立位歩行困難で受診し短時間で方向が交代する眼振を認めた転換性障害の1例

抄録

Conversion disorder (CD) is a mental health condition in which psychological stress manifests as physical symptoms that cannot be attributed to medical or neurological conditions. These symptoms may include paralysis, difficulty in swallowing, dysphonia, and/or sensory disturbances. While CD falls within the domain of child psychiatry, affected patients may present to an otorhinolaryngologist with complaints such as difficulty in standing and walking.

Brief direction-changing nystagmus like periodic alternating nystagmus (PAN) should primarily be considered as a sign of a central lesion involving the cerebellum or brainstem. PAN is characterized by cyclical nystagmus, in which right-beating and left-beating phases alternate, and could be either congenital or acquired; acquired PAN is typically associated with cerebellar disease.

We report the case of an 11-year-old male patient who presented with difficulty in standing and walking. He did not experience dizziness while sitting or eating, and ataxia-like movements occurred only when he attempted to stand. He exhibited spontaneous nystagmus and saccadic pursuit. While the brief direction-changing nystagmus could not initially be identified, it was recognized subsequently. A comprehensive systemic examination revealed no evidence of a central nervous system disorder. During a pediatric consultation, significant household stress was identified, and a subsequent pediatric psychiatric evaluation led to the diagnosis of CD. The patient’s nystagmus was ultimately presumed as representing congenital nystagmus. Following a few weeks of cognitive behavioral therapy, his ability to stand and walk improved markedly.