--- title: Catamenial epilepsy: what it means and why it happens description: Catamenial epilepsy means seizures that cluster around specific points in the menstrual cycle, driven by the same hormone shifts linked to PMS and PMDD. url: https://niyora.com/glossary/catamenial-epilepsy/ --- - [Niyora](https://niyora.com/) - [Glossary](https://niyora.com/glossary/) - Catamenial epilepsy: what it means Term # Catamenial epilepsy: what it means Catamenial epilepsy is a pattern of seizures that cluster around specific points in the menstrual cycle, not a separate type of epilepsy. It's thought to affect around 40% of women with epilepsy, and it's linked to the same progesterone drop that's tied to PMDD. The brain's seizure threshold and its mood response can both shift when that hormone falls. Updated 14 October 2026 Niyora editorial ## At a glance - Catamenial epilepsy describes seizures clustering perimenstrually (C1), at ovulation (C2), or through the luteal phase (C3), seen in about 40% of women with epilepsy [1, 4]. - The falling progesterone behind catamenial seizures is the same hormone shift implicated in PMDD, both tied to the metabolite allopregnanolone [2, 6, 7]. - Progesterone treatment helps in case reports but hasn't been confirmed in randomized trials overall, though it helped the C1 pattern specifically in one large trial [2, 3, 5, 8]. - A doctor confirms the exact pattern with a seizure and period diary over several cycles before choosing hormonal or non-hormonal treatment. ## What is catamenial epilepsy? Catamenial epilepsy describes seizures that cluster around specific days of the menstrual cycle instead of happening at random. Researchers use the term to describe a pattern within an existing epilepsy diagnosis. An estimated 40% of women with epilepsy show one of these patterns [1, 4]. | Pattern | When it clusters | Hormone link | | --- | --- | --- | | C1 (perimenstrual) | Just before and during bleeding | Progesterone drops | | C2 (periovulatory) | Around ovulation | Estrogen surges | | C3 (luteal) | Through an inadequate luteal phase | Progesterone stays low | Progesterone and estrogen act directly on brain cells, which is why mapping seizures against [menstrual cycle hormones](https://niyora.com/cycle/menstrual-cycle-hormones/) can reveal a pattern that feels random day to day. ## How does catamenial epilepsy relate to PMS and PMDD? Catamenial epilepsy and PMDD are separate diagnoses that share a hormone mechanism. Progesterone breaks down into [allopregnanolone](https://niyora.com/glossary/allopregnanolone/), a neurosteroid that calms brain cells through the GABA system. When progesterone falls before a period, allopregnanolone falls with it [2, 6, 7]. That same drop plays out differently depending on which system it reaches: - In the C1 and C3 patterns, that progesterone drop is thought to lower the seizure threshold [1, 4]; in the C2 pattern, a pre-ovulatory estrogen surge is implicated instead. - In [PMDD](https://niyora.com/pmdd/), the same drop is linked to mood symptoms in people whose brains react differently to it, not to abnormal hormone levels (see [what causes PMDD](https://niyora.com/questions/what-causes-pmdd/)). The two conditions aren't the same, but a seizure-vulnerable week and a mood-vulnerable week often land in the same stretch of the cycle, the [luteal phase](https://niyora.com/luteal-phase/) into the period. If you live with epilepsy and also notice heavier mood symptoms beforehand, both are worth tracking on one calendar. ## What does the research say about treatment? Treatment for catamenial epilepsy depends on which pattern fits and whether periods are regular. None of it is something to start or stop without a doctor. | Approach | What it does | What the evidence shows | | --- | --- | --- | | Luteal-phase progesterone | Added during the vulnerable days | Helped in case reports and uncontrolled studies, not confirmed in randomized trials [2, 3, 5] | | Non-hormonal add-ons (clobazam, acetazolamide) | Extra anti-seizure medication timed to the vulnerable days | Used in current practice, limited controlled evidence [1, 4, 8] | | Stopping periods altogether (Depo-Provera, GnRH analogues) | Removes the cyclic hormone swing | Considered for irregular cycles when timed treatment isn't practical [1, 4, 8] | One large trial of natural progesterone found a benefit specifically for the C1 (perimenstrual) pattern, not the others [8]. Confirming which pattern applies usually means: - Keeping a seizure diary alongside period dates. - Marking cycle day for each seizure over several cycles. - Looking for clustering around bleeding, ovulation, or the luteal phase with a doctor. That's why a doctor needs your exact pattern before choosing a treatment. ## What related terms should you know? A few terms show up often alongside catamenial epilepsy: - **Luteal phase**: the second half of the cycle, after ovulation, when progesterone should rise then fall. - **Corpus luteum**: the structure that makes progesterone after ovulation. See [corpus luteum](https://niyora.com/glossary/corpus-luteum/). - **Allopregnanolone**: progesterone's calming metabolite, linked to both seizure threshold and mood. See [allopregnanolone](https://niyora.com/glossary/allopregnanolone/). Niyora is a PMS and PMDD support app, and it doesn't track seizures. But if the same week brings a harder mood alongside a harder time for your epilepsy, Niyora's estimated PMS window can sit next to a seizure diary, so you're reading one calendar instead of two. For more on the hormone research behind both conditions, see [PMS and PMDD research](https://niyora.com/research/). From the research library ## Research on epilepsy 54 studies in the library look at epilepsy in PMS and PMDD. They were published from 1962 to 2025, and each one has a short summary of what was tested and found. 54 studies, 1962 to 2025 How strong the studies are Strong study design 2 Moderate study design 9 Early or limited evidence 43 - [Systematic review, 2023What hormonal treatments have been tested for PMDD, menstrual migraine, and catamenial epilepsy?Hormonal treatments have been tested 56 times for premenstrual mood disorder, 21 times for menstrual migraine, and 8 times for catamenial epilepsy. Combined oral contraceptives were a frequent focus.Strong study design](https://niyora.com/research/papers/a-scoping-review-of-hormonal-clinical-trials-in-menstrual-cycle-related-brain-2023/) - [Review, 2003How do menstrual cycle hormones affect the brain and cause mood disorders like PMDD?A hormone called allopregnanolone acts on brain receptors. Changes in this hormone during the cycle may cause mood and behavioral symptoms in up to 20% of people through three mechanisms: direct effects, building tolerance, and withdrawal effects.Strong study design](https://niyora.com/research/papers/pathogenesis-in-menstrual-cycle-linked-cns-disorders-2003/) - [Cohort study, 2025Do women with epilepsy show different brain patterns during different phases of their menstrual cycle?Yes. Women with epilepsy showed abnormal changes in brain activity during the perimenstrual phase compared to women without epilepsy, suggesting increased brain excitation during this time.Moderate study design](https://niyora.com/research/papers/females-with-epilepsy-show-abnormal-changes-to-perimenstrual-sensory-induced-2025/) - [Study, 2025How can researchers better track hormone changes throughout the menstrual cycle?Researchers created a new method called PACTS that better tracks how hormones change across your entire menstrual cycle, making patterns easier to spot and potentially improving diagnosis.Moderate study design](https://niyora.com/research/papers/how-to-study-the-menstrual-cycle-as-a-continuous-variable-implementing-phase-2025/) - [Systematic review, 2019Do lithium and valproate levels change during the menstrual cycle?In women with bipolar disorder, lithium levels decreased during the luteal phase (before the period) despite stable doses, linked to worsening mood symptoms. In healthy women, lithium levels were not affected by the menstrual cycle.Moderate study design](https://niyora.com/research/papers/lithium-and-valproate-serum-level-fluctuations-within-the-menstrual-cycle-a-2019/) - [Review, 2010Can neurosteroids help with anxiety and brain disorders?The review suggests neurosteroids might help with anxiety, epilepsy, and depression, but clinical evidence is limited.Moderate study design](https://niyora.com/research/papers/neurosteroids-endogenous-role-in-the-human-brain-and-therapeutic-potentials-2010/) [See all 54 studies on epilepsy](https://niyora.com/research/topics/comorbidity-epilepsy/) ## Questions people ask Is catamenial epilepsy a separate type of epilepsy? + Catamenial epilepsy isn't a separate diagnosis. It's a pattern where seizures cluster around specific points in the menstrual cycle, perimenstrually, at ovulation, or through the luteal phase, in someone who already has epilepsy. Around 40% of women with epilepsy show one of these patterns [1, 4]. Does catamenial epilepsy affect PMDD symptoms? + Catamenial epilepsy and PMDD don't cause each other, but they share a hormone mechanism. Both are linked to falling progesterone and its metabolite allopregnanolone before a period. Someone can have one, both, or neither, and the vulnerable days can overlap in the same cycle [2, 6, 7]. Does progesterone treatment work for catamenial epilepsy? + Progesterone treatment for catamenial epilepsy has helped in case reports and uncontrolled studies, but randomized controlled trials haven't confirmed a benefit overall. One large trial found progesterone helped specifically with the perimenstrual (C1) pattern [2, 3, 5, 8]. A doctor decides whether it fits a particular case. When should I see a doctor about seizure patterns tied to my cycle? + See a GP or neurologist if your seizures seem to cluster around certain cycle days, or if a treatment isn't controlling them well. Bring two to three months of seizure dates alongside period dates, so the pattern (C1, C2, or C3) is clear before treatment is chosen. ## Sources - 1. [Treatments for seizures in catamenial (menstrual-related) epilepsy](https://doi.org/10.1002/14651858.cd013225.pub3), The Cochrane database of systematic reviews, 2021 - 2. [Progesterone and its derivatives for the treatment of catamenial epilepsy: A systematic review](https://doi.org/10.1016/j.seizure.2023.05.004), Seizure, 2023 - 3. [A novel therapeutic approach for treatment of catamenial epilepsy](https://doi.org/10.1016/j.nbd.2017.12.009), Neurobiology of disease, 2018 - 4. [Treatments for seizures in catamenial (menstrual-related) epilepsy](https://doi.org/10.1002/14651858.cd013225.pub2), The Cochrane database of systematic reviews, 2019 - 5. [Is Adjunctive Progesterone Effective in Reducing Seizure Frequency in Patients With Intractable Catamenial Epilepsy? A Critically Appraised Topic](https://doi.org/10.1097/nrl.0000000000000167), The neurologist, 2018 - 6. [Neurosteroid replacement therapy for catamenial epilepsy, postpartum depression and neuroendocrine disorders in women](https://doi.org/10.1111/jne.13028), Journal of neuroendocrinology, 2022 - 7. [Catamenial Epilepsy: Discovery of an Extrasynaptic Molecular Mechanism for Targeted Therapy](https://doi.org/10.3389/fncel.2016.00101), Frontiers in cellular neuroscience, 2016 - 8. [A Treatment Approach to Catamenial Epilepsy](https://doi.org/10.1007/s11940-016-0413-6), Current treatment options in neurology, 2016 Ask AI about this page Copy prompt ChatGPT ↗ Claude ↗ Perplexity ↗ Google AI Mode ↗ Grok ↗ On this page - [What is catamenial epilepsy?](#what-is-catamenial-epilepsy) - [How does catamenial epilepsy relate to PMS and PMDD?](#how-does-catamenial-epilepsy-relate-to-pms-and-pmdd) - [What does the research say about treatment?](#what-does-the-research-say-about-treatment) - [What related terms should you know?](#what-related-terms-should-you-know) - [Research](#research) - [Questions](#faq) Niyora PMS & PMDD support For the hard moment before your period. Private, no account. [Get it on iPhone](https://apps.apple.com/app/niyora-pms-emotions/id6764561688) ## Keep reading Condition PMDD (premenstrual dysphoric disorder), explained Condition The luteal phase: what's happening in your body and mood Question What causes PMDD? Cycle guide Menstrual cycle hormones, phase by phase Guide All 26 research findings Term Corpus luteum: what it means Term What Does PMS Mean in Text and Slang? Term Allopregnanolone: what it means for PMDD