Which symptom indicates a potential problem with the cerebral cortex?

Changes in level of consciousness are indeed an important indicator of potential problems with the cerebral cortex. The cerebral cortex is responsible for higher brain functions, including awareness, perception, and cognitive abilities. When there is dysfunction in the cerebral cortex due to injury, stroke, or other neurological disorders, it can significantly impact a person's ability to stay conscious and alert, leading to altered or diminished levels of consciousness.

In contrast, symptoms like vomiting might suggest issues related to the brainstem or other areas, while fixed and dilated pupils often indicate increased intracranial pressure or damage to specific brain regions that control pupil response, which may not be directly linked to the cortical functions. Pain in the neck can be associated with various conditions, including meningitis or cervical issues, but it does not specifically point to dysfunction within the cerebral cortex itself. Therefore, changes in consciousness are the most direct indicator of cerebral cortical involvement.