A Burgeoning Brand of Brain Surgery with Legal Significance

By: Neil Issar, Vanderbilt Law School-

The FDA is authorized to provide access to novel and experimental therapies for patients who suffer from rare or unusual conditions via a number of processes, one of which is the humanitarian device exemption (HDE). The HDE allows manufacturers to market a device without subjecting it to the typical tests of effectiveness. Deep brain stimulation (DBS) for various neuropsychiatric disorders is one area of medicine that is frequently granted HDEs. However, the use of brain devices to treat incompletely-understood disorders without stringent patient oversight can have many ethical and legal implications. Yet, DBS is an area of surgical medicine about which legal professionals often know little, consequently warranting examination.

Procedure

DBS is a neurosurgical intervention primarily used to treat movement disorders such as Parkinson’s disease (PD), tremor, and dystonia. It involves inserting microelectrodes into specific brain regions to modulate neural activity via a battery-controlled external stimulator in the patient’s thorax. DBS is also being tested in intractable psychiatric conditions such as Tourette’s syndrome, depression, and obsessive-compulsive disorder. Moreover, with studies having shown that DBS of a region called the nucleus accumbens (NAc) decreases alcohol intake in alcohol-preferring rats, and reports of alcohol consumption and craving having been reduced in a few long-term patients using NAc DBS, drug addiction has been proposed as another area in which to more extensively test DBS.

 Advantages

Older surgical approaches to movement disorders involved physical destruction of brain tissue and were therefore irreversible. In contrast, DBS allows neurosurgeons to control the abnormal activity of brain cells near the stimulating electrode without destroying tissue. In addition, the stimulator can be adjusted or turned off, allowing for greater flexibility in the treatment of neurological conditions. In general, it is believed that DBS is superior to and safer than previous surgical techniques, and the procedure has produced positive results in patient populations that had not previously responded to psychotherapy, pharmacotherapy, or electroconvulsive therapy.

Risks

While the benefits of DBS are notable, there are significant surgical and non-surgical risks. A 2006 review analyzing the results and complications of 37 DBS cohorts from 1993 to 2004 found the most common serious surgical complication to be intracranial bleeding in 3.9% of patients, though many cohorts reported no complications. Minor side effects included dysarthria, disequilibrium, and dysphagia, while other serious side effects included infection and transient postoperative hemiparesis. There have also been reports of increased suicide rates, postoperative euphoria and/or hypomanic states, and other psychiatric side effects.

Of course, DBS as a treatment is being refined at an exponential pace. However, many are worried that weak evidence bases are still being used to assess the long-term safety and efficacy of DBS, particularly to treat psychiatric disorders. Concerns are also fueled by reports of device recalls and inadequate complaint procedures, which inevitably enmesh lawyers and regulators alike.

Ethical and Legal Issues

As DBS is a relatively novel treatment for many disorders, lawyers, healthcare agencies, and medical organizations must be wary of selective reporting in publications and an uncritically positive portrayal by the media. Public events about DBS run the risk of exclusively conveying treatment benefits by presenting patients with large motor and quality-of-life improvements trumpeting treatment success and the lack of complications. Many of the aforementioned risks are rarely reported in a similarly demonstrative way, potentially resulting in their dismissal or omission by the public.

A registry of all individual DBS patient trials to minimize selective publication of positive outcomes is becoming paramount. Fortunately, a large step in the right direction has been taken with the advent of the National Neurosurgery Quality and Outcomes Database, the first nationwide effort to collect data on safety, quality, and cost-effectiveness in the field of neurosurgery.

In addition, the justification for an invasive neurosurgical procedure to treat psychiatric disorders and addiction is not as clear-cut as movement disorders. Unlike PD, for example, the course of addiction is not inexorably one of deterioration towards severe disability, dementia, and death. Combined with the limited preclinical data on DBS treatment of addiction and psychiatric disorders, many would argue that there is insufficient evidence to justify clinical trials, increasing the chances of litigation. This apprehension is exacerbated by researchers and physicians obtaining HDEs for DBS treatment of an increasingly wider range of disorders.

Finally, as DBS is being used in patients with severe neurological and neuropsychiatric disorders, a critical legal question is whether these patients are able to effectively consent to treatment and how to assess this capacity in individual cases. The very cognitive state that patients are trying to ameliorate with DBS may prevent them from being able to consent to it. And given some of the psychiatric side effects discussed above, unexpected consequences of DBS itself may diminish a patient’s capacity to consent to continuing or ending stimulation.

Conclusion

Despite extensive clinical use, the underlying physiology and mechanism of DBS are still debated. Continued preclinical investigation is needed before the potential to optimize stimulation parameters can be realized. In addition, further technological research is needed to improve patient management (e.g. frameless stereotactic technology, smaller pulse generators, remote programming, rechargeable batteries etc.), and this will inevitably involve a collaborative effort between healthcare practitioners, health lawyers, and medical device manufacturers. However, clinical results have been promising for a number of disorders. A continued emphasis on ethico-legal considerations and a focus on decreasing surgical risks and complications are vital to ensure the future of DBS treatment remains bright.

Neil Issar resides in Nashville, Tennessee, and is a student at the Vanderbilt School of Law. He is expected to graduate in the summer of 2016. He attended McGill University prior to law school, earning a B.Sc in 2010. He is a Vanderbilt Law School Chancellor’s Scholar and Deans Scholar.

The final winning post from the Winter 2013 Law School Legal Scholar program will be posted on Friday, January 24th.