Skip to content

Stereotactic Laser Ablation for Temporal Lobe Epilepsy (Slate)

Stereotactic Laser Ablation for Temporal Lobe Epilepsy

Status
Completed
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT02844465
Acronym
SLATE
Enrollment
167
Registered
2016-07-26
Start date
2016-12-31
Completion date
2023-12-11
Last updated
2025-01-17

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Temporal Lobe Epilepsy

Keywords

epilepsy, laser ablation, Visualase, laser interstitial thermal therapy

Brief summary

The study is designed to evaluate the safety and efficacy of the Visualase MRI-guided laser ablation system for mesial temporal epilepsy (MTLE).

Detailed description

The purpose of the study is to evaluate the safety and efficacy of the Visualase MRI-guided laser ablation system for necrotization or coagulation of epileptogenic foci in patients with intractable mesial temporal lobe epilepsy. The study will include approximately 150 adult patients with drug-resistant MTLE treated at selected epilepsy centers across the United States. After the Visualase procedure, patients will be followed for 12 months and evaluated for freedom from seizures, quality of life, adverse events, and neuropsychological outcomes.

Interventions

DEVICEVisualase MRI-Guided Laser Ablation

All subjects will undergo MRI-guided laser ablation of the amygdala and hippocampus with the Visualase System.

Sponsors

MedtronicNeuro
Lead SponsorINDUSTRY

Study design

Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE

Eligibility

Sex/Gender
ALL
Age
18 Years to 70 Years
Healthy volunteers
No

Inclusion criteria

* History of drug-resistant mesial temporal lobe epilepsy (MTLE) * If the subject has a vagus nerve stimulator (VNS), must have failed to achieve sustained seizure freedom with the VNS implanted for at least 6 months * On stable antiepileptic drugs (AEDs) (and/or stable VNS setting, if applicable) and compliant with medication use * An average of at least 1 complex partial or secondarily generalized seizure compatible with MTLE per month * Seizure symptoms and/or auras compatible with MTLE * Video EEG shows evidence of seizures from one temporal lobe consistent with MTLE * MRI has evidence consistent with mesial temporal lobe sclerosis * Willing and able to remain on stable AEDs (and stable VNS setting, if applicable) for 12 months following the Visualase procedure * Willing and able to comply with protocol requirements * Able to complete study assessments in English or Spanish language

Exclusion criteria

* Unwilling or unable to sign the study informed consent form * Pregnant or intends to become pregnant during the course of the study * Currently implanted with a device contraindicating MRI * Progressive brain lesions and/or tumors not associated with epileptic disease state * History of previous intracranial surgery for treatment of epileptic seizures * Persistent extra-temporal or predominant contralateral focal interictal spikes or slowing, or generalized interictal spikes on EEG * Seizures with contralateral or extra-temporal ictal onset on EEG * Aura and/or ictal behavior suggest an extra-temporal focus * MRI evidence of epileptogenic, extra-temporal lesions, dual pathology in the temporal lobe, or contralateral hippocampal MRI increased signal and/or loss of architecture * If additional testing has been performed, results are discordant with the seizure focus scheduled for ablation * Non-compliance with AED requirements * IQ \< 70 * Dementia or other progressive neurological disease * Unstable major psychiatric illness, psychogenic non-epileptic seizures, or medical illness that would contraindicate the Visualase procedure or affect the neuropsychological assessments * Participation in other research that may potentially interfere with SLATE endpoint(s) * Allergy to gadolinium

Design outcomes

Primary

MeasureTime frameDescription
Incidence of Qualifying Adverse Events12 monthsThe 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%.
Seizure Freedom, Defined as Engel Classification of Postoperative Outcome Class I12 monthsSeizure 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.

Secondary

MeasureTime frameDescription
Change in Boston Naming Test ScoresBaseline and 12 monthsWithin-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.
Change in Rey Auditory Verbal Learning Test ScoresBaseline and 12 monthsWithin-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.
Change in Quality of Life in Epilepsy (QOLIE-31) ScoresBaseline and 12 monthsWithin-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.
Seizure Freedom Compared to Historical Controls (Medical Therapy)12 monthsSeizure 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.
Change in SF-36 Physical Component ScoreBaseline and 12 MonthsWithin-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.
Seizure Freedom Compared to Historical Controls (Open Surgical Resection)12 MonthsSeizure 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%.
Change in SF-36 Mental Component ScoreBaseline and 12 MonthsWithin-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.
Seizure Freedom, Including Subjects Retreated With Visualase12 monthsSeizure 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%.

Countries

United States

Participant flow

Participants by arm

ArmCount
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.
114
Total114

Withdrawals & dropouts

PeriodReasonFG000
Overall StudyLost to Follow-up1
Overall StudyRetreatment1
Overall StudyScreen Failure36
Overall StudyWithdrawal by Subject5
Overall StudyWithdrawal Prior to Procedure17

Baseline characteristics

CharacteristicTreatment
Age, Continuous44.2 years
STANDARD_DEVIATION 13.9
Average Monthly Seizure Frequency over the 12 Months Prior to Enrollment: All Seizure Types11.5 seizures
STANDARD_DEVIATION 15.4
BMI27.49 kg/m^2
STANDARD_DEVIATION 5.88
Epilepsy Diagnosis (years from diagnosis)24.0 years
STANDARD_DEVIATION 17.2
Ethnicity (NIH/OMB)
Hispanic or Latino
20 Participants
Ethnicity (NIH/OMB)
Not Hispanic or Latino
94 Participants
Ethnicity (NIH/OMB)
Unknown or Not Reported
0 Participants
Language Dominance
Bilateral
4 Participants
Language Dominance
Inconclusive
1 Participants
Language Dominance
Left
53 Participants
Language Dominance
Not Evaluated
50 Participants
Language Dominance
Right
6 Participants
Race (NIH/OMB)
American Indian or Alaska Native
1 Participants
Race (NIH/OMB)
Asian
2 Participants
Race (NIH/OMB)
Black or African American
12 Participants
Race (NIH/OMB)
More than one race
0 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
1 Participants
Race (NIH/OMB)
Unknown or Not Reported
5 Participants
Race (NIH/OMB)
White
93 Participants
Region of Enrollment
United States
114 participants
Sex: Female, Male
Female
67 Participants
Sex: Female, Male
Male
47 Participants
Side of Brain Intended for MRI-Guided Stereotactic Laser Ablation
Left
74 Participants
Side of Brain Intended for MRI-Guided Stereotactic Laser Ablation
Right
40 Participants
Subject Handedness
Left-handed
15 Participants
Subject Handedness
Mixed-handed
2 Participants
Subject Handedness
Right-handed
97 Participants
Vague Nerve Stimulator Currently Implanted5 Participants

Adverse events

Event typeEG000
affected / at risk
deaths
Total, all-cause mortality
0 / 167
other
Total, other adverse events
31 / 167
serious
Total, serious adverse events
16 / 167

Outcome results

Primary

Incidence of Qualifying Adverse Events

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%.

Time frame: 12 months

ArmMeasureValue (NUMBER)
TreatmentIncidence of Qualifying Adverse Events7.9 percentage of participants
Primary

Seizure Freedom, Defined as Engel Classification of Postoperative Outcome Class I

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.

Time frame: 12 months

ArmMeasureValue (NUMBER)
TreatmentSeizure Freedom, Defined as Engel Classification of Postoperative Outcome Class I56.0 percentage of subjects Engel Class I
Secondary

Change in Boston Naming Test Scores

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.

Time frame: Baseline and 12 months

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

ArmMeasureValue (MEAN)Dispersion
TreatmentChange in Boston Naming Test Scores-0.1 score on a scaleStandard Deviation 7.2
Comparison: It is hypothesized that the Boston Naming Test score will not decrease from baseline to 12 months following the Visualase procedure. The hypotheses associated with this endpoint are as follows:~Null Hypothesis: μ (V-BNT - BSL-BNT) + δ ≤ 0 Alternate Hypothesis: μ (V-BNT - BSL-BNT) + δ \> 0 Where μ (V-BNT - BSL-BNT) = mean difference in the Boston Naming Test score from baseline to Month 12 post Visualase.p-value: <0.0001Paired t-test
Secondary

Change in Quality of Life in Epilepsy (QOLIE-31) Scores

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.

Time frame: Baseline and 12 months

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

ArmMeasureCategoryValue (COUNT_OF_PARTICIPANTS)
TreatmentChange in Quality of Life in Epilepsy (QOLIE-31) ScoresClinically Significant Decrease (<=-11.8)1 Participants
TreatmentChange in Quality of Life in Epilepsy (QOLIE-31) ScoresNon-Clinically Significant Change (-11.7 to +11.7)54 Participants
TreatmentChange in Quality of Life in Epilepsy (QOLIE-31) ScoresClinically Significant Increase (>= 11.8)38 Participants
Comparison: It is hypothesized that the QOLIE-31 score will increase (improve) from baseline to 12 months following the Visualase procedure. The hypotheses associated with this endpoint are as follows:~Null Hypothesis: M (V-QOLIE-31 - BSL-QOLIE-31) ≤ 0 Alternate Hypothesis: M (V-QOLIE-31 - BSL-QOLIE-31) \> 0 Where M (V-QOLIE-31 - BSL-QOLIE-31) = sign-test statistic (\[increases-decreases\]/2) in the Quality of Life in Epilepsy inventory from baseline to Month 12 post Visualase.p-value: <0.0001Sign test
Secondary

Change in Rey Auditory Verbal Learning Test Scores

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.

Time frame: Baseline and 12 months

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

ArmMeasureValue (MEAN)Dispersion
TreatmentChange in Rey Auditory Verbal Learning Test Scores-0.9 score on a scaleStandard Deviation 8.9
Comparison: It is hypothesized that the Rey Auditory Verbal Learning Test 5-Trial Total score will not decrease from baseline to 12 months following the Visualase procedure. The hypotheses associated with this endpoint are as follows:~Null Hypothesis: μ (V-RAVLT - BSL-RAVLT) + δ ≤ 0 Alternate Hypothesis: μ (V-RAVLT - BSL-RAVLT) + δ \> 0 Where μ (V-RAVLT - BSL-RAVLT) = mean difference in the Rey Auditory Verbal Learning Test 5-Trial Total score from baseline to Month 12 post Visualase.p-value: <0.0001Paired t-test
Secondary

Change in SF-36 Mental Component Score

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.

Time frame: Baseline and 12 Months

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

ArmMeasureCategoryValue (COUNT_OF_PARTICIPANTS)
TreatmentChange in SF-36 Mental Component ScoreClinically Significant Decrease (<= - 4.58)13 Participants
TreatmentChange in SF-36 Mental Component ScoreNon-Clinically Significant Change (-4.57 to +4.57)33 Participants
TreatmentChange in SF-36 Mental Component ScoreClinically Significant Increase (>=4.58)39 Participants
Comparison: It is hypothesized that the SF-36 Mental Component Score (MCS) will increase (improve) from baseline to 12 months following the Visualase procedure. The hypotheses associated with this endpoint are as follows:~Null Hypothesis: M (V-SF-36 - BSL-SF-36-MCS) ≤ 0 Alternate Hypothesis: M (V-SF-36 - BSL-SF-36-MCS) \> 0 Where M (V- SF-36-MCS - BSL- SF-36-MCS) = sign-test statistic (\[increases-decreases\]/2) in the SF-36 quality of life questionnaire MCS from baseline to Month 12 post Visualase.p-value: 0.0004Sign test
Secondary

Change in SF-36 Physical Component Score

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.

Time frame: Baseline and 12 Months

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

ArmMeasureCategoryValue (COUNT_OF_PARTICIPANTS)
TreatmentChange in SF-36 Physical Component ScoreNon-Clinically Significant Change (-3.01 to +3.01)28 Participants
TreatmentChange in SF-36 Physical Component ScoreClinically Significant Decrease (<=-3.02)12 Participants
TreatmentChange in SF-36 Physical Component ScoreClinically Significant Increase (>= 3.02)44 Participants
Comparison: It's hypothesized that the SF-36 Physical Component Score (PCS) will increase (improve) from baseline to 12 months following the Visualase procedure. The hypotheses associated with this endpoint are as follows:~Null Hypothesis: M (V-SF-36-PCS - BSL-SF-36-PCS) ≤ 0 Alternate Hypothesis: M (V-SF-36-PCS - BSL-SF-36-PCS) \> 0 Where M (V-SF-36-PCS - BSL- SF-36-PCS) = sign-test statistic (\[increases-decreases\]/2) in the SF-36 quality of life questionnaire PCS from baseline to Month 12 post Visualase.p-value: <0.0001Sign test
Secondary

Seizure Freedom Compared to Historical Controls (Medical Therapy)

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.

Time frame: 12 months

ArmMeasureValue (NUMBER)
TreatmentSeizure Freedom Compared to Historical Controls (Medical Therapy)56.0 percentage of subjects Engel Class I
Secondary

Seizure Freedom Compared to Historical Controls (Open Surgical Resection)

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%.

Time frame: 12 Months

ArmMeasureValue (NUMBER)
TreatmentSeizure Freedom Compared to Historical Controls (Open Surgical Resection)56.0 percentage of subjects Engel Class I
95% CI: [46.2, 65.8]
Secondary

Seizure Freedom, Including Subjects Retreated With Visualase

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%.

Time frame: 12 months

ArmMeasureValue (NUMBER)
TreatmentSeizure Freedom, Including Subjects Retreated With Visualase56.0 percentage of subjects Engel Class I

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026