ORIGINAL ARTICLES   

Journal of Neurosurgical Sciences 2003 September;47(3):119-28

Copyright © 2004 EDIZIONI MINERVA MEDICA

lingua: Inglese

Bilateral high frequency subthalamic stimulation in Parkinson’s disease: long-term neurological foll ow-up

Romito L. M. ¹, Scerrati M. ², Contarino M. F. ³, Iacoangeli M. ², Bentivoglio A. R. ³, Albanese A. ³

¹ “Carlo Besta” National Neurologic Institute, Milan, Italy 2 Department of Neurosurgery, Azienda Ospedaliera Umberto I, University of Ancona, Ancona, Italy 3 Division of Neurology, Catholic University of The Sacred Heart, Rome, Italy

Aim. High fre­quen­cy stim­u­la­tion of the sub­tha­lam­ic nucle­us (STN) is gain­ing rec­og­ni­tion as a new symp­to­mat­ic treat­ment for Parkinson’s dis­ease (PD). The ­first avail­able ­long-­term obser­va­tions ­show the stabil­ity of the effi­ca­cy of ­this pro­ce­dure in ­time.
Methods. Quadripolar ­leads ­were implant­ed bilat­er­al­ly ­under ster­eo­tac­tic con­di­tions in the STN of ­patients ­with ­advanced PD. High fre­quen­cy stim­u­la­tion was ­applied for 24 ­hours a day. Following ­implant, anti­par­kin­so­nian med­i­ca­tion was ­reduced as ­much as pos­sible and stim­u­la­tion was grad­u­al­ly ­increased. The ­patients ­were eval­u­at­ed in the prac­ti­cal­ly ­defined “off” con­di­tion and in the “on” con­di­tion ­using the uni­fied PD rat­ing ­scale (­UPDRS) and the Schwab & England ­scale. Neuropsychological test­ing was per­formed ­before and ­after the ­implant. Thirty-­three ­patients ­were fol­lowed up for at ­least 3 ­months and 13 ­among ­them ­until 36 ­months.
Results. The ­patients had a ­mean age of 56.8±7.1 ­years and a ­mean dis­ease dura­tion of 13.8±5.5 ­years; ­they ­were fol­lowed-up for an aver­age of 25.7±13.5 ­months. At the ­time of the ­last avail­able vis­it, the stim­u­la­tion ampli­tude was 2.47±0.40 V (the ­total ener­gy deliv­ered aver­aged 1.57±0.8 μW). The lev­o­do­pa-equiv­a­lent dai­ly ­dose was ­reduced by 56.2% (p<0.001). Parkinsonian fea­tures ­were ­improved in all ­patients, the great­est chang­es ­were ­seen for trem­or, ­gait, bra­dy­ki­ne­sia and pos­tu­ral stabil­ity, ­then rigid­ity and ­limb aki­ne­sia. Compared ­with the pre-­implant con­di­tions, the ­UPDRS ­motor ­score in the “off” con­di­tion was ­improved by 51.6% at the ­time of the ­last vis­it (p<0.001), the ­UPDRS activ­ities of dai­ly liv­ing ­score was ­improved by 68.5% (p<0.001), the Schwab & England ­scale was ­improved by 196.8% (p<0.001). The neu­ro­psy­cho­log­i­cal ­data did not ­show sig­nif­i­cant chang­es. Night ­sleep ­improved in all ­patients, due to ­increased mobil­ity at ­night. In ­almost all ­patients insom­nia was ­resolved. All ­patients ­gained ­weight ­after sur­gery ­with an ­increase of 11.1% (p<0.001) com­pared to ­their pre-­implant ­weight.
The ­most com­mon per­ma­nent ­side ­effects con­sist­ed in hypo­pho­nia and dys­ar­thria, tran­sient ­side ­effects ­were ­increased sex­u­al­ity and ­mania, the ­most com­mon ­side ­effects relat­ed to stim­u­la­tion ­were bal­lic or cho­re­ic dys­ki­ne­sias. The ­most com­mon ­adverse ­event relat­ed to the sur­gi­cal pro­ce­dure was tran­sient psy­cho­sis; unex­plained switch­ing-off of the stim­u­la­tor was the ­most com­mon ­device-relat­ed ­effect.
Conclusion. This ­study ­extends our recente­ly pub­lished 3-­years FU ­series. It con­firms ­again ­that symp­to­mat­ic effi­ca­cy of STN stim­u­la­tion is ­retained dur­ing the 2nd and 3­rd ­years fol­low­ing the ­implant, with­out any obvi­ous ­decay of effi­ca­cy or ­need for ­increase of ener­gy deliv­ered. Improvement of dys­ki­ne­sias ­also per­sists and the pro­ce­dure is ­well tol­er­at­ed. Side ­effects and ­adverse ­events are some­times ­severe, but can be man­aged in ­most cas­es. The improve­ment of dai­ly liv­ing activ­ities out­weighs by far the ­motor ben­e­fit, indi­cat­ing ­that the use of ­this pro­ce­dure sig­nif­i­cant­ly ­improves the ­patients’ life­style.