[Acute hemiplegia and hemianesthesia together with decreased tendon reflexes mimicking acute stroke representing a conversion disorder].

Acute hemiplegia and hemianesthesia is commonly caused by obstruction of major cortical arteries. Such a presentation secondary to a conversion reaction is very rare, especially in the pediatric age group. The authors report an adolescent presenting with acute complete left-sided hemiplegia and sensory loss together with decreased tendon reflexes mimicking an acute arterial stroke. Examination revealed Hoover's sign was present and the patient was oblivious to his stern neurological state. Movement of his paralytic limbs was observed during sleep. Cortical and spinal CT, cortical MRI, motor and somatosensory evoked potentials and a PET study were all normal. As such, the diagnosis of psychogenic hemiplegia was established, apparently within a period that the patient had experienced severe emotional stress while questioning his gender identity. After three days, the adolescent began to move the paralytic limbs along gradual resolution of sensory deficit, leading to complete clinical recovering within two months. Although extremely rare, a conversion reaction should be taken into account in children presenting with acute hemiplegia and anaesthesia, even accompanied with decreased tendon reflexes, when the patient is oblivious to his alleged grave state, and when clinical observations such as Hoover's sign remain intact, substantiated by normal extensive radiological and neurophysiological investigation. Intact motor evoked potentials serve as a key for the diagnosis of psychogenic hemiplegia and, should therefore be performed in suspected cases.