Sudden unexpected death in epilepsy is a category of unexpected death in a person with epilepsy for which another adequate cause is not established under the applicable investigation criteria. It is a defined outcome category, rather than proof of one universal lethal mechanism.

Studies can investigate associations with seizures and cardiorespiratory dysfunction, but an association or an autopsy finding alone must not be treated as the unique cause in every case.^[ref]

An epileptic seizure is a transient event caused by abnormal excessive or synchronized activity in brain networks. Its manifestations depend on the recruited circuits and can include motor changes, altered sensation or impaired awareness.

The mechanism distinguishes it from a superficially similar event with another cause. Electroencephalography can supply physiological evidence, but the observed behavior and the clinical time course remain important to interpretation.

The postictal state is the period of altered function following an epileptic seizure. It can include sleepiness, confusion or temporary focal impairment, with duration and features varying across events and individuals.

Measurements made during this period do not necessarily represent the person's baseline function. Distinguishing the seizure itself, recovery and the interval between events helps interpret neural and behavioral observations.

Status epilepticus is prolonged epileptic activity, or repeated epileptic seizures without adequate recovery between them. Operational time thresholds depend on seizure type; ongoing convulsive activity for five minutes is treated as a time-critical threshold in current clinical guidance.

This differs from several brief seizures separated by recovery. The duration and recovery pattern are therefore part of the definition being measured.^[ref]

Loss of adhesion between epidermal cells. It is one mechanism of intraepidermal blister formation.

A cell of the epidermis.

The stratum corneum is the outer barrier layer of the epidermis, composed of highly differentiated flattened cells and associated extracellular lipids. Its organization restricts water loss and external entry. Barrier performance depends on the arrangement of both cellular and lipid components.

When each chemical reaction only changes the state of one enzyme molecule, summing all enzyme-state concentrations gives a conserved total. For sequential complexes satisfying ${\dot{C}}_0=-R_1$, ${\dot{C}}_i=R_i-R_{i+1}$, ${\dot{C}}_n=R_n$, the sum telescopes to zero. Bound substrate must be included separately in substrate mass conservation.

Systems and practices that safely separate human waste from contact with people and the environment. It connects infrastructure and behavior with interruption of fecal contamination pathways.^[ref]

Presence of airborne substances or particles at concentrations that can cause harmful effects. Exposure depends on composition, concentration and duration, so a single total quantity does not characterize every hazard.^[ref]

Exchange of indoor and outdoor air through designed or incidental pathways. Flow can dilute an indoor contaminant, but its effectiveness depends on supply, removal and mixing rather than room volume alone.

Addition or substitution of materials in bread examined in historical food-safety investigations. Chemical and microscopic identification supplied evidence about composition, while judgments of harm depended on the material and amount present.^[ref]

The physical area and volume allotted around a hospital bed. Floor area, air volume and ventilation rate are different quantities, so more space alone does not specify the rate at which contaminated air is removed.

An energy unit with several historical definitions. The thermochemical small calorie is exactly $4.184$ joules; a kilocalorie is one thousand such calorie units. A calorimetric calculation must specify its unit convention.

Energy accounted for through a system's chemical composition and state. A galvanic cell can convert part of the change associated with a redox into electrical work; the system boundaries determine which thermal losses also enter the balance.

The sarcoplasmic reticulum is the specialized endoplasmic reticulum of muscle cells that stores and releases calcium. Pump uptake, channel-mediated release and passive leak exchange calcium with the cytoplasm; these internal transfers cancel in the appropriately volume-weighted total-calcium balance. They can nevertheless change cytoplasmic calcium rapidly and control contraction.

Microbial infection of the endocardial surface, commonly a cardiac valve. Local vegetations can interfere with valve function or release material into the blood circulation, linking a focal infection with distant complications.

Vascular obstruction by transported material containing infectious organisms. It can combine loss of perfusion with a new infectious focus, distinguishing it from a sterile clot fragment.

Electrical charging associated historically with rubbing materials. It supplies ordinary electric charge, not a separate electrical substance. Compared with a chemical source, a friction machine can have a very different voltage, charge delivery and internal impedance.