| Domain | Evidence-backed finding | Suggested ontology terms/IDs | Evidence type/strength |
|---|---|---|---|
| Disease definition / PPR | Photosensitive epilepsy (PSE) is a reflex epilepsy/EEG trait in which flickering light or patterned visual stimuli provoke epileptiform activity; the EEG hallmark is the photoparoxysmal response (PPR), ranging from occipital to generalized spike-wave activity. Pure PSE (only visually induced seizures) should be distinguished from epilepsy with photosensitivity (spontaneous + visually provoked seizures). (pqac-00000001, pqac-00000002, pqac-00000015) | MONDO:0015643 photosensitive epilepsy; MeSH: Epilepsy, Reflex; HPO: Photoparoxysmal response, Reflex seizure, Photosensitivity | Human clinical reviews + human EEG-fMRI background evidence; moderate-strong |
| Major phenotypes | Common seizure phenotypes include generalized tonic-clonic, myoclonic, absence, eyelid myoclonia, and less often focal occipital seizures; in a 2023 pediatric cohort, IPS induced electroclinical seizures in 41.94% and EEG-only discharge in 58.06%. (pqac-00000001, pqac-00000013, pqac-00000014) | HPO: Generalized tonic-clonic seizure; Myoclonic seizure; Absence seizure; Eyelid myoclonia; Occipital seizure | Human cohort + reviews; strong for seizure spectrum |
| Age / sex pattern | Onset is usually in childhood/adolescence, often around puberty, with female predominance; the Chinese pediatric cohort reported mean onset 7.8 ± 3.28 years and male:female ratio 1:3.43. (pqac-00000001, pqac-00000002, pqac-00000013) | HPO: Childhood onset; Adolescent onset; Female predominance | Human cohort + reviews; moderate-strong |
| Triggers / provoking factors | Highest IPS sensitivity is typically around 10–20 Hz; triggers include sunlight flicker, television/screens, video games, LED/light flashes, and patterns; eye-closure sensitivity is prominent in many patients. (pqac-00000003, pqac-00000013, pqac-00000014, pqac-00000016) | HPO: Seizure triggered by flickering light; Eye closure sensitivity; Environmental exposure terms for flashing light/pattern stimulation | Human cohort, trial protocol, reviews; strong |
| Anatomy / systems affected | Primary system: central nervous system, especially visual cortex/occipital cortex with spread to parietal, frontal, sensorimotor, cingulate, supplementary motor, and thalamic networks. (pqac-00000012, pqac-00000015) | UBERON: brain; occipital lobe / visual cortex; thalamus; anterior cingulate cortex; supplementary motor area | Human EEG-fMRI/network studies; moderate |
| Cell types | Evidence most strongly implicates cortical excitatory-inhibitory microcircuits and thalamocortical neurons; syndrome-associated literature also points to interneuron dysfunction in broader generalized epilepsy biology. (pqac-00000015, pqac-00000019) | CL: glutamatergic neuron; GABAergic interneuron; thalamic relay neuron | Indirect human mechanistic inference + broader epilepsy evidence; moderate/indirect |
| Core mechanism | Current model favors abnormal visual-network excitability plus impaired inhibitory control rather than a purely local occipital trigger. PSE patients show altered 3–4 Hz connectivity and reduced alpha-related inhibition of visual/sensorimotor networks at rest. (pqac-00000012, pqac-00000015) | GO: regulation of membrane potential; synaptic transmission, GABAergic; visual perception; neuronal network synchronization; thalamocortical signaling | Human EEG-fMRI + scalp EEG network study; moderate-strong |
| Upstream/downstream pathophysiology | Upstream: genetically influenced susceptibility and visually evoked cortical-thalamocortical hyperexcitability. Downstream: PPR propagation from occipital to distributed frontoparietal/sensorimotor networks, producing myoclonus, absence, or generalized convulsions. (pqac-00000012, pqac-00000015) | GO: sensory stimulus response; action potential propagation; seizure; neuron-neuron synaptic transmission | Human mechanistic studies + reviews; moderate |
| Genetics | PSE is genetically heterogeneous. Evidence supports susceptibility and syndrome association rather than a single universal causal gene. CHD2 is repeatedly highlighted; photosensitivity also occurs in SCN1A-related Dravet syndrome and in broader epilepsy gene contexts including GABRA1/GABRG2 and SYNGAP1. (pqac-00000015, pqac-00000019) | Gene terms: CHD2, SCN1A, GABRA1, GABRG2, SYNGAP1; MONDO-linked syndrome annotation as applicable | Human genetic review/primer evidence; moderate, heterogeneous |
| Inheritance | Inheritance is usually complex or syndrome-specific; familial aggregation is recognized, but penetrance/expressivity depend on the underlying epilepsy syndrome or susceptibility background. (pqac-00000001, pqac-00000002, pqac-00000015) | HPO: Family history of seizures; inheritance term often multifactorial/variable | Reviews + limited cohort observations; moderate |
| Diagnostics | Standard diagnosis relies on EEG with intermittent photic stimulation (IPS), often across eye-open, eyes-closed, and eye-closure conditions, with quantification by standardized photosensitivity range (SPR). Differential diagnosis includes migraine/headache disorders, nonepileptic visual discomfort, and focal occipital epilepsies/syndromes. (pqac-00000002, pqac-00000014, pqac-00000020) | LOINC/EEG term names; HPO: Abnormal EEG with generalized spike-wave complexes; Photoparoxysmal response | Human clinical practice/review + protocol evidence; strong |
| Treatment | Broad-spectrum ASMs are standard; valproate and levetiracetam are repeatedly reported as effective/common choices. In a proof-of-principle trial, cenobamate partially or completely suppressed PPR in most evaluable patients at 250–400 mg. (pqac-00000011, pqac-00000013) | NCIT: Valproic Acid; Levetiracetam; Cenobamate; Anticonvulsant therapy | Human cohort + interventional study; moderate for PPR suppression, weaker for long-term seizure control |
| Prevention / non-pharmacologic management | Trigger avoidance is central: reduce exposure to flicker/patterns/screens, use monocular occlusion in acute exposure, and consider protective tinted lenses. A lens protocol cites prior Z1 lens abolition of PPRs in 75.9% of 610 patients. (pqac-00000002, pqac-00000003, pqac-00000016) | NCIT/intervention terms: Protective eyewear; Behavioral avoidance; Patient education | Review + clinical trial protocol citing prior large series; moderate |
| Epidemiology | Photosensitivity is reported in about 5–10% of epilepsy overall, but much higher in some syndromes (for example JME, Dravet syndrome). In the 2023 single-center Chinese pediatric sample, PSE represented 7.79% of children with epilepsy. (pqac-00000001, pqac-00000012, pqac-00000013, pqac-00000015) | Epidemiology descriptors only | Human cohort + reviews; moderate |
| Recent developments (2023–2024) | Recent work includes a 2023 pediatric electroclinical cohort, 2023 VR/ML work on automated PPR detection, and a 2024 network study showing frequency- and type-dependent connectivity abnormalities; these advances mainly refine diagnosis/biomarkers rather than establish new disease-specific therapies. (pqac-00000012, pqac-00000013, pqac-00000020) | Diagnostic biomarker terms; EEG-based digital biomarker | Recent human cohort/computational/preprint evidence; emerging |
| Models / comparative biology | Useful but indirect models include photosensitive baboon and chicken models, plus zebrafish/mouse epilepsy systems for mechanistic and antiseizure screening work; model translation to human PSE remains incomplete. (pqac-00000001) | NCBI Taxon terms as applicable; model organism annotation | Preclinical/indirect evidence; limited |
| Major evidence gaps | No single definitive causal gene for all PSE; limited validated biomarkers beyond IPS-EEG/PPR; sparse data on quality of life, long-term prognosis, protective genetic factors, and PSE-specific omics (single-cell, spatial transcriptomic, proteomic, metabolomic, epigenomic) or chromosomal abnormalities. (pqac-00000002, pqac-00000012, pqac-00000019, pqac-00000020) | Knowledge gap annotation; no robust ontology ID needed | Evidence gap synthesis; strong confidence in absence/scarcity of data |


*Table: This compact table summarizes evidence-backed findings for a photosensitive epilepsy knowledge-base entry, including disease definition, phenotypes, mechanisms, genetics, diagnostics, treatment, epidemiology, and key gaps. It is designed for ontology-aware curation while avoiding overstatement where evidence is limited or indirect.*