Skip to content
How It Works
Explore
Ask a Question Resources Pricing
Who It's For
Patients
Decode results, prep for appointments, weigh options.
Caregivers & advocates
Carry the research load for someone you love.
Providers & clinicians
Resources for patients in your practice.
Log In Sign Up
PubMed This is a summary of 18 peer-reviewed journal articles Updated
Epileptology

The Diagnostic Pathway for MTLE-HS

At a Glance

MTLE-HS is diagnosed by matching a person’s seizure history with epilepsy-protocol MRI, video-EEG, neuropsychological testing, and sometimes PET, SPECT, or invasive monitoring. The goal is to confirm that the findings point to the same seizure network before surgery.

Diagnosing Mesial Temporal Lobe Epilepsy with Hippocampal Sclerosis (MTLE-HS) is not about a single test; it is about finding “concordance.” This means your doctors look for different pieces of evidence—from your history, your brain’s structure, and its electrical activity—that all point to the same spot in the brain [1][2].

The Possible Presurgical Pathway

The diagnosis is typically made in stages. While a regular MRI and EEG are part of an initial workup, a comprehensive presurgical evaluation includes specialized tests to map the seizure network:

  • [ ] Epilepsy-Protocol MRI (at the best available field strength, often 3T)
  • [ ] Prolonged Video-EEG Monitoring (Telemetry)
  • [ ] Comprehensive Neuropsychological Evaluation (Cognitive/Memory testing)
  • [ ] Functional Imaging (FDG-PET or Ictal SPECT, if needed)
  • [ ] Multidisciplinary Team Review (Epileptologists, Surgeons, Radiologists)

The Epilepsy-Protocol MRI

A routine MRI used for headaches or general checkups is often not detailed enough to see the subtle changes of MTLE-HS. To find hippocampal sclerosis (scarring), you need a dedicated epilepsy-specific protocol, such as the HARNESS (Harmonized Neuroimaging of Epilepsy) approach [3][4].

Key features of this specialized scan include:

  • Hippocampal Angulation: The imaging plane must be prescribed obliquely (specifically coronal T2 and FLAIR slices) to match the long axis of the hippocampus. This allows doctors to see its internal architecture clearly [3][5].
  • Thin Slices: These scans use very thin sections to detect shrinking (atrophy) or abnormal brightness that signals scarring [5][6].
  • Advanced Field Strength: While a properly acquired 1.5T MRI can be useful, 3-Tesla (3T) is preferred where available. Some centers even use 7T MRI when standard scans are unrevealing [4][7].

Video-EEG Telemetry: Watching the ‘Network’

While a standard 30-minute EEG might catch “spikes” between seizures, Video-EEG Telemetry involves staying in the hospital for several days to record your actual seizures [2].

  • The Goal: Doctors want to see your “habitual” seizures. They synchronize the video of your physical movements (like lip-smacking or staring) with the electrical activity in your brain [2][8].
  • Sleep Matters: Recording brain waves during sleep is important. Non-REM sleep can often activate epileptic spikes, while REM sleep may sometimes suppress them; both states provide important clues [9].
  • Is it Always Needed?: Scalp video-EEG is excellent for classifying events, but it may not perfectly show the exact onset of a deep mesial seizure. In very clear cases where the MRI, history, and outpatient EEG all point to the exact same spot, a long hospital stay may not always be required, but it remains the standard for most surgical evaluations [10][11]. When noninvasive tests are discordant, invasive monitoring (like Stereo-EEG) may be required.

Neuropsychological Testing: Mapping Function

MTLE-HS often affects the hippocampus, which is the brain’s “filing cabinet” for memories. If you are being considered for surgery, a neuropsychological evaluation is essential [12].

  • Baseline Status: This battery of tests measures your verbal and visual memory, language skills, and attention [12][13].
  • Predicting Risk: By assessing cognitive patterns, doctors can predict the risk of cognitive changes after treatment [12][14]. (Note: While testing informs memory reserve, functional MRI or selective Wada testing may also be used to confirm memory and language dominance).
  • Mood Screening: These tests also screen for depression or anxiety, as your emotional health is a major factor in your long-term quality of life [15][16].

When More Information is Needed

If your MRI and EEG results don’t perfectly match (they are “discordant”), your team may use functional “adjunct” tests:

  • FDG-PET: This scan looks at how your brain uses sugar (glucose). In MTLE-HS, the affected area often uses less sugar even when you aren’t having a seizure (hypometabolism) [17][18].
  • Ictal SPECT: This rare test involves injecting a tracer at the very second a seizure begins to see where blood flow increases the most.
  • Wada Test: Occasionally, a doctor may use a specialized procedure to temporarily “put to sleep” one half of the brain to confirm which side controls your speech and memory [12].

Common questions in this guide

What tests are used to diagnose MTLE-HS before epilepsy surgery?
Doctors look for agreement among your seizure history, epilepsy-protocol MRI, video-EEG, neuropsychological testing, and sometimes PET or SPECT. A multidisciplinary team reviews these results to determine whether they point to the same seizure source.
Why do I need an epilepsy-protocol MRI instead of a routine MRI?
A routine MRI may miss subtle hippocampal scarring. An epilepsy-protocol scan uses thin slices and images angled along the hippocampus, often at 3T, to look for shrinkage and abnormal signal.
What happens during video-EEG telemetry?
You usually stay in the hospital for several days while cameras and scalp electrodes record your movements and brain waves, including during sleep. The goal is to capture your typical seizures and compare what happens on video with the electrical changes.
Why is neuropsychological testing part of the MTLE-HS evaluation?
It measures memory, language, attention, and mood before treatment. The results establish a baseline and help your team estimate the risk of memory or other cognitive changes if surgery is considered.
What happens if my MRI and EEG do not point to the same place?
When noninvasive tests disagree, doctors may add FDG-PET, ictal SPECT, functional MRI or selective Wada testing, and sometimes stereo-EEG. These tests provide additional information about brain metabolism, blood flow, language, memory, or seizure onset.

Questions For You

Answer a question to get research tailored to you. Your answers are private.

Get notified when new evidence is published on Mesial temporal lobe epilepsy with hippocampal sclerosis.

We monitor PubMed for new peer-reviewed studies on this topic and email a short summary when something meaningful changes.

Questions to Ask Your Doctor

Curated prompts to bring to your next appointment.

  1. 1.Was my MRI performed using the specialized 'HARNESS' or epilepsy-specific protocol, and was it reviewed by a neuroradiologist who specializes in epilepsy?
  2. 2.Were the coronal MRI images angled specifically to match the 'long axis' of my hippocampus?
  3. 3.Based on my video-EEG and MRI results, do you feel my seizure 'network' is restricted to one side, or is it bilateral or 'temporal-plus'?
  4. 4.Do my neuropsychological test results suggest my 'healthy' side of the brain is strong enough to support my memory if the 'seizure' side is treated?
  5. 5.If we proceed toward surgery, will I need additional functional imaging like an FDG-PET or an ictal SPECT scan to be certain of the location?

References

References (18)
  1. 1

    Cost-effectiveness of HARNESS-MRI protocol in focal drug-resistant epilepsy in a limited-resources country: An Egyptian study.

    Kishk NA, Shamloul R, Moawad MK, et al.

    Clinical neurology and neurosurgery 2023; (233()):107946 doi:10.1016/j.clineuro.2023.107946.

    PMID: 37639829
  2. 2

    MTLE with hippocampal sclerosis in adult as a syndrome.

    Baulac M

    Revue neurologique 2015; (171(3)):259-66.

    PMID: 25727907
  3. 3

    MR Imaging Protocols for Epilepsy.

    LaVere MG, Betting T, Krecke KN, et al.

    Neuroimaging clinics of North America 2026; (36(2)):293-301 doi:10.1016/j.nic.2025.10.004.

    PMID: 41932778
  4. 4

    Diagnostic value of MRI in the presurgical evaluation of patients with epilepsy: influence of field strength and sequence selection: a systematic review and meta-analysis from the E-PILEPSY Consortium.

    Rados M, Mouthaan B, Barsi P, et al.

    Epileptic disorders : international epilepsy journal with videotape 2022; (24(2)):323-342 doi:10.1684/epd.2021.1399.

    PMID: 34961746
  5. 5

    Automated volumetry of hippocampus is useful to confirm unilateral mesial temporal sclerosis in patients with radiologically positive findings.

    Silva G, Martins C, Moreira da Silva N, et al.

    The neuroradiology journal 2017; (30(4)):318-323 doi:10.1177/1971400917709627.

    PMID: 28632041
  6. 6

    Hippocampal internal architecture and postoperative seizure outcome in temporal lobe epilepsy due to hippocampal sclerosis.

    Elkommos S, Weber B, Niehusmann P, et al.

    Seizure 2016; (35()):65-71.

    PMID: 26803053
  7. 7

    Ultra-high field magnetic resonance imaging in human epilepsy: A systematic review.

    van Lanen RHGJ, Colon AJ, Wiggins CJ, et al.

    NeuroImage. Clinical 2021; (30()):102602 doi:10.1016/j.nicl.2021.102602.

    PMID: 33652376
  8. 8

    Features of scalp EEG in unilateral mesial temporal lobe epilepsy due to hippocampal sclerosis: Determining factors and predictive value for epilepsy surgery.

    Malter MP, Bahrenberg C, Niehusmann P, et al.

    Clinical neurophysiology : official journal of the International Federation of Clinical Neurophysiology 2016; (127(2)):1081-1087 doi:10.1016/j.clinph.2015.06.035.

    PMID: 26321666
  9. 9

    How do people with drug-resistant mesial temporal lobe epilepsy sleep? A clinical and video-EEG with EOG and submental EMG for sleep staging study.

    Scarlatelli-Lima AV, Sukys-Claudino L, Watanabe N, et al.

    eNeurologicalSci 2016; (4()):34-41 doi:10.1016/j.ensci.2016.06.002.

    PMID: 29430547
  10. 10

    Is inpatient ictal video-electroencephalographic monitoring mandatory in mesial temporal lobe epilepsy with unilateral hippocampal sclerosis? A prospective study.

    Alvim MKM, Morita ME, Yasuda CL, et al.

    Epilepsia 2018; (59(2)):410-419 doi:10.1111/epi.13977.

    PMID: 29238960
  11. 11

    Long-term seizure outcomes of epilepsy surgery in patients with mesial temporal lobe epilepsy caused by hippocampal sclerosis based on preoperative ictal versus non-ictal video-EEG: A 10-year follow-up.

    Martínez-Medina S, Gonzalez-Salido J, Marin-Castañeda LA, et al.

    Epilepsy & behavior : E&B 2025; (172()):110714 doi:10.1016/j.yebeh.2025.110714.

    PMID: 41061411
  12. 12

    Wada test results contribute to the prediction of change in verbal learning and verbal memory function after temporal lobe epilepsy surgery.

    Conradi N, Rosenberg F, Knake S, et al.

    Scientific reports 2021; (11(1)):10979 doi:10.1038/s41598-021-90376-3.

    PMID: 34040075
  13. 13

    Volumetric Changes in Hippocampal Subregions and Memory Performance in Mesial Temporal Lobe Epilepsy with Hippocampal Sclerosis.

    Ji C, Zhu L, Chen C, et al.

    Neuroscience bulletin 2018; (34(2)):389-396 doi:10.1007/s12264-017-0186-2.

    PMID: 29094314
  14. 14

    Predictive factors of long-term outcomes of surgery for mesial temporal lobe epilepsy associated with hippocampal sclerosis.

    Mathon B, Bielle F, Samson S, et al.

    Epilepsia 2017; (58(8)):1473-1485 doi:10.1111/epi.13831.

    PMID: 28656696
  15. 15

    Validation of diagnostic tests for depressive disorder in drug-resistant mesial temporal lobe epilepsy.

    de Lemos Zingano B, Guarnieri R, Diaz AP, et al.

    Epilepsy & behavior : E&B 2015; (50()):61-6.

    PMID: 26119622
  16. 16

    Predictors of meaningful improvement in quality of life after temporal lobe epilepsy surgery: A prospective study.

    Pauli C, Schwarzbold ML, Diaz AP, et al.

    Epilepsia 2017; (58(5)):755-763 doi:10.1111/epi.13721.

    PMID: 28332703
  17. 17

    Neuropsychological functioning and brain energetics of drug resistant mesial temporal lobe epilepsy patients.

    Osório CM, Latini A, Leal RB, et al.

    Epilepsy research 2017; (138()):26-31 doi:10.1016/j.eplepsyres.2017.10.009.

    PMID: 29040828
  18. 18

    Determinants of brain metabolism changes in mesial temporal lobe epilepsy.

    Chassoux F, Artiges E, Semah F, et al.

    Epilepsia 2016; (57(6)):907-19 doi:10.1111/epi.13377.

    PMID: 27061896

This page is for informational purposes only and does not constitute medical advice. Your epileptologist and epilepsy surgery team should explain what your specific MRI, EEG, and cognitive test results mean.