Periods of crying or screaming may begin suddenly, for no apparent reason, and last for hours. Some children may experience fears and anxiety. Other unusual behaviors.
[mayoclinic.org]
[…] of purposeful hand movements, gait disturbance), and 6 of 11 supportive criteria (impaired sleep, abnormal tone, vasomotor disturbance, scoliosis, growth retardation, and screaming
[ncbi.nlm.nih.gov]
Abnormal sleep patterns can include irregular sleep times, falling asleep during the day and being awake at night, or waking in the night with crying or screaming.
[mayoclinic.org]