Functional Stereotactic Surgery for Treatment of Cervical Dystonia: Review of the Experience from the Lesional Era

Abstract

Background: Functional stereotactic neurosurgery has been rediscovered as a powerful tool to treat various manifestations of medically refractory dystonia. The purpose of this study was to provide the first systematic review of previous experience with thalamic and basal ganglia surgery in the treatment of cervical dystonia (CD). Methods: A comprehensive review of the literature published between 1950 and 1990 was performed. In addition, data from an unpublished doctoral thesis on 162 patients with CD operated on by Mundinger between 1972 and 1986 were analyzed. Results: Overall, there is published documentation of experience with more than 300 patients with CD who underwent functional stereotactic surgery between the late 1950s and the early 1980s. In general, amelioration of CD was achieved in about 50–70% of patients in most studies. Bilateral surgery generally provided better outcomes than unilateral surgery. Postoperative benefit was reported to become evident only after a delay in several studies. Some reports demonstrated sustained benefit after follow-up of more than 5 years. Bilateral procedures, in particular bilateral thalamotomies, were clearly associated with a higher rate of postoperative side effects, such as dysarthria, dysphagia and ataxia, ranging from 20 to 70%. In the first decade after its introduction, thalamotomy was the preferred procedure. Later, the subthalamic area was targeted more frequently in order to affect pallidal outflow. Experience with targeting the pallidum proper was limited. Functional stereotactic surgery for CD was abandoned in the late 1970s for several reasons, including the general decline in movement disorder surgery at that time, the introduction of selective peripheral denervation and the widespread and beneficial use of botulinum toxin soon thereafter. Conclusions: Functional stereotactic surgery for treatment of CD has a rich history. There are several lessons to be learned from review of earlier experience. Contemporary techniques have led to a significant improvement in the benefit to risk ratio, in particular regarding bilateral surgery.

Three-Dimensional Eye–Head Coordination After Injection of Muscimol Into the Interstitial Nucleus of Cajal (INC)

“…From a clinical perspective, after muscimol injection our animals showed symptoms of gaze-paretic nystagmus (a position-dependent drift of the eye) in the vertical and torsional components (Ranalli et al 1988), a contralateral ocular tilt reaction (torsional tilt of the eyes) (Westheimer and Blair 1975), and rotatory spasmodic torticollis (ST) (Loher et al 2004). All of these deficits have long been associated with midbrain damage in humans (Bertrand et al 1978;Plant et al 1989;Raeva et al 1987;Vasin et al 1985) and the physiological relationship of the INC to the oculomotor components of these disorders was previously considered in detail elsewhere (Crawford and Vilis 1993;Fukushima 1987;Helmchen et al 1998;Ranalli et al 1988).…”

“…Lesions in the midbrain (as well as other structures) were previously suggested to play a major role in ST (Bertrand et al 1978;Plant et al 1989;Raeva et al 1987;Vasin et al 1985). ST may include both horizontal and rotatory (i.e., head tilts around an anteroposterior axis in which one of the ears approaches the ipsilateral shoulder) offsets in head posture (Loher et al 2004). Other than these offsets, ST patients still show torsionally restricted position ranges with the characteristic "Fick twist" (Medendorp et al 1999).…”

Deep Brain Stimulation for Dystonia in Adults

“…The animal experiments of the neurophysiologist W.R. Hess in Zürich, for which he was awarded the Nobel prize, probably present the first traces in the history of DBS for treatment of dystonia [7]. In the early 1950s, the German neurologist R. Hassler, who is known today chiefly for his thalamic nomenclature, travelled to Zürich to review the kinematographic data and the histologic serial cuts from Hess' experiments in cats.…”

“…About 300 patients with CD were reported to have undergone functional stereotactic surgery in the 1960s and 1970s [7]. Historical reports are difficult to interpret, but it appears that most patients experienced mild to moderate benefit.…”

Comparison of Treatment Results between Selective Peripheral Denervation and Deep Brain Stimulation in Patients with Cervical Dystonia

“…However, controversy exists regarding the role of the different surgical options and the identification of predictive factors. There is no clear picture of when patients were referred primarily for GPi DBS or for SPD [6] . Bertrand [11] introduced the principle of SPD and described the postoperative outcome as excellent in 40% of the patients, as very good in 48%, as fair in 10% and as poor in 1%.…”