AN INTRODUCTION TO CRANIAL ELECTROTHERAPY
STIMULATION
Cranial electrotherapy stimulation (CES) is the application
of low-level, pulsed electrical currents (usually not exceeding
one milliampere), applied to the head for medical and/or psychological
purposes. It is primarily used to treat both state (situational)
and trait (chronic) anxiety, depression, insomnia, stress
related and drug addiction disorders, but it is also proving
indispensable for treating pain patients (Lichtbroun, Raicer
& Smith, 2001; Kirsch & Smith, 2000; Thuile &
Kirsch, 2000).
Drs. Leduc and Rouxeau of France were first to experiment
with low intensity electrical stimulation of the brain in
1902. Initially, this method was called electrosleep as it
was thought to be able to induce sleep. Since then, it has
been referred to by many other names, the most popular being
transcranial electrotherapy (TCET) and neuroelectric therapy
(NET). Research on using what is now referred to as cranial
electrotherapy stimulation (CES) began in the Soviet Union
during the 1950’s.
Cranial electrotherapy stimulation is a simple treatment
that can easily be administered at any time. The current is
applied by easy-to-use clip electrodes that attach on the
ear lobes, or by stethoscope-type electrodes placed behind
the ears. In the 1960’s and early 1970’s, electrodes
were placed directly on the eyes because it was thought that
the low level of current used in CES could not otherwise penetrate
the cranium. This electrode placement was abandoned over 20
years ago. Recent research has shown that from 1 mA of current,
about 5 µA/cm2 of CES reaches the thalamic area at a
radius of 13.30 mm which is sufficient to affect the manufacture
and release of neurotransmitters (Ferdjallah, 1996).
Anxiety reduction is usually experienced during a treatment,
but may be seen hours later, or as late as one day after treatment.
Although in some people it may require a series of five to
ten daily treatments to be effective. Severe depression often
takes up to three weeks to establish a therapeutic effect.
Cranial electrotherapy stimulation leaves the user alert
while inducing a relaxed state. Psychologists call this an
alpha state. The effect differs from pharmaceutical treatment
in that people usually report feeling that their bodies are
more relaxed, while their minds are more alert. Most people
experience a feeling that their bodies are lighter, while
thinking is clearer and more creative. A mild tingling sensation
at the electrode sites may also be experienced during treatment.
The current should never be raised to a level that is uncomfortable.
One 20-minute session is often all that is needed to effectively
control anxiety for at least a day, and the effects are usually
cumulative. If the patient can only tolerate a small amount
of current (<200 µA), due to vertigo or nausea, more
time is required. Cranial electrotherapy stimulation may also
be used as an adjunct to anxiolytic or anti-depressive medication,
but the dosage of medication should then be reduced by approximately
one-third. It is also proven to be an effective complimentary
treatment along with psychotherapy, biofeedback training,
and surgical anesthesia (Kirsch, 1999). For people who have
difficulty falling asleep, CES should be used in the morning
to avoid the possibility of increased alertness that may interfere
with sleep.
Most people can resume normal activities immediately after
treatment. Some people may experience an euphoric feeling,
or a state of deep relaxation that may temporarily impair
their mental and/or physical abilities for the performance
of potentially hazardous tasks, such as operating a motor
vehicle or heavy machinery, for up to several hours after
treatment.
At present, there are over 100 research studies on CES in
humans and 20 experimental animal studies (Kirsch, 1999).
No significant lasting side effects have ever been reported.
Occasional self-limiting headache (1 out of 450), discomfort
or skin irritation under the electrodes (1 out of 811), or
lightheadedness may occur. A rare patient with a history of
vertigo may experience dizziness for hours or days after treatment.
Most cranial electrotherapy stimulators are limited to 600
µA. To put this into perspective, it takes one-half
of an ampere to light an ordinary 60 watt light bulb. To truly
compare the work done per second by these two different currents,
we must multiply the currents by the respective voltages that
drive them. The product of current x voltage is a measure
of the rate of generation of energy, and is referred to as
the power output. By definition, when a device outputs one
ampere of current with a one volt driving force, the power
output of the device is one watt. Therefore a device producing
a maximum output of 600 µA is limited to about 11,000
times less power than the light bulb: (600/1,000,000)amperes
x 9 volts = 0.0054 watts. Some people do not even feel this
amount of current.
As in many areas of biology and therapy, the evidence of
CES effectiveness is empirical. It is generally believed that
the effects are primarily mediated through a direct action
on the brain at the limbic system, the hypothalamus and/or
reticular activating system (Brotman, 1989; Gibson & O’Hair,
1987; Madden & Kirsch, 1987). The primary role of the
reticular activating system is the regulation of electrocortical
activity. These are primitive brain stem structures. The functions
of these areas and their influence on our emotional states
were mapped using electrical stimulation. Electrical stimulation
of the periaqueductal gray matter has been shown to activate
descending inhibitory pathways from the medial brainstem to
the dorsal horn of the spinal cord, in a manner similar to
ß-endorphins (Salar, 1981; Pert, 1981; Ng, 1975). Cortical
inhibition is a factor in the Melzack-Wall Gate Control theory
(Melzack, 1975). Toriyama (1975) suggested it is possible
that CES may produce its effects through parasympathetic autonomic
nervous system dominance via stimulation of the vagus nerve
(CN X). Taylor (1991) added other cranial nerves such as the
trigeminal (CN V), facial (CN VII), and glossopharyngeal (CN
IX). Fields (1975) showed that electrocortical activity produced
by stimulation of the trigeminal nerve is implicated in the
function of the limbic region of the midbrain affecting emotions.
Substance P and enkephalin have been found in the trigeminal
nucleus, and are postulated to be involved in limbic emotional
brain structures (Hokfelt, 1977). The auditory-vertigo nerve
(CN VIII) must also be effected by CES, accounting for the
dizziness one experiences when the current is too high. Ideally,
CES electrodes are placed on the ear lobes because that is
a convenient way to direct current through the midbrain and
brain stem structures.
From studies of CES in monkeys, Jarzembski (1970) measured
42% to 46% of the current entering the brain, with the highest
concentration in the limbic region. Rat studies by Krupisky
(1991) showed as much as a threefold increase in ß-endorphin
concentration after just one CES treatment. Pozos (1971) conducted
mongrel dog research that suggests CES releases dopamine in
the basal ganglia, and that the overall physiological effects
appear to be anticholinergic and catecholamine-like in action.
Richter (1972) found the size, location, and distribution
of synaptic vesicles were all within normal limits after a
series of ten, one-hour treatments in Rhesus monkeys. Several
studies in stump-tailed macaques and humans revealed a temporary
reduction in gastric hypersecretion (Reigel, 1970; Reigel,
1971; Wilson, 1970; Kotter, 1975).
A recent review by Kirsch (1999) of 106 human studies involving
5,439 subjects (4,058 receiving cranial electrotherapy stimulation,
while the remainder served as sham-treated or placebo controls)
revealed significant changes associated with anxiolytic relaxation
responses, such as lowered reading on electromyograms (Gibson,
1987; Forster, 1963; Heffernan, 1995; Overcash, 1989; Voris,
1995), slowing on electroencephalograms (Braverman, 1990;
Cox, 1975; Heffernan, 1996; Heffernan, 1997; Krupitsky, 1991;
McKenzie, 1971; Singh, 1971), increased peripheral temperature,
an indicator of vasodilatation (Brotman, 1989; Heffernan,
1995), reductions in gastric acid output (Kotter, 1975), and
in blood pressure, pulse, respiration, and heart rate (Heffernan,
1995; Taylor, 1991).
The efficacy of CES has also been clinically confirmed through
the use of 27 different psychometric tests. The significance
of CES research for treating anxiety has been reconfirmed
through meta-analyses conducted at the University of Tulsa
by O’Connor (1991), and by Klawansky (1995) at the Department
of Health Policy and Management, Harvard School of Public
Health.
Seventeen studies conducted follow-up investigations from
one week to two years after treatment (Brotman, 1989; Brovar,
1984; Cartwright, 1975; Flemenbaum, 1974; Forster, 1963; Hearst,
1974; Heffernan, 1995; Hochman, 1988; Koegler, 1971; Magora,
1967; Matteson, 1986; Moore, 1975; Overcash, 1999; Patterson,
1988; Smith, 1999; Turaeva, 1967; Weiss, 1973). Sixteen of
16 (100%) reported that at least some of the subjects had
a continued improvement after a single CES treatment, or a
series of CES treatments. The other follow-up report only
commented on safety (Forster, 1963). None of the 17 studies
revealed any long term harmful effects.
When restricted to anxiety populations or studies that measured
for physiological and/or psychological changes in anxiety,
there are 40 scientific studies of CES, involving 1,835 patients.
Thirty-four of the 40 (85%) studies reported efficacious results
in the treatment of anxiety. Five of the studies on CES (all
using the Alpha-Stim) support the effectiveness for managing
anxiety during or after a single treatment (Gibson, 1987;
Heffernan, 1995; Smith, 1999; Voris, 1995; Winick, 1999).
None of the 6 of 40 (15%) anxiety studies categorized by
the authors as having negative or indeterminate results were
recent, five were done in the 1970’s, and one in 1980.
Three showed both actual treatment and sham groups to improve
significantly, most likely because both groups were also taking
medications (Levitt, 1975; Passini, 1976; Von Richtofen, 1980).
One was a depression study in which the author noted that
acute anxiety was not relieved and again, the study did not
control for medications (Hearst, 1974). One reported no significant
change on anxiety or depression scales, but subjective insomnia
improved (P<.05) during active treatment (Moore, 1975).
Only one study conducted on a population of insomniacs, with
an average duration of symptoms for almost 20 years, did not
show any significant change at all in any parameters (Frankel,
1973). [Perhaps the device used in Frankel’s study was
defective.]
Cranial electrotherapy stimulation has been well researched
and clearly proven to be the most effective, and safest method
of treatment for anxiety, and anxiety-related disorders. It
is also highly effective for depression and insomnia, muscle
tension, fibromyalgia and headaches. As an increasing number
of patients seek alternatives to the side effects and potential
addiction to mood-altering pharmaceuticals and controlled
substances, CES offers a viable solution. It is easy enough
to offer CES in a psychologist’s, dentist’s or
physician’s office, clinic, or hospital, and chronically
stressed patients will find it cost-effective over time to
own their own CES device.
Indications
In addition to the primary claims for anxiety, depression
insomnia, and pain, CES has been researched with significant
results for many other conditions. Smith and Shiromoto (1992)
showed it to be highly effective in blocking fear perception
in phobic patients. Favorable results have also been reported
for labor, epilepsy, hypertension, surgery, spinal cord injuries,
chronic pain, arthritis, cerebral atherosclerosis, eczema,
dental pain, asthma, ischemic heart disease, stroke, motion
sickness, digestive disorders as well as various addictive
disorders including cocaine, marijuana, heroin and alcohol
abuse (Wharton, McCoy, & Cofer, 1982; Schmitt, Capo, et
al., 1984; Smith, 1975; Smith, 1982; Patterson, 1983; Daulouede,
1980; Gomez & Mikhail, 1978; Brovar, 1984; Feighner, Brown,
& Olivier, 1973; Overcash & Siebenthall, 1989).
Reflex sympathetic dystrophy (RSD) and fibromyalgia syndrome
(FS) are two significant pain diagnoses from primary central
and autonomic nervous system etiologies that respond best
to CES (Alpher & Kirsch, 1998; Lichtbroun et al., 1999).
Adding somatic treatment with MET to these two conditions
does not seem to improve the outcomes.
Besides specific pathological disorders, there are a growing
number of studies being conducted that show increases in cognitive
functions. Michael Hutchison (1986) discussed several mind
enhancement techniques in his book Megabrain, devoting chapter
9 to CES as a tool for attaining higher levels of consciousness.
Sparked by Hutchison, Madden and Kirsch (1987) completed a
study that demonstrated CES to be a useful tool for improving
psychomotor abilities. Smith (1999) demonstrated that CES
significantly improved stress related cognitive dysfunction,
such as attention deficit disorder (ADD), after only three
weeks of treatment, and maintained the effect through an 18-month
follow-up assessment.
Methodology
Cranial electrotherapy stimulation devices are generally
similar in size and appearance to TENS units, but produce
very different waveforms. Standard milliampere-current TENS
devices must never be applied transcranially. CES electrodes
can be placed bitemporally, forehead to posterior neck, bilaterally
in the hollow just anterior to the mastoid processes, or through
electrodes clipped to the earlobes. The ear clip method, developed
by the author, is the easiest and possibly most effective
electrode placement.
The electrodes must first be wet with an appropriate conducting
solution. When using ear clip electrodes, apply them to the
superior aspect of the ear lobes, as close to the jaw as possible.
Start with a low current and gradually increase it. If the
current is too high the patient may experience a painful stinging
sensation at the electrodes, dizziness, or nausea. If any
of these three symptoms arise, immediately reduce the current
and the symptoms will subside in a few moments. After a minute
or two, try increasing the current again, but keep it at a
comfortable level. It is okay for the patient to feel the
current as long as it is not uncomfortable.
The ideal treatment time is 20 to 60 minutes, but some patients
may achieve the full benefits of a CES treatment within 10
minutes. Many dentists use it instead of nitrous oxide gas
to help relax patients during dental procedures (Winick, 1999).
Sometimes these dental procedures last for hours with the
patient undergoing CES treatment the entire time.
Although CES treatment is indicated for insomnia, because
of the increased alertness some patients find it difficult
to fall asleep immediately after a treatment. Accordingly,
it is recommended that CES be used at least three hours before
going to bed. Also, in most cases after daily treatments for
the first week or two, treating every other day is usually
more effective than daily treatment.
The CES Experience
During the treatment, most patients will experience a subjective
change in their body weight. They may feel heavier at first
and then lighter, or they may feel lighter initially. The
patient may feel worse during the heavy cycle and this feeling
can last for hours or even days in rare cases unless extra
treatment time is given. Therefore it is important to continue
the treatment if the patient feels heavier at the end of the
allotted time, even if it has already been 20 minutes or more.
Continue for at least two to five minutes after the patient
feels lighter. Not all patients will be aware of these weight-perception
changes.
Following CES, most people feel better, less distressed,
and more focused on mental tasks. They generally sleep better
and report improved concentration, increased learning abilities,
enhanced recall, and a heightened state of well-being
Psychologists first described these general feelings during
the 1970's as an alpha state of consciousness. Meditation,
biofeedback training, relaxation instructions, chanting, hypnotherapy,
and certain religious rituals also produce such states. This
is not the same as the alpha brain wave frequency of 8 to
13 Hz. Often, practitioners are confused by device representatives
who claim that their particular device will output and entrain
a brain to the alpha frequency. There is no evidence to support
that CES devices work on an entrainment principle.
Contraindications
There have not been any significant lasting harmful side
effects reported in any of the research literature from either
MET or CES. As with all electrical devices, caution is advised
during pregnancy, and with patients using an older model (pre-1998)
demand-type pacemaker. In addition, it is recommended that
patients do not operate complex machinery or drive automobiles
during and shortly after a CES treatment.
Summary
Microcurrent electrical therapy and cranial electrotherapy
stimulation are electromedical modalities that use low level
currents that usually do not exceed one milliampere. Beneficial
effects have been reported for a wide variety of pain, psychological
distress, and addiction-related disorders.
Pain is a complex process encompassing the entire nervous
system. To achieve optimal results through electromedical
intervention, the peripheral and central nervous systems should
both be treated. Cranial electrotherapy stimulation induces
a relaxed, alert state. It is a primary modality effective
for controlling anxiety, depression, insomnia and generalized
stress ubiquitous in pain patients. In addition, there is
mounting evidence that CES can enhance cognitive functions.
Because of its safety and effectiveness, the combination of
MET and CES used with the protocols described here are highly
recommended for a broad range of pain and stress-related disorders.
Chapter Reprint from:
PAIN MANAGEMENT: A PRACTICAL GUIDE FOR CLINICIANS
Daniel L. Kirsch, Ph.D., D.A.A.P.M.
The Textbook of the American Academy of Pain Management
CRC Press, Boca Raton, Florida, 2001 Revision.
Chapter © copyright 2001 by D. L. Kirsch, Mineral Wells,
Texas.
All Rights Reserved
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