Functional and Idiopathic Cervical Dystonia in Two Family Members: A Challenging Diagnosis.

Background: Cervical dystonia (CD) often occurs in the same family. Case report: A 40-year-old woman presented with a longstanding history of CD and signs of inconsistency at history taking and neurological examination; her 65-year-old mother was diagnosed instead with idiopathic CD, which had begun 7 years after the onset of CD in her daughter. Discussion: Idiopathic and functional CD share common clinical and endophenotypic traits, making the differential diagnosis particularly challenging. A complete examination is warranted.