althy skin, and the empty sac compressed by a pad of wool and an
elastic bandage.

Operative treatment is seldom to be recommended in a young child
unless it is otherwise viable and the swelling is increasing rapidly
and threatening to burst, and there is reason to believe that the
paralysis is due to pressure. The immediate results of operation are
usually satisfactory, but in a large proportion of cases the child
subsequently develops hydrocephalus, from which it ultimately
succumbs. The hope of improvement in the motor symptoms after
operation depends on the site of the spina bifida; above the twelfth
thoracic vertebra there is no prospect of improvement; below this
level, inasmuch as it is the tip of the conus or the cauda equina that
is involved, there may be regeneration of nerve fibres and return of
power in the lower extremities, and control of the sphincters may be
regained. Murphy has practised resection of cicatricial or atrophied
portions of the cauda, with end-to-end suture.

The term #spina bifida occulta# is applied to a condition in which
there is no protrusion of the contents of the vertebral canal,
although the vertebral arches are deficient. The skin over the gap is
often puckered and adherent, and is frequently covered with a growth
of coarse hair.

A mass of fat may project towards the surface, and when situated in
the lumbo-sacral region may suggest a caudal appendage or tail (Fig.
222).

[Illustration: FIG. 222.--Tail-like Appendage over Spina Bifida
Occulta in a boy aet. 5, and associated with incontinence of urine.
Operation was followed by temporary retention.]

The clinical importance of spina bifida occulta lies in the fact that
it is sometimes associated with congenital club-foot, and with nerve
symptoms, in the form of sensory, motor, and trophic disturbances
referable to the lower limbs, such as perforating ulcer, and to the
sphincters. These nerve symptoms usually result from the presence of a
tough cord composed of connective tissue, fat, and muscle, stretching
from the skin through the vertebral canal to the lower end of the
spinal cord. As this strand of tissue does not grow in proportion
with the body, in the course of years it drags the cord against the
lower border of the membrana reuniens, which closes in the vertebral
canal posteriorly. These symptoms may be relieved by the removal of
this strand of tissue from the gap in the vertebral arches, or by
incising the membrana re