Ablative functional neurosurgery can be useful in some selected patien
ts for the treatment of harmful spasticity in the lower limbs. Microsu
rgical drezotomy was introduced in 1972, on the basis of anatomical st
udies of the human dorsal root entry zone (DREZ) showing a topographic
al segregation of the afferent fibers according to their size and thus
functional destinations. It consists of a 3 mm deep microsurgical les
ion directed at a 45 degree angle in the postero-lateral sulcus, penet
rating the DREZ in its ventro-lateral aspect, at the level of all the
rootlets considered as involved in spasticity (and pain). It destroys
mainly the lateral (nociceptive) and central (myotatic) afferent fiber
s as well as the facilitatory medial part of the Lissauer tract, whils
t sparing most of the medial (lemniscal) fibers and the inhibitor late
ral part of the Lissauer tract. We report a series of 121 bedridden pa
tients suffering: from harmful spasticity in one (15) or both (106) lo
wer limbs and treated with microsurgical drezotomy. Surgery was decide
d on because of abnormal postures in flexion in two-thirds of the pati
ents and in hyperextension in one-third, additional pain in 75 of them
, and hyperactive bladder in 38 cases. The post-operative results were
evaluated after a mean follow-up time of 5 years and 6 months. Both s
pasticity and spasms were significantly decreased or suppressed respec
tively in 78 % and 88 % of the patients. When present, pain was reliev
ed without abolition of sensation in 82 %. These benefits resulted in
either disappearance or marked reduction of the abnormal postures and
articular limitation in 90 % of the patients. When present preoperativ
ely, urinary leakage disappeared in 85 % of the cases Mild to severe c
omplications occurred in 32 patients and precipirated or were responsi
ble for death in 6 cases (5 %). This is explained by the fact that mos
t of the patients, especially those affected by multiple sclerosis, we
re in very precarious general and neurological conditions. Microsurgic
al drezotomy has however enabled a large majoritory of these severely
disabled patients to sit and lie comfortably. and allowed them to reac
h a significantly improved quality of life.