What is the first and most common neurologic presentation from a hemorrhage over the cerebral convexities?

The first and most common neurologic presentation from a hemorrhage over the cerebral convexities is hyperirritability and a hyperalert appearance. This symptom occurs due to the irritative effects of blood on the cortical tissue, typically seen in neonates. In cases of subarachnoid hemorrhage or intraventricular hemorrhage, irritation of the brain can lead to increased neuronal excitability, resulting in a state where the infant appears excessively alert and irritable.

This reaction signifies the brain's response to the blood and can often be a precursor to more severe symptoms, making its identification crucial. Recognizing hyperirritability is important in clinical practice because it can guide further assessment and intervention to prevent potential complications.

In contrast, other presentations like loss of consciousness, seizures, or decreased muscle tone may occur later and are not the initial signs indicative of this type of hemorrhage. Understanding these presentations helps facilitate timely and appropriate care for neonates experiencing bleeding in the brain.