1) Diapulse Electromagnetic Therapy

2) Oscillating Field Stimulation

3) Repetitive Transcranial Magnetic Stimulation

1) Diapulse electromagnetic therapy: Diapulse is a device that directs a pulsed-electromagnetic field (PEMF) to an area of injury. Animal and human studies indicate that this treatment soon after SCI protects neurons, promotes regeneration, and minimizes lost function. In addition, Diapulse greatly accelerates the healing of SCI-associated pressure sores.

Description: Diapulse directs electromagnetic energy to a specific body area via a cylindrical treatment head mounted on an adjustable bracket.  Because the device pulses its electromagnetic output, it emits energy for only a fraction of time, allowing any heat associated with the transferred energy to dissipate. Diapulse’s electromagnetic output is often pulsed at 600 pulses per second with each pulse lasting 65 microseconds (1 second = 1 million microseconds). Hence, this pulse rate corresponds to the device being off 25 times longer than it is on.

History: The Diapulse prototype was developed in the early 1930s by physician Abraham Ginsberg and physicist Arthur Milinowski, who reported their initial clinical experience and animal research with the device to the 1934 & 1940 New York Academy of Medicine. Because the technology behind the device was used to develop radar, the device’s emergence as a healing modality was delayed due to World War II security concerns. Research was resumed in the 1950s by the US military, which after extensive studies concluded that the device was safe and effective. About this time, the driving force behind Diapulse shifted from Ginsburg to Dr. Jesse Ross, a biophysicist who created the Diapulse Corporation of America (Great Neck, NY) and launched ambitious research with universities and clinicians around the world.

Diapulse Research

Numerous studies support Diapulse’s potential to treat neurologically associated problems and exert neuroprotective and -regenerative influences. After nervous-system injury, Diapulse helps to restore the membrane potential (concentration difference of charged solutes between the cell’s inside and outside) necessary to ensure cell survival and to enhance recovery-promoting blood flow.

Blood Flow: Dr. W. Erdman (Philadelphia, Pennsylvania) demonstrated that Diapulse increases systemic blood flow without elevating pulse rate or blood pressure (Am J Ortho 2, 1960). This effect is most likely due to the ability of Diapulse-generated fields to induce cells to align in a pearl-chain fashion. When the device was turned off, the cells reassumed a random distribution. With such a pearl-chain alignment, blood cells can more efficiently pass through a given vascular space, like cars traveling in the same direction on parallel lanes instead of “bumper” cars.

As in all injuries, blood flow affects recovery after SCI. Specifically, the injury to the cord compromises blood flow, which, as a consequence, aggravates neurological damage. Given Diapulse’s ability to enhance blood flow, it is not surprising that the device promotes healing after SCI.

Supporting Animal Studies : Drs. D. Wilson and P. Jagadeesh (Leeds, UK) examined the effects of Diapulse therapy on cats whose spinal cords were half cut (hemicordotomy) (Paraplegia 14, 1976). Three months after hemicordotomy, compared to controls, Diapulse improved functional recovery, reduced scar formation and adhesions, increased the number of axons transversing the injury site, and promoted the integration of peripheral nerve grafts that had been inserted to bridge the lesion.

Because surgeons are beginning to use peripheral nerve tissue to bridge spinal cord lesions in human, Diapulse’s ability to accelerate regeneration in peripheral tissue also has important therapeutic implications for SCI.

Dr. Wise Young (New York, New York) showed that Diapulse reduces calcium at the injury site in cats injured through impact. Because calcium causes secondary neuronal cell death, this Diapulse-induced reduction lessened neurological damage and, in turn, preserved function. Specifically, Young reported that 1) the majority of Diapulse-treated cats were walking four months after surgery compared to none in the control group and 2) that the device was superior to treatment with the steroid methylprednisolone, now considered a post-injury treatment standard due ironically to Young’s efforts (Presentations at1983 & 1984 Meetings of American Paralysis Association and 1984 Meeting of the Society of Neurological Surgeons).

SCI Human Studies: Dr. M Weiss et al (Warsaw, Poland) carried out a promising SCI study in 1980. Acutely injured patients were picked up by helicopter and brought to Warsaw where they were treated with Diapulse. Of the 97 treated patients, 38 had pronounced neurological improvement; of these, 28 had substantial functional gains, and 18 were discharged with only slight impairment of the extremities (Narz Ortoped, Pol 45(3) 1980). Unfortunately, because Weiss died soon after publishing these initial results, combined with post-communism social upheaval, this promising research was not continued.

Dr. W. Ellis anecdotally noted that PEMF given for pain in patients with chronic SCI resulted in sensory or motor improvement in seven of 13 patients (Bioelectromagnetics 8(2) 1987). Ellis hypothesized that these fields can normalize viable but dysfunctional neuronal structures.

Finally, Diapulse therapy was recently used in conjunction with a function-restoring surgery in which olfactory tissue was transplanted into the SCI injury site (Lisbon, Portugal). Specifically, two Americans with quadriplegia were treated with Diapulse several days before and after surgery to promote neuronal regeneration (private communication). Although it is difficult to sort out the relative contributions of the surgery, post-surgical rehabilitation, or Diapulse therapy, one of the patients had so much functional recovery that she was featured on a PBS documentary. 

Pressure Sores: A number of studies demonstrate that Diapulse treatment greatly accelerates the healing of pressure sores, a serious SCI-associated problem.  In a specific SCI-focused, double-blind study, Dr. C. A. Salzberg et al (Valhalla, NY) showed that the pressure sores of Diapulse-treated patients with SCI healed on average in 13 compared to 31.5 days for controls (Wounds 7(1), 1995).

The following case study, reported in PN/Paraplegia News (September 2003), is indicative of Diapulse’s potential for treating SCI-related pressure sores:

2) Oscillating Field Stimulation for Acute SCI: Evidence indicates that oscillating field stimulation (OFS) minimizes neurological damage after acute SCI. The therapy has been developed by Dr. Richard Borgens and colleagues at Purdue University (Indiana, U.S.).

OFS therapy is based upon numerous observations that appropriate electrical cues guide and promote neuronal growth. For example, studies suggest that in early development, naturally occurring voltage gradients channel nascent neurons down the neural tube, the spinal cord’s anatomical precursor. In addition, studies indicate that 1) regenerating axons are attracted to an electric field cathode (i.e., negative pole of applied field) and 2) such a field may alter glial cell density and organization within the injury scar in a fashion that is less inhibitory to regeneration.

Because implanting the cathode above or below the SCI injury site will promote neuronal growth only in one direction through the injury site, Borgens et al developed the OFS device in which polarity is alternated every 15 minutes. With such a device, regeneration in both ascending and descending neurons is stimulated.

OFS therapy is only beneficial for acute injury. If device implantation is delayed several months, regenerative benefits will not accrue.  

Animal Research: The OFS approach is based on extensive research by Borgens and colleagues using dogs with naturally occurring SCI, often due to explosive disk herniation that rapidly progresses into complete SCI. This research includes two randomized, controlled trials in dogs (Borgens et al. J Restorative Neurol Neurosci 5, 1993 and Borgens et al. J Neurotrauma 16 1999), which laid the foundation for the recent trial in humans discussed below.

In Borgens’ 1999 dog study, OSF devices were implanted in 20 paraplegic dogs and compared to 14 dogs with an implanted sham device. After six months, overall improvement, measured by a variety of neurological assessments, was greater in OFS-treated dogs.

Human Study: Given the results of these dog studies, the Food and Drug Administration (FDA) approved a Phase-1 clinical trial to assess safety in 10 patients with complete injuries ranging from the C5 to T10 level (J Neurosurg Spine 2, 2005). The patients age ranged from 18 to 43 (median age 23) and all but one were males. Six injuries were due to motor or all-terrain vehicle accidents, two from falls, one from diving, and one from violence.

Within 18 days of injury, the cylindrical OFS device (11-cm long; 1-cm diameter) was implanted in the patient’s paraspinous musculature below the injury site to minimize pain or discomfort. Emanating from the device are two sets of three electrodes. The electrodes in one set are sutured to the spine’s spinous process and right and left facet joints one segment above the injury site, and the other leads are connected to the same points a segment below the injury site. For example, for a C6 injury, the electrodes would be connected at the C5 and C7 level. The OFS device was removed at 15 weeks.

Study results indicated that the procedure was safe, the goal of this Phase-1 trial.

A variety of functional assessments were carried out at six months and one year after implantation. All subjects demonstrated improved sensation, and some regained significant motor or sexual function.

However, because no controls were included in this study designed to assess safety, overall efficacy could not be directly evaluated as in the case of the aforementioned dog studies. Although improvements were noted for most subjects a year after implantation, some recovery is routinely noted during this post-injury period. As such, since the study had no built-in reference point, results were compared to patient improvements documented in the third NASCIS (National Acute Spinal Cord Injury Study) trial. This comparison strongly suggests that OFS therapy exerts beneficial effects after acute injury in humans.   

The FDA has improved additional testing in patients with acute SCI, and Purdue University has licensed the technology to Andara Life Sciences, Inc. Recently reported animal research has suggested that in addition to its primary role, the OFS device may be an useful platform for delivering various factors to the injury site that enhance neuronal growth, such as inosine.

3) Repetitive Transcranial Magnetic Stimulation (rTMS) generates a pulsed electromagnetic field about the strength of an MRI scan. By placing the device close to the scalp, it stimulates the brain’s cerebral cortex, in turn activating descending neuronal pathways. Traditionally, rTMS has been used to treat depression and other psychiatric disorders.

Poirrier et al (University of Liege, Belgium) showed that rTMS promotes restoration of locomotion in rats with acute, incomplete injuries, especially lower thoracic injuries. The investigators speculated that in such low injuries, rTMS therapy activates the spinal cord’s ambulation-promoting central pattern generator.

Dr. Davey and colleagues at United Kingdom’s Charring Cross Hospital and Stoke Mandeville Hospital have treated four individuals with chronic, incomplete injuries with rTMS. The investigation was based on the belief that rTMS weakens intracortical inhibition and thereby enhances cortical drive to surviving corticospinal neurons, i.e., it easier for the brain’s signals to reach the body.

Of the four subjects, three were men (age 41, 54, & 54; 7-8 years post injury) and one was female (age 26; 15 months post injury). All had sustained C5-incomplete injuries as determined by ASIA criteria (American Spinal Injury Association)

These subjects were initially treated an hour daily for five days with a sham treatment (consisting of occipital cortex stimulation) and then for the same period with the therapeutic treatment (motor cortex stimulation). Various electrophysiological, clinical, and functional measurements were carried out before, during, and after treatments.

Results indicated no difference between baseline functioning and after sham treatment. However, the therapeutic treatment (i.e., over motor cortex) resulted in a 38% drop in intracortical inhibition as measured electrophysiological assessments. This reduction was accompanied by both motor and sensory improvements as evaluated by perception of skin electrical stimulation, ASIA scores, and the time required to complete a peg-board test. The treatment-associated benefits lasted for several weeks.

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