Which of the following symptoms does NOT suggest brain stem or posterior circulation issues?

Amaurosis fugax is a temporary loss of vision in one eye, often described as a curtain coming down over the visual field, and it typically indicates issues related to the retinal or arterial supply to the eye, particularly from the carotid arteries. This symptom is primarily associated with anterior circulation problems, such as transient ischemic attacks (TIAs) affecting the anterior circulation or embolic events originating from carotid artery disease.

In contrast, symptoms like dizziness, vertigo, and ectasia are associated more closely with issues in the brain stem or posterior circulation. Dizziness can result from balance disruptions caused by brain stem anomalies. Vertigo, characterized by a false sense of movement or spinning, often originates from vestibular disturbances, which can be linked to posterior circulation problems. Ectasia, which refers to abnormal dilation of blood vessels, can also signify vascular complications affecting the brain's blood supply.

Thus, amaurosis fugax stands out as the symptom that does not indicate brain stem or posterior circulation issues, making it the correct answer in the context of this question.