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Biomedical subjects

G S Brindley

Publications and source records attributed to G S Brindley.

At least 19 recordsLinked to original sources
PubMed1994

Implant provision of key, pinch and power grips in a C6 tetraplegic.

An 11-channel multiplexed stimulator of nerves and muscles in the left forearm was implanted for hand control in January 1986 in a 21 year old woman who, after sustaining a C6 spinal lesion 7 years earlier, had voluntary shoulder and elbow movement but paralysed hands, trunk and legs. The patient controls the stimulation via a microcomputer control box and an RF transdermal link. We have investigated the control of her stimulated hand with a joystick under her contralateral hand which she moves from the shoulder and elbow. Since 1986, we have tried a variety of joystick control schemes involving power and key grips. Currently, for grip adjustment, forward and backward joystick movements correspond to thumb extension and abduction, respectively giving in addition both finger and wrist extension, whereas right and left joystick movements yield fist closure and thumb opposition/adduction and flexion, respectively. Useful grasps are available by moving the joystick forward and then left (key grip), by moving the joystick backward and left (pinch grip), or by moving the joystick back and right (power grip). Thus, three distinct grips may be selected using these three quadrants of joystick movement. An additional control mode was found to be desirable to augment the patient's limited voluntary wrist positioning and provide wrist stability while adjusting finger grip.

Adult↗
PubMed1994

Bladder pressure sensors in an animal model.

Urinary incontinence due to detrusor hyperreflexia might be inhibited on demand if changes in bladder pressure could be detected by sensors and transferred into pudendal nerve electrostimulation. The aim of this study is to investigate how the bladder wall reacts on different sensor implants. Sensors were implanted in twelve goats. In group 1 (n = 8) real sensors were placed on the peritoneal surface of the bladder dome, between the peritoneum and the muscular layer, and between the cervix and bladder. In group 2 (n = 4), dummy sensors were placed between the mucosal and muscular layers. During follow-up as long as 25 months, urodynamic studies, radiographic control and urine cultures were done. In group 1, sensors placed between the peritoneum and muscular layer gave the best results. In group 2, 11 of the 12 sensors eroded. The authors conclude that implantation of sensors in the bladder wall is feasible.

Animals↗
PubMed1991

A case of ocular tilt reaction and torsional nystagmus due to direct stimulation of the midbrain in man.

A case is presented of a patient who underwent insertion of a periaqueductal grey electrode for the relief of chronic pain. Shortly after insertion, the patient developed a left-sided ocular tilt reaction (OTR). The electrode tip, initially to the right of the midline, was then withdrawn slightly so that it was now on the left side. Stimulation at this point gave rise to a worsening of the tilt reaction, in addition to bilateral counter-clockwise torsional nystagmus. Computerized tomography and stereotactic coordinates indicated that the tip of the electrode was finally situated in the region of the left interstitial nucleus of Cajal (INC). The production of an OTR by stimulation in this region is similar to the phenomenon previously reported in monkeys and cats. The side of the OTR is consistent with previous evidence, suggesting that the utricular pathways cross between medulla and midbrain.

Electric Stimulation↗
PubMed1990

Treatment of urinary and faecal incontinence by surgically implanted devices.

Three kinds of implant to treat incontinence are considered. The sacral anterior root stimulator (with sacral posterior rhizotomy) is already effective in urinary incontinence due to spinal cord injury, and will have wider application. The conditional pudendal nerve stimulator and the conditional gracilis nerve stimulator are, respectively, almost untried and entirely untried devices; but they show promise, and if successful may help very many patients.

Colorectal Surgery↗
PubMed1990

Long-term follow-up of patients with sacral anterior root stimulator implants.

The first 50 patients to receive a sacral anterior root stimulator for bladder control were reviewed by questionnaire in mid-1989. At that time, the follow-up period varied from 5 to 11 years, and 48 of the group were alive; 2 had died from unrelated causes. Forty-one used their implants regularly for micturition and of these, 37 were always or usually continent. Twenty-nine reported no symptomatic urinary infections in the previous year, and only 4 had 3 infections or more. Twenty-seven used their implant to assist defaecation, and 13 of 32 male users reported full implant-driven erections. Side effects are minor, except for stimulus evoked pain sensation, which prevents use of the implant in 3 of the 7 non-users. Two of the other non-users were awaiting repair of their implant faults.

Defecation↗
PubMed1990

Extradural implantation of sacral anterior root stimulators.

A technique for extradural deafferentation of the S2 to S5 segments and extradural implantation of stimulating electrodes is described, and its application to twelve patients with spinal cord lesions is reported. Nine patients use their implants for micturition, and seven are fully continent. The advantages and disadvantages of this technique compared with the more usual intrathecal procedure are discussed.

Adult↗
PubMed1989

Hypogastric plexus stimulators for obtaining semen from paraplegic men.

Radio-linked devices to stimulate the hypogastric plexus have been implanted into 7 patients with spinal injuries and 1 with primary anorgasmia. They caused seminal emission in all patients and still do so in the spinal injury patients. Insemination with semen thus obtained has yielded 5 pregnancies (2 live births) in the wives of 4 patients. The range of application is discussed.

Adult↗
PubMed1989

Implant infections and antibiotic-impregnated silicone rubber coating.

A method is described for coating silicone rubber-encapsulated implant devices with an outer layer of silicone rubber impregnated with a mixture of gentamicin sulphate and diethanolamine fusidate. A coating of this sort provides bactericidal activity lasting for a few days in the film of fluid surrounding such an implant. When used for coating our implants, the retrospective rate of implant infections believed to have been introduced at the time of surgery was reduced to 0.7% (coated), compared with 10.0% (uncoated), a highly significant difference (p less than 0.001). Systemic perioperative antibiotic prophylaxis was not shown to confer any such benefit.

Escherichia coli Infections↗