Based on the patient's symptoms and medical history, the physician should evaluate the possibility of a potential medical emergency, such as a stroke or aneurysm, and refer the patient for immediate medical attention. The combination of neck pain, stiffness, and an extreme headache could indicate a serious condition such as a subarachnoid hemorrhage.
Given the patient's medical history of high blood pressure, atherosclerosis, and cocaine abuse, it is also important to consider the possibility of other neurological conditions such as hypertensive crisis, carotid artery dissection, or drug-induced cerebral vasculitis.
The physician will likely perform a thorough physical examination and imaging studies, such as a CT or MRI scan, to determine the underlying cause of the patient's symptoms. Treatment will depend on the specific diagnosis but may involve medications to manage blood pressure, pain, or inflammation, as well as cessation of cocaine use and lifestyle modifications to manage the underlying cardiovascular risk factors.