Glossary of Sleep-related terms
- Ictal discharge
- Imidazopyridines
- Imipramine
- Inappropriate Sleep Episodes
- Incubus attack
- Infradian rhythm
- Insomnia
- Inspiratory Phase
- Intermediary Sleep Stage
- Internal desynchronization
- Invasive
- IPAP
Incubus attack
An episode of sudden awakening from sleep, often with a feeling of suffocation, overwhelming anxiety and palpitations, which is usually associated with a bloodcurdling cry. Mental imagery is sparse, usually consists of a single scene, and lacks the thematic progression of a terrifying dream (REM nightmare). Now also called NREM nightmare.4