This peculiar disturbance, which was first described by Kennedy in 1850 and six years later in more detail by Chassaignati, has since been made the subject of numerous investigations. While the various authors agree in their description of the disease itself, they offer a variety of explanations; the majority are of the opinion that the disturbance is due to a psychic or inhibition palsy (Vierordt) and that the children avoid moving the arm because they remember the initial pain long after the part has ceased to be painful (Brunon, Laborde, Vierordt). Other authorities, on the other hand, adopt Chassaignac's original theory of a local le.sion to the plexus. Bezy and his pupils, Charpy and Abelous, attempted to prove by experimentation, on the one hand, that rapid elevation of the arm causes excessive stretching of the brachial plexus or of certain portions of the plexus, and, on the other hand, that stretch ing the nerves in the same way in animals produces paralytic phenomena similar to those which are observed in the paralysie daulourease of chil dren. A number of investigators seek the cause in some injury to the joint (partial luxation). Among these are Goyrand, Guersant, Moreau, and Oilier. The last-mentioned author particularly assumed what he called entorse juxtaepiphysaire, i.e., distortion of the epiphysis with laceration of the periosteurn. All these theories still have their adher ents to the present day, and in spite of Bezy's experiments we find in the latest papers on this subject the theory of a plexus lesion (Lovegren) in sharp contrast to the theory of an inhibition palsy occurring in a neuropathic child (Galatti).
The conditions must be differentiated from actual injuries to the arm (especially fracture of the clavicle) and poliomyelitis. In the former the skiagraphic findings are positive, while poliomyelitis is character ized by the absence of pain; in both conditions the clinical course is characteristic. No treatment is required, but I am in the habit of band aging the arm and believe that by doing so I obtain more rapid healing.
A similar condition has also been observed in the leg (Chassaignac and Brunon).
5. Palsies of the Nerves of the Arm Paralysis of the extensor muscles, with typical wrist drop, flexion of the fingers on the hand, and absence of movements of extension and supination, are sometimes observed in children in eases of peripheral palsy of the radial nerve, which niay be congenital or acquired.
The congenital form /nay be due either to the pressure of an am niotic band, in which case pressure marks may be seen on the arm at the point where the radial nerve passes around the member (Spieler) or it occurs without any recognizable cause, in which case it may be the result of intra-uterine or intrapartum pressure on the radial nerve (per sonal observation). The prognosis in the former case is unfavorable; in the second the paralysis disappears in a few weeks. These congenital palsies of the radial nerve are usually unilateral.
In later childhood radial palsies may result from lead poisoning or traumatism. Neuritis due to lead poisoning will be discussed later. Pressure (pressure palsy during sleep), unusual muscular efforts, over exertion and other causes of radial palsy which are important in adults are less prominent in children, although they may become operative in fractures of the humerus and during ansthesia. The occurrence of
traumatic radial palsy in children, however, is very rare.
Peripheral palsy in the distribution of the median and ulnar nerves are exceptional conditions, which are extremely rare in childhood and do not differ from similar conditions in the adult.
6. Palsies in the Lower Extremities Peripheral palsies in the lower extremities are much more rare in children than palsies in the upper extremities.
In rare cases a leg may be involved in a birth injury, resulting in crural palsy affecting the muscles of the thigh.
Isolated affections of the peroneal nerve resulting from traumatism may also be mentioned. While it is a well-established fact that the peroneal muscles as well as the tibialis anticus may be affected alone in poliomyelitis and in all toxic neuritides of childhood, no satisfactory explanation has as yet been offered. There is footdrop and, in eases with contracture of the muscles of the calf, the member is spastic and as sumes the position of pes equinus, cannot be elevated and in walking the toes drag along the ground.
Unilateral and bilateral club foot is a very common congenital anomaly in the lower extremities. There is neither palsy nor atrophy of the affected muscles, and no pathologic changes are found either in the peripheral or in the spinal nervous system. Whether club foot is caused by a primary muscular action (contraction of the tibialis anticus) or by the position of the child in utero is undecided. In favor of the latter we have the fact that in newborn infants depressions are sometimes seen on the legs or abdomen and that, by fitting the club feet into these depressions, a faulty intra-uterine position may be produced.
Whether meralgia parresthetica, consisting in diminished sensibility in the distribution of the external femoral cutaneous nerve with para (esthesiT, occurs in children I do not know. Since the affection occurs with flat foot, it is reasonable to suppose that it might develop in later childhood.
Whether the condition described by Oppenheim as congenital myolonia is nervous or muscular in origin is still doubtful. There is con genital flaccidity and immobility of the muscles of the leg, and more rarely, of other regions of the body, associated with diminution of elec tric irritability and absent or diminished tendon reflexes. The disease is congenital and, especially when treated by electricity, tends toward rapid improvement. Oppenheim attributes this form of palsy to delayed development of the muscles and possibly to a functional weakness of the motor cells in the anterior horns.
The pseudoparaplegia of rachitic children (Comby, Vierordt) has never been fully explained. The condition is observed in older rachitic children and manifests itself in sudden inability to walk. The legs are flaccid and there is muscular atony; the tendon reflexes and electric irritability are usually preserved. The power of walking is restored after a few weeks even without electric treatment. Whether the pseudo paraplegia is due to a reflex palsy tVierordt) front the painful condition of the bones or to increase of the normal muscular flaccidity observed in rachitic subjects or, finally, represents a nervous phenomenon, is as yet undecided.