MainMenu Back Next Index


Bilateral lumbosacral somatic motor center lesions (Figure 239.1 D) may produce paraparesis. The neurological deficit depends on the level of the lesion. Neonates with a lesion at or below S2 have bilateral toe flexion weakness and bladder and rectal sphincter dysfunction. Neonates with lesions at L5 and below have, in addition to the previous deficits, weakness of knee flexion, ankle dorsiflexion, and plantar flexion, and decreased ankle jerk reflex. Neonates with lesions at L3 and below have, in addition to the previous deficits, weakness of hip adduction and knee extension, and decreased knee jerk reflex.

Figure 239.1. Possible sites of anatomical injury producing paraparesis. A: parasagittal region; B: bilateral periventricular regions; C: spinal cord below T1; D: lumbosacral center; V: ventricles; T: thalamus; UQ: upper quadrant; FN: facial nerve; LQ: lower quadrant; BP: brachial plexus; LSP: lumbosacral plexus. The colored rectangles indicate the location of weakness produced by damage to the varous components of the somatic motor system.

 

MainMenu Back Next Index
lumbosacral center lumbosacral center spinal cord below T1 spinal cord below T1 lumbosacral plexus brachial plexus bilateral periventricular regions parasagital region fibers to the lower facial quadrant facial nerve fibers to the upper facial quadrant thalamus thalamus thalamus lateral ventricle lateral ventricle To identify a structure pause the pointer over the abbrevations, or the structure in question; to idenyify the sites of injury pause pointer over the letters; do not click. Not all structures are labeled. Figure must be centered.