Thinking Differently
L. Syd M Johnson, Karen S. Rommelfanger in The Routledge Handbook of Neuroethics, 2017
But how, exactly, might neural engineering alter our thinking? Some implantable devices aim to regulate areas of the brain that operate atypically (to be a “pacemaker” for the brain). A deep brain stimulator (DBS), for instance, involves electrodes implanted in relatively deep regions of the brain and set to deliver stimulation at a steady pace or in regular intervals. DBS has proven effective for treating tremors associated with Parkinson’s disease and essential tremors. Trials of DBS for movement disorders have in rare instances resulted in unusual side effects, such as increased impulsivity, gambling, and personality changes (Wang et al., 2016; Rossi, Gunduz, and Okun, 2015; Lipsman and Glannon, 2013; Parsons et al., 2006), but also sometimes had unintended beneficial effects, such as enhancing mood or control. Perhaps as a result, DBS is now also being tested for conditions such as OCD, Tourette syndrome, depression, epilepsy, and anorexia. Neural engineers are still not certain of the mechanism by which the stimulation achieves the desired effect, and some treat it as a relatively blunt tool for treatment, but that hasn’t dampened the optimism and the attention it receives as a new mode of treating conditions that have so far been relatively resistant to more traditional treatments.
Neurosurgery
Brian J Pollard, Gareth Kitchen in Handbook of Clinical Anaesthesia, 2017
Stereotatic neurosurgery is used to facilitate precise localisation of intracranial lesions. CT, MRI or digital angiography is used to image the brain and provide a three-dimensional reference to accurately define the lesion. The initial step is to apply the extracranial stereotactic frame which attaches to the head under GA or a scalp block and sedation; this then acts as the reference point for localisation. This method is still utilised for the insertion of deep brain stimulators (DBS) for movement disorders and Parkinson’s, epilepsy and when treating deep brain lesions closely associated with important functional centres. More recently frameless technology has developed using small adhesive reference markers (fiducials) that are attached to the patient’s scalp while awake, giving better surgical and anaesthetic access but slightly less precision. Many surgical procedures including tumour excision that utilised frames in the past are now excised reliably with image guided technology such as Brain Lab®.
Objections to the Russo–Williamson Thesis
Donald Gillies in Causality, Probability, and Medicine, 2019
I will now consider, as promised earlier, Howick’s list of counter-examples to the Russo–Williamson thesis (RWT). Howick begins his critical discussion of the RWT in 2011a, p. 130. On p. 131, he mentions the Semmelweis case, and then goes on (2011a, pp. 131–2) to give his full list of statistical counter-examples to the RWT as follows: there are many … examples where treatments were widely accepted before any semblance of a mechanism was established. To name a few, Percival Pott’s hypothesis that soot caused scrotum cancer (1775) was accepted years before benzpyrene was identified (1933). Edward Jenner introduced smallpox vaccines (1798) decades before anyone really understood how they worked. John Snow helped eliminate cholera with cleaner water (1849) years before the Vibrio cholerae was identified (1893), and Carlos Finlay reduced the rates of yellow fever by killing mosquitoes (1881) decades before flavivirus was identified (1927). In the last century, general anaesthesia, aspirin, and the steroids were widely used for decades before their mechanisms were understood. In this century, deep brain stimulation has been used to suppress tremors in patients with advanced Parkinson’s disease, and also to cure other motor function disorders such as dystonia or Tourette’s syndrome, yet researchers have not been able to identify its mechanism of action with any certainty.
Healthcare-associated ventriculitis: current and emerging diagnostic and treatment strategies
Published in Expert Review of Anti-infective Therapy, 2021
Intrathecal infusion pumps are currently used in the therapy of spasticity with baclofen or to treat pain with opiates [22–24]. The catheter of the pump is inserted intrathecally in the lumbar region. The rate of infections varies by the location of the infusion pump: 3.6% rate if it is placed underneath the fascia but up to 20% in those pumps placed subcutaneously [21]. The most common of infectious complications are post-operative wound infections with a minority of patients developing meningitis [21–24]. Deep brain stimulators can be used to treat Parkinson’s disease, intractable seizures, essential tremor, dystonia, and obsessive-compulsive disorder [25,26]. The deep brain stimulator has three components: a generator that is placed in the infra-articular area, a connector, and an intracranial lead [25]. All three components can become infected with an incidence rate that varies from 0% to 15% [2]. Two recent studies show an incidence rate of infectious complications to be 5–6% with half of them developing in the 30 days post-implantation [25,26]. The most common pathogens are staphylococci with the majority of patients requiring partial or complete removal of the device for cure. Removal of intrathecal infusion pump or deep brain stimulator with re-implantation of the device once repeats a negative CSF culture is recommended [1,2]. Intracranial pressure transducers are commonly used to monitor intracranial pressures and are universally colonized with bacteria with biofilm but are unlikely recognized as a cause of HCAVM [27].
Mapping the Dimensions of Agency
Published in AJOB Neuroscience, 2021
Andreas Schönau, Ishan Dasgupta, Timothy Brown, Erika Versalovic, Eran Klein, Sara Goering
Most end users of neural technologies are active agents who seek to express themselves—their feelings, emotions, thoughts, and desires—through goal-directed actions. Often, a neural device enables end users to regain abilities lost due to a disease or an injury. A person with Parkinson’s disease, for example, may benefit from a deep brain stimulator (DBS) that alleviates tremor and rigidity, and thus restores the ability to fluently perform movements. A person living with spinal cord injury may benefit from a brain computer interface (BCI) to control a robotic arm, or even to regain a lost sensation of touch. A person with amyotrophic lateral sclerosis (ALS) may use a BCI to communicate with loved ones through the translation of thought to computer-generated speech. A depressed person may use a DBS to improve mood, in the hope of regaining a brighter, more authentic self.
Patients’ Beliefs About Deep Brain Stimulation for Treatment-Resistant Depression
Published in AJOB Neuroscience, 2018
Ryan E. Lawrence, Catharine R. Kaufmann, Ravi B. DeSilva, Paul S. Appelbaum
Participants were also concerned about adverse events. Many of their concerns were related to the surgery itself (e.g., bleeding, infection, brain damage, death). The literature actually suggests that adverse events rates associated with the surgery are low. One review (n = 123 surgeries, most were for Parkinson’s disease) reported no mortality or persistent morbidity from the surgical procedure, and all serious adverse events that occurred within 4 weeks of surgery were reversible (Buhmann et al. 2017). However, in this study long-term adverse events were common: 106 of 123 patients had 433 adverse events (mean follow up 4.7 years, 578 patient-years) (Buhmann et al. 2017). In the depression literature, Holtzheimer et al. reported that 28 of 90 deep brain stimulator recipients had 40 serious adverse events during 12-month follow up (Holtzheimer et al. 2017). Notably, this literature is reporting all adverse events, whether or not they were directly caused by the deep brain stimulator; however, this does suggest a substantial long-term risk of adverse events. Our data suggest that persons weighing the risks and benefits of deep brain stimulation may need to be taught to look beyond the surgical risks, and to consider the long-term risk of adverse events.
Related Knowledge Centers
- Neurosurgery
- Neurostimulation
- Brain
- Nucleus
- Parkinson's Disease
- Essential Tremor
- Dystonia
- Obsessive–Compulsive Disorder
- Epilepsy
- Chronic Pain