Neck rigidity as a physical manifestation of higher brain hypo-function/dysfunction.

A total of 308 patients, who received inpatient rehabilitation in department of Neurology in Sapporo City General Hospital, were studied. The patients were divided into four subgroups according to the presence or absence of Parkinsonism and the location of organic neurological lesions: group A consisted of 47 patients with brain lesions who presented with Parkinsonism; group B consisted of 135 patients with manifestations deriving from brain disorders other than Parkinsonism; group C consisted of 68 patients with manifestations deriving from spinal cord, peripheral nerve, and muscle disorders; and group D consisted of 58 patients with non-organic functional disorders and patients with organic lesions not responsible for clinical manifestations. The patients were administered a battery of 5 tests for evaluating frontal lobe and/or higher brain function. In result, our study confirmed higher brain/frontal lobe dysfunction to affect the grade of neck rigidity unless there is an interruption, in the control of peripheral organs, by the brain. Consequently the association between higher brain/frontal lobe dysfunction and the grade of neck rigidity were confirmed. Although neck rigidity may be a minor clinical manifestation, it can provide important clues to brain function.