F CLINICAL ASPECTS OF SPINAL CORD INJURIES
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hip, as the gluteal muscles are of full power, and so is flexion of the leg as the biceps
femoris is intact. The ankle jerk may be weakly positive. Plantar stimulation may produce
dorsiflexion of the toes (peripheral Babinsld), due to the paralysis or weakness of the
plantar flexors of the toes. The foot shows claw-toes formation as a result of the paralysis
of the intrinsic muscles of the toes.
Sensibility is lost over the upper posterior aspect of the calf the postero-lateral
aspect of the thigh and the saddle area.
83-55 SEGMENTS
There is no paralysis of any leg muscles. The paralysis is confined to bladder, bowels
and sexual functions. The knee and ankle jerks are present but the anal and bulbo-
cavernosus reflex is abolished. The loss of sensibility involves the saddle area, including
the posterior and the two distal thirds of the anterior aspects of the scrotum, the glans
penis, perineum, the anal area and extends to the upper third of the posterior aspect of
the thighs.
Various authors have published charts of the segmental innervation of individual
muscles (Bruns, Lazarus, Flatau, Edinger, Bing, Villiger). My own muscle chart is
mainly in accordance with that of Foerster (1927) with certain modifications arising
from my own experience on spinal cord injuries (Tables 9-11).
B. INCOMPLETE LESIONS OF THE SPINAL CORD
There are great variations in incomplete cord lesions depending on aetiology, level of
the lesion and degree of damage to the various components of the neural elements. They
can be conveniently divided into two main groups, viz. (i) pathological processes affect
ing diffusely more or less all the neurons as well as the efferent and afferent tracts at any
level but not resulting in complete interruption of their functions, and (2) circumscribed
processes affecting distinct parts of the cord and resulting in incomplete lesions of
dissociated type.
As far as the peripheral neurons of the anterior horns and their synapses are con
cerned, either there may be paralysis of lower motor neuron type of all muscles inner
vated by the segment or segments at the level of the lesion, or some muscles supplied
by the same segment have escaped damage completely or are only slightly damaged.
In acute incomplete lesions following vertebral fractures affecting the supranuclear
pathways, namely the pyramidal and extrapyramidal tracts, there is at first hypo- or
areflexia during the stage of spinal shock, but, as a rule, the reflexes below the level of the
lesion will soon return and become exaggerated. However, in severe though incomplete
traumatic lesions of the cord both at high level and, in particular, below Tio, Til and Ti2
level, reflex return below the level of the lesions may be considerably delayed. In the
majority of cases, provided the initial positioning of the paralysed legs was correct,
there may be preponderance of extension synergy rather than flexion synergy, but the
contrary, namely flexion synergy, may occur if the legs were kept in continuous flexion.
