| Hypnic jerk | Bruxism | Benign sleep myoclonus of infancy | Propriospinal myoclonus at sleep onset | Nocturnal leg cramp | Exploding head syndrome | |
| Behavior | Quick single jerk with or without tactile, kinetic, visual, or auditory sensation | Sudden closure of jaw or grinding of teeth | Brief jerks, usually bilateral and symmetric | Sudden jerk, typically in the trunk, neck, and limbs | Sustained muscle contraction | Painless sensation of explosion in the head, may be associated with a startle movement |
| Age of onset | Any | Any | Infancy | Childhood or adulthood | Childhood or adulthood | Adulthood |
| Family history | No | Variable | Variable | No | Variable | No |
| Time of occurrence | Sleep onset | Sleep onset or upon resumption of sleep | Any time during sleep | Light NREM sleep | Any | Usually near sleep onset but can be variable |
| Frequency | Variable | Multiple per night | Multiple per night | Multiple per night | Variable | Rare |
| Duration | Milliseconds | Seconds | Milliseconds | Milliseconds | Up to several minutes | Seconds |
| Memory of event | Yes | No | No | Yes | Yes | Yes |
| Stereotypical movements | Yes | No | No | No | No | Yes (similar sensation each time) |
| PSG findings | Sudden jerk at sleep onset | Temporalis and masseter activation, rhythmic periodic chin muscle artifact | Brief myoclonus | Brief myoclonus in NREM sleep | Prolonged muscle contraction | Usually occurs in light sleep |
| Associated clinical findings | None (benign) | Clenching sound, tooth wear, scars inside cheeks and tongue | None (benign) | Can be seen in individuals with spinal cord pathology | None | None (benign) |
