The subject of sleep is quite complex, as is the topic of sleep disturbances. However, there are simple interventions that can likely help children suffering from this medical condition.
The first rule of treating insomnia is preventing it from getting worse. From your viewpoint, a child who awakes in the middle of the night and is weeping is ultimately crying out for help. However, in many instances, that is not the case. Nighttime awakenings are normal and usually happen in the middle of the rapid eye movement (REM) cycle. Shedding tears is simply a response to the confusion of displaced reality.
To manage the crying associate with awakenings, I recommend two techniques. The first is to simply ignore the crying child. This works quite well in families willing to tolerate a night or two of histrionics as the child adjusts to the new routine. The second is to wake up the child approximately an hour before the usual expected spontaneous awakening. Then, let him go back to sleep immediately. If the waking is brief and does not coincide with REM sleep, it disturbs the sleep architecture just enough to inhibit the habitual spontaneous awakening.
With sleep onset insomnia, sleep hygiene— the removal of stimulation from the child’s routine for one or more hours preceding, as well as during, sleep time— is the first line of treatment.
Melatonin at bedtime also appears to be a safe and effective method of regulating sleep onset timing when sleep hygiene is not enough.
Your doctor can help in cases when these interventions do not, as the insomnia may be due to many factors, from hormonal and medication side effects, to psychological and neurologic conditions. Be sure to speak with your physician for additional insomnia treatments.