Application of 2D Gait Analysis for the Assessment of Gait Disturbance in Patients with Spastic Tetraparesis.

The aim of the study was to explore the use of 2D gait analysis for assessing gait abnormalities in patients with spastic tetraparesis associated with spinal cord injury and other lesions of the cervical spinal cord. Materials and Methods: The study included 12 patients with tetraparesis of various etiologies. Gait assessment was performed by video analysis using reflective markers (1.5 cm) and a special walking platform. The spatial coordinates of the markers were determined by capturing the reflected light with infrared LEDs located around the lenses of video cameras. Results: Using 2D gait analysis, numerical indicators of gait disturbance in spastic tetraparesis were obtained. We found a prolongation of the stand phase with a shortening of the swing phase (from 81.9 [76.1; 89.2] to 85.3 [74.4; 90.2]%; p=0.97) and the period of the double step (from 0.50 [0.45; 0.96] to 0.40 [0.34; 0.66]; p=0.4) in comparison with the target (normal) values (60% - for the stand phase; 1.41 - for the double-step period). The movements in the hip, knee, and ankle joints are described using numerical values.We then compared the data obtained from the left and right sides of the patient's body: there were no statistically significant differences between the two sets of data. We also compared the gait characteristics before and after treatment (in 4 patients). Statistically significant differences in values were obtained for the stand and swing phases (p=0.035), the range of motion in the hip joint (p=0.01), and gait velocity (p=0.046). Kendall's analysis revealed no significant correlation between the data obtained by video gait analysis and the gait changes by the Modified Ashworth Scale (р>0.05). Conclusion: 2D gait analysis is a promising method for quantifying gait disturbance in patients with spastic tetraparesis. It allows one to identify characteristic gait patterns, in particular, an increase in the stand phase with a shortening of the swing phase and the double step period, as well as a decrease in the range of motion in the hip joints with an increase in the knee and ankle ones.

[Spinal cord stimulation in the treatment of chronic pain]. / Khronicheskaya elektrostimulyatsiya spinnogo mozga u patsientov s khronicheskoi bol'yu.

Despite the numerous analgesic drugs, the prevalence of intractable neuropathic pain remains high making up about 5%. Intervention methods, including methods of chronic electrostimulation, are used to treat these patients. Spinal cord stimulation (SCS) is the most common surgical method worldwide that replaced destructive and ablation procedures. Currently, common tonic SCS, HF-10 stimulation and burst SCS are applied, and the choice of method is based on clinical and neurophysiological data. Also, the introduction of nanomaterial-enabled neural stimulation could significantly minimize surgery risk.

[Motor cortex stimulation in deafferentation facial pain]. / Stimuliatsiia motornoi kory pri deafferentatsionnoi litsevoi boli.

OBJECTIVE: To demonstrate the results of treatment of poorly controlled deafferentation facial pain using motor cortex stimulation and to review the relevant literature. MATERIAL AND METHODS: The study included 8 patients (3 males and 5 females) with deafferentation facial pain who were implanted with a system of constant motor cortex stimulation at the Illinois University in Chicago in 2004-2016 and Novosibirsk Federal Center of Neurosurgery in 2017. The patients' age ranged from 37 to 81 years (mean age, 57.5 years). Scale-based assessment of the pain severity was performed at admission to hospital, at discharge, and during follow-up. The visual analogue pain scale, Barrow Neurological Institute pain scale (BNIPS), and McLaughlin scale were used. RESULTS: Immediately after surgery, a significant improvement in the form of pain reduction by 80-100% occurred in 4 patients. The pain intensity at discharge from the hospital decreased by 55%, on average. During the follow-up period, the efficacy of motor cortex stimulation was assessed (McLaughlin scale) as very good by 3 of the 8 patients, as good by 4 patients, and as unsatisfactory by 1 patient. CONCLUSION: Our findings and recent studies have demonstrated that motor cortex stimulation is one of the treatment options for deafferentation facial pain. Even a slight decrease in the intensity of excruciating and debilitating pain (assessed by patients as a good effect) gives grounds for application of the procedure. Further research is needed to define more precise criteria for selecting patients for this treatment and to increase the efficacy of stimulation.

A hypothesis on possible neurochemical mechanisms of action of cervical spinal cord stimulation in prevention and treatment of cerebral arterial vasospasm after aneurysmal subarachnoid hemorrhage.

Subarachnoid hemorrhage (SAH) is associated with the high incidence of development of cerebral vasospasm that results in morbidity and mortality due to delayed cerebral ischemia. So far there are no consistently effective therapies for treatment of vasospasm in patients suffering from SAH. It is well known that cervical spinal cord stimulation (SCS) can induce vasodilatation and increase cerebral blood flow (CBF). Based on the experiments in animals and the studies in humans, we have proposed the possibility to use SCS as a therapeutic strategy for prevention and treatment of cerebral vasospasm after SAH. However, the physiological mechanisms of action of SCS in this regard are poorly understood. Better understanding of the pathophysiology of vasospasm after SAH may provide insight into the role of SCS in such conditions. We hypothesize that effect of SCS on vasodilatation may be related to modulation of activity of phosphodiesterases 5 (PDE-5) and nitric oxide synthase (eNOS), resulting in enhancement of nitric oxide (NO)-cyclic guanosine monophosphate (cGMP) pathway, which may help prevent and/or treat vasospasm after SAH. Further investigations on the physiological mechanisms of action of SCS would be necessary to support this hypothesis.

An update on peripheral nerve stimulation.

Electrical stimulation of peripheral nerves is an established modality in treatment of chronic pain. Although introduced half a century ago, it has enjoyed rapid growth in popularity and acceptance over the last decade or so. The spectrum of clinical situations where peripheral nerve stimulation (PNS) has been successfully used includes chronic pain in extremities, neck, lower back, chest and abdominal wall, and head and face regions. Based on several multicenter studies, PNS has been recently approved for clinical use in Europe for treatment of chronic low back pain and intractable chronic migraines. Such administrative recognition of clinical value of PNS necessitates update on PNS status for interested readers. The goal of this article is to provide a comprehensive overview of the different types of peripheral neurostimulation that are used today and providing the most updated information on the current state of the modality. As clinical interest and experience with PNS continue to grow, we expected steady accrual of objective evidence in terms of safety, efficacy, best indications and optimal stimulation parameters, all of which will be necessary for worldwide regulatory approval of PNS and for the benefit of patients who are still suffering from chronic neuropathic pain.

Use of cervical spinal cord stimulation in treatment and prevention of arterial vasospasm after aneurysmal subarachnoid hemorrhage. Technical details.

Based on past laboratory and anecdotal clinical experience, we hypothesized that prolonged cervical spinal cord stimulation (SCS) in the acute settings of aneurysmal subarachnoid hemorrhage (aSAH) would be both safe and feasible, and that 2-week stimulation will reduce incidence of cerebral arterial vasospasm. The goal of our clinical study was to establish feasibility and safety of cervical SCS in a small group of selected aSAH patients. Single-arm non-randomized prospective study of cSCS in aSAH patients involved percutaneous implantation of 8-contact electrode in 12 consecutive aSAH patients that satisfied strict inclusion criteria. The electrode insertion was performed immediately upon surgical or endovascular securing of the ruptured aneurysm while the patient was still under general anesthesia. Patients were stimulated for 14 consecutive days or until discharge. There were no complications related to the electrode insertion or to SCS during the study and no long-term side effects of SCS during 1-year follow-up. There was 1 unrelated death and two electrode pullouts. This article summarizes technical details of SCS electrode insertion and the stimulation parameters used in the research study. Our study of SCS for prevention of vasospasm after aSAH conclusively shows both safety and feasibility of this promising treatment approach. Despite high level of acuity in aSAH patients, impaired level of consciousness, frequent patient re-positioning, need in multiple tests and variety of monitors, SCS electrodes may be safely implanted and maintained for the two-week period. Long-term follow up shows no adverse effects of cervical SCS in this patient category.

Peripheral nerve stimulation for the treatment of neuropathic craniofacial pain.

Treatment of neuropathic pain in the region of head and face presents a challenging problem for pain specialists. In particular, those patients who do not respond to conventional treatment modalities usually continue to suffer from pain due to lack of reliable medical and surgical approaches. Peripheral nerve stimulation (PNS) has been used for treatment of neuropathic pain for many decades, but only recently it has been systematically applied to the craniofacial region. Here we summarize published experience with PNS in treatment of craniofacial pain and discuss some technical details of the craniofacial PNS procedure.

Stellate ganglion block may relieve hot flashes by interrupting the sympathetic nervous system.

Stellate ganglion block is routinely used in pain clinics. The mechanism of action of the stellate ganglion block is uncertain; the most common explanation is that it produces peripheral vasodilation, resulting in neural inhibition in the ganglion's sphere of innervation. However, the wide range of conditions that have been reported to respond favorably to stellate ganglion block suggest that its effectiveness may not be solely the result of increased blood flow nor restricted just to its sphere of innervation. We have found that stellate ganglion block is effective in the treatment of hot flashes in postmenopausal women, as well as those with estrogen depletion resulting from breast cancer treatment. Based on evidence that hot flashes may be centrally mediated and that the stellate ganglion has links with the central nervous system nuclei that modulate body temperature, we hypothesize that the stellate ganglion block provides relief of hot flashes by interrupting the central nervous system connections with the sympathetic nervous system, allowing the body's temperature-regulating mechanisms to reset. If this mechanism can be confirmed, this would provide women with intractable hot flashes with an effective, potentially long-lasting means of relieving their symptoms, and potentially widen the range of indications for stellate ganglion block to include other centrally mediated syndromes.

Direct visualization of the human subthalamic nucleus with 3T MR imaging.

BACKGROUND AND PURPOSE: Electrical stimulation of the subthalamic nucleus (STN) is an accepted treatment for advanced Parkinson disease (PD). Although procedural details are well established, targeting STN remains problematic because of its variable location and relatively small size (20-30 mm(3)). A combination of anatomic imaging with a stereotactic frame, atlas coordinates, and intraoperative neurophysiology is currently considered the most reliable approach for STN targeting. CT imaging is dependent on atlas coordinates, because the STN is not visualized. The STN is also difficult to visualize directly by using MR imaging at 1.5 T. METHODS: We performed preoperative stereotactic MR imaging at 3T to visualize the STN in 13 patients undergoing deep-brain stimulation for PD. With the patient positioned within a standard Leksell type G stereotactic frame localizer, rapidly acquired scout images are used to prescribe volumes of contiguous high-resolution T2-weighted fast spin-echo images in the axial, sagittal, and coronal planes through the midbrain and basal ganglia. The STN is identified in all 3 planes by cross-referencing in a 3-plane viewer. These coordinates are used for surgical targeting. RESULTS: At 3T, the STN was visualized as a small, hypointense, almond-shaped structure in 3 planes located immediately lateral to the anterior edge of the red nucleus, medial to the internal capsule, about 5 mm inferior, 1-2 mm posterior, and 9-12 mm lateral to the midcommissural point. Intraoperative microelectrode recordings confirmed these coordinates in all cases from the first microelectrode pass, thereby eliminating prolonged intraoperative electrophysiological STN searching and tissue disruption that may occur from multiple passes. CONCLUSION: 3T MR imaging appears to be an excellent tool for reliable and accurate direct visualization of the human STN, necessary for precise surgical targeting.

Spontaneous regression of a large lumbar disc herniation: report of an illustrative case.

A case of spontaneous regression of a large herniated disc at the lumbar level is presented. The disc regression correlated with clinical improvement and was documented on serial MRI studies. Although the phenomenon of spontaneous disappearance of decrease in size of herniated disc fragments is well known, the exact mechanism underlying this process remains unclear. This report discusses three possible explanations for disc regression: retraction into the intervertebral space, dehydration/shrinkage, and resorption due to inflammatory reaction.

On the natural history of trigeminal neuralgia.

OBJECTIVE: Trigeminal neuralgia is usually considered a separate entity from atypical trigeminal neuralgia. The exact relationship among these two and several other syndromes of facial pain remains unknown. There is no long-term prospective study of the natural history of trigeminal neuralgia nor any explanation for the existence of different, albeit somewhat similar, facial pain syndromes. DESCRIPTION OF CONCEPT: On the basis of our clinical experience, we propose a theory that may explain different facial pain syndromes as sequential stages of the same disease process. Typical trigeminal neuralgia caused by microvascular compression of the trigeminal nerve root in the posterior fossa may become transformed over time into atypical trigeminal neuralgia, if left untreated. This transformation involves change in the character of pain and development of sensory impairment. Two representative cases are presented to support this theory. CONCLUSION: If the theory of progressive change in character of pain and degree of sensory impairment in the course of otherwise typical trigeminal neuralgia is correct, trigeminal neuralgia, atypical neuralgia, and trigeminal neuropathic pain may represent different degrees of injury to the trigeminal nerve, therefore comprising a continuous spectrum rather than discrete diagnoses.

Extensive arachnoid ossification with associated syringomyelia presenting as thoracic myelopathy. Case report and review of the literature.

The authors present the case of progressive thoracic myelopathy caused by the extensive ossification of the arachnoid membrane and associated intramedullary syrinx. Based on their findings and results of the literature search, they describe a pathological basis for this rare condition, discuss its incidence and symptomatology, and suggest a simple classification for various types of the arachnoid ossification. They also discuss the magnetic resonance imaging features of arachnoid ossification and associated spinal cord changes. The particular value of plain computerized tomography, which is highly sensitive in revealing intraspinal calcifications and ossifications, in the diagnostic evaluation of patients with a clinical picture of progressive myelopathy is emphasized.

Stereotactic ventral intermedial thalamotomy for the treatment of essential tremor: results of a series of 37 patients.

We have analyzed 43 ventral intermediate thalamotomies performed in our center for treatment of medically intractable essential tremor (ET) in 37 patients. The mean age of patients was 70.9 years (range 42-84), duration of symptoms 33.3 years (1-65). The surgery in all cases was performed with stereotactic technique using MRI or CT localization. Intraoperative neurophysiological confirmation of the target location was obtained using a macrostimulation technique. All patients experienced either complete abolition of the contralateral tremor or significant improvement in tremor intensity immediately after the surgery. At follow-up examination 1-13 months after the operation, 60.5% of patients had no tremor, and 13.9% had mild residual tremor without interference with daily life. Tremor recurrence was observed in 5 patients, all of whom underwent repeat ventral intermedial (VIM) thalamotomy with excellent results. Transient problems with speech and motor functions were observed after 15 thalamotomies, permanent hemiparesis and speech difficulties were seen in 6 patients. We conclude that VIM thalamotomy is a highly effective procedure for medically intractable ET and may be performed with no mortality and low morbidity rate.

Comparison of three techniques for calculation of target coordinates in functional stereotactic procedures.

We compared three techniques of target coordinate determination for various functional stereotactic procedures. All procedures were based on preoperative MRI with contiguous 3-mm cuts. The first technique involved determination of anatomical landmarks and fiducial markers of the stereotactic frame on the monitor screen of an MRI scanner and calculation of the target point using a series of formulas; the second technique used a Leksell tabletop localizer, and the third technique is a part of 'Stealth' stereotactic navigation software. Final coordinates for the procedure were derived from all three techniques and subsequently adjusted using intraoperative electrical macrostimulation. We found that difference between techniques was on average 0.9 +/- 0.4 mm in each of three directions, and 1.8 +/- 0.9 mm in absolute distance. There were 7 cases in which one of the techniques had a discrepancy of more than 3 mm (more than 1 MRI slice thickness) compared with the other two, indicating a potential error in coordinate determination. This difference could potentially result in inappropriate placement of the electrode, thus affecting the procedure outcome. In 6 cases, such an error apparently occurred with the first or second technique of calculation. The average number of mapping trajectories decreased from 1.8 to 1.4 since this stereotactic software became a part of operative planning. We conclude that use of computerized planning software increases the precision of target coordinate calculation and improves the accuracy of functional stereotactic procedures.

Efficacy of transverse tripolar stimulation for relief of chronic low back pain: results of a single center.

The goal of this study was to evaluate the efficacy of the transverse tripolar spinal cord stimulation system (TTS) in providing relief of low back pain in patients with chronic non-malignant pain. Transverse tripolar electrodes were implanted in the lower thoracic region (T(8-9) to T(12)-L(1)) in 10 patients with chronic neuropathic pain, all of whom reported a significant component of low back pain in combination with unilateral or bilateral leg pain. One patient reported inadequate pain relief during the trial and was not implanted with a permanent generator. A visual analogue scale of low back pain showed a nonsignificant decrease from 64 +/- 19 to 47 +/- 30 (p = 0.25; paired t test) after 1 month of stimulation. Similarly, functional disability evaluated using Oswestry Low Back Pain Questionnaire was not improved (p = 0. 46; paired t test). We conclude that chronic low back pain is not particularly responsive to the transverse stimulation provided by the TTS system.

Changes in cerebral oxygen saturation with change in posture: a preliminary report.

BACKGROUND: Disease of the major vessels in the neck can disrupt autoregulation and lead to changes in the cerebral blood flow and cerebral autoregulation. These changes can be reflected by means of cerebral oxygen saturation. METHODS: We measured cerebral oxygen saturation in 20 patients with atherosclerotic disease of the carotid and vertebral arteries and compared results with 10 normal subjects. Saturation was measured using a noninvasive near-infrared device, the transcranial cerebral oximeter. RESULTS: There were marked decreases in cerebral oxygen saturation in patients with carotid-vertebral artery disease when the position of the patient was changed, from supine to erect. CONCLUSION: Changes in regional cerebral oxygen saturation inpatients with carotid-vertebral artery disease may reflect disruption of cerebral autoregulation.

Magnetic characteristics of Yasargil aneurysm clips.

BACKGROUND: Metallic bioimplants are subject to great scrutiny in order to ensure that they are totally harmless to patients. Aneurysm clips are no exception to this rule. Considering the number of aneurysm clips used and their potential for injury, they should be evaluated very meticulously. Determining the magnetic characteristics of these clips is an important part of the evaluation process. In this study, a new method for evaluating magnetism is described and the importance of that information is briefly discussed. METHODS: Twenty Yasargil aneurysm clips were analyzed using a vibrating sample magnetometer under 1.5 Tesla. This device is highly sensitive, and is capable of measuring the magnetism of small objects. RESULTS: Our measurements showed magnetism of the aneurysm clips ranged from 0.0334-0.1369 electromagnetic units (emu). CONCLUSIONS: Magnetometer measurements and real life tests under magnetic resonance imaging (MRI) have shown that these clips have a very low magnetism and are safe to use in 1.5 Tesla MRI scanners. This study also proves that the vibrating sample magnetometer is a useful device for analyzing the magnetism of aneurysm clips, and their emu values can be used as another industry standard in the production line to increase the safety of these clips.