Safety of RNS60 in Large Vessel Occlusion Stroke Patients Undergoing Endovascular Thrombectomy

The mRS is a clinician-reported outcome measure for participants who have suffered a stroke. It measures functional recovery as the degree of disability or dependence in daily activities in a 6-point disability scale with possible scores ranging from 0 to 5: 0-no symptoms at all; 1-no significant disability despite symptoms; able to carry out all usual duties and activities; 2-slight disability: unable to carry out all previous activities but able to look after own affairs without assistance; 3-moderate disability: requiring some help, but able to walk without assistance; 4-moderately severe disability: unable to walk without assistance and unable to attend to own bodily needs without assistance; 5-severe disability; bedridden, incontinent, requiring constant nursing care and attention. A score of 6 is used for participants who expire (death). Non-disability was defined as a score ranging from 0 to 2. Disability was defined as a score ranging from 3-6.

Infarct progression/regression was measured by Magnetic Resonance Imaging (MRI) of the brain. The mean change from post-EVT baseline in the volume of injured tissue was calculated at 48 hours.

The NIHSS is a standardized neurological examination scale that is a measure of disability and recovery after acute stroke. The NIHSS assessment is a standardized 15-item impairment scale intended to evaluate neurologic outcome and degrees of recovery for subjects with stroke. The scale assesses levels of consciousness, extraocular movements, visual fields, facial muscle function, extremity strength, sensory function, coordination (ataxia), language (aphasia), speech (dysarthria), and hemi-inattention (neglect). The NIHSS was scored by those trained in the use of this scale. Each item was scored in ranges 0-2, 0-3, or 0-4. A score of 0 indicates normal performance. Total scores on the NIHSS ranged from 0-42, with higher values reflecting increasing severity. Stroke severity was further stratified in the following way: > 25: Very severe; 15-24: Severe; 5-14: Mild to moderately severe; < 5: Mild.

Worsening of stroke was defined as progression, or hemorrhagic transformation of the index stroke, as documented by brain imaging, which is (a) life-threatening requiring intervention and/or (b) results in increased disability as gauged by a ≥ 4-point increase from lowest NIHSS pre-decline and/or (c) results in death. Proportion of participants with worsening of stroke was calculated as number of participants with worsening of stroke divided by the total number of participants observed over the 90-day period in each arm.

The BI is an index of functional independence. Its values range from 0 to 100, with higher scores indicating greater independence. Score range in BI items: Feeding 0-10; Bathing 0-5; Grooming 0-5; Dressing 0-10; Bowels 0-10; Bladder 0-10; Toilet use 0-10; Transfers (bed to chair and back) 0-15; Mobility (on level surfaces) 0-15; Stairs 0-10. Item scores vary in increments of 5 points. Functional independence at Day 90 was evaluated. Participants having a score ≥95 on the BI Score were deemed to have achieved functional independence, whereas those scoring <95 at Day 90 were deemed to have failed to achieve functional independence.

EQ-5D-5L is a generic instrument for measuring health-related quality of life. It consists of a 5-item questionnaire, which was interviewer administered by study staff. The 5-item questionnaire comprises 5 dimensions (mobility, self-care, usual activities, pain/discomfort, anxiety/depression) and each dimension has 5 response levels (1-no problems, 2-slight problems, 3-moderate problems, 4-severe problems, 5-unable to/extreme problems). The health state is then summarized to be a single number, EQ-5D-5L Index score, by applying a country-specific standard value set. EQ-5D-5L Index score for the United States ranges from -0.59 to 1, where 1 indicates a better health condition.