Microsurgical DREZ-otomy for the treatment of spasticity and pain in the lower limbs.

The authors report on a series of 53 bedridden patients suffering from harmful spasticity in one (6) or both (47) lower limbs, who were treated with microsurgical DREZ-otomy. Surgery was performed to treat fixed abnormal postures in flexion in 49 patients and hyperextension in 3, and, additionally, to treat pain in 37 patients. Microsurgical DREZ-otomy was introduced in 1972, on the basis of anatomical studies of the human dorsal root entry zone (DREZ) showing a topographical segregation of the afferent fibers according to their size and functional destinations. It consists of a 2 mm deep microsurgical lesion directed at a 45 degrees angle in the posterolateral sulcus and penetrating the dorsal root entry zone in its ventrolateral aspect, at the level of all the rootlets considered involved in spasticity (and pain). It destroys mainly the lateral (nociceptive) and central (myotatic) afferent fibers as well as the facilitatory medial part of the Lissauer tract, while sparing most of the medial (lemniscal) fibers, the suppressor lateral part of the Lissauer tract, and more or less of the dorsal horn (DH). The postoperative results were evaluated after a mean follow-up period of 3 years and 4 months. Both spasticity and spasms were significantly decreased or suppressed in 75% and 88.2% of the patients, respectively. When present, pain was relieved without abolition of sensation in 91.6%. These benefits--combined with complementary orthopedic surgery in 23 patients--resulted in either disappearance or marked reduction of the abnormal postures in 85.3% of the patients and of articular limitations in 96.8%. Mild-to-severe complications occurred in 25 patients and precipitated or were responsible for death in 5. This is explained by the fact that the general and neurological conditions of most of the patients--especially those affected by multiple sclerosis--were precarious. MDT has, however, enabled a majority of these severely disabled patients to sit and lie comfortably, and has allowed them to reach a significantly improved quality of life.