Observational Study of the Differences in Characteristics of the Spontaneous Electroencephalogram, Derived From the Left and Right Hemisphere in Patients With Unilateral Intracranial Tumor During Routine Anesthesia: Comparison With a Control Group Without Intracranial Pathology
Observational Study of the Differences in Characteristics of the Spontaneous Electroencephalogram, Derived From the Left and Right Hemisphere in Patients With Unilateral Intracranial Tumor During Routine Anesthesia: Comparison With a Control Group Without Intracranial Pathology
Study of the influence of brain tumor on bilateral electroencephalogram (EEG) during
 anaesthesia.
Inclusion Criteria:

 -  Adult ≥ 18 - 80 years old

 -  Able to comprehend, sign, and date the written informed consent document to
 participate in the clinical trial

 -  Scheduled for "procedure"

 -  ASA Class I, II or III as assigned by the anaesthesiologist

 Exclusion Criteria:

 -  Allergy or inability to tolerate "product"

 -  Body weight less than 70% or more than 130% of ideal body weight

 -  Pregnant or nursing females

 -  Participation in a clinical trial within the past 30 days

 -  Congenital mental disability or congenital anatomical brain abnormality

 -  A medical history of cerebrovascular accident or thrombosis

 -  A medical history of carotic artery occlusive pathology

 -  A medical history of degenerative cerebral pathology (MS, Dementia, ALS, para-or
 tetraplegia due to a traumatic disruption of the spinal cord)

 -  A medical history of severe psychiatric pathology (Schizophrenia, severe depression,
 alcoholism, drug abuse) Mild depression evoked by coping with the diagnosis of cancer
 is not excluded

 -  Patients with a history of epileptic insults. Patients receiving preventive
 anti-epileptic treatment due to the tumoral process are not excluded.

 -  Patients with low cardiac output conditions due to pre-existing cardiac pathology
 (Cardiac insufficiency, valve pathology, dysrhythmia, myocardial infarction). Patients
 presenting with stable coronary artery disease with a normal myocardial function are
 not excluded)

 -  Arterial hypertension is not an exclusion criteria, nor is the use of antihypertensive
 medication, except beta blockers for their potential interfering effects on
 spontaneous EEG.