Biomedical subjects

F Andrew Kozel

Publications and source records attributed to F Andrew Kozel.

4 recordsLinked to original sources

PubMed2003

Transcranial magnetic stimulation.

TMS is a powerful new tool with extremely interesting research and therapeutic potentials. Further understanding of the ways by which TMS changes neuronal function, especially as a function of its use parameters, will improve its ability to answer neuroscience questions as well as to treat diseases. Because of its noninvasiveness, it does not readily fit under the umbrella of neurosurgery. Nevertheless, it is important for neurosurgeons to be aware of TMS, because findings from TMS studies will have implications for neurosurgical approaches like DBS and VNS. Indeed, it is possible to think of using TMS as a potential noninvasive initial screening tool to identify whether perturbation of a circuit has short-term clinical effects. In the example of chronic refractory depression or OCD, which is generally a chronic illness, it might then follow that rather than having daily or weekly TMS for the rest of their lives, patients would have DBS electrodes implanted in the same circuit. Whatever road the future takes, TMS is an important new tool that will likely be of interest to neurosurgeons over the next 20 years and perhaps even longer.

Brain↗

PubMed2003

Left prefrontal transcranial magnetic stimulation (TMS) treatment of depression in bipolar affective disorder: a pilot study of acute safety and efficacy.

OBJECTIVES: Repetitive transcranial magnetic stimulation (rTMS) has been shown to improve depressive symptoms. We designed and carried out the following left prefrontal rTMS study to determine the safety, feasibility, and potential efficacy of using TMS to treat the depressive symptoms of bipolar affective disorder (BPAD). METHODS: We recruited and enrolled 23 depressed BPAD patients (12 BPI depressed state, nine BPII depressed state, two BPI mixed state). Patients were randomly assigned to receive either daily left prefrontal rTMS (5 Hz, 110% motor threshold, 8 sec on, 22 sec off, over 20 min) or placebo each weekday morning for 2 weeks. Motor threshold and subjective rating scales were obtained daily, and blinded Hamilton Rating Scale for Depression (HRSD) and Young Mania Rating Scales (YMRS) were obtained weekly. RESULTS: Stimulation was well tolerated with no significant adverse events and with no induction of mania. We failed to find a statistically significant difference between the two groups in the number of antidepressant responders (>50% decline in HRSD or HRSD <10 - 4 active and 4 sham) or the mean HRSD change from baseline over the 2 weeks (t = -0.22, p = 0.83). Active rTMS, compared with sham rTMS, produced a trend but not statistically significant greater improvement in daily subjective mood ratings post-treatment (t = 1.58, p = 0.13). The motor threshold did not significantly change after 2 weeks of active treatment (t = 1.11, p = 0.28). CONCLUSIONS: Daily left prefrontal rTMS appears safe in depressed BPAD subjects, and the risk of inducing mania in BPAD subjects on medications is small. We failed to find statistically significant TMS clinical antidepressant effects greater than sham. Further studies are needed to fully investigate the potential role, if any, of TMS in BPAD depression.

Adult↗

PubMed2002

Novel treatments of mood disorders based on brain circuitry (ECT, MST, TMS, VNS, DBS).

Advances in understanding the functional and structural anatomy of depression outlined in this issue set the stage for attempting to manipulate implicated brain regions as potential antidepressant therapies. On the one hand, these circuit- and device-based approaches to treating depression are not new. Electroconvulsive therapy (ECT) dates back to the beginning of modern biologic psychiatry with the discovery and rapid increase of first chemical (around 1910), and then later ECT. On the other hand, this area represents an important paradigm shift with treatments that are radical and different. A dizzying array of diverse technologies now allows researchers to stimulate the brain in undreamed of ways. However, the approaches described in this article are still considered experimental and are not approved for use in the United States by the Food and Drug Administration (FDA), except ECT, which predates the FDA. These device-based approaches to brain stimulation offer promise as potential acute and even longterm treatments. Additionally, the research determining whether and how these devices work to influence mood promises to help unravel the neurophysiology of mood regulation. These novel treatments are thus the translational tools to bridge from advances in brain imaging, into new treatments for depressed patients.

Brain↗

PubMed2002

Mechanisms and state of the art of transcranial magnetic stimulation.

In 1985, Barker et al. built a transcranial magnetic stimulation (TMS) device with enough power to stimulate dorsal roots in the spine. They quickly realized that this machine could likely also noninvasively stimulate the superficial cortex in humans. They waited a while before using their device over a human head, fearing that the TMS pulse might magnetically "erase the hard-drive" of the human brain. Almost 10 years later, in 1994, an editorial in this journal concerned whether TMS might evolve into a potential antidepressant treatment. In the intervening years, there has been an explosion of basic and clinical research with and about TMS. Studies are now uncovering the mechanisms by which TMS affects the brain. It does not "erase the hard-drive" of the brain, and it has many demonstrated research and clinical uses. This article reviews the major recent advances with this interesting noninvasive technique for stimulating the brain, critically reviewing the data on whether TMS has anticonvulsant effects or modulates cortical-limbic loops.

Animals↗