The efficacy of LENS neurofeedback treatment for ADHD

Convergent data from neuroimaging, neuropsychological, genetics, and
neurochemical studies have implicated fronto-striatal network abnormalities
(lateral prefrontal cortex, dorsal anterior cingulate cortex (ACC), caudate
nucleus, and putamen) as likely contributing to the pathophysiology of ADHD
(Bush, Valera et al. 2005). Deficient behavioral inhibition (BI) processes are
considered a core feature of ADHD (Alderson, Rapport et al. 2007). BI processes
are usually assessed using go- no go paradigms, such as the stop-signal task
(Lubar and Lubar 1984). Relative to typically developing children, children
with ADHD were found to reveal significantly slower mean reaction time (MRT),
greater reaction time variability (SDRT), and slower stop-signal reaction time
(SSRT). Stop-signal reaction time differences are viewed to reflect a more
generalized deficit in attention/cognitive processing rather than behavioral
inhibition (Alderson, Rapport et al. 2008).
Preliminary evidence is emerging that neurofeedback training can help to
improve behavioral and cognitive functioning of individuals with ADHD.
Lubar and Lubar (Lubar and Lubar 1984) treated six children with ADHD with
neurofeedback and academic treatment. The training consisted of two sessions
per week for 10 to 27 months, with a gradual phase-out. Feedback was provided
for either increasing 12- to 15-Hz sensorimotor rhythm (SMR) or 16- to 20-Hz
beta activity. Inhibit circuits were employed for blocking the SMR or beta when
gross movement, excessive EMG, or theta (4-8 Hz) activity was present.
Treatment combined biofeedback with academic training, including reading,
arithmetic, and spatial tasks to improve attention. All children showed
increased SMR or beta and decreased slow EEG and EMG activity. Changes could be
seen in their power spectra after training in terms of increased beta and
decreased slow activity. All six children demonstrated considerable improvement
in their schoolwork in terms of grades or achievement test scores. Using fMRI
recordings, Levesque and colleagues (Levesque, Beauregard et al. 2006) found
that neurofeedback training (NFT) normalized functioning of the ACC, an
essential brain structure for the regulation of attention and behavior. The
training, employing the Lubar protocol (Lubar and Lubar 1984) during 40
(60-minute) sessions over 13 weeks, was divided in two phases (20 sessions in
each phase): in the first phase, subjects were trained to enhance the amplitude
of the sensorimotor rhythm (12-15 Hz) and decrease the amplitude of theta
activity (4-7 Hz); in the second phase, subjects learned to inhibit the
amplitude of their theta waves (4-7 Hz) and increase the amplitude of their
beta-1 waves (15-18 Hz).
Monastra et al. (Monastra, Monastra et al. 2002) investigated 100 children,
ages 6-19, with ADHD, either inattentive or combined types. All of the patients
participated in a 1-year, multimodal, outpatient program that included Ritalin,
parent counseling, and academic support at school. Fifty-one of the
participants also received EEG biofeedback therapy. Significant improvement was
noted on the Test of Variables of Attention and the Attention Deficit Disorders
Evaluation Scale when participants were tested while using Ritalin. However,
only those who had received EEG biofeedback sustained these gains when tested
without Ritalin. The results of a Quantitative Electroencephalographic Scanning
Process revealed significant reduction in cortical slowing only in patients who
had received EEG biofeedback.
Classical neurofeedback such as employed by Lubar and Lubar (1984) and Levesque
et al. (2006) employs basic principles of biofeedback. Patients receive
immediate feedback of the electrical activity of (parts of) their brain, that
allows them to learn how to regulate their mental condition. Neurofeedback
training is aimed at teaching trainees a method of self-regulation. The
learning process is governed by the laws of operant conditioning. When the
characteristics of the EEG-signals match the desired EEG profile, reward is
delivered. Through a trial-and-error process, although not necessarily at a
conscious level of processing, the trainee develops strategies to modify his or
her EEG to maximize reward, and thus learns to self-regulate brain functioning
to match the desired EEG-parameters.
In the present study, we aim to investigate the effects of the Low Energy
Neurofeedback System (LENS) on ADHD-patients. Instead of displaying information
on a computer screen to assist the patient in conditioning brainwave patterns,
the LENS, developed by Ochs (2006), uses weak electromagnetic signals as a
carrier wave for the feedback to assist in reorganizing brain physiology,
administered at a positive offset frequency from the person*s own dominant EEG
frequency. Although the feedback remains invisible for the person who is being
treated and the subject remains passive throughout the treatment procedure,
clinical evidence supports the efficacy of the LENS across a spectrum of
conditions.
Preliminary evidence of the clinical efficacy of the LENS treatment for several
disorders, that involve the central nervous system, has been published. Among
others, patients with traumatic brain injury (N = 12; age 21 - 53 years) have
been investigated. Time since injury ranged from 36 months to 21 years.
Comparison of two groups receiving, respectively, direct LENS treatment (25
sessions) and waiting list, indicated improvement after treatment for
participants* reports of depression, fatigue, and other symptoms, as well as
for some measures of cognitive functioning. Most participants experienced
meaningful improvement in occupational and social functioning (Schoenberger,
Shiflett et al. 2001). The efficacy of the LENS method in the treatment of
fibromyalgia patients has received preliminary support (Mueller, Donaldson et
al. 2001) when combined with physical therapy for the pain symptoms. Thirty
patients who met the 1990 American College of Rheumatology criteria for
fibromyalgia syndrome (FS) were included in a prospective study. Patients were
initially treated with the LENS neurofeedback (called electroencephalograph
(EEG)-driven stimulation by the latter authors) until they reported noticeable
improvements in mental clarity, mood, and sleep. Self-reported pain, then,
having changed from vaguely diffuse to more specifically localized, was treated
with modest amounts of physically oriented therapies. Pre- to posttreatment and
extended follow-up comparisons of psychological and physical functioning
indices, specific FS symptom ratings, and EEG activity revealed statistically
significant improvements, that were attributed to the neurofeedback treatment.
The present study is, to the best of our knowledge, the first to investigate
the efficacy of LENS neurofeedback treatment for individuals with ADHD.

Primary Objective: The present study aims to test the efficacy of treatment of
patients with ADHD, using LENS neurofeedback.

A prospective, randomized (waiting list and placebo) controlled trial with
between-groups and within-subject comparisons using repeated measures.

The duration of the neurofeedback treatment is 10 weeks. Participants receive
20 treatment sessions of 30 minutes, including EEG preparation. The treatment
is performed using the LENS Biofeedback system, implemented on a laptop
computer.
Brain potentials are recorded using one solid silver electrode which is placed
on the scull at the Fz position in accordance with the international 10-20
system and two electrodes at, respectively, the left ear lobe (reference
electrode) and the right ear lobe (ground). The impedance is checked and kept
below 5 k*. The skin is lightly abraded using scrubbing gel.
The sampling rate is 256 Hz. The frequency range of the recorded brain activity
is 0-60 Hz.
In each 30-minute treatment session, after electrode placement, the patient is
seated in an ordinary armchair. No specific instructions are given.
The feedback algorithm of the LENS determines the feedback frequency by adding
the continuously changing dominant (peak) EEG frequency and an offset value.
The latter is a changeable but fixed variable. Most feedback is delivered at a
1% duty cycle, meaning that, at a feedback frequency of 1 Hz, the actual
duration of the feedback pulse is .01 seconds; at a feedback frequency of 30
Hz, the actual duration of the feedback pulse is .003 seconds. Radiated signal
levels from the LENS are: during feedback 1*10-22 Watts/cm2; during baseline:
1*10-25 Watts/cm2.

LENS and placebo treatment are delivered as follows:
1. A LENS practitioner who is not involved with the participants in the study
creates a LENS High Efficiency (HE) map as well as Least Stimulation maps for
each participant in the study.
2. The maps are subsequently used by the therapist for this patient when
assigned to the LENS and placebo condition.
3. The LENS and placebo groups have different sets of software, although the
screens are identical. There is no readout or traces of the EEG on the screens
of either group. As a result, the therapist remains blinded for which software
set is used.
4. The direct LENS treatment group uses the HE applications; the placebo group
uses the Least Stimulation applications.

It is possible that patients with ADHD may not benefit from this neurofeedback
treatment. There is no indication from previous studies of LENS neurofeedback
or from the treatment outcome literature regarding ADHD that LENS neurofeedback
might result in further increase of ADHD complaints. In controlled studies of
efficacy of neurofeedback treatment of children with ADHD, no adverse events or
short- or long-term risks were noted (Fox, Tharp et al. 2005), nor were any
adverse events or side effects noted in other neurofeedback studies. If any
sign of deterioration of the participants* condition is detected, neurofeedback
treatment will immediately be terminated, and alternative treatment will be
offered.