The radiographic findings in neurogenic bladder.

Abstract

Numerous articles have documented the clinical symptomatology and the many causative factors associated with neurogenic lesions affecting the bladder, but the associated radiographic findings (1) have been infrequently and often incompletely presented. Among the more common causes of neurogenic bladder are such entities as trauma with damage to the spinal cord or cauda equina, congenital lesions such as spina bifida, multiple sclerosis, syphilis, diabetes mellitus, and neoplasm. The clinical picture varies, depending on the severity of the lesion and its level. In some cases there will be urinary retention with associated overflow incontinence. In other instances there may be total loss of urinary control, with inability to initiate or inhibit the stream, continuous dribbling, or involuntary evacuation of urine at regular intervals. The radiographic findings associated with neurogenic bladder are caused directly by the neuromuscular effects of the neurogenic lesions on the bladder and sphincters and indirectly by the resulting obstruction. The roentgen picture is also altered by secondary infection and calculi formation. Radiographic Findings The accompanying illustrations, selected from the cystourethrograms of 50 patients with neurogenic bladder, demonstrate the usual radiographic findings. The major abnormalities reflect changes in the shape, size, and position of the bladder, the configuration of the urethra, the status of the external urethral sphincter, and the competence of the ureteral orifices. Figure 1 is the cystogram of a girl of three and a half years with neurogenic bladder resulting from lumbosacral spina bifida and posterior meningocele that had been repaired at three weeks of age. There is a large atonic bladder with bilateral vesico-ureteral reflux of such a degree as to make possible visualization of the entire excretory system of both kidneys. The bladder is deviated to the right. A funnel urethra is poorly demonstrated. This is an example of the less common large atonic neurogenic bladder with ureteral reflux and characteristically eccentric position (5). Figure 2, the cystourethrogram of a 26-year-old male, shows a typical “hourglass” deformity following a traumatic cord lesion at L-1. Cystometry revealed hypertonicity of the bladder. The causes of the hourglass deformity are unknown, but it may result from asymmetrical innervation of the bladder secondary to the neurologic lesion, with a spastic muscular area causing the narrowing in the midportion. The trigone may be either above or below the indentation. There are bilateral ureteral reflux and a funnel urethra, just distal to which is a moderately spastic external sphincter. The “pine-tree”-shaped bladder shown in Figure 3 is an unusual deformity of neurogenic origin. In this patient, an adult male, there was complete absence of the sacrum and coccyx, with a neurogenic lesion existing from birth. The cystometric reading showed the bladder to be hypertonic.