4 Clinical Trials for Various Conditions
Assessing the function of the optic nerve is paramount during various neurosurgical procedures. Effective optic nerve monitoring has remained elusive as Visual Evoked Potentials (the current existing tool) provides only diffuse and delayed assessment of nerve function. Here, the investigators propose a prospective study involving adult patients (aged 18 years and older) undergoing endonasal or open cranial approaches around the optic nerves, who will receive pre- and post-operative visual evaluations. During surgery, the optic nerve and chiasm will be stimulated, and the response will be recorded in both eyes and the occipital cortex via skin electrodes. The investigators aim to utilize anterograde optic nerve microstimulation to assess the nerve's integrity during open and endoscopic cranial approaches. Electrophysiological readings will be acquired, as is routine in the operating room, by our team of experts, and intraoperative findings will be correlated with post- surgical clinical outcomes. Our objective is to utilize existing technology in the operating room to safely and effectively monitor optic nerve function during surgery.
The purpose of this investigator-initiated study is to compare the use of pupilometer and ultrasound assessment of optic nerve sheath diameter in predicting the ICP and to see if there is a value that could be used to indicate elevated ICP with either modality as these numbers are inconsistent throughout the literature. Patients that have either an external ventricular drain (EVD) or bolt placed will be enrolled in the study. After the EVD and bolt are placed the patient will undergo pupilometer examination (standard of care) followed by ultrasound assessment of the optic nerve sheath diameter (ONSD). The three values will be recorded. The same patient may have multiple readings performed if there is a change in ICP either spontaneously or due to intervention.
Optic Nerve Ultrasound (ONUS) is a promising non-invasive tool for the detection of raised Intracranial Pressure (ICP). Variability in the optimal Optic Nerve Sheath Diameter (ONSD) threshold corresponding to elevated ICP in multiple studies limits the value of ONUS in clinical practice. The investigators goal is to develop and validate an automated image analysis algorithm for standardization of ONSD measurement from ultrasound videos. Patients with acute brain injury requiring invasive ICP monitoring will undergo bedside ONUS, with blinded ONSD measurement by an expert investigator. The image analysis algorithm will then be used to measure ONSD and accuracy determined compared to the "reference standard" expert measurement.
The purpose of this study is to determine the feasibility of producing artificial vision in persons with blindness. Study participants will have wireless electrical stimulators implanted into the cortical vision processing areas of their brains. The ability of the participants to perceive artificial vision in response to electrical stimulation will be assessed.