Table 1.

Essential, Primary, Senile, and Idiopathic: Covering gaps in knowledge

Early nomenclature	Revised nomenclature	Implication
Primary dystonia	Isolated dystonia	“Primary”: not reliable for etiology
Essential myoclonus	Myoclonus dystonia54 Benign hereditary chorea55	“Essential myoclonus” encompassed a syndrome
Essential palatal tremor	Isolated palatal tremor including special skills, functional palatal tremor and tics56, 57	“Essential” included other recognizable palatal tremors
Senile gait	Highest-level gait disorder Parkinsonian gait	“Senile”58 wrongly implied changes due to normal aging
Senile chorea	Most often late-onset Huntington disease, antiphospholipid antibody syndrome, hypocalcemia, or tardive dyskinesia59	“Senile” chorea wrongly suggests it may be due to normal aging
Idiopathic Parkinson’s disease	PARK1, 2, 4, 7, 8… Ongoing genetic-molecular phenotyping	“Idiopathic” becomes an ever narrowing slice of PD, as genetic/molecular etiologies are unveiled