[Generalized nocifensor reflexes--II. A modified reflex pattern caused by functional disorders of the thalamus].

In the past, clinically relevant diagnostic procedures using nocifensive reflexes have been restricted mainly to ascertaining the functional status of the efferent or afferent portion of the reflex arc. The method described here, which evoked global nocifensive reflexes, permits differentiated conclusions to be drawn regarding possible supraspinal influences on nocifension. The reflex patterns yielded by the procedure can provide information regarding the functional status of the formatio reticularis, which is subject to modulatory influences of the pallidostriatum and thalamus. The results show that specific, pathohistologically confirmed lesions of the thalamus de-inhibit the formatio reticularis for motor reticulospinal activity and that this is reflected in the nocifensive pattern. Thus, the nocifensive reflex on the contralateral side to the thalamic process is stronger and has a shorter latent time than that on the clinically healthy side. This phenomenon has so far been confirmed on all patients with an impaired thalamus function.