Executive Summary. Thirteen studies, in which a total of 648 patients with various types of cognitive dysfunction were treated with cranial electrotherapy stimulation (CES), were combined statistically in order to get a more confident look at the effectiveness of CES for treating this condition. While many of the studies were of the classic double blind protocol, others used either the single blind or open clinical trial. The result of the analysis showed that the overall effectiveness of CES was 44% improvement.
In most of the studies, cognitive confusion was but one symptom within a larger syndrome. For example, in most of the studies, substance abuse was the presenting syndrome, while in three of the 13 studies, fibromyalgia was the presenting syndrome. And while all presented symptoms of cognitive confusion of some type, it is obvious from the above secondary analysis, that the cognitive dysfunction among the substance abuse patients was very likely of a different, physiological etiology than that of the fibromyalgia patients, who may have been experiencing cognitive distraction due to the stress of the unrelenting pain of their condition.
Researchers earlier received a strong impetus to study CES in substance abuse patients when in the 1970s it was found that the abstinence syndrome, including such features as depression, anxiety and insomnia, was seen to come under control very quickly with CES. Serendipitously it was also discovered that what had up until the 1980s been termed “permanent brain damage” in these patients responded to three weeks of CES treatment by bringing these patients back within the normal functioning range.
A word about the study types. In the open clinical study, the patients know they are being actively treated for their level of cognitive functioning, the clinicians know who is being treated, and the statistician who summarizes the study data also knows, since there is only one group of patients.
In the single blind study, the patients do not know which are getting treated and which are getting sham treatment, but the clinician providing the treatment knows which are the treated patients. In the single blind study, the clinician doing the post study evaluation of the patients is often blinded to treatment conditions when he completes his evaluation. The statistician is usually blinded also, so that he is given two sets of scores to compare, and doesn’t know which group received the treatment. This study design was used earlier on before treatment blinding devices came on stream. In such studies, the treatment was administered sub sensation threshold, in which the clinician turned up the current intensity until the patient just felt it, then turned it back down until the patient said he could no longer feel the stimulation. At that point, the clinician either left the current at that level or turned the unit off (down to, but not including the final click). Because both the patients and the statistician are both blind to the study conditions, some authors have unwittingly published this design as a double blind experiment. But that term is generally reserved for the true double blind experimental design as described next.
The double blind study, the gold standard of science, is usually confined to studies in which neither the patient nor the clinician knows who is being studied. Those designs became available when a double blinding box could be inserted between the patient and the CES device. The double blinding box often had three, four or more settings in addition to a “0” setting in which current flowed freely between the CES unit and the patient. Among the other settings available, some passed current to the patient and some blocked it entirely. The clinician would begin the double blind treatment session by setting all double blinding boxes to the “0” position, would connect the patient to the CES electrodes, turn the current up slowly until the patient signaled he could just feel it, then reduce the stimulus level until the patient signaled that he could no longer feel it. At that point, the clinician set the double blinding box to one of the other settings available and left the patient on the device for 30 minutes to an hour, not knowing who was receiving actual treatment..
Interestingly, in a good double blind experimental design, such as was the case in the majority of those reported in the table, the persons who were responsible for measuring or rating patient improvement were also blind as to whom was treated, as was the statistician who was given anonymous groups of data to analyze. Note that, in effect, that makes such studies quadruple blind, but that term is not used in science.
In the crossover design, half the patients get treated the first week or two of the study, while the other half receive sham treatment. In the second half of the study, the formerly treated patients now receive sham treatment while the formerly sham treated patients receive treatment. If the crossover does not involve a sham treatment condition, then the crossover study is treated as an open clinical trial where all patients and staff know who is being treated at each cross of the study. That design is often referred to as a study with “wait in line” controls, in that the patients waiting to begin treatment are tested before and at the end of the waiting period before going into treatment. That is thought to control for environmental factors such as unusual stressors on the 10 O’clock news, any local dramatic weather changes, and so forth.
By Ray B. Smith, Ph. D.