Symptoms Associated with AHC
Children with AHC often have a wide range of other symptoms, including other types of abnormal movements. These include tonic attacks (stiffening of a limb), dystonic posturing (twisting postures), abnormal involuntary eye movements, developmental delays, fluctuating mental status and even true seizures.
Up to 50% of children with AHC develop "true seizures" sometime during the course of their illness. "True seizures" can be distinguished by characteristic findings on an EEG, and may be associated with tonic-clonic activity (repeated flexion and extension of limbs) and loss of consciousness, in contrast to other types of abnormal movements.
Episodes of tonic stiffening can sometimes represent seizure activity and sometimes not, so EEG testing is often necessary to determine what type of episode it represents. "Autonomic" symptoms can also occur with episodes, and consist of changes in the color or temperature of an involved limb.
