Use the labels in the right column to find what you want. Or you can go thru them one by one, there are only 12876 posts. Searching is done in the search box in upper left corner. I blog on anything to do with stroke.DO NOT DO ANYTHING SUGGESTED HERE AS I AM NOT MEDICALLY TRAINED, YOUR DOCTOR IS, LISTEN TO THEM. BUT I BET THEY DON'T KNOW HOW TO GET YOU 100% RECOVERED. I DON'T EITHER, BUT HAVE PLENTY OF QUESTIONS FOR YOUR DOCTOR TO ANSWER.
Deans' stroke musings
Changing stroke rehab and research worldwide now.Time is Brain!Just think of all thetrillions and trillions of neuronsthateach daybecause there areeffective hyperacute therapies besides tPA(only 12% effective). I have 493 posts on hyperacute therapy, enough for researchers to spend decades proving them out. These are my personal ideas and blog on stroke rehabilitation and stroke research. Do not attempt any of these without checking with your medical provider. Unless you join me in agitating, when you need these therapies they won't be there.
What this blog is for:
Shortly after getting out of the hospital and getting NO information on the process or protocols of stroke rehabilitation and recovery I started searching on the internet and found that no other survivor received useful information. This is an attempt to cover all stroke rehabilitation information that should be readily available to survivors so they can talk with informed knowledge to their medical staff. It's quite disgusting that this information is not available from every stroke association and doctors group. My back ground story is here:http://oc1dean.blogspot.com/2010/11/my-background-story_8.html
Saturday, February 18, 2017
Upper Alpha Based Neurofeedback Training in Chronic Stroke: Brain Plasticity Processes and Cognitive Effects
the present study, we investigated the effects of upper alpha based
neurofeedback (NF) training on electrical brain activity and cognitive
functions in stroke survivors. Therefore, two single chronic stroke
patients with memory deficits (subject A with a bilateral subarachnoid
hemorrhage; subject B with an ischemic stroke in the left arteria
cerebri media) and a healthy elderly control group (N
= 24) received up to ten NF training sessions. To evaluate NF training
effects, all participants performed multichannel electroencephalogram
(EEG) resting measurements and a neuropsychological test battery
assessing different cognitive functions before and after NF training.
Stroke patients showed improvements in memory functions after successful
NF training compared to the pre-assessment. Subject B had a
pathological delta (0.5–4 Hz) and upper alpha (10–12 Hz) power maximum
over the unaffected hemisphere before NF training. After NF training, he
showed a more bilateral and “normalized” topographical distribution of
these EEG frequencies. Healthy participants as well as subject A did not
show any abnormalities in EEG topography before the start of NF
training. Consequently, no changes in the topographical distribution of
EEG activity were observed in these participants when comparing the pre-
and post-assessment. Hence, our results show that upper alpha based NF
training had on the one hand positive effects on memory functions, and
on the other hand led to cortical “normalization” in a stroke patient
with pathological brain activation patterns, which underlines the
potential usefulness of NF as neurological rehabilitation tool.
Following stroke, changes in electrical brain activity as well as cognitive impairment are often evident (Melkas et al. 2014; Jordan 2004; Kaplan and Rossetti 2011; Finnigan and van Putten 2013; Niedermeyer 2005).
In this context, EEG based neurofeedback (NF) might be a useful
rehabilitation tool. There is evidence that NF training can lead to
changes in electrical brain activity which goes along with cognitive
improvements (Kober et al. 2015a, b; Reichert et al. 2016; Kropotov 2009; Gruzelier 2014).
Using NF, participants can learn to voluntarily modulate their
electrical brain activity. Specific parameters of the EEG, such as power
values in specific frequency bands, can be extracted and analyzed in
real-time and fed back to the participants via auditory and/or visual
feedback. Hence, with the method of NF, the electrical activity of the
brain is modulated directly and, therefore, the cortical substrates of
cognitive functions. This direct access to neural activity by means of
NF may alter or accelerate functional reorganization in the brain
following stroke. NF might speed up functional recovery or even enable
functional recovery that otherwise would not have occurred (Nelson 2007).
Therefore, the aim of the present study was to evaluate the effects of
EEG based NF training on brain plasticity processes and cognitive
functions in stroke survivors.
It has been
demonstrated that the electroencephalogram (EEG) is a highly sensitive
measure to detect cerebral ischemic or hemorrhagic stroke. Stroke
patients show EEG abnormalities compared to healthy people, which change
over the course of the disease. The quantitative EEG during the acute
and sub-acute state has a high prognostic value concerning the outcome
from stroke (Finnigan et al. 2007; Finnigan and van Putten 2013; Tecchio et al. 2007; Sheorajpanday et al. 2011).
In this context, slow wave EEG activity in the delta range (0.5–4 Hz)
as well as faster oscillatory activity in the alpha range (8–12 Hz)
turned out to play an essential role (Niedermeyer 2005).
Delta power was found to be negatively correlated with regional
cerebral blood flow (rCBF) while alpha power showed a relatively strong
positive correlation with rCBF (Tolonen and Sulg 1981; Finnigan and van Putten 2013).
In stroke patients with unilateral cerebral infarction delta activity
is typically most pronounced over the affected hemisphere in the acute
state (Finnigan and van Putten 2013; Jordan 2004; Tecchio et al. 2006).
Across a few hours during the acute stroke period, the scalp topography
of delta activity shifts from a maximum over the affected hemisphere to
a maximum over the healthy, unaffected hemisphere. This
interhemispheric shift of scalp delta power maxima is associated with
worsening of cerebral pathophysiology and clinical state in stroke
patients (Finnigan et al. 2008; Tecchio et al. 2007; Zappasodi et al. 2007; Niedermeyer 2005; Rossini et al. 2003).
There is evidence that pathological asymmetry in EEG delta power
decreases after thrombolytic therapy, which in turn leads to
improvements in clinical symptoms (Finnigan et al. 2006; de Vos et al. 2008). Alpha amplitude attenuation is also generally indicative for cortical injury (Finnigan and van Putten 2013; Finnigan et al. 2007; Klimesch 1999).
Alpha power in the acute state is negatively related to the severity of
stroke symptoms in patients with unilateral lesions in the arteria
cerebri media (ACM) (Finnigan et al. 2007).
In stroke patients with acute subarachnoid hemorrhage (SAH), EEG delta
activity is increased and alpha activity is reduced, too (Vespa et al. 1997; Claassen et al. 2004; Niedermeyer 2005; Labar et al. 1991). Some EEG studies also investigated changes in EEG activity in the post-acute and chronic stage (Mattia et al. 2003).
These studies showed that the greatest improvement in EEG activity
occurred during the first 3 months after stroke (Giaquinto et al. 1994; de Weerd et al. 1988; Jonkman et al. 1984).
Stroke patients with a unilateral insult in the ACM showed decreases in
delta power and increases in alpha power levels over the injured
hemisphere during this time period. Alpha power levels also increased
over the healthy hemisphere. An overall increase in alpha power was also
partially associated with improvements in motor functions and
activities in daily living (Giaquinto et al. 1994).
Furthermore, delta and alpha power became more symmetrically
distributed over both hemispheres with clinical recovery, which might be
an indicator of “normalization” of electrical brain activity (Giaquinto
et al. 1994; Tecchio et al. 2006).
the present investigation, we evaluated whether EEG based NF training
can be used as therapeutic tool to evoke changes in electrical brain
activation patterns in chronic stroke patients, which may be accompanied
by cognitive improvements. In NF training paradigms, participants can
learn to voluntarily increase or decrease the amplitude of specific EEG
frequencies. There is some empirical evidence that voluntary modulation
of EEG amplitudes determines other aspects of electrical brain activity
in healthy people, which are responsible for improved cognitive
performance (Egner et al. 2004; Egner and Gruzelier 2004; Kropotov et al. 2005; Kober et al. 2015a; Reichert et al. 2016).
A few single-case studies in stroke patients reported heterogeneous
results. Some found positive effects of NF training on cognitive
functions as well as a EEG normalization after NF training (Rozelle and
Budzynski 1995; Bearden et al. 2003; Laibow et al. 2002; Putman 2002; Hofer et al. 2014), others could not find any significant effects (Doppelmayr et al. 2007).
However, the generalizability of these prior findings is limited due to
the incomplete description of training-specific EEG signal changes as
well as the absence of control groups. The majority of NF training
studies examined the effects of NF only on the behavioral level (see
for a review). Generally, successful modulation of EEG band power is
associated with cognitive and behavioral improvements (Kropotov 2009; Gruzelier 2014; Kober et al. 2015a, b; Hofer et al. 2014; Reichert et al. 2016).
For instance, voluntary up-regulation of the upper alpha frequency band
(UA, about 10–12 Hz) generally leads to improvements in working memory
(WM) and short-term memory performance (Escolano et al. 2011, 2012, 2013, 2014; Angelakis et al. 2007; Nan et al. 2012).
It is assumed that alpha activity inhibits unnecessary or conflicting
processes to the task being performed, thus facilitating attention and
memory by actively suppressing distracting stimuli (Klimesch et al. 2007).
Beside voluntary modulation of the magnitude of EEG amplitudes, NF can
be also used to change the topographical distribution of EEG activity.
For instance, NF is used to tread depressive symptoms by changing
hemispheric asymmetry in alpha band power (8–12 Hz) in prefrontal brain
areas (Kropotov 2009).
up, we aimed at investigated the effects of NF training on (i)
electrical brain activity, such as power in different EEG frequencies
and the topographical distribution of EEG activity, and (ii) cognitive
functions in chronic stroke patients. Therefore, we present two cases, a
stroke patient with a unilateral middle cerebral artery (ACM) stroke
and a stroke patient with a bilateral subarachnoid hemorrhage (SAH). We
used an UA based NF training, since the two chronic stroke patients
showed deficits in memory functions prior to the NF training. Based on
the literature, UA based NF training should have specific positive
effects on memory functions (Escolano et al. 2011, 2012, 2013, 2014; Angelakis et al. 2007; Nan et al. 2012).
We compared the results of the two stroke patients to the results of a
healthy, elderly control group. We expected that pathological EEG
patterns in stroke patients would change due to UA based NF training,
which should be associated with cognitive recovery.