Background Early theories for cervical dystonia, as promoted by Hassler, emphasized the role of midbrain interstitial nucleus of Cajal. Focus then shifted to basal ganglia, and it was further supported with the success of deep brain stimulation. Contemporary theories suggested the role of cerebellum. But even more recent hypotheses renewed interest in midbrain. Although pretectum was visited on several occasions, we still do not know about the physiology of midbrain neurons in cervical dystonia. Methods We analyzed the unique database of pretectal neurons collected in 1970s and 1980s during historic stereotactic surgeries aimed to treat cervical dystonia. This database is valuable because such recordings could otherwise never be obtained from humans. Results We found three types of eye or neck movement sensitivity, eye-only neurons responded to pure vertical eye movements; the neck-only neurons were sensitive to pure neck movements; and the combined eye-neck neurons. There were two neuronal subtypes – burst-tonic and tonic. The eye-neck or eye-only neurons sustained their activity during eccentric gaze holding. In contrast, the response of neck-only and eye-neck neurons exponentially decayed during neck movements. Conclusions Modern quantitative analysis of historic database of midbrain single-units from patients with cervical dystonia might support novel hypotheses for normal and abnormal head movements. This data, collected almost four decades ago, must be carefully viewed, especially because it was acquired using a less sophisticated technology available at that time, the aim was not to address specific hypothesis but to make an accurate lesion providing optimal relief from dystonia.

Objectives: The aim of this investigation is to assess the effectiveness of spinal cord stimulation (SCS) in different groups of patients with spasticity of different origin. Materials and Methods: A retrospective study of the use of the method of SCS in 71 patients. The patient population was divided into two groups: 52 cerebral palsy (CP) cases and 19 patients diagnosed with spasticity caused by spinal injury. The mean age was 7.14 ± 4.06 and 35.68 ± 12.42 years, respectively. The CP group included 41 cases of paraparesis and 11 cases tetraparesis. One quadripolar electrode was implanted into the posterior epidural space at Th10-Th12 level and an implantable pulse generator (Itrel3, Medtronic) was placed in a standard fashion. We performed 3-5 stimulation sessions per day; each lasted 30 min. The stimulation parameters were as follows: rate 100-130 Hz, pulse width 120-300 ms, amplitude 1.5-4 V. The follow-up ranged from 2 to 9 years. Results: Decrease in muscle tone was observed in all cases in the group of patients with spinal spasticity: from 3.71 ± 0.61 on the Ashworth scale before the operation to 2.26 ± 0.56 after the operation (p < 0.001). In the group of cerebral spasticity a significant decrease in muscle tone was observed only in patients with spastic lower paraparesis: from 3.36 ± 0.41 before the operation to 1.97 ± 0.91 after the operation (p < 0.005). In patients with spastic tetraparesis we did not observe any significant change in muscle tone. In 8 cases we discontinued the therapy several years after the procedure due to improvement in spasticity: in the CP group in 7 cases and in 1 spinal spasticity case, where SCS systems were explanted. Conclusion: Chronic SCS may be a method of choice for patients with moderate spinal and cerebral spasticity with predominant spastic lower paraparesis. In patients with spastic tetraparesis SCS therapy did not prove to be effective. We encountered improvement of the spasticity and no need for further SCS therapy in a small group of patients (11%). This phenomenon requires further investigation.

Chronic epidural MCS is an effective and safety method for the treatment of some chronic neurogenic medically-refractory pain syndromes. Further research is necessary to specify the patient selection criteria and the MCS efficacy predictors.

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<p>Critical limb ischemia (CLI) is a state of substantial reduction of blood flow in the extremities, mostly due to severe obstruction of the arteries. In lower limbs, it produces severe pain after even a short distance walk (intermittent claudication) and/or skin ulcers or sores. Surgical revascularization is a “golden standard” in CLI therapy, but it is contraindicated or not accessible for a large proportion of patients, while the medical prognosis is poor for conservative therapy. This situation stimulated the development of alternative approaches, including spinal cord stimulation (SCS) and various methods of “indirect” revascularization. In this paper, the authors give a short description of the latest approaches and a detailed review of the SCS method, while paying special attention to the studies that demonstrate not only a palliative effect of SCS (pain reduction), but also clinically significant changes in the indicators of lower limb muscles blood supply. CLI is characterized with a "vicious circle": pain causes reduced mobility and changes in the preferred limb position, which in turn lead to edema triggering an increase of ischemia and further elevation of pain. The clinical effects of SCS in CLI patients are related both with pain relief leading to a break of this vicious circle, and with the direct vasodilatory effects of the stimulation itself. There are several possible biological mechanisms of these actions, but most probably the therapeutic actions of SCS arise from their combination. Examination of different opinions about the appropriateness of spinal cord stimulation in patients with CLI, including those related to the economic efficiency of the method, leads to the conclusion that the evidence on these issues is currently insufficient. The reviewed data demonstrate the need for further development of the CLI treatment methods and high urgency of this problem.</p><p>Received 6 April 2017. Accepted 23 April 2017.</p><p><strong>Funding:</strong> The study did not have sponsorship.<br /><strong>Conflict of interest:</strong> The authors declare no conflict of interest.</p>