Neonatal sharp-wave transients

Criteria & assessment

• A spike lasts <100 ms at baseline; a sharp wave lasts 100-200 ms; the transient must stand apart from background rather than be only sharply contoured background.
• Physiologic negative sharp waves are usually 100-200 ms, solitary, symmetric, and mid-temporal/central/centro-temporal against a PMA-normal background; frontal, vertex, and occipital locations are uncommon.
• Abnormal negative transients are supported by abnormal background, concentration in one region or hemisphere, atypical location, high abundance, or repetitive runs; source-cited outcome data call rates >11/hour preterm and >13/hour term abnormal.
• Positive Rolandic/vertex sharp waves are centered at C3/C4 or vertex with adjacent field; excessive positive mid-temporal waves can indicate focal pathology, while cited upper normal observations are 3/hour preterm and 1.5/hour term.