Accessibility and Ease of Use in Neuromodulation Devices

BACKGROUND

The utilization of neuromodulation therapy continues to grow as therapeutic indications expand. These conditions often present with comorbid physical, visual, and auditory impairments. Patients with disabilities in these categories may have difficulty operating their devices. Thus, reviewing the accessibility and inclusive design of neuromodulation devices is imperative to ensure equal access for patients of all ability levels. To date, the literature provides little insight into this topic.

MATERIALS AND METHODS

Manufacturers of Food and Drug Administration-approved neuromodulation devices in the United States completed our electronic survey to assess neuromodulation device features, universal/inclusive design guidelines, and methods used to make the device accessible to patients with disabilities.

RESULTS

We assessed 11 devices from seven manufacturers. Of those, there were six spinal cord, two peripheral nerve, and three deep brain stimulators. Of all respondents, 91% used universal inclusive design guidelines. Of the studied devices, 91% have an interface that uses visual feedback, and 82% have an interface that uses auditory feedback. All surveyed devices were reported to have an interface that requires physical handling.

DISCUSSION

Our study found that most devices incorporate auditory signals, buttons with raised indentations, speech commands, or other useful features to assist those with visual disabilities. Visual interfaces may be sufficient for a patient with hearing impairment to use all the surveyed devices. However, dual sensory impairment presents a significant limitation in all devices surveyed. Furthermore, the biggest barrier to using neuromodulation devices was physical impairment because all surveyed devices require physical handling.

CONCLUSIONS

Manufacturers have awareness of universal inclusive design principles. However, our study was unable to find a device that is accessible to all users regardless of ability. As such, it is critical to involve universal design principles to ensure that inclusive devices are available to improve patient adherence, treatment efficacy, and outcomes.

Cervical Spinal Cord Stimulation: A Review

PURPOSE OF REVIEW

This literature review critically examines existing studies on cervical spinal cord stimulation (cSCS) for the treatment of chronic pain. The objective is to evaluate the current evidence, identify knowledge gaps, and collate data to inform clinical decision-making and suggest future research avenues. The review covers indications, contraindications, surgical and anesthetic approaches, trials, efficacy, and complications of cSCS.

RECENT FINDINGS

Recent advancements highlight the evolving role of cSCS in chronic pain management. New neuromodulation techniques involve optimal placement of leads based on the pain's innervation level, maximizing therapeutic outcomes. Contemporary studies underscore the broadening benefits of cSCS, including enhanced functional abilities and sleep quality. However, alongside these innovations come challenges; emerging data bring attention to complications such as hardware issues and infections. Significantly, modern research emphasizes the crucial role of accurate patient selection, factoring in prior therapy responses and comprehensive evaluations. cSCS emerges as a promising tool for chronic pain management, with benefits beyond mere pain relief. As surgical techniques, patient selection criteria, and postoperative care refine, the potential of cSCS expands to benefit a broader patient demographic. However, further comprehensive research is necessary to enhance its application, validate its role earlier in treatment, and ultimately ameliorate the lives of those with chronic pain.

Isolation and characterization of human gingival microvascular endothelial cells

BACKGROUND AND OBJECTIVE

Endothelial cells have a substantial role in maintaining vascular homeostasis, and their dysregulation can contribute to the development of pathology. The plasminogen activators and their inhibitors may, arguably, be the single most important proteolytic system of the endothelium for vascular maintenance by controlling plasminogen activation and other proteolytic cascades that impact on clotting, hemodynamics, angiogenesis and the character of the vascular wall. In chronic periodontal disease, significant changes to the microvasculature occur in association with the severity of the disease. Investigation of the role played by endothelial cells in periodontal health and disease has been limited to in situ immunolocalization or to the use of endothelial cells of nongingival origin, such as human umbilical vein endothelial cells. The objective of this research was to establish a replicable protocol for isolating microvascular endothelial cells from the gingiva.

MATERIAL AND METHODS

From inflamed gingiva, isolated cells were characterized by morphology, the expression of factor VIII-related antigen, the expression of UEA-1 ligand, the uptake of acetylated low-density lipoprotein, network formation on Matrigel, and by the expression levels of urokinase plasminogen activator, tissue plasminogen activator, plasminogen activator inhibitor-1 and collagen IV.

RESULTS AND CONCLUSION

Gingival endothelial cells were most readily obtained from inflamed gingival tissues, and these endothelial cells, when isolated by the protocol established herein, demonstrated endothelial characteristics and constitutively secreted plasminogen activators and plasminogen activator inhibitor-1 in culture.

S-adenosylhomocysteine hydrolase deficiency in a 26-year-old man

This paper reports the third proven human case of deficient S-adenosylhomocysteine (AdoHcy) hydrolase activity. The patient is similar to the only two previously reported cases with this disorder in having severe myopathy, developmental delay, elevated serum creatine kinase (CK) concentrations, and hypermethioninaemia. Although he has been followed from infancy, the basic enzyme deficiency was established only at age 26 years. The diagnosis was based on markedly elevated plasma concentrations of both AdoHcy and S-adenosylmethionine, some 20% of the mean control activity of AdoHcy hydrolase activity in haemolysates of his red-blood cells, and two missense mutations in his gene encoding AdoHcy hydrolase. He had low values of erythrocyte phosphatidylcholine and plasma free choline and marginally elevated excretion of guanidinoacetate, suggesting that the elevated AdoHcy may have been inhibiting methylation of phosphatidylethanolamine and guanidinoacetate. His leukocyte DNA was globally more methylated than the DNA's of his parents or the mean extent of methylation measured in age-matched control subjects.

S-Adenosylhomocysteine hydrolase deficiency: a second patient, the younger brother of the index patient, and outcomes during therapy

S-Adenosylhomocysteine (AdoHcy) hydrolase deficiency has been proven in a human only once, in a recently described Croatian boy. Here we report the clinical course and biochemical abnormalities of the younger brother of this proband. This younger brother has the same two mutations in the gene encoding AdoHcy hydrolase, and has been monitored since birth. We report, as well, outcomes during therapy for both patients. The information obtained suggests that the disease starts in utero and is characterized primarily by neuromuscular symptomatology (hypotonia, sluggishness, psychomotor delay, absent tendon reflexes, delayed myelination). The laboratory abnormalities are markedly increased creatine kinase and elevated aminotransferases, as well as specific amino acid aberrations that pinpoint the aetiology. The latter include, most importantly, markedly elevated plasma AdoHcy. Plasma S-adenosylmethionine (AdoMet) is also elevated, as is methionine (although the hypermethioninaemia may be absent or nonsignificant in the first weeks of life). The disease seems to be at least to some extent treatable, as shown by improved myelination and psychomotor development during dietary methionine restriction and supplementation with creatine and phosphatidylcholine.

Cognitive factors influence outcome following multidisciplinary chronic pain treatment: a replication and extension of a cross-lagged panel analysis

Reducing maladaptive cognitions is hypothesized to constitute an active therapeutic process in multidisciplinary pain programs featuring cognitive-behavioral interventions. A cross-lagged panel design was used to determine whether: a) early-treatment cognitive changes predicted late-treatment pain, interference, activity and mood changes, but not vice versa; b) three cognitive factors made unique contributions to outcome; c) substantial cognitive changes preceded substantial improvements in outcome. Sixty-five chronic pain patients, participating in a 4-week multidisciplinary program, completed measures of pain helplessness, catastrophizing, pain-related anxiety (process factors), pain severity, interference, activity level and depression (outcomes) at pre-, mid- and posttreatment. Results showed that early-treatment reductions in pain helplessness predicted late-treatment decreases in pain and interference, but not vice versa, and that early-treatment reductions in catastrophizing and pain-related anxiety predicted late-treatment improvements in pain severity, but not vice versa. Findings suggested that the three process factors predicted improvements mostly in common. However, little evidence was found that large early-treatment reductions in process variables preceded extensive improvements in pain. Findings replicate those of a recent report regarding cross-lagged effects, and offer support that cognitive changes may indeed influence late-treatment changes in outcomes.

Anxiolytic profile of GR 38032F in the potentiated startle paradigm

The potentiated startle paradigm has been demonstrated to be a model of anxiety sensitive to a range of established and putative anxiolytics. This study reports a preliminary investigation of the effects of the 5-HT(3) antagonist GR 38032F on potentiated startle. Doses of 0.01 and 0.1mg/kg each showed an anxiolytic profile in significantly reducing startle amplitude, with the lower dose having an effect comparable to chlordiazepoxide at 5.0mg/kg. 5-hydroxytryptophan at 25mg/kg significantly enhanced startle amplitude, and a mutual antagonism was found when 5-HTP was combined with GR 38032F. The results extend previous work with other models of anxiety suggesting anxiolytic potential for GR 38032F, and further demonstrate the possibility that the anxiolytic effect is mediated by serotonergic mechanisms.

Transvenous embolization of a dural arteriovenous fistula of the cavernous sinus through the contralateral pterygoid plexus

We report a new transvenous endovascular route for treatment of dural arteriovenous fistulas of the cavernous sinus. The cavernous sinus was approached from the contralateral pterygoid plexus and embolization of a dural fistula was performed successfully with Guglielmi detachable coils.

Assessment of intraaxial and extraaxial brain lesions with digitized computed tomographic images versus film: ROC analysis

RATIONALE AND OBJECTIVES

The authors evaluated the diagnostic accuracy of viewing computed tomographic (CT) scans as film versus soft-copy images at a workstation.

METHODS

Receiver operating characteristic analysis of the interpretation of 202 CT scans (103 were normal, 99 were abnormal) by five neuroradiologists was performed. Abnormal images contained high- or low-attenuation intraaxial lesions or extraaxial fluid (subdural, subarachnoid, or epidural hemorrhage). Hard copies were read on a standard light box, and digital images were examined at a 1,024 x 1,250 workstation. Lesion location and type and confidence ratings were recorded on a worksheet.

RESULTS

There were no statistically significant differences in diagnostic accuracy between the two display modes. Reader performance was slightly better with the workstation in the assessment of low-attenuation lesions.

CONCLUSION

Diagnostic accuracy is similar for CT scans displayed at a workstation and those displayed as hard copy in the assessment of subtle intra- and extraaxial brain lesions.

Eye-head coordination during large gaze shifts

1. Three-dimensional (3D) eye and head rotations were measured with the use of the magnetic search coil technique in six healthy human subjects as they made large gaze shifts. The aims of this study were 1) to see whether the kinematic rules that constrain eye and head orientations to two degrees of freedom between saccades also hold during movements; 2) to chart the curvature and looping in eye and head trajectories; and 3) to assess whether the timing and paths of eye and head movements are more compatible with a single gaze error command driving both movements, or with two different feedback loops. 2. Static orientations of the eye and head relative to space are known to resemble the distribution that would be generated by a Fick gimbal (a horizontal axis moving on a fixed vertical axis). We show that gaze point trajectories during eye-head gaze shifts fit the Fick gimbal pattern, with horizontal movements following straight "line of latitude" paths and vertical movements curving like lines of longitude. However, horizontal (and to a lesser extent vertical) movements showed direction-dependent looping, with rightward and leftward (and up and down) saccades tracing slightly different paths. Plots of facing direction (the analogue of gaze direction for the head) also showed the latitude/longitude pattern, without looping. In radial saccades, the gaze point initially moved more vertically than the target direction and then curved; head trajectories were straight. 3. The eye and head components of randomly sequenced gaze shifts were not time locked to one another. The head could start moving at any time from slightly before the eye until 200 ms after, and the standard deviation of this interval could be as large as 80 ms. The head continued moving for a long (up to 400 ms) and highly variable time after the gaze error had fallen to zero. For repeated saccades between the same targets, peak eye and head velocities were directly, but very weakly, correlated; fast eye movements could accompany slow head movements and vice versa. Peak head acceleration and deceleration were also very weakly correlated with eye velocity. Further, the head rotated about an essentially fixed axis, with a smooth bell-shaped velocity profile, whereas the axis of eye rotation relative to the head varied throughout the movement and the velocity profiles were more ragged. 4. Plots of 3D eye orientation revealed strong and consistent looping in eye trajectories relative to space.(ABSTRACT TRUNCATED AT 400 WORDS)

Imidazo[1,2-b]pyridazines. XV. Synthesis and Anxiolytic Activity of Some 3-(Benzamidomethyl and fluorobenzamidomethyl)-6-(fluoro, chloro and methylthio)-2-(4-tolyl and 3,4-methylenedioxyphenyl)imidazo[1,2-b]pyridazines

Syntheses are reported for some 3-( benzamido-and fluorobenzamido -methyl)-6-( fluoro , chloro and methylthio )-2(4-methyl-, 4-t-butyl-, 4-cyclohexyl- and 3,4-methylenedioxy-phenyl) imidazo-[1,2-b] pyridazines from the relevant 3-unsubstituted imidazo [1,2-b] pyridazines and the N-( hydroxymethyl ) benzamides. In tests of the ability of these compounds to displace [3H]diazepam from rat brain membrane, 3-(3- or 4-fluorobenzamidomethyl)-2-(3,4-methylenedioxyphenyl)-6-methylthioimidazo[1,2-b]- pyridazine bound most strongly, with IC50 2nM; but in behavioural tests in rats the most active compounds were 6-chloro(and methylthio )-3-(2-fluorobenzamidomethyl)-2-(3,4-methylenedioxyphenyl) imidazo [1,2-b] pyridazines which showed a significant anxiolytic activity at 2.5 mg/kg.

Violations of Listing's law after large eye and head gaze shifts

1. Kinematic constraints were examined in static eye and head positions after large gaze shifts to visual targets. Three-dimensional eye and head rotations were measured in six adult human subjects by the use of the magnetic field search coil technique. 2. Eye positions in space were found to obey Donder's law; i.e., for any given gaze direction there was a unique three-dimensional orientation. In other words, angular eye positions in space (expressed as quaternions) were constrained to a two-dimensional surface. 3. When only the eye moved (head stationary), the shape of this surface resembled a plane and thus the eye position in space obeyed Listing's law. However, after gaze shifts involving both the eye and the head, the eye in space surface became twisted and thus nonplanar. This twist was similar to that achieved by a Fick gimbal model of rotations in which the horizontal axis is nested within a fixed vertical axis. During oblique gaze shifts, the head made predominantly horizontal movements whereas the eye made predominantly vertical movements. This, combined with the fact that the eye is mounted within the head, causes the eye in space surface to resemble that of a Fick gimbal. 4. The angular position of the head in space was also constrained to a two-dimensional surface. This surface was also not planar (Listinglike) and twisted in a manner similar to that of the eye in space. 5. Whereas the angular position of the eye in head was found to obey Listing's law after head-fixed gaze shifts, violations of Listing's law occurred after head-free gaze shifts. These violations showed significant intersubject variation in their magnitude and character. 6. Given that the eye in space violates Listing's law after head movements, the supposition that Listing's law serves the perceptual purpose of maintaining radial constancy is untenable. The Fick gimballike behavior of the head in space and eye in space may hold several advantages over a Listing's system. When the head in space behaves like a Fick gimbal, a horizontal line through the eyes remains parallel to the horizon. By having the eye in space behave like a Fick gimbal, the work done against gravity may be minimized by having the eye contribute more to vertical gaze shifts than does the head.

Behavioural effects of selective tachykinin agonists in midbrain dopamine regions

The effects of selective NK-1, NK-2 and NK-3 tachykinin agonists in midbrain dopamine cell containing regions were investigated in the rat. The NK-3 agonist senktide induced locomotion, rearing and sniffing following infusion into the substantia nigra pars compacta, and to a lesser extent in the ventral tegmental area. These behavioural responses were not seen following infusion of the selective NK-1 agonist [Sar9,Met (O2)11]SP or the NK-2 agonist [N1e10]NKA4-10. In contrast, grooming was induced only by the NK-1 agonist administered into the substantia nigra. Yawning, chewing mouth movements and wet dog shakes were all seen following infusion of senktide into the ventral tegmental area. These findings suggest that (i) dopamine-mediated behavioural responses seen following tachykinin administration into the midbrain are dependent upon stimulation of NK-3 tachykinin receptors, (ii) tachykinin-induced grooming is mediated by stimulation of NK-1 receptors and (iii) some of the previously described 5-HT mediated behaviours seen following administration of NK-3 tachykinin agonists are probably generated by stimulation of 5-HT cell bodies in the ventral tegmental area.

Evidence that the amygdala is involved in benzodiazepine and serotonergic effects on punished responding but not on discrimination

Interactions between the benzodiazepines (BZs) chlordiazepoxide (CDP) and midazolam (MDZ), the BZ antagonist R0 15-1788, the inverse BZ receptor agonists CGS 8216 and FG 7142, gamma-aminobutyrate (GABA), serotonin (5-HT), the 5-HT2 antagonist methysergide and the putative 5-HT agonist 8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT) were investigated using peripheral and intra-amygdaloid treatments. A multiple schedule consisting of rewarded, nonrewarded (Time out: TO) and conflict periods was used to compare in parallel effects on successive discrimination between rewarded and nonrewarded periods and punished responding. The three components were presented in both a fixed order (Experiment 1) and a random order (Experiments 2 and 3). Intra-amygdaloid treatments with GABA and the BZs selectively increased rates of punished responding. CDP given systemically, on the other hand, increased both TO and conflict rates, suggesting an additional impairment of discrimination, which was more marked in the random than the fixed order condition. R0 15-1788, CGS 8216 and FG 7142 given by both routes counteracted the anti-conflict effects of CDP given centrally or systemically. However increases in TO rates induced by IP CDP were antagonized only by IP treatments with these compounds. The two inverse agonists, but not R0 15-1788, also counteracted increases in punished responding which were found after intra-amygdaloid GABA infusions. In Experiments 2 and 3 where baseline rates of pressing in Conflict periods were sufficiently high to detect decreases, CGS 8216 and FG 7142 reduced responding below control level, suggesting a specific anxiogenic activity. Evidence for effects of R0 15-1788 by itself was inconclusive. 5-HT injected into the amygdala also reduced punished responding below control level, whereas methysergide increased it with both central and peripheral treatment. Effects of 8-OH-DPAT varied according to route of administration. With IP treatment Conflict rates were increased, but after amygdaloid infusion both TO and Conflict rates were marginally reduced below control level, with a more consistent depression of punished responding. These results provide evidence that effects of BZs on punished responding are mediated by a GABAergic system which includes the lateral/basolateral amygdala, but which does not participate in BZ-induced disruption of discrimination. They also indicate that the antagonistic effects of CGS 8216 and FG 7142 involve a decrease in GABA transmission, and that these compounds may also be anxiogenic.(ABSTRACT TRUNCATED AT 400 WORDS)

Kinetics of single doses of fenbufen in patients with renal insufficiency

Fenbufen (gamma-oxo[1,1'-biphenyl]-4-butanoic acid) is a nonsteroidal anti-inflammatory analgesic that is metabolized to four major metabolites: gamma-hydroxy [1,1'-biphenyl]-4-butanoic acid (II), [1,1'-biphenyl]-4-acetic acid (III), 4'hydroxy [1,1'-biphenyl]-4-acetic acid (IV), and gamma, 4'-dihydroxy [1, 1'-biphenyl]-4-butanoic acid (V). Fenbufen and metabolites II and III circulate to plasma and are pharmacologically active; metabolites IV and V are normally excreted in urine. Single 800-mg doses of fenbufen were safely administered to 10 healthy subjects and to 16 patients with varying degrees of renal insufficiency. Drug and metabolite concentrations in serum and urine were determined at intervals for 3 days. It was found that renal impairment altered the metabolic pattern of fenbufen. Although t1/2 beta was the same for fenbufen and II, their plasma levels fell. No change was found in the plasma levels of III. There was evidence of moderate cumulation in plasma of the two more polar urinary metabolites (IV, V) corresponding to the degree of renal insufficiency. The total of all five compounds excreted into the urine was diminished. To account for this, either biliary and gastrointestinal excretion increased or there may have been further hepatic biotransformation of the metabolites.