Rigor

This article discusses the rigors as a disturbance of muscle tone in the living, for the rigor mortis see rigor mortis .

This article or the following section is not adequately provided with supporting documents ( e.g. individual evidence ). Information without sufficient evidence could be removed soon. Please help Wikipedia by researching the information and including good evidence.

Rigor ( Latin for "rigidity") is a medical term for muscle rigidity or ("waxy") muscle stiffness . It describes an increase in muscle tone , which comes about through the centrally controlled simultaneous activation of muscles and their counterparts (agonist-antagonist co-activation). The affected person experiences it as a feeling of stiffness, sometimes with pulling discomfort.

root cause

Muscles have a certain basic tension, the resting tone . This is regulated by the central nervous system. Both the pyramidal (sending information about cerebral cortex-spinal cord pathways) and above all the extrapyramidal (reaching the spinal cord in other ways) system play a role. Both systems influence each other. Rigor arises as a dysfunction of the extrapyramidal system , typically due to a dopamine deficiency in the context of Parkinson's syndrome . The control mechanism is not fully known.

examination

In the neurological examination, the rigor is tested in the sitting or lying patient by passive movement of individual joints (the patient should relax the muscles). A waxy rigidity can then be felt as a tough, even resistance. In contrast to spasticity , the degree of resistance does not depend on the speed of passive movement. By actively moving the extremities of each other , it increases. Sometimes there can be rhythmic interruptions of the rigors while moving (“ gear wheel phenomenon ”). The cogwheel phenomenon is not part of the definition of rigidity, but only often associated with it.

The reduced swinging of the arm when walking is seen as an early sign of rigidity.

Occurrence

Rigor typically occurs as one of the four main symptoms of Parkinson's syndromes, which are usually caused by cell death in circumscribed areas of the brain ( substantia nigra ), but e.g. B. can also occur as a side effect of neuroleptics .

This article is about a health issue. It is not used for self-diagnosis and does not replace a diagnosis by a doctor. Please note the information on health issues !