Which sign is NOT associated with brain herniation due to high ICP?

In the context of brain herniation due to elevated intracranial pressure (ICP), specific signs and symptoms commonly arise as a result of increased pressure on the brain structures. Fixed and dilated pupils, sudden loss of consciousness, and abnormal posturing are all indicative of severe neurological compromise and the potential progression of herniation.

Fixed and dilated pupils can result from increased pressure affecting the oculomotor nerve pathways, leading to impaired pupil response. Sudden loss of consciousness typically occurs when the brain's ability to function is severely compromised, often indicating significant herniation. Abnormal posturing, such as decerebrate or decorticate posturing, suggests that the brain is under extreme stress, and brainstem function may be disrupted.

In contrast, increased reflexes are generally not associated with brain herniation due to high ICP. During states of increased ICP and severe cerebral dysfunction, reflexes may be diminished or absent as brainstem function declines. Therefore, increased reflexes do not fit the clinical picture of brain herniation and are less relevant to the symptoms usually observed in this critical condition. This understanding helps to differentiate signs that are characteristic of various neurological impairments related to ICP elevation.