546 Table 3 Wingspread classification of anorectal malformations Female High Anorectal agenesis With rectovaginal fistula Without fistula Rectal atresia Intermediate Rectovestibular fistula Rectovaginal fistula Anal agenesis without fistula Low Anovestibular fistula Anocutaneous fistula Anal stenosis Cloacal malformation Rare malformation Male High Anorectal agenesis With rectourethral (prostatic) fistula Without fistula Rectal atresia Intermediate Rectovestibular urethral fistula Anal agenesis without fistula Low Anocutaneous fistula Anal stenosis Rare malformation VACTERL association (the mnemonic denotes all affected organs: V vertebral; A anal; C cardiac; TE tracheoesopha- geal fistula; R renal; L limb). Unilateral renal agenesis, vesicoureteral reflux and spinal cord tethering are the most common abnormalities affecting the urinary tract [50]. Urinary, and fecal, incontinence issues that become prom- inent as the child matures, due to progressive denervation of the lowermost nerves modulating bladder and urethral and anal muscle function, are likely clinical scenarios. This is most commonly seen in children where the rectum has ended above the levator ani muscle (50%), but it is also seen when the rectum ends below that pelvic floor muscle (18%) [51]. A spinal vertebral bony image is not a reliable sign that spinal cord abnormality is present [52]. A spinal ultrasound in newborns, and MRI of the spine in older children, are a mandatory part of the investigation in these children. An upper motor neuron lesion with detrusor overactivity and/or detrusor sphincter dyssynergy are most likely to develop, but an acontractile detrusor and sphincter denervation are also seen as a result of spinal cord tethering [49, 53]. It has been shown that the earlier neurosurgical intervention is undertaken, the better the individual’s chances of having normal sacral spinal cord and lower urinary tract function [54]. Therefore, early detection of this condition is necessary to improve the child’s chance of maintaining healthy kidneys and becoming continent. Central nervous system disorders Cerebral palsy This condition results from a non-progressive injury to the brain, occurring in the perinatal period, that produces a neuromuscular disability or a specific symptom complex of 1 2 – 1 – – 2 – – 3 – Pediatr Nephrol (2008) 23:541–551 cerebral dysfunction [55]. It is caused by perinatal infection or a period of anoxia (or hypoxia) affecting the tissues of the central nervous system [56] (Table 4). It appears in babies who are less than 2 kg at birth, have had intraventricular hemorrhage, experienced a neonatal seizure or received mechanical ventilation for a prolonged period of time in the postnatal period [57]. The incidence of cerebral palsy is increasing, as more severely premature infants are surviving and going home. Affected children have delayed gross motor development, abnormal fine motor performance, altered muscle tone, abnormal stress gait, tight heel cords and exaggerated deep tendon reflexes [58]. These findings can vary substantially, from being quite obvious to very subtle, unless a careful neurologic examination is performed. These abnormalities may not be manifest in the early postnatal period, but become evident over time, because myelination of axons and maturation of neurons in the basal ganglia are required before spasticity, dystonia, and athetosis become apparent. Some less affected children have even milder forms of the disease, with only learning disabilities, attention deficit, or attention deficit hyperactivity disorders being seen. Most children with cerebral palsy develop total urinary control, albeit at an age later than most unaffected children. Incontinence is a feature in some (24% of surveyed families in one study) [59], but the exact incidence has never been truly determined. The presence of incontinence is often related to the extent of the physical impairment, primarily because the handicap prevents the child from reaching the bathroom on time, causing an episode of wetting [60]. Urinary infection and vesicoureteral reflux are not features of this disease, and the kidneys are invariably normal on ultrasonic imaging. An upper motor neuron type of bladder dysfunction with detrusor overactivity (80%), but not necessarily with Table 4 Perinatal risk factors in cerebral palsy. Adapted from [61], used with permission. UMN upper motor neuron lesion, LMN lower motor neuron lesion UMN LMN (no. of patients) (no. of patients) Factor Prematurity Respiratory distress/arrest/apnea Neonatal seizures Infection Traumatic birth Congenital hydrocephalus Placenta previa/abruption Hypoglycemia seizures Intracranial hemorrhage Cyanosis at birth No specific factor noted 10 9 5 5 5 3 2 2 2 1 15