6 Different Locations for Deep Brain Stimulation in Depression

The Dutch Psychiatrist Walter van den Broek runs under the pseudonym Dr. Shock MD, PhD an excellent weblog on peer reviewed data on neurostimulation. 

We would like to point out 2 great post on putative neuromodulation targets for depression:

• 6 Different Locations for Deep Brain Stimulation in Depression and
  
• Potential surgical targets for deep brain stimulation in treatment-resistant depression
  

Coating Improves Electrical Stimulation Therapy Used For Parkinson's, Depression, Chronic Pain

ScienceDaily (Sep. 18, 2008) — Researchers at UT Southwestern Medical Center have designed a way to improve electrical stimulation of nerves by outfitting electrodes with the latest in chemically engineered fashion: a coating of basic black, formed from carbon nanotubes.

The nanotube sheathing improves the signals received and transmitted by electrodes, which researchers say is a potentially critical step for advancing electrical nerve stimulation therapy. This type of therapy increasingly shows promise for diseases ranging from epilepsy to depression to chronic leg and back pain.
By implanting electronic nerve stimulators, doctors elsewhere have provided a quadriplegic patient with the ability to move a computer cursor at will, and monkeys have been able to move objects in a virtual world with mere mind power. For individuals who lose an arm or leg and rely on prosthetics, implanted stimulators offer promise in restoring feelings of sensation.

"The key to success for these types of brain-machine interfaces is where the electrode meets the nerve tissue," said Dr. Edward Keefer, instructor of plastic surgery at UT Southwestern and lead author of the study appearing in a recent issue of Nature Nanotechnology. "When we coat the electrodes with carbon nanotubes, it improves the stimulation of the nerve and the feedback from the sensors."

Depending on the way the nanotubes are fashioned, researchers were able to bolster either the stimulation or receptive capabilities to improve performance. In some tests, the nanotube coating improved performance by fortyfold, while in others it improved by a factor of as much as 1,600.

Nanotubes look like lattices rolled into a tube on a microscopic scale. Although they are 1/50,000 the width of a human hair, nanotubes are nonetheless among the stiffest and strongest fibers known, as well as excellent conductors of electricity.

Those properties proved to be just the attributes needed to help electrophysiologists conquer some of the hurdles facing them – issues such as battery power and chemical stability.

The carbon nanotube coating improves conductivity, which means less energy is needed to power the nerve stimulator. That can help reduce routine maintenance, such as the need to change batteries in implanted stimulation devices, as well as reduce tissue damage caused by the electrical charge.
"Our process is like taking a Ford Pinto, pouring on this chemical coating, and turning it into a Ferrari," Dr. Keefer said.

Researchers have tried several types of electrochemical coatings to see if they could improve conductivity, but the coatings often break down quickly or fail to stay affixed to the electrodes. The carbon nanotube coating shows far more promise, although further research is still needed, Dr. Keefer said.

"The development of new technologies by Dr. Keefer to potentially restore function in wounded tissues and future transplantations is exciting," said Dr. Spencer Brown, assistant professor of plastic surgery who heads research in the Nancy Lee and Perry R. Bass Advanced Plastic Surgery and Wound Healing Laboratory at UT Southwestern.

Other UT Southwestern researchers involved with the study include Dr. Barry Botterman, associate professor of cell biology, and Dr. Mario Romero-Ortega, assistant professor of plastic surgery. Researchers from Texas Scottish Rite Hospital for Children, Vanderbilt University and the University of North Texas also participated. The research was supported in part by Dallas-based Plexon, Inc

Adapted from materials provided by UT Southwestern Medical Center.

Functional Neurosurgery in the Treatment of severe Obsessive Compulsive Disorder and Major Depression

Functional Neurosurgery in the Treatment of severe Obsessive Compulsive Disorder and Major Depression: Overview of Disease Circuits and Therapeutic Targeting for the Clinician

An excellent review article by  Dhwani B. Shah, MD; Angeliki Pesiridou, MD; Gordon H. Baltuch, MD, PhD; Donald A. Malone, MD; and John P. O’Reardon, MD which you can access here.

Psychiatry (Edgemont) 2008;5(9):24–33

Brain pacemakers give jolt to hard-to-treat illnesses

Another DBS article in the Chicago Tribune.

Read it here.

Many illnesses may be in for a shock

An interesting article appeared today in the Chicago Tribune.

Read it here.

Transcranial Stimulation Improves Memory in Alzheimer's Disease

By Will Boggs, MD

NEW YORK (Reuters Health) Aug 22 - Transcranial direct current stimulation (tDCS) improves recognition in patients with Alzheimer disease, according to a report in the August 12th issue of Neurology.

"Our preliminary data on Alzheimer's disease patients are promising as we observed beneficial effects after a single tDCS session, suggesting that chronic daily application might induce even greater improvement," Dr. Alberto Priori from the University of Milan told Reuters Health. "Our studies encourage broader research programs using different stimulation protocols and longer clinical follow-up to clarify the impact therapy might have on patients' daily functional activities."

Dr. Priori and colleagues investigated whether anodal tDCS (which generally increases the function of the underlying areas of the cerebral cortex) applied over the temporoparietal cortex could improve recognition memory in 10 patients with Alzheimer's disease.

Anodal tDCS significantly improved word recognition memory accuracy, the authors report, whereas cathodal tDCS (which generally suppresses the function of the underlying cerebral cortex) significantly worsened it. Sham tDCS had no impact on memory.

The results were similar after correcting memory performance for guessing, the report indicates.

Neither anodal tDCS nor cathodal tDCS induced specific changes in the attention task, compared with sham tDCS, the researchers note.

"Interestingly," the investigators say, "the tDCS-induced improvement in the word recognition test we observed in patients with Alzheimer's disease is comparable to the 16% improvement induced by long-term pharmacologic treatment with cholinesterase inhibitors."

"We are assessing possible long-lasting effects of tDCS in Alzheimer's disease patients using repeated session protocols in a larger sample with longer clinical follow-up," Dr. Priori said.

"We believe that the best results, especially in Alzheimer's disease patients, could be obtained by combining tDCS with cognitive rehabilitation," Dr. Priori added.

Neurology 2008;71:493-498.

Acupuncture for Psychiatric Illness: A Literature Review

I guess this is brain stimulation also ...

Cortical stimulation for Depression

A rather interesting transcript of a conference call for investors of Northstar Neuroscience, Inc. (NSTR). A quotation from this transcript:

There's a great deal of attention and focus on devices with the potential to treat severe depression. And this area is widely considered to be one of the biggest future opportunities in medical technology. In particular, there is considerable scientific evidence to support neurostimulation as an effective treatment for this population. Electroconvulsive shock treatment is administered to over 100,000 patients annually, even though its effects can be transient and patients can experience significant side effects such as memory loss.

and another, (which I certainly do not agree with...)

Cortical stimulation is much less invasive than deep brain stimulation treatments currently being studied.

Read here.