Trial Outcomes & Findings for Stereotactic Laser Ablation for Temporal Lobe Epilepsy (Slate) (NCT NCT02844465)

Last Updated: 2025-01-17

Results Overview

The incidence of qualifying device, procedure and/or anesthesia related adverse events. These events must also be moderate or severe and permanent for the following AEs: anxiety, aphasia, blurry vision, depression, diplopia, emotional lability, hemianopia, hemiparesis, memory impairment/difficulty, neurologic deficits, paralysis, psychological/psychiatric complications, quadrantanopia, sensory loss, sleep problems or insomnia. An exact 95% confidence interval (CI) will be calculated to determine if the upper bound of the CI for qualified AEs is less than 40%.

Recruitment status

COMPLETED

Study phase

Target enrollment

167 participants

Primary outcome timeframe

12 months

Results posted on

2025-01-17

Participant Flow

Participant milestones

Participant milestones
Measure	Treatment Visualase MRI-guided laser ablation procedure Visualase MRI-Guided Laser Ablation: All subjects will undergo MRI-guided laser ablation of the amygdala and hippocampus with the Visualase System.
Overall Study STARTED	167
Overall Study COMPLETED	107
Overall Study NOT COMPLETED	60

Reasons for withdrawal

Reasons for withdrawal
Measure	Treatment Visualase MRI-guided laser ablation procedure Visualase MRI-Guided Laser Ablation: All subjects will undergo MRI-guided laser ablation of the amygdala and hippocampus with the Visualase System.
Overall Study Screen Failure	36
Overall Study Withdrawal Prior to Procedure	17
Overall Study Withdrawal by Subject	5
Overall Study Lost to Follow-up	1
Overall Study Retreatment	1

Baseline Characteristics

Stereotactic Laser Ablation for Temporal Lobe Epilepsy (Slate)

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Treatment n=114 Participants Visualase MRI-guided laser ablation procedure Visualase MRI-Guided Laser Ablation: All subjects will undergo MRI-guided laser ablation of the amygdala and hippocampus with the Visualase System.
Age, Continuous	44.2 years STANDARD_DEVIATION 13.9 • n=5 Participants
Sex: Female, Male Female	67 Participants n=5 Participants
Sex: Female, Male Male	47 Participants n=5 Participants
Ethnicity (NIH/OMB) Hispanic or Latino	20 Participants n=5 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	94 Participants n=5 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	0 Participants n=5 Participants
Race (NIH/OMB) American Indian or Alaska Native	1 Participants n=5 Participants
Race (NIH/OMB) Asian	2 Participants n=5 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	1 Participants n=5 Participants
Race (NIH/OMB) Black or African American	12 Participants n=5 Participants
Race (NIH/OMB) White	93 Participants n=5 Participants
Race (NIH/OMB) More than one race	0 Participants n=5 Participants
Race (NIH/OMB) Unknown or Not Reported	5 Participants n=5 Participants
Region of Enrollment United States	114 participants n=5 Participants
BMI	27.49 kg/m^2 STANDARD_DEVIATION 5.88 • n=5 Participants
Epilepsy Diagnosis (years from diagnosis)	24.0 years STANDARD_DEVIATION 17.2 • n=5 Participants
Average Monthly Seizure Frequency over the 12 Months Prior to Enrollment: All Seizure Types	11.5 seizures STANDARD_DEVIATION 15.4 • n=5 Participants
Language Dominance Left	53 Participants n=5 Participants
Language Dominance Right	6 Participants n=5 Participants
Language Dominance Bilateral	4 Participants n=5 Participants
Language Dominance Inconclusive	1 Participants n=5 Participants
Language Dominance Not Evaluated	50 Participants n=5 Participants
Subject Handedness Left-handed	15 Participants n=5 Participants
Subject Handedness Right-handed	97 Participants n=5 Participants
Subject Handedness Mixed-handed	2 Participants n=5 Participants
Vague Nerve Stimulator Currently Implanted	5 Participants n=5 Participants
Side of Brain Intended for MRI-Guided Stereotactic Laser Ablation Left	74 Participants n=5 Participants
Side of Brain Intended for MRI-Guided Stereotactic Laser Ablation Right	40 Participants n=5 Participants

PRIMARY outcome

Timeframe: 12 months

Outcome measures

Outcome measures
Measure	Treatment n=114 Participants Visualase MRI-guided laser ablation procedure Visualase MRI-Guided Laser Ablation: All subjects will undergo MRI-guided laser ablation of the amygdala and hippocampus with the Visualase System.
Incidence of Qualifying Adverse Events	7.9 percentage of participants Interval 3.7 to 14.5

PRIMARY outcome

Timeframe: 12 months

Seizure freedom at 12 months following the Visualase procedure (starting at 30 days post-procedure through 365 days post procedure). Engel Class I: Free of disabling seizures includes subclasses: A. Completely seizure free since surgery, B. Nondisabling simple partial seizures only since surgery, D. Generalized convulsions with antiepileptic drugs (AED) discontinuation only. An exact 95% CI will be calculated to determine if the lower bound of the CI for seizure freedom at 12 months following the Visualase procedure will be greater than 43%. Multiple imputation was used if subject diary data was not compliant. Retreated subjects are treated as failures.

Outcome measures

Outcome measures
Measure	Treatment n=114 Participants Visualase MRI-guided laser ablation procedure Visualase MRI-Guided Laser Ablation: All subjects will undergo MRI-guided laser ablation of the amygdala and hippocampus with the Visualase System.
Seizure Freedom, Defined as Engel Classification of Postoperative Outcome Class I	56.0 percentage of subjects Engel Class I Interval 46.2 to 65.8

SECONDARY outcome

Timeframe: 12 months

Seizure freedom (Engel Class I) compared to historical control for continued medical therapy. It is hypothesized that the seizure freedom at 12 months following the Visualase procedure will be superior to 8% reported in the literature for continued medical therapy. An exact 95% CI for the percentage of subjects who are seizure free will be calculated.

Outcome measures

Outcome measures
Measure	Treatment n=114 Participants Visualase MRI-guided laser ablation procedure Visualase MRI-Guided Laser Ablation: All subjects will undergo MRI-guided laser ablation of the amygdala and hippocampus with the Visualase System.
Seizure Freedom Compared to Historical Controls (Medical Therapy)	56.0 percentage of subjects Engel Class I Interval 46.2 to 65.8

SECONDARY outcome

Timeframe: 12 months

Seizure freedom (Engel Class I) including subjects who were retreated with Visualase. The outcome after retreatment will count towards the endpoint. It is hypothesized that the lower bound of the 95% CI for seizure freedom at 12 months following the Visualase procedure, including subjects retreated with Visualase, will be greater than 43%. Subjects retreated with Visualase will count toward the secondary efficacy endpoint based on their outcome after retreatment. If they have become seizure free and have reached 12 months follow-up from time of retreatment, they are counted as seizure free. Otherwise, they will count as not seizure free. An exact 95% CI will be calculated to determine if the lower bound of the CI for seizure freedom at 12 months following a subject's last Visualase procedure, including patients retreated with Visualase, will be greater than 43%.

Outcome measures

Outcome measures
Measure	Treatment n=114 Participants Visualase MRI-guided laser ablation procedure Visualase MRI-Guided Laser Ablation: All subjects will undergo MRI-guided laser ablation of the amygdala and hippocampus with the Visualase System.
Seizure Freedom, Including Subjects Retreated With Visualase	56.0 percentage of subjects Engel Class I Interval 46.2 to 65.8

SECONDARY outcome

Timeframe: Baseline and 12 months

Population: Participants who had both a baseline and 12 month BNT total score

Within-subject change of Boston Naming Test score (English language version) from baseline to 12 months following the Visualase procedure. The Boston Naming Test is a neuropsychological assessment tool to measure confrontational word retrieval. The test contains 60 line drawings graded in difficulty which the participants need to name. The total score ranges from 0-60 with a higher score meaning a better outcome.

Outcome measures

Outcome measures
Measure	Treatment n=89 Participants Visualase MRI-guided laser ablation procedure Visualase MRI-Guided Laser Ablation: All subjects will undergo MRI-guided laser ablation of the amygdala and hippocampus with the Visualase System.
Change in Boston Naming Test Scores	-0.1 score on a scale Standard Deviation 7.2

SECONDARY outcome

Timeframe: Baseline and 12 months

Population: Participants with both a baseline and 12 month RAVLT 5-Trial Total Learning Score

Within-subject change of Rey Auditory Verbal Learning Test (RAVLT) 5-Trial Total score (English language version) from baseline to 12 months following the Visualase procedure. It is used for assessing episodic memory by providing scores for evaluating different aspects of memory. The RAVLT presents a list of 15 words across 5 consecutive trials. The list is read to the participant and the participant is asked to recall as many words as possible. This is repeated for 5 consecutive trials. The scores range from 0-75 with a higher score indicating a better outcome.

Outcome measures

Outcome measures
Measure	Treatment n=92 Participants Visualase MRI-guided laser ablation procedure Visualase MRI-Guided Laser Ablation: All subjects will undergo MRI-guided laser ablation of the amygdala and hippocampus with the Visualase System.
Change in Rey Auditory Verbal Learning Test Scores	-0.9 score on a scale Standard Deviation 8.9

SECONDARY outcome

Timeframe: Baseline and 12 months

Population: Participants who had both a baseline and 12 month QOLIE English language version assessment completed

Within-subject change of the QOLIE-31 score (English language version) from baseline to 12 months following the Visualase procedure, categorized as -1 if the decrease is clinically significant (\<= -11.8), categorized as 0 if not clinically significant (-11.7 to +11.7), and categorized as +1 if the increase is clinically significant (\>= 11.8). The QOLIE-31 evaluates a participant's quality of life in relation to their epilepsy. It is used to asses a person's overall wellness, including their social functioning and cognitive impact. The QOLIE scores range from 0-100 with a higher score meaning a better outcome.

Outcome measures

Outcome measures
Measure	Treatment n=93 Participants Visualase MRI-guided laser ablation procedure Visualase MRI-Guided Laser Ablation: All subjects will undergo MRI-guided laser ablation of the amygdala and hippocampus with the Visualase System.
Change in Quality of Life in Epilepsy (QOLIE-31) Scores Clinically Significant Decrease (<=-11.8)	1 Participants
Change in Quality of Life in Epilepsy (QOLIE-31) Scores Non-Clinically Significant Change (-11.7 to +11.7)	54 Participants
Change in Quality of Life in Epilepsy (QOLIE-31) Scores Clinically Significant Increase (>= 11.8)	38 Participants

SECONDARY outcome

Timeframe: Baseline and 12 Months

Population: Number of participants who had both a baseline and 12 month Mental Component Score in English.

Within-subject change of short form (SF)-36 quality of life questionnaire Mental Component Score (English language version) from baseline to 12 month following the Visualase procedure, categorized as -1 if the decrease is clinically significant (\<=-4.58), categorized as 0 if not clinically significant (-4.57 to +4.57), and categorized as +1 if the increase is clinically significant (\>=4.58). The SF-36 is a 36-item, patient-reported survey of patient health. It consists of eight scaled scores, which are the weighted sums of the questions in their section. The SF-36 Mental Component Score ranges from 0-100 with a higher score meaning a better outcome, on the assumption that each questions carries equal weight.

Outcome measures

Outcome measures
Measure	Treatment n=85 Participants Visualase MRI-guided laser ablation procedure Visualase MRI-Guided Laser Ablation: All subjects will undergo MRI-guided laser ablation of the amygdala and hippocampus with the Visualase System.
Change in SF-36 Mental Component Score Clinically Significant Decrease (<= - 4.58)	13 Participants
Change in SF-36 Mental Component Score Non-Clinically Significant Change (-4.57 to +4.57)	33 Participants
Change in SF-36 Mental Component Score Clinically Significant Increase (>=4.58)	39 Participants

SECONDARY outcome

Timeframe: Baseline and 12 Months

Population: Participants who had both a baseline and 12 month SF-36 Physical Component Score in English.

Within-subject change of short form (SF)-36 quality of life questionnaire Physical Component Score (English language version) from baseline to 12 month following the Visualase procedure, categorized as -1 if the decrease is clinically significant (\<=-3.02), categorized as 0 if not clinically significant (-3.01 to +3.01), and categorized as +1 if the increase is clinically significant (\>=3.02). The SF-36 is a 36-item, patient-reported survey of patient health. It consists of eight scaled scores, which are the weighted sums of the questions in their section. The SF-36 Physical Component Scores range from 0-100 with a higher score meaning a better outcome, on the assumption that each questions carries equal weight.

Outcome measures

Outcome measures
Measure	Treatment n=84 Participants Visualase MRI-guided laser ablation procedure Visualase MRI-Guided Laser Ablation: All subjects will undergo MRI-guided laser ablation of the amygdala and hippocampus with the Visualase System.
Change in SF-36 Physical Component Score Clinically Significant Decrease (<=-3.02)	12 Participants
Change in SF-36 Physical Component Score Non-Clinically Significant Change (-3.01 to +3.01)	28 Participants
Change in SF-36 Physical Component Score Clinically Significant Increase (>= 3.02)	44 Participants

SECONDARY outcome

Timeframe: 12 Months

Seizure freedom (Engel Class I) compared to historical control for open surgical resection. It is hypothesized that the seizure freedom at 12 months following the Visualase procedure will not be inferior to 64% reported in the literature for open surgical resection. An exact 95% CI for the percentage of subjects who are seizure free will be calculated and its lower boundary compared to zero after subtraction of the historical open surgical resection percentage of 64% and the addition of the equivalence delta percentage of 10%.

Outcome measures

Outcome measures
Measure	Treatment n=114 Participants Visualase MRI-guided laser ablation procedure Visualase MRI-Guided Laser Ablation: All subjects will undergo MRI-guided laser ablation of the amygdala and hippocampus with the Visualase System.
Seizure Freedom Compared to Historical Controls (Open Surgical Resection)	56.0 percentage of subjects Engel Class I Interval 46.2 to 65.8

Adverse Events

Treatment

Serious events: 16 serious events

Other events: 31 other events

Deaths: 0 deaths

Serious adverse events

Serious adverse events
Measure	Treatment n=167 participants at risk Visualase MRI-guided laser ablation procedure Visualase MRI-Guided Laser Ablation: All subjects will undergo MRI-guided laser ablation of the amygdala and hippocampus with the Visualase System.
Infections and infestations Pharyngitis	0.60% 1/167 • Number of events 1 • Enrollment to 12 months post procedure
Infections and infestations Postoperative wound infection	0.60% 1/167 • Number of events 1 • Enrollment to 12 months post procedure
Injury, poisoning and procedural complications Meningitis chemical	0.60% 1/167 • Number of events 1 • Enrollment to 12 months post procedure
Investigations Blood sodium decreased	0.60% 1/167 • Number of events 1 • Enrollment to 12 months post procedure
Metabolism and nutrition disorders Hypovolaemia	0.60% 1/167 • Number of events 1 • Enrollment to 12 months post procedure
Nervous system disorders Cerebrovascular accident	0.60% 1/167 • Number of events 1 • Enrollment to 12 months post procedure
Nervous system disorders Focal dyscognitive seizures	1.2% 2/167 • Number of events 2 • Enrollment to 12 months post procedure
Nervous system disorders Headache	0.60% 1/167 • Number of events 1 • Enrollment to 12 months post procedure
Nervous system disorders Memory impairment	0.60% 1/167 • Number of events 1 • Enrollment to 12 months post procedure
Nervous system disorders Partial seizures with secondary generalisation	0.60% 1/167 • Number of events 1 • Enrollment to 12 months post procedure
Nervous system disorders Psychogenic seizure	0.60% 1/167 • Number of events 1 • Enrollment to 12 months post procedure
Nervous system disorders Seizure	0.60% 1/167 • Number of events 1 • Enrollment to 12 months post procedure
Nervous system disorders Status epilepticus	0.60% 1/167 • Number of events 1 • Enrollment to 12 months post procedure
Psychiatric disorders Confusional state	0.60% 1/167 • Number of events 1 • Enrollment to 12 months post procedure
Psychiatric disorders Mental status changes	0.60% 1/167 • Number of events 1 • Enrollment to 12 months post procedure
Renal and urinary disorders Nephrolithiasis	0.60% 1/167 • Number of events 1 • Enrollment to 12 months post procedure
Reproductive system and breast disorders Ovarian cyst	0.60% 1/167 • Number of events 1 • Enrollment to 12 months post procedure

Other adverse events

Other adverse events
Measure	Treatment n=167 participants at risk Visualase MRI-guided laser ablation procedure Visualase MRI-Guided Laser Ablation: All subjects will undergo MRI-guided laser ablation of the amygdala and hippocampus with the Visualase System.
Nervous system disorders Headache	7.8% 13/167 • Number of events 13 • Enrollment to 12 months post procedure
Nervous system disorders Quadrantanopia	12.6% 21/167 • Number of events 21 • Enrollment to 12 months post procedure

Additional Information

Clinical Study Manager

MedtronicNeuro

Phone: (877) 590-7835

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee PIs are required to submit proposals through the publication committee and receive approval from the publication committee before publishing results.
Publication restrictions are in place

Restriction type: OTHER