The use of Fogs' test to assess associated movements in Parkinsonism, dystonia, and controls

The Fogs' test elicits non-homologous associated movements which reflect underlying pathology or immaturity of the CNS, but has not been thoroughly studied. We filmed participants performing a modified Fogs' test and developed a reliable scoring system for the associated movements. We assessed scores in healthy controls of all ages and compared scores in dystonia and parkinsonism to age similar controls. Associated movements were marked in children, lessened as they matured into adults, and then increased in old age. Associated movements were marked in dystonia but not in parkinsonism. Our scoring system showed robust inter- and intra-rater reliability. The Fogs' test is a reliable addition to the clinical examination that can be used to screen for both normal and abnormal neurological status. We suggest a potential neural pathway via cervical-lumbosacral connections within the spinal cord which are modulated by propriospinal and cerebral input.