This case-study presents in detail the clinical assessment of a 29-year-old mother and her daughter who first presented to infant mental health specialists at age 16-months, with a hospital record suggesting the presence of a dyadic disturbance since age 8-months. Data from psychiatric and neurological assessments, as well as observational measures of child and mother are reviewed with attention to issues of disturbed attachment, intergenerational trauma, and cultural factors for this inner-city Latino dyad. Severe maternal affect dysregulation in the wake of chronic, early-onset violent-trauma exposure manifested as psychogenic seizures, referred to in the mother's native Spanish as "ataques de nervios," the latter, an idiom of distress, commonly associated with childhood trauma and dissociation. We explore the mechanisms by which the mothers' reexperiencing of violent traumatic experience, together with physiologic hyperarousal and associated negative affects, are communicated to the very young child and the clinician-observer via action and language from moment to moment during the assessment process. The paper concludes with a discussion of diagnostic and treatment implications by Drs. Marshall, Gaensbauer, and Zeanah.