Beurteilung der prognostischen Relevanz der Auflösungszeit des "Lateral Spreads" bei der Mikrovaskulären Dekompression für Spasmus Hemifazialis

Lateral Spread Reflex (LSR) can be usually identified in individuals experiencing hemifacial spasm. The prognostic significance of LSR over the long-term result of microvascular decompression (MVD), specifically whether they resolve or persist, has been a topic of debate and inquiry. Nonetheless, the correlation between the timing of LSR disappearance and overall outcomes has not yet been extensively explored. This study seeks to assess the prognostic impact on spasms improvement following MVD, considering the timing of LSR relief.

Prospective documenting of the state of lateral spread reflex (LSR) during the procedure, alongside our routinely collected data was done. Reassessing the persistence or disappearance of (LSR) was done at certain milestones of the procedure. These milestones encompassed the skin incision, craniotomy, dural opening, and the opening of the cisterns (opening phase). Second phase involved arachnoid dissection on the cranial nerves to expose the facial nerve, while the third phase entailed the active decompression of the nerve using Teflon or Gortex. Evaluation of outcomes (improvement vs no improvement) occurred at a follow-up of at least 3 months.

220 patients were enrolled with mean age(SD) of 54.7±(11.7) years and a follow-up(SD) of 22.8±(18.2) months. Male-to-female ratio is 1.7:1.No LSRs were detected in 38 patients (17.3%), and they exhibited 92.1% improvement. LSRs persisted in 6 patients (2.7%), yet theses patients demonstrated a 100% improvement. In 16 patients (7.3%), LSR vanished during the initial stages of the procedure (opening phase), with 100% final improvement. 44 patients (20%) lost their lateral spreads during arachnoidal dissection, experiencing improved spasms of 90.9%. Decompression led to the disappearance of spasms in 90 patients (40.9%), correlating with a clinical improvement of 85.9%. Finally, during the closure 26 patients (11.8%) witnessed the resolution of lateral spreads and 100% improvement.

While all the patients" groups demonstrated a notable improvement in spasms exceeding 85%, those in whom the LSRs vanished during the decompression phase exhibited comparatively poorer outcomes than those whose LSR disappearance occurred in the predecompression phase of the procedure.