Clinical characteristics of children with functional neurological disorder presented with motor symptoms in Department of Pediatrics in general hospital

Objective To summarize the clinical characteristics of children with functional neurological disorder (FND) presented with motor symptoms. Methods and Results Total 18 children with FND mainly manifested by motor symptoms were admitted to Department of Pediatrics in Peking University Third Hospital from July 2017 to June 2023. The clinical phenotypes included 8 cases of myoclonus, 3 of tremor, 3 of myasthenia, 2 of dystonia, and 2 of psychogenic non⁃epileptic seizure (PNES). There was no overlap of movement disorder symptoms in all patients. Of the 8 cases with clonus, 5 showed bilateral symmetry myoclonus, and 3 involved only the right upper limb or right hand. Three cases of tremor presented with rapid tremor on one or both upper limbs or hands. Three patients with myasthenia showed weakness of both lower limbs and inability to walk. Of the 2 patients with dystonia, one had paroxysmal upper limb and trunk torsion postural abnormalities, and one had intermittent muscle tone and hip flexion of the lower limb. Two cases of PNES were characterized by gaze, neck tilt, limb extension and flexion tremors, and tapping. One case had mild abnormal EEG and repeated small chromosome fragments. Tirteen cases had mild symptoms and good prognosis after treatment. Five cases with severe symptoms combined with mental symptoms were transferred to Department of Psychiatry for further treatment. Conclusions The most common manifestations of children with FND presented with motor symptoms are myoclonus, tremor and myasthenia, which can be traced to related causes, and may be accompanied by a variety of other physical or psychiatric symptoms. Some children need to be referred to Department of Psychiatric for further treatment.