The purpose of this study is to prospectively determine the association between incidence of neurological morbidity and minimum fractional blood pressure reached during laminectomy procedures under general anesthesia in hypertensive and normotensive subjects 40 years old and older.

Inclusion Criteria:

• English as first language, or as a learned language as long as the patient is proficient
• No history of any neurological disease with the exception of patients without functional impairment who suffered a single episode of transient ischemic attack
• No history of axis I psychiatric diagnosis or drug abuse
• 40 years old or older
• Undergoing laminectomy under general anesthesia
• Must not take antihypertensive medication for purposes other than treatment of hypertension

Exclusion Criteria:

• Anyone who do not fit the inclusion criteria.

- individuals 40 years of age and older, undergoing laminectomy under general anesthesia.