<p></p><p><img src="@@PLUGINFILE@@/Autism%20Profiles%20in%20EEG.png" alt="Autism Profiles" width="700" height="560" class="img-responsive atto_image_button_middle"></p><p>The following is of the work of Coben et al, 2015 (as cited in Table 2). The first endophenotype found in ASD is
paroxysmal EEG (epileptiform activity). This endophenotype has an incidence of
approximately 35-40%.&nbsp;With this subtype, the abnormality often appears on the left temporal lobe where speech and language occur. Neurofeedback can normalize this left abnormal pattern, at which time language often improves.</p>

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<p>The presence of mu characterizes the
second EEG phenotype seen in ASD cases. This “wicket”-shaped EEG pattern seen
in the central region is neurologically normal. This pattern is normally seen only when the frontal
lobes’ mirror neuron system is not engaged and disappears when the mirror
neuron system is engaged. The mirror neuron system underlies the production of
language in the left hemisphere, including mimicking sounds and cadence.
Emotional empathy, spatially encoded facial expressions, body language,
emotional (prosodic) content, and prosodic comprehension occur in the right
hemisphere (Marshall &amp; Meltzoff, 2011). The mirror neuron system is engaged
when meaningful stimuli of these types are perceived, and its activation of the
frontocentral region during engagement will normally block the mu, or idling,
rhythm from occurring. In 70% of the ASD population, however, the mu pattern
continues to spindle even when engagement of the mirror neuron system occurs (Oberman et
al., 2005).</p><p>The processes of
these brain areas are relevant to the behaviors often seen in ASD patients. In
these patients, the mu remains and
the mirror neuron system is unable to activate. Thus, neurofeedback training is
designed to reduce or eliminate the mu pattern. A secondary centrotemporal
portion of the mirror neuron system provides the necessary encoding of the
primary frontocentral behavior into the cortex. This second stage feeds data to
the temporal lobe, allowing comprehension of language to Wernicke’s area (the
area of the brain indicated in language development). An equivalent location on
the right is involved in representing emotional comprehension and nonverbal
memories. These bilateral posterior temporal locations are also involved in
autism because of their role in language, emotional comprehension, and
expression problems</p>

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<p>The high beta subtype is the third
pattern that can be observed in EEG findings with ASD individuals. This subtype
is characterized by an easily kindled, or irritable, cortex known as the “beta
spindle.” This can be associated with sensory hypersensitivity when it involves
sensory areas in the brain, but it can also be related to impulsivity and
explosivity when seen frontally, especially on the right. When seen in the
cingulate (a deeper midline structure), this pattern can be associated with
obsessivity, anxiety, and overfocusing and compulsive or other perseverative
disturbances. Individuals with the high beta pattern often present with
perseverative habits and have significant difficulty with transitions. Beta
spindling was originally identified in the 1930s as a component of epilepsy by
Drs. Frederick and Erna Gibbs (Gibbs &amp; Gibbs, 1950), who were
electroencephalographers in Chicago. Later, after beta spindles were observed
in other disorders (including bipolar disorder, some forms of anxiety, and
obsessive-compulsive disorder [OCD]), they were reconceptualized as easily
activated indicators of cortical irritability. </p>

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<p>Coherence dysregulation is a fourth
endophenotype within the ASD population. It is now known that there are no
brain tasks that happen in a single part of the brain, and a larger percentage
of the brain is needed for individual tasks than was previously understood.
Coben and Myers (2008) have used QEEG multivariate connectivity data to develop
a typology of autism connectivity patterns. They identified patterns of
hyperconnectivity across bilateral frontotemporal regions and between left
hemisphere locations, while hypoconnectivity was seen in orbitofrontal, frontal
to posterior, right posterior, or left hemisphere sites. Additionally, these
investigators identified a pattern of hypoconnectivity that underlies a mu
rhythm complex. More recently, Coben and colleagues (2010) have described
additional coherence-based subtypes of autism in the frontal regions, including
hypercoherence (too much connectivity), which often relates to obsessiveness,
and hypocoherence (too little connectivity), which is related to inattention
and cognitive difficulties. Other common coherence patterns are hypocoherence
in the left and right temporal regions. Hypocoherence in the right
temporal/parietal areas is often related to the types of social and emotional
deficits that commonly occur with ASD and Asperger’s syndrome in particular;
hypocoherence in the left temporal areas can be related to speech and language
difficulties.</p>

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<p>The fifth autism subtype is very high
delta activity, which represents significant cortical slowing and often
corresponds to (Coben et al., 2010; Linden, 2004). In Linden’s 2004 paper, he
first identified four distinct QEEG patterns of autism and two for Asperger’s
syndrome based on 19 channel EEG recordings and analysis of raw EEG, and the
absolute power, relative power, and multivariate connectivity metrics (see QEEG
section). In their 2010 paper, Coben, Linden, and Myers expanded the number of
autism subtypes to six and again identified two Asperger’s syndrome subtype
patterns. We next describe each of these endophenotypes in greater detail (see
Table 2).&nbsp;&nbsp;</p><p><span style="font-size: 1rem;">Autism endophenotype 6: In some ASD cases a sixth
pattern is seen, characterized by very low voltage EEG and dominated by slower
wave activity. This low voltage slow EEG is classically identified in diffuse
encephalopathies and specifically suggests that toxic or metabolic etiologies
be ruled out. Some researchers believe that this low voltage pattern may be
related to environmental influences (such as mercury in vaccines, pollution,
pesticides, and so forth) or to metabolic issues such as mitochondrial or
hormonal changes.&nbsp;</span></p><p><span style="font-size: 1rem;">Asperger’s syndrome endophenotypes: Two EEG/QEEG patterns
have been found to be present in most individuals with Asperger’s syndrome
(Coben et al., 2010; Linden, 2004; Thompson et al., 2010). The first is either
slow (theta/alpha) or fast beta EEG activity in the right temporal and parietal
regions. These sites are involved in social skills and emotional recognition
mechanisms as well as emotional expression and emotional control. The second is
either too low (hypo) or too high (hyper) coherence between the right
temporal/parietal brain regions and other regions. For example, hypocoherence
between the right parietal and frontal regions (related to attention) may
present as difficulty paying attention to emotional and social cues.&nbsp;</span></p><p><span style="font-size: 1rem;">The authors estimate the prevalence of the subtypes
in children with ASD as follows: § High
beta subtype (70%) §
Coherence abnormalities (70%) §
Abnormal EEG subtype (33%) §
Delta/theta subtype (30%) §
Metabolic/toxic (low voltage/low frequency) subtype (10%).&nbsp;</span><br></p><p><span style="font-size: 1rem;">Coben and colleagues
(in press) recently published data that used QEEG analysis to reveal five
subtypes in relative power for 91 individuals with autism and 310 normal
controls. In contrast to our clinical and research estimates, these researchers
observed pure excesses of beta and alpha in about one-fourth of the ASD sample
(26.5% and 25.3%, respectively) and excess theta in approximately 4.1%.
Specific frontal dysfunction, including excesses of theta and alpha, was
evident in 10.9% of the ASD group. Overall, more than four-fifths (83%) of the
individuals with autism exhibited connectivity anomalies when compared with
normal controls. In our experience, many types of dysfunction overlap in people
with autism, and most reveal a combination of QEEG findings. Our current work
strongly suggests that all people with ASD display multiple brain wave pattern
subtypes. In addition, individuals with autism can exhibit Asperger’s patterns
(and vice versa), and individuals with Asperger’s may also have ADD/ADHD QEEG
patterns (for example, the high theta/beta ratio that is related to
impulsivity, hyperactivity, and inattentive behaviors and symptoms). Thus,
multiple diagnoses are possible and can be illuminated by EEG and QEEG subtype
pattern</span></p><br><p></p>