Lasegue Sign

LASEGUE SIGN, SYNDROME, occurs with hoarseness, rapid fatigue during speech, and changes in sensitivity of the laryngeal mucosa, mainly on the same side. L. s. n. more often occurs with disease of the vagus nerve (separately or together with the nervus glossopharyngeus) in multiple nerve diseases in various infections and intoxications (alcoholism, diphtheria, etc.); nerves of both sides are more often affected. Various processes inside the skull, affecting the vagus nerve, also reflect on L. s. p. (encephalitis, meningitis, brain tumors, etc.). Finally, L. s. n. can be affected in diseases of the central nervous system (tabes dorsalis, bulbar paralysis, etc.). With the presence of the above-described clinical picture, it is not difficult to diagnose the disease of L. s. p.; it only remains to clarify the etiological factor in order to prescribe appropriate treatment.

LASEGUE SIGN, SYNDROME (Lasegue), named after the author who described it in 1864. L. p. is one of the main symptoms of sciatic nerve damage, either on one side or both sides, and consists of the following: if you lift the heel of an extended leg without bending it at the knee, the patient experiences sharp pain at a certain height, which is most often in the buttock area, sometimes in the lumbar region and in the popliteal fossa, sometimes along the entire course of the nerve. L. p. can be elicited in both the lying and standing positions of the patient. In both cases, the symptom has two phases, different in both positions. In the lying position, the first phase consists of passive dorsal flexion (extension) of the foot of the affected limb during the lifting of the extended leg, which leads to increased pain; the second phase consists of bending the lifted leg at the knee, which immediately leads to the disappearance of pain. When attempting to straighten the leg again, the pain returns; the second phase is given decisive importance, since the first phase also occurs in coxitis. L. p. in the vertical position is elicited if the patient bends forward without bending the knees, which leads to the appearance of sharp pain in the affected leg (in the same areas as in the lying position), and bending forward is impossible to the full extent due to pain. In this case, the first phase refers to the appearance of pain when bending forward, and the second phase refers to the disappearance of pain when bending the knees. The degree of expression of L. p. depends on the degree of damage to the sciatic nerve by the process, and the criterion is considered to be the angle formed by the limb being lifted from the bed (lying down), or the degree of bending (standing). A small angle and slight bending are indicators of severe expression of L. p. In both methods of eliciting L. p., it is caused by tension of the sciatic nerve on the bone-ligamentous block, over which it passes when exiting the pelvis. When eliciting L. p., not only the nerve but also the lower lumbar and upper sacral roots are stretched, which is why sometimes pain in the lower back is also experienced. Some authors consider L. p. to be a sign of reflex contraction of certain muscle groups when lifting the leg and bending the patient. L. p. is considered the main symptom in sciatica, as it occurs in 91.5% of all sciatica patients, according to Reichman and Margulis, 97% according to Steblow and Osetinsky, etc. Even in cases of secondary sciatica, according to Shamburov, L. p. occurs in 85% of patients. According to data from the neurological department of the Clinical Hospital of the 1st Moscow State University, in the first case L. p. occurs in 95% and in the second in 86% of patients. Based on L. p., several authors (Montaud-Martin, Bekhterev, Bonnet, Sicard) described less constant symptoms of pain when stretching the nerve from various other positions (adduction-Bonnet; crossed L. p., i.e., pain in the affected limb when lifting the healthy leg-Bekhterev, Montaud-Martin; forced plantar flexion of the foot-Sicard).