator of the forearm) and supi nator brcvis (supinator of the forearm). These muscles are supplied by the brachial plexus which is formed by branches of the four lower cervical and the greater pa-rt of the first dorsal nerves. Erb found a point corresponding to the point where the sixth cervical nerve emerges between the musculi sealeni, from which point it is possible with the faradic current, to produce, simultaneously, contractions in the above named muscles (deltoid, biceps, brachialis anticus, supinator longus and supinator brevis). A lesion at this point produces the above described symptom-eomplex.
Whereas the Erb-Duchenne type involves muscles supplied by the fifth and sixth cervical nerves (upper plexus paralysis, upper arm type), there is another rarer form of obstetrical paralysis in which muscles supplied by the seventh and eighth cervical nerves arc involved either alone or together with the muscles affected in the upper plexus paral ysis (lower plc.rus paralysis, Klumpke's type, lower arm type). In such cases we have a fairly complete paralysis of the arm, forearm and fingers, with extensive sensory involvement and—especially character istic—oculoptipillary symptoms: narrowing of the palpebral aperture, and a myosis in which the contracted pupil promptly reacts to light and accommodation. The narrowing of the palpebral aperture is caused by a ptosis which, as well as myosis, is due to an involvement of the sympathetic nerve (Seeligmtiller), the communicating branch of which, coming from the first dorsal nerve, connects with the lowest part of the brachial plexus and is involved in the lesion. Seeligmiiller also reports a case in which there was an atrophy of the cheek. l\1urupkc's type is to be met with, uncomplicated, in only a part of the cases, in the others, the muscles of the Erb-Duchenne type are also involved and in occa sional cases all the muscles of the upper extremity are paralyzed.