Table 2

Results of fVEPs, aEEG and CUS prior to and after neurosurgical intervention

Before interventionAfter interventionp Value
VEP data
 P1 latency in ms (mean±SD)222±18.4188±18.70.02
 Z score P1 latency (mean±SD)1.8±1.4−0.17±1.70.02
 P1 latency within normal range (%)16.6%83.4%
 N2 latency in ms (mean±SD)345±36.8295±39.6<0.001
 Z score N2 latency (mean±SD)3.7±1.41.0±1.7<0.001
 N2 latency within normal range (%)5.8%58.8%
 P2 latency in ms (mean±SD)512±59.9421±48.9<0.001
 Z score P2 latency (mean±SD)3.8±1.20.6±1.6<0.001
 P2 latency within normal range (%)0%68.7%
Mean day of neurosurgical intervention (mean±SD)24.4±14.3
aEEG data
 aEEG score1±0.60.5±0.70.01
 aEEG normal (%)23.5%58.8%
 SWC present58.8%82.3%0.02
 Seizures present29.4%11.7%NS
CUS data
 Ventricular width in mm (mean±SD)15.8±3.511.2±2.4<0.001
 Ventricular index>97th percentile (%)94.1%47.1%0.005
 Ventricular index>97th percentile+4 mm (%)58.8%0%0.002
 AHW mm (mean±SD)6.6±2.23.8±1.50.005
 TOD mm (mean±SD)24.2±4.516.5±3.90.009
 Resistance index (mean±SD)0.8±0.070.77±0.06NS
 Sedative/analgetic/anticonvulsive medication52.9%47%NS
  • aEEG, amplitude-integrated electroencephalography; AHW, anterior horn width; CUS, cranial ultrasound; fVEPs, flash visual evoked potential; SWC, sleep-wake cycling; TOD, thalamo-occipital distance; VEP, visual evoked potential.