Sedatives' Effects on Neurological Function in Patients With Eloquent Area Glioma

Cohort Study of Sedatives' Effects on Neurological Function in Patients With Eloquent Area Glioma: Comparison With a Control Group Without Intracranial Pathology

Sedation in the operating room, the Post Anesthesia Care Unit and the Intensive Care Unit is common and often necessary for patients with intracranial brain tumor. Repeated neurological function assessments is needed in those locations, especially in patients with tumors in or near eloquent regions, this is to monitor their neurologic performance to determine if there are alterations that require treatment. Some slowly infiltrative low-grade gliomas near eloquent regions do not show any detectable neurologic deficits, perhaps from reorganization, but with sedation by some sedatives such as benzodiazepine midazolam and anesthetic hypnotic propofol, the disease may seem much worse resulting in inappropriately aggressive treatment. This may be especially problematic in patients undergoing awake craniotomy for tumors in eloquent regions. This is a single-center perspective study. Patients will be mildly sedated to keep them responsive and cooperative. Motor and sensory function will be evaluated before and after mild sedation. Specific benzodiazepine antagonist will be used if sedated by midazolam. The purpose of this study is to observe if commonly used benzodiazepine midazolam exacerbates or unmasks motor and sensory function in patients with intracranial eloquent area gliomas. Hypothesis: mild sedation can unmasks or exacerbate motor and sensory deficits in patients with eloquent area glioma but not in non-neurosurgical patients/healthy volunteers. If the neurologic deficits induced by benzodiazepine agonist, then can be reversed by flumazenil.

Patients in this group will be administered sedatives (midazolam or propofol or dexmedetomidine) titrating to mild sedation.

patients in this group will be administered the same sedative midazolam as compared glioma group, and titrate to mild sedation.

specific benzodiazepine agonist midazolam will be used titrate to desired sedation level, its specific antagonist flumazenil will also be used

this is a focal neurologic deficits induced by sedatives, the outcome is the performing time changes after sedation as : sedation-baseline.

OAA/S is Observer Assessment of Sedation with 5 levels (5 = alert, 4 = lethargic, 3 = aroused by voice, 2 = aroused by shaking, 1 = deep sleep), all participants have to achieve OAA/S=4 after sedation.

the WHO grade and the type of glioma (WHO glioma grade I~II is regarded as low grade glioma, WHO glioma grade III~IV is regarded as high grade glioma)

Inclusion Criteria: Age between 18-60 year-old American Society of Anesthesiology(ASA) status I~II Elective craniotomy patients with supratentorial eloquent glioma diagnosed by MRI (In control group: volunteers without neuro-diseases) Exclusion Criteria: Unable to comprehend and cooperate with the neurologic examination Impaired mental status Taking sedative drugs in the past 24 hours Taking pain reliever in the past 24 hours Drug and/or alcohol abuse Pregnant and/o lactating women Recurrent brain tumors Multiple brain tumors Accepting radiotherapy or chemotherapy Complicated with intracranial trauma and vascular diseases Complicated with grand mal epilepsy ( in midazolam group) Complicated with neuromuscular diseases Complicated with cutaneous paresthesia