cogwheel rigidity


rigidity

 [rĭ-jid´ĭ-te] inflexibility or stiffness.clasp-knife rigidity increased tension in the extensor of a joint when it is passively flexed, giving way suddenly on exertion of further pressure; seen especially in upper motor neuron disease. Called also clasp-knife reflex.cogwheel rigidity tension in a muscle that gives way in little jerks when the muscle is passively stretched; seen in parkinson's disease.decerebrate rigidity see decerebrate rigidity.decorticate rigidity see decorticate rigidity.paratonic rigidity an intermittent abnormal increase in resistance to passive movement in a comatose patient.

cog·wheel ri·gid·i·ty

a type of rigidity seen in parkinsonism in which the muscles respond with cogwheellike jerks to the use of constant force in bending the limb.
A circular jerking rigidity in flexion and extension in a background of tremor, which continues throughout an entire range of movement, a finding typical of parkinsonism; it may also be ‘smoothly’ rigid, in which case it is termed lead pipe rigidity

cog·wheel ri·gid·i·ty

(kog'wēl ri-jid'i-tē) A type of rigidity seen in parkinsonism in which the muscles respond with cogwheellike jerks to the use of constant force in bending the limb.