I'm sure your doctor, if any good at all, can find something in here to create a protocol on brain stimulation. I really don't want to have all the 10 million yearly stroke survivors figure out a way to electrically stimulate their brains without frying them to pieces. But I bet you'll have to wait 50 years before this becomes standard practice because we have NO stroke strategy or anyone that has taken on the responsibility to implement one.We are fucking screwed and really no one cares.
Non-invasive brain stimulation in early rehabilitation after stroke
Abstract
The
new tendency in rehabilitation involves non-invasive tools that, if
applied early after stroke, promote neurorecovery. Repetitive
transcranial magnetic stimulation and transcranial direct current
stimulation may correct the disruption of cortical excitability and
effectively contribute to the restoration of movement and speech. The
present paper analyses the results of non-invasive brain stimulation
(NIBS) trials, highlighting different aspects related to the repetitive
transcranial magnetic stimulation frequency, transcranial direct current
stimulation polarity, the period and stimulation places in acute and
subacute ischemic strokes. The risk of adverse events, the association
with motor or language recovery specific training, and the cumulative
positive effect evaluation are also discussed.
Novel techniques of neuromodulation and neurorehabilitation
Transcranial
direct current stimulation (tDCS) of the brain is an
electrophysiological method which may be used to modulate the
neocortical excitability. A direct current generator is connected to two
patch electrodes (an active and a reference one) positioned over the
scalp, to stimulate the subjacent tissue with low amplitudes currents
(0.5 - 2.0 mA) and to modify the threshold for discharge of cortical
neurons. The modulation of cortical excitability is polarity-dependent:
“anodal stimulation” (increased in network excitability) – when the
active electrode generates a positive potential compared to the
reference electrode; “cathodal stimulation” (decreased in network
excitability) – when the active electrode generates a negative potential
[4].
Repetitive
transcranial magnetic stimulation (rTMS) is another therapeutic tool
that can contribute to the modulation and reconfiguration of different
cortical areas. In contrast to tDCS, rTMS results in the induction of
action potentials and depolarization of the neuronal membrane. The
principle of transcranial magnetic stimulation is to produce a
perpendicular magnetic field, by a stimulating coil, which induces an
electric field, which, in contact with the cerebral tissue, is
transmitted as an electric current, parallel to the generating coil. The
depth of the stimulation depends on the type of coil and the intensity
of the stimulation. The excitatory or inhibitory effect is correlated
with the frequency of rTMS: high frequencies (≥ 5 Hz) are excitatory,
while low frequencies (≤ 1 Hz) are inhibitory [4,7].
By
modulating cortical excitability with respect to neural plasticity,
these two non-invasive brain stimulation (NIBS) techniques represent
potential therapeutic tools in recovery after stroke [8,9].
There
are two main directions of NIBS treatment in neurorehabilitation: the
motor deficit and the speech disorders. The improvement of motor and
language performances is based on interhemispheric competition theory [10-14].
This model suggests that the balance between the left and the right
hemisphere of stroke patients is altered by an increased
interhemispheric inhibition from the unaffected hemisphere to the
affected hemisphere. Accordingly, a therapeutic effect may be obtained
either by increasing the excitability of the affected hemisphere, or by
decreasing the excitability of the unaffected hemisphere [10].
The mechanism of excitability enhancement in the motor cortex underlies
the motor learning and the use-dependent plasticity, which are impaired
in the affected hemisphere. Other positive effects of the NIBS are the
enhancement of neural coupling between the primary and secondary motor
areas in the affected hemisphere, the reduction of the hyperactivity in
the primary and secondary motor areas in the unaffected hemisphere, and
the excitability modulation in both hemispheres [10].
The
advantages of inhibitory NIBS over the intact hemisphere are the
uniform response and the lower risk of potential epileptic seizures,
which are more probably to appear after rTMS in the infarcted area [15].
The major disadvantage is the deterioration of bimanual movement due to
the reduction of transcallosal inhibition that controls that kind of
movement. This possible consequence may be prevented by applying a low
frequency rTMS concomitant with anodal tDCS over the affected hemisphere
[16].
The neural modulation induced by NIBS and the improvement of motor and
speech deficits can be sustained by subsequent motor training and speech
therapies [10,13].
Although
it was demonstrated that the early rehabilitation facilitates motor
recovery after stroke, the application of NIBS in acute stages is
controversial [17,18].
The genetic polymorphism can be involved and may explain the different
response of stroke patients to this therapy. BDNF is one of the factors
strongly involved in synaptic plasticity of the human motor cortex [9]. The consequence of BDNF val66met, a common single nucleotide polymorphism, is the reduced secretion of BDNF [19]. This is clinically expressed by a poorer retention in short-term motor learning and slower cognitive and motor recovery [9,19]. Therewith, the individual variation in response to rTMS may be explained by the difference in BDNF concentration [20].
The
majority of the clinical studies evaluating the role of rTMS in
rehabilitation were performed in subacute and chronic stroke patients,
few data being available for acute stroke [21].
In this respect, a recent Cochrane meta-analysis evaluated the efficacy
and safety of rTMS in recovery after stroke regardless of the duration
of illness [22].
Nineteen randomized controlled trials (RCTs) with a total of 588
patients were included. Even if the rTMS treatment was not associated
with a significant improvement in activities of daily living, or a
significant improvement of motor function, a positive trend was noted,
larger and homogeneous RCTs being needed in order to confirm the results
[22].
The
most encountered adverse events reported in clinical trials evaluating
rTMS are transient or mild headache (2.4%), anxiety (0.3%),
neurocardiogenic syncope after initial exposure to rTMS (0.6%),
exacerbation of pre-existing insomnia (0.3%) and local discomfort at the
site of the stimulation [22]. Also, epileptiform discharge on EEG and seizures, can be noted especially after high-frequency rTMS (10 Hz) [11].
Much more at link, including all the references.
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