Rev Med Suisse. 2005 Sep 21;1(33):2162-4, 2166. |
Novel brain stimulation techniques: therapeutic perspectives in psychiatry.
[Article in French]
Berney A, Vingerhoets F.
Service de psychiatrie de liaison, CHUV, 1011 Lausanne. Alexandre.Berney@chuv.ch
Recent advances have allowed the development of new physical
techniques in neurology and psychiatry, such as Transcranial Magnetic
Stimulation (TMS), Vagus Nerve Stimulation (VNS), and Deep Brain
Stimulation (DBS). These techniques are already recognized as
therapeutic approaches in several late stage refractory neurological
disorders (Parkinson’s disease, tremor, epilepsy), and currently
investigated in psychiatric conditions, refractory to medical treatment
(obsessive-compulsive disorder, resistant major depression). In
Paralell, these new techniques offer a new window to understand the
neurobiology of human behavior.
Curr Psychiatry Rep. 2005 Oct;7(5):381-90. |
Transcranial magnetic stimulation for the treatment of depression in neurologic disorders.
Fregni F, Pascual-Leone A.
Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, KS 452, Boston, MA 02215, USA.ffregni@bidmc.harvard.edu
Depression is commonly associated with neurologic disorders. Although
depression in neurologic conditions often is associated with a negative
impact on quality of life, it frequently is poorly managed. Some
factors, such as a multidrug regimen, lack of efficacy, and side effects
of antidepressants may explain why depression is not adequately treated
in patients with neurologic disorders. Therefore, this population needs
new approaches for depression treatment, and repetitive transcranial
magnetic stimulation (rTMS) may be one of them because it has been shown
to be effective for the treatment of depression alone and depression in
certain neurologic diseases such as Parkinson’s disease and stroke.
rTMS is a noninvasive, focal, and painless treatment associated with
few, mild side effects. It may be effective in the treatment of
neurologic diseases such as Parkinson’s disease, stroke, and epilepsy.
In this paper, we discuss the potential risks and benefits of rTMS
treatment for depression in Parkinson’s disease, epilepsy, stroke,
multiple sclerosis, and Alzheimer’s disease. Lastly, a framework that
includes the parameters of stimulation (intensity, frequency, number of
pulses, and site of stimulation) for the treatment of depression in
neurologic diseases is proposed.
Seizure. 2005 Sep;14(6):387-92. |
Low-frequency repetitive transcranial magnetic stimulation for
seizure suppression in patients with extratemporal lobe epilepsy-a pilot
study.
Kinoshita M, Ikeda A, Begum T, Yamamoto J, Hitomi T, Shibasaki H.
Department of Neurology, Graduate School of Medicine, Kyoto University, 54 Shogoin-Kawaharacho, Sakyoku, Kyoto 606-8507, Japan.
We evaluated the effect of low-frequency repetitive transcranial
magnetic stimulation (rTMS) on seizure frequency in adult patients with
medically intractable extratemporal lobe epilepsy (ETLE). Seven patients
with medically intractable ETLE received low-frequency rTMS at 0.9 Hz,
basically two sets of 15 min stimulation per day for five days in a
week, with the stimulus intensity of 90% of resting motor threshold
(RMT). The number of seizures during two weeks before and after the
stimulation of one week was compared. Furthermore, RMT and active motor
threshold (AMT) were measured before and after rTMS for each daily
session. After low-frequency rTMS of one week, the frequency of all
seizure types, complex partial seizures (CPSs) and simple partial
seizures was reduced by 19.1, 35.9 and 7.4%, respectively. The patients
with smaller difference between RMT and AMT before rTMS had higher
reduction rate of CPSs. A favorable tendency of seizure reduction,
though not statistically significant, during two weeks after
low-frequency rTMS was demonstrated in medically intractable ETLE
patients. As far as CPSs are concerned, smaller decrease of motor
threshold by voluntary muscle contraction was associated with better
response to rTMS.
Epilepsy Behav. 2005 Sep;7(2):182-9. |
Transcranial magnetic stimulation treatment for epilepsy: can it also improve depression and vice versa?
Fregni F, Schachter SC, Pascual-Leone A.
Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, USA. ffregni@bidmc.harvard.edu
Comorbidity with depression is an important determinant of the
quality of life for patients with epilepsy. Antidepressant medications
can effectively treat depression in epileptic patients, but drug-drug
interactions and epileptogenic effects of these drugs pose therapeutic
challenges. The mood-stabilizing effects of antiepileptic medications
may not be sufficient to treat depression. Therefore, treatments that
alleviate the burden of depression without increasing seizure risk or,
better yet, with the possibility of improving seizure control are worth
exploring. Neuroimaging techniques, such as functional magnetic
resonance imaging, are providing novel insights into the pathophysiology
of depression in epilepsy. For example, there appears to be prominent
brain prefrontal hypoactivity, which may be sustained by the
hyperactivity of the seizure focus. If so, neuromodulatory approaches
that suppress epileptic focus hyperactivity and concurrently enhance
prefrontal activity may be ideally suited. Indeed, vagus nerve
stimulation has been shown to yield simultaneous antiseizure and mood
effects. Another neuromodulatory technique, transcranial magnetic
stimulation (TMS), can also modulate brain activity, but in a
noninvasive, painless, and focal manner. Depending on the stimulation
parameters, it is possible to enhance or reduce activity in the targeted
brain region. Furthermore, TMS has been shown to be effective in
treating depression, and preliminary data suggest that this treatment
may also be effective for epilepsy treatment. This article reviews these
data and explores further the question of whether depression and
epilepsy can be simultaneously treated with TMS for optimal therapeutic
impact.
Seizure. 2005 Sep;14(6):387-92. |
Low-frequency repetitive transcranial magnetic stimulation for
seizure suppression in patients with extratemporal lobe epilepsy-a pilot
study.
Kinoshita M, Ikeda A, Begum T, Yamamoto J, Hitomi T, Shibasaki H.
Department of Neurology, Graduate School of Medicine, Kyoto University, 54 Shogoin-Kawaharacho, Sakyoku, Kyoto 606-8507, Japan.
We evaluated the effect of low-frequency repetitive transcranial
magnetic stimulation (rTMS) on seizure frequency in adult patients with
medically intractable extratemporal lobe epilepsy (ETLE). Seven patients
with medically intractable ETLE received low-frequency rTMS at 0.9 Hz,
basically two sets of 15 min stimulation per day for five days in a
week, with the stimulus intensity of 90% of resting motor threshold
(RMT). The number of seizures during two weeks before and after the
stimulation of one week was compared. Furthermore, RMT and active motor
threshold (AMT) were measured before and after rTMS for each daily
session. After low-frequency rTMS of one week, the frequency of all
seizure types, complex partial seizures (CPSs) and simple partial
seizures was reduced by 19.1, 35.9 and 7.4%, respectively. The patients
with smaller difference between RMT and AMT before rTMS had higher
reduction rate of CPSs. A favorable tendency of seizure reduction,
though not statistically significant, during two weeks after
low-frequency rTMS was demonstrated in medically intractable ETLE
patients. As far as CPSs are concerned, smaller decrease of motor
threshold by voluntary muscle contraction was associated with better
response to rTMS.
J Neurol Sci. 2005 Jul 15;234(1-2):37-9. |
Low-frequency transcranial stimulation for epilepsia partialis continua due to cortical dysplasia.
Misawa S, Kuwabara S, Shibuya K, Mamada K, Hattori T.
Department of Neurology, Chiba University School of Medicine, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan. sonoko.m@mb.infoweb.ne.jp
The potential therapeutic role of repetitive transcranial magnetic
stimulation (rTMS) in epilepsy has been increasingly recognized. We
investigated the effects of low-frequency rTMS in a patient with
epilepsia partialis continua (EPC) due to cortical dysplasia. A
31-year-old female patient experienced EPC in the right upper and lower
extremities, which had lasted for 15 years without generalized seizures.
MRI showed focal megaencephaly around the motor cortex suggestive of
cortical dysplasia. A figure of eight magnetic coil was placed over the
hand motor area, and 100 stimuli with an intensity at 90% of motor
threshold were given at 0.5 Hz. Immediately after rTMS, EPC was nearly
abolished. The effects had continued approximately for 2 months, and the
second trial resulted in the similar effects and time-course.
Low-frequency rTMS was safe and well tolerated in this patient. These
findings support the concept that rTMS decreases cortical excitability,
and may be an effective treatment for focal partial seizures.
J ECT. 2005 Jun;21(2):88-95. |
Transcranial magnetic stimulation in persons younger than the age of 18.
Quintana H.
Department of Psychiatry, Division of Child and Adolescent
Psychiatry, Louisiana State University Health Science Center, School of
Medicine, New Orleans, Louisiana 70112-2822, USA. Hquint@lsuhsc.edu
OBJECTIVES: To review the use of transcranial magnetic stimulation
(single-pulse TMS, paired TMS, and repetitive TMS [rTMS]) in persons
younger than the age of 18 years. I discuss the technical differences,
as well as the diagnostic, therapeutic, and psychiatric uses of TMS/rTMS
in this age group.
METHODS: I evaluated English-language studies from 1993 to August
2004 on nonconvulsive single-pulse, paired, and rTMS that supported a
possible role for the use of TMS in persons younger than 18. Articles
reviewed were retrieved from the MEDLINE database and Clinical
Scientific index.
RESULTS: The 48 studies reviewed involved a total of 1034 children
ages 2 weeks to 18 years; 35 of the studies used single-pulse TMS (980
children), 3 studies used paired TMS (20 children), and 7 studies used
rTMS (34 children). Three studies used both single and rTMS. However,
the number of subjects involved was not reported.
CONCLUSIONS: Single-pulse TMS, paired TMS, and rTMS in persons
younger than 18 has been used to examine the maturation/activity of the
neurons of various central nervous system tracts, plasticity of neurons
in epilepsy, other aspects of epilepsy, multiple sclerosis, myoclonus,
transcallosal inhibition, and motor cortex functioning with no reported
seizure risk. rTMS has been applied to psychiatric disorders such as
ADHD, ADHD with Tourette’s, and depression. Adult studies support an
antidepressant effect from repetitive TMS, but there is only one study
that has been reported on 7 patients that used rTMS to the left dorsal
prefrontal cortex on children/adolescents with depression (5 of the 7
subjects treated responded). Although there are limited studies using
rTMS (in 34 children), these studies did not report significant adverse
effects or seizures. Repetitive TMS safety, ethical, and neurotoxicity
concerns also are discussed.
Neurobiol Dis. 2005 Jun-Jul;19(1-2):119-28. |
Repetitive low-frequency stimulation reduces epileptiform synchronization in limbic neuronal networks.
D’Arcangelo G, Panuccio G, Tancredi V, Avoli M.
Dipartimento di Neuroscienze, Universita degli Studi di Roma Tor Vergata, 00173, Roma, Italy.
Deep-brain electrical or transcranial magnetic stimulation may
represent a therapeutic tool for controlling seizures in patients
presenting with epileptic disorders resistant to antiepileptic drugs. In
keeping with this clinical evidence, we have reported that repetitive
electrical stimuli delivered at approximately 1 Hz in mouse
hippocampus-entorhinal cortex (EC) slices depress the EC ability to
generate ictal activity induced by the application of 4-aminopyridine
(4AP) or Mg(2+)-free medium (Barbarosie, M., Avoli, M., 1997. CA3-driven
hippocampal-entorhinal loop controls rather than sustains in vitro
limbic seizures. J. Neurosci. 17, 9308-9314.). Here, we confirmed a
similar control mechanism in rat brain slices analyzed with field
potential recordings during 4AP (50 microM) treatment. In addition, we
used intrinsic optical signal (IOS) recordings to quantify the intensity
and spatial characteristics of this inhibitory influence. IOSs reflect
the changes in light transmittance throughout the entire extent of the
slice, and are thus reliable markers of limbic network epileptiform
synchronization. First, we found that in the presence of 4AP, the IOS
increases, induced by a train of electrical stimuli (10 Hz for 1 s) or
by recurrent, single-shock stimulation delivered at 0.05 Hz in the deep
EC layers, are reduced in intensity and area size by low-frequency (1
Hz), repetitive stimulation of the subiculum; these effects were
observed in all limbic areas contained in the slice. Second, by testing
the effects induced by repetitive subicular stimulation at 0.2-10 Hz, we
identified maximal efficacy when repetitive stimuli are delivered at 1
Hz. Finally, we discovered that similar, but slightly less pronounced,
inhibitory effects occur when repetitive stimuli at 1 Hz are delivered
in the EC, suggesting that the reduction of IOSs seen during repetitive
stimulation is pathway dependent as well as activity dependent. Thus,
the activation of limbic networks at low frequency reduces the intensity
and spatial extent of the IOS changes that accompany ictal
synchronization in an in vitro slice preparation. This conclusion
supports the view that repetitive stimulation may represent a potential
therapeutic tool for controlling seizures in patients with
pharmaco-resistant epileptic disorders.
Neuron. 2005 Jan 20;45(2):181-3. |
Towar establishing a therapeutic window for rTMS by theta burst stimulation.
Paulus W.
Department of Clinical Neurophysiology, University of Goettingen, D-37075 Goettingen, Germany.
In this issue of Neuron, Huang et al. show that a version of the
classic theta burst stimulation protocol used to induce LTP/LTD in brain
slices can be adapted to a transcranial magnetic stimulation (TMS)
protocol to rapidly produce long lasting (up to an hour), reversible
effects on motor cortex physiology and behavior. These results may have
important implications for the development of clinical applications of
rTMS in the treatment of depression, epilepsy, Parkinson’s, and other
diseases.
Neurology. 2004 Dec 14;63(11):2051-5. |
Cortical excitability in drug-naive patients with partial epilepsy: a cross-sectional study.
Varrasi C, Civardi C, Boccagni C, Cecchin M, Vicentini R, Monaco F, Cantello R.
Department of Medical Sciences, Section of Neurology, Universita del Piemonte Orientale A. Avogadro, Novara, Italy.
OBJECTIVE: To use paired-pulse transcranial magnetic stimulation
(TMS) to investigate cortical excitability in drug-naive patients with
partial epilepsy.
METHODS: Twenty-one drug-naive patients with partial epilepsy and 15
control subjects were studied. The relaxed threshold to TMS, the central
silent period, and the intracortical inhibition/facilitation were
measured. Statistics implied cluster analysis methods. Also assessed
were the patient interictal EEG epileptiform abnormalities (EAs) on a
semiquantitative basis. Then the TMS was contrasted to the clinical and
EEG findings, using chi2 or Fisher exact tests.
RESULTS: One-third of the patients made up a “pathologic” cluster
with a disrupted intracortical inhibition (p < 0.01). Two-thirds had a
normal inhibition. Interictal EAs predominated in the pathologic
cluster, for frequency (p < 0.04), duration (p < 0.04), and
focality (p < 0.02).
CONCLUSIONS: Intracortical inhibition, which was impaired in
one-third of the patients, reflects gamma-aminobutyric acid (GABA)
activity within cortical area 4. Defective GABA inhibition is a typical
pathogenic factor in partial epilepsy. Transcranial magnetic stimulation
proved able to detect it. The weaker cortical inhibition had a direct
relation to the severity of interictal epileptiform abnormalities.
Child Adolesc Psychiatr Clin N Am. 2005 Jan;14(1):193-210, viii-ix. |
Electoconvulsive therapy and repetitive transcranial magnetic
stimulation in children and adolescents: a review and report of two
cases of epilepsia partialis continua.
Morales OG, Henry ME, Nobler MS, Wassermann EM, Lisanby SH.
Magnetic Brain Stimulation Laboratory, Department of Biological
Psychiatry, New York State Psychiatric Institute, 1051 Riverside Drive,
Box 126, New York, NY 10032-2695, USA. om2102@columbia.edu
Brain stimulation for the treatment of psychiatric disorders has
received increasing attention over the past decade. The introduction of
experimental means to stimulate the brain noninvasively with magnetic
fields not only has raised interest in these novel means of modulating
brain activity but also has refocused attention on a mainstay in the
treatment of severe major depression and other disorders
(electroconvulsive therapy). This article reviews the current state of
knowledge concerning the use electroconvulsive therapy, repetitive
transcranial magnetic stimulation, and magnetic seizure therapy in
children and adolescents. Two cases of medically intractable epilepsia
partialis continua are presented to add to the limited literature on the
use of repetitive transcranial magnetic stimulation in children and
adolescents and illustrate the concept of using functional neuroimaging
results to target the application of a focal intervention in an attempt
to dampen hyperactive regions of the cortex.
Zh Vyssh Nerv Deiat Im I P Pavlova. 2005 Mar-Apr;55(2):202-6. |
Transcranial magnetic stimulation in research of emotion in the healthy and patients with epilepsy.
[Article in Russian]
Gimranov RF, Kurdiukova EN.
The main aim of this work was by using transcranial magnetic
stimulation to investigate mechanisms of interhemispheric organization
the emotion in the healthy and patients with epilepsy. The research was
carried out on three groups: the first and second groups of healthy and
third group of the patients with idiopatical epilepsy. The first and
third groups received transcranial magnetic stimulation on right and
left frontalis area. The second group was control (sham transcranial
magnetic stimulation). Is shown, that transcranial magnetic stimulation
of right frontalis area increases the examining time on negative photos
and decreases on positive photos. Transcranial magnetic stimulation of
left frontalis area in the healthy and patients with epilepsy increases
the examining time on positive photos and decreases on negative photos.
The right hemisphere at the healthy and patients with epilepsy in the
greater degree is connected to negative marks of emotions, and left
hemisphere with positive marks of emotions.
Child Adolesc Psychiatr Clin N Am. 2005 Jan;14(1):1-19, v. |
Emerging brain-based interventions for children and adolescents: overview and clinical perspective.
Hirshberg LM, Chiu S, Frazier JA.
The NeuroDevelopment Center, 260 West Exchange Street, Suite 302, Providence, RI 02903, USA. lhirshberg@neruodevelopmentcenter.com
Electroencephalogram biofeedback (EBF), repetitive transcranial
magnetic stimulation (rTMS), and vagal nerve stimulation (VNS) are
emerging interventions that attempt to directly impact brain function
through neurostimulation and neurofeedback mechanisms. This article
provides a brief overview of each of these techniques, summarizes the
relevant research findings, and examines the implications of this
research for practice standards based on the guidelines for recommending
evidence based treatments as developed by the American Academy of Child
and Adolescent Psychiatry for attention deficit hyperactivity disorder
(ADHD). EBF meets the “Clinical Guidelines” standard for ADHD, seizure
disorders, anxiety, depression, and traumatic brain injury. VNS meets
this same standard for treatment of refractory epilepsy and meets the
lower “Options” standard for several other disorders. rTMS meets the
standard for “Clinical Guidelines” for bipolar disorder, unipolar
disorder, and schizophrenia. Several conditions are discussed regarding
the use of evidence based thinking related to these emerging
interventions and future directions.
Clin Neurophysiol. 2004 Dec;115(12):2728-37. |
Seizure incidence during single- and paired-pulse transcranial magnetic stimulation (TMS) in individuals with epilepsy.
Schrader LM, Stern JM, Koski L, Nuwer MR, Engel J Jr.
Department of Neurology, David Geffen School of Medicine at UCLA, 710
Westwood Plaza, Room 1-194 RNRC, Los Angeles, CA 90095, USA. ischrader@mednet.ucla.edu
OBJECTIVE: We reviewed published data and our own data to determine a
quantitative incidence of seizure in subjects with epilepsy undergoing
single- and paired-pulse transcranial magnetic stimulation (spTMS and
ppTMS) and to explore conditions that may increase this risk.
METHODS: A PubMed literature search was performed, and articles from
this search were reviewed. Subjects from our institution also were
included.
RESULTS: The crude risk of a TMS-associated seizure ranges from 0.0
to 2.8% for spTMS and 0.0-3.6% for ppTMS. Medically intractable epilepsy
and lowering antiepileptic drugs were associated with increased
incidence. There was significant center-to-center variability that could
not be explained by differences in patient population or by differences
in reported stimulation parameters. In all cases, seizures were similar
to each subject’s typical seizure and without long-term adverse
outcome. In most cases, doubt was expressed in the original reports as
to whether the seizures were induced by TMS or merely coincidental.
CONCLUSIONS: The incidence of seizure in a subject with epilepsy
during spTMS and ppTMS appears to be small and not associated with
long-term adverse outcome. The incidence is higher under the specific
conditions mentioned above.
SIGNIFICANCE: These findings may enable researchers to more accurately inform subjects of seizure risk during TMS.
Rev Bras Psiquiatr. 2004 Jun;26(2):131-4. Epub 2004 Oct 27. |
Transcranial magnetic stimulation: review of accidental seizures.
[Article in Portuguese]
Rosa MA, Odebrecht M, Rigonatti SP, Marcolin MA.
Instituto e Departamento de Psiquiatria, Hospital das Clinicas, Faculdade de Medicina, Universidade de Sao Paulo, SP, Brazil. moarosa@yahoo.com
Transcranial magnetic stimulation (TMS) is a new technique that has
been used for the treatment of neuropsychiatric disorders, specially
depression. It uses a magnetic stimulator that generates a magnetic
field that is applied over the patient’s skull with a coil. Possible
seizures may be induced accidentally by TMS. TMS is usually used with
sub threshold stimuli and seizures may occur by chance, especially when
over the safety parameters. This article reviews the eight cases of
undesirable seizures occurred with rTMS The possible mechanisms of
seizure induction and the patients profile with a higher risk of
convulsion are also described.
J Neurol Sci. 2004 Oct 15;225(1-2):157-60. |
Epilepsia partialis continua as an isolated manifestation of motor cortical dysplasia.
Misawa S, Kuwabara S, Hirano S, Shibuya K, Arai K, Hattori T.
Department of Neurology, Chiba University School of Medicine, Inohana 1-8-1, Chuo-ku, Chiba 260-8670, Japan. sonoko.m@mb.infoweb.ne.jp
Cortical dysplasia has been increasingly recognized as a cause of
epilepsy. We describe herein a 31-year-old female patient with epilepsia
partialis continua (EPC) in the right extremities, which had lasted for
15 years without generalized seizures and other neurological
deteriorations. MRI showed a focal thickening around the left motor
area, indicative of cortical dysplasia, with adjacent subcortical
abnormal T2 high intensity, suggestive of dysmyelination. Transcranial
magnetic stimulation revealed low motor thresholds and markedly
prolonged latencies of motor-evoked potentials (MEP) of the affected
side, consistent with hyperexcitability of the cortical motoneurons
accompanied by dysmyelination. This case demonstrates that motor cortex
dysplasia can result in a mild and non-progressive form of epilepsia
partialis continua, associated with the characteristic MRI and MEP
abnormalities.
Mult Scler. 2004 Aug;10(4):475-6. |
Transcranial magnetic stimulation as a provocation for epileptic seizures in multiple sclerosis.
Haupts MR, Daum S, Ahle G, Holinka B, Gehlen W.
Department of Neurology, Ruhr University/Knappschaftskrankenhaus, In der Schornau 23-25, D-44892 Bochum, Germany. Michael.Haupts@ruhr-uni-bochum.de
Epileptic seizures may be of a provoked origin in acute phases of
multiple sclerosis (MS), while chronic epilepsy typically occurs in
advanced stages of the disease. A case of seizure provocation during
diagnostic transcranial magnetic stimulation (TMS) is described here
with a corresponding central nervous system (CNS) lesion in cranial
magnetic resonance imaging. A subsequent chronic epileptogenesis
originating from the opposite cerebral hemisphere was observed without
further TMS influence after several years. The case in its clinical
rarity demonstrates that standard single pulse TMS may trigger epileptic
seizures only under limited conditions. Single pulse TMS is still
regarded a safe procedure in MS.
Rinsho Shinkeigaku. 2003 Nov;43(11):799-801. |
Current diagnosis and treatment of status epilepticus.
[Article in Japanese]
Akamatsu N, Tsuji S.
We reviewed the current diagnosis and treatment of status epilepticus
(SE). The SE is defined as the condition in which a seizure persists
for a sufficient length of time or is repeated frequently enough that
recovery between attacks does not occur. Until recently, the most
popular duration of seizures qualifying as SE has been 30 min.
Nonetheless some clinicians suggest that the duration of the seizures
that qualifies the SE should be shorter. In clinical settings the
diagnosis of SE could be difficult without EEGs in patients who have
complex partial SE or subtle SE, as their manifestation is coma without
apparent motor sings. Pseudo-SE (psychogenic seizures) should be
included in the differential diagnosis. Antiepileptic treatment should
be administered immediately according to the protocol once the diagnosis
of SE is made. In patients with refractory SE, general anesthesia with
propofol or midazolam is recommended. Repetitive transcranial magnetic
stimulation to the brain is effective for the treatment of SE in
experimental animals, however further studies are necessary for clinical
use.
Arq Neuropsiquiatr. 2004 Mar;62(1):21-5. Epub 2004 Apr 28. |
Experimental therapy of epilepsy with transcranial magnetic stimulation: lack of additional benefit with prolonged treatment.
Brasil-Neto JP, de Araujo DP, Teixeira WA, Araujo VP, Boechat-Barros R.
Laboratorio de Neurociencias e Comportamento, Departamento de
Ciencias Fisiologicas, Instituto de Biologia, Universidade de Brasilia,
Brasilia, DF, Brasil. jbrasil@unb.br
OBJECTIVE: To investigate the effect of three months of low-frequency
repetitive transcranial magnetic stimulation (rTMS) treatment in
intractable epilepsy.
METHODS: Five patients (four males, one female; ages 6 to 50 years),
were enrolled in the study; their epilepsy could not be controlled by
medical treatment and surgery was not indicated. rTMS was performed
twice a week for three months; patients kept records of seizure
frequency for an equal period of time before, during, and after rTMS
sessions. rTMS was delivered to the vertex with a round coil, at an
intensity 5% below motor threshold. During rTMS sessions, 100 stimuli
(five series of 20 stimuli, with one-minute intervals between series)
were delivered at a frequency of 0.3 Hz.
RESULTS: Mean daily number of seizures (MDNS) decreased in three
patients and increased in two during rTMS–one of these was treated for
only one month; the best result was achieved in a patient with focal
cortical dysplasia (reduction of 43.09% in MDNS). In the whole patient
group, there was a significant (p<0.01) decrease in MDNS of 22.8%.
CONCLUSION: Although prolonged rTMS treatment is safe and moderately
decreases MDNS in a group of patients with intractable epilepsy,
individual patient responses were mostly subtle and clinical relevance
of this method is probably low. Our data suggest, however, that patients
with focal cortical lesions may indeed benefit from this novel
treatment. Further studies should concentrate on that patient subgroup.
Clin EEG Neurosci. 2004 Jan;35(1):4-13. |
Current status of the utilization of antiepileptic treatments in mood, anxiety and aggression: drugs and devices.
Barry JJ, Lembke A, Bullock KD.
Department of Psychiatry, Stanford University Medical Center, 401 Quarry Road MC 5723, Stanford, CA 94305, USA.jbarry@leland.stanford.edu
Interventions that have been utilized to control seizures in people
with epilepsy have been employed by the psychiatric community to treat a
variety of disorders. The purpose of this review will be to give an
overview of the most prominent uses of antiepileptic drugs (AEDs) and
devices like the Vagus Nerve Stimulator (VNS) and Transcranial Magnetic
Stimulation (TMS) in the treatment of psychiatric disease states. By
far, the most prevalent use of these interventions is in the treatment
of mood disorders. AEDs have become a mainstay in the effective
treatment of Bipolar Affective Disorder (BAD). The U.S. Food and Drug
Administration has approved the use of valproic acid for acute mania,
and lamotrigine for BAD maintenance therapy. AEDs are also effectively
employed in the treatment of anxiety and aggressive disorders. Finally,
VNS and TMS are emerging as possibly useful tools in the treatment of
more refractory depressive illness.
Zh Nevrol Psikhiatr Im S S Korsakova. 2004;104(3):25-31. |
Clinical and neurophysiological aspects of epilepsy with photosensitivity.
[Article in Russian]
Karlov VA, Dondov B, Gnezditskii VV, Savitskaia NV, Andreeva OV.
Using mapping EEG with dipole source location, transcranial magnetic
stimulation (TMS), and visual evoked potential (VEP),
clinico-neurophysiological analysis of photosensitivity was carried out
in 7 patients with different types of epilepsy. In all the patients, an
increase of visual response amplitude in VEP assessment and location of
photogenic and eye-closing spike activity was observed in parietal and
occipital areas that suggested a significant role of the striate and
para striate cortex, along with primary projection cortex, in
photosensitivity. Although motor cortex excitability by TMS causes
hypersynchronization of the background activity and increase of slow
wave discharge on the EEG after TMS. TMS is supposed to cause an
activation of antiepileptic system.
Acta Neurol Scand. 2004 Apr;109(4):290-6. |
rTMS reduces focal brain hyperperfusion in two patients with EPC.
Graff-Guerrero A, Gonzales-Olvera J, Ruiz-Garcia M, Avila-Ordonez U, Vaugier V, Garcia-Reyna JC.
Instituto Nacional de Psiquiatria Ramon de la Fuente, Division de Neurociencias, Laboratorio de Neurofisiologia, Mexico DF. agraff@imp.edu.mx
OBJECTIVE: This study was performed to evaluate the acute effect of a
single repetitive transcranial magnetic stimulation (rTMS) session in a
focal hyperperfusion epileptogenic region to induce a transitory
decrease of epileptiform activity.
CASE REPORT: Two epilepsia partialis continua (EPC)-diagnosed
patients, received one session with 15 trains of rTMS (20 Hz; 2 s train,
inter-train of 58 s). Before rTMS session, a brain ictal single photon
emission computed tomography (SPECT) was performed to localize the focal
frontal hyperperfusion region to establish the stimulation site.
Immediately after the rTMS session another ictal SPECT was performed.
Both patients showed a decrease of perfusion in the stimulated regions.
For patient 1 epileptic seizures became intermittent until they stopped
in the following 24 h. Patient 2 showed only a minimal improvement with a
frequency decrease of epileptic spikes.
CONCLUSIONS: Our findings suggest that a single rTMS session reduces
focal epileptogenic activity and could be an alternative approach for
epileptic-resistant patients, but efficacy should be confirmed in a
larger series.
Rev Neurol. 2004 Feb 16-29;38(4):374-80. |
Transcranial magnetic stimulation. Applications in cognitive neuroscience.
[Article in Spanish]
Calvo-Merino B, Haggard P.
Institute of Movement Neuroscience, University College, Londres, UK. b.calvo@ion.ucl.ac.uk
OBJECTIVE: In this review we trace some of the mayor developments in
the use of transcranial magnetic stimulation (TMS) as a technique for
the investigation of cognitive neuroscience. Technical aspects of the
magnetic stimulation are also reviewed.
DEVELOPMENT: Among the many methods now available for studying
activity of the human brain, magnetic stimulation is the only technique
that allows us to interfere actively with human brain function. At the
same time it provides a high degree of spatial and temporal resolution.
Standard TMS applications (central motor conduction time, threshold and
amplitude of motor evoked potentials) allow the evaluation of the motor
conduction in the central nervous system and more complex TMS
applications (paired pulse stimulation, silent period) permit study the
mechanisms of diseases causing changes in the excitability of cortical
areas. These techniques also allow investigation into motor disorder,
epilepsy, cognitive function and psychiatric disorders.
CONCLUSIONS: Transcranial magnetic stimulation applications have an
important place among the investigative tools to study cognitive
functions and neurological and psychiatric disorders. Even so, despite
the many published research and clinical studies, a systematic study
about the possible diagnostic value and role in neurocognitive
rehabilitation of TMS testing need to be realized to offer new
possibilities of future applications.
Lancet Neurol. 2004 Feb;3(2):111-8. |
Brain stimulation for epilepsy.
Theodore WH, Fisher RS.
Clinical Epilepsy Section, National Institute of Neurological
Diseases and Stroke, National Institutes of Health, Bethesda, MD 20892,
USA. theodorw@ninds.nih.gov
Neural stimulation is a promising new technology for the treatment of
medically-intractable seizures. Vagus-nerve stimulation (VNS) is
licensed in several countries as an adjunctive therapy. VNS is as
effective as antiepileptic drug therapy, and serious complications are
rare. Transcranial magnetic stimulation is simple, non-invasive, and
widely used in neurophysiology. Therapeutic results in a few studies are
equivocal at best. Deep brain stimulation, although experimental, has
been applied to the cerebellum, caudate nucleus, centromedian thalamus,
anterior thalamus, subthalamus, hippocampus, and neocortical seizure
foci. Preliminary results are encouraging, but not conclusive. Electrode
implantation in the brain for indications other than seizures has been
associated with a 5% risk for intracranial haemorrhage and 5% for
infection. A controlled study of anterior thalamic stimulation in
patients with intractable partial and secondarily generalised seizures
has been started. Future investigations are likely to study
extrathalamic sites of stimulation, and effects of stimulation
contingent upon detection of or prediction of EEG patterns of
epileptiform activity.
J Pharmacol Exp Ther. 2004 Apr;309(1):1-7. Epub 2004 Jan 16. |
Brain stimulation for neurological and psychiatric disorders, current status and future direction.
Chang JY.
Department of Physiology and Pharmacology, Wake Forest University School of Medicine, Winston-Salem, NC 27157-1083, USA. jchang@wfubmc.edu
Interest in brain stimulation therapies has been rejuvenated over the
last decade and brain stimulation therapy has become an alternative
treatment for many neurological and psychiatric disorders, including
Parkinson’s disease (PD), dystonia, pain, epilepsy, depression, and
schizophrenia. The effects of brain stimulation on PD are well
described, and this treatment has been widely used for such conditions
worldwide. Treatments for other conditions are still in experimental
stages and large-scale, well controlled studies are needed to refine the
treatment procedures. In the treatment of intractable brain disorders,
brain stimulation, especially transcranial magnetic stimulation (TMS),
is an attractive alternative to surgical lesioning as it is relatively
safe, reversible, and flexible. Brain stimulation, delivered either via
deeply implanted electrodes or from a surface-mounted transcranial
magnetic device, can alter abnormal neural circuits underlying brain
disorders. The neural mechanisms mediating the beneficial effects of
brain stimulation, however, are poorly understood. Conflicting theories
and experimental data have been presented. It seems that the action of
stimulation on brain circuitry is not limited to simple excitation or
inhibition. Alterations of neural firing patterns and long-term effects
on neurotransmitter and receptor systems may also play important roles
in the therapeutic effects of brain stimulation. Future research on both
the basic and clinical fronts will deepen our understanding of how
brain stimulation works. Real-time computation of neural activity allows
for integration of brain stimulation signals into ongoing neural
processing. In this way abnormal circuit activity can be adjusted by
optimal therapeutic brain stimulation paradigms.
Neurosci Lett. 2004 Jan 9;354(2):91-4. |
Intracranial measurement of current densities induced by transcranial magnetic stimulation in the human brain.
Wagner T, Gangitano M, Romero R, Theoret H, Kobayashi M, Anschel D, Ives J, Cuffin N, Schomer D, Pascual-Leone A.
Laboratory for Magnetic Brain Stimulation, Beth Israel Deaconess
Medical Center, Harvard Medical School, 330 Brookline Ave KS-454,
Boston, MA 02215, USA.
Transcranial magnetic stimulation (TMS) is a non-invasive technique
that uses the principle of electromagnetic induction to generate
currents in the brain via pulsed magnetic fields. The magnitude of such
induced currents is unknown. In this study we measured the TMS induced
current densities in a patient with implanted depth electrodes for
epilepsy monitoring. A maximum current density of 12 microA/cm2 was
recorded at a depth of 1 cm from scalp surface with the optimum
stimulation orientation used in the experiment and an intensity of 7% of
the maximal stimulator output. During TMS we recorded relative current
variations under different stimulating coil orientations and at
different points in the subject’s brain. The results were in accordance
with current theoretical models. The induced currents decayed with
distance form the coil and varied with alterations in coil orientations.
These results provide novel insight into the physical and
neurophysiological processes of TMS.
Epilepsia. 2004 Jan;45(1):77-80. |
Motor responses to afferent stimulation in juvenile myoclonic epilepsy.
Manganotti P, Tamburin S, Bongiovanni LG, Zanette G, Fiaschi A.
Department of Neurological Sciences and Vision, Section of
Neurological Rehabilitation Clinical Neurology, University of Verona,
Verona, Italy.
PURPOSE: To document whether the mechanisms responsible for myoclonic
jerks in juvenile myoclonic epilepsy (JME) are similar to those causing
other forms of myoclonus.
METHODS: We studied somatosensory evoked potentials, the conditioning
effect of cutaneous afferents on motor potentials evoked by
transcranial magnetic stimulation (TMS), and intracortical inhibition
and facilitation in response to paired TMS in a group of nine patients
with JME and 20 normal controls.
RESULTS: Intracortical inhibition was abnormal, whereas cortical
somatosensory evoked potentials and TMS conditioned by cutaneous
afferents were unaltered in JME patients.
CONCLUSIONS: Abnormal processing of cutaneous afferents would not appear to contribute to myoclonus in JME.
J Neurosci. 2003 Nov 26;23(34):10867-72. |
Priming stimulation enhances the depressant effect of low-frequency repetitive trnscranial magnetic stimulation.
Iyer MB, Schleper N, Wassermann EM.
Brain Stimulation Unit, National Institute of Neurological Disorders
and Stroke, National Institutes of Health, Bethesda, Maryland
20892-1430, USA.
Low-frequency (1 Hz) repetitive transcranial magnetic stimulation
(rTMS) can depress the excitability of the cortex locally and has been
proposed for the treatment of disorders such as schizophrenia and
epilepsy. Some have speculated that the depressant effect is related to
long-term depression (LTD) of cortical synapses. Because in vitro LTD
can be enhanced by pretreatment of synapses with higher-frequency
stimulation, we hypothesized that if rTMS depression had mechanisms in
common with LTD, higher-frequency priming would increase it also. In 25
healthy volunteers in two experiments, we measured motor-evoked
potentials (MEPs) from TMS of the motor cortex to define the baseline
response. Subthreshold rTMS (6 Hz, fixed rate or frequency modulated)
was used to prime the motor cortex, followed by suprathreshold 1 Hz
stimulation for 10 min at just above the MEP threshold. Over the next 60
min, we recorded MEPs every 10 sec and found significant increases in
the amount of cortical depression with both types of 6 Hz priming rTMS
relative to sham. The MEP depression from 6 Hz-primed 1 Hz rTMS showed
no evidence of decay after 60 min. Pretreatment with 6 Hz primes both 1
Hz rTMS depression and LTD. Although not conclusive evidence, this
strengthens the case for overlapping mechanisms and suggests a potent
new technique for enhancing low-frequency rTMS depression that may have
experimental and clinical applications.
Epilepsy Behav. 2003 Oct;4 Suppl 3:S46-54. |
Treatment of depression in patients with epilepsy: problems, pitfalls, and some solutions.
Krishnamoorthy ES.
T.S. Srinivasan Institute of Neurological Sciences and Research, Public Health Centre, Chennai, India. E.S.Krishnamoorthy@ion.ucl.ac.uk
Many people with epilepsy suffer from comorbid depression. Despite
this, there have been few studies addressing the treatment of depression
in this population, and the literature on psychiatric management
techniques in patients with epilepsy is composed largely of opinions
rather than evidence from randomized, controlled trials or other
systematic investigations. Antidepressant drugs, including tricyclics
and selective serotonin reuptake inhibitors, can be used to treat
patients with epilepsy and comorbid depression. Nonpharmacological
treatment options include vagus nerve stimulation, transcranial magnetic
stimulation, and psychological therapies including cognitive-behavioral
therapy, individual or group psychotherapy, patient support groups,
family therapy, and counseling. Another important area that remains
largely uninvestigated is psychiatric research in patients with epilepsy
in non-Western cultures (with the exception of Japan). Factors such as
problems with access to and acceptability of therapies in many
developing nations have further implications for the treatment of
psychiatric disorders in epilepsy.
Neurosci Lett. 2003 Nov 6;351(1):9-12. |
Anti-kindling effect of slow repetitive transcranial magnetic stimulation in rats.
Anschel DJ, Pascual-Leone A, Holmes GL.
Laboratory for Magnetic Brain Stimulation, Beth Israel Deaconess
Medical Center, and Department of Neurology, Harvard Medical School, 330
Brookline Avenue, Boston, MA 02215, USA. danschel@stanford.edu
The cerebrospinal fluid (CSF) of animals exposed to electroconvulsive
shock (ECS) has anticonvulsant properties when injected into naive
animals. The present study investigated whether the CSF of humans
exposed to 1 or 10 Hz repetitive transcranial magnetic stimulation
(rTMS) has similar properties. Using a 4 day rat flurothyl kindling
seizure model we found that the kindling rate was significantly
decreased by intraventricular injection of CSF from depressed patients
exposed to 1 Hz rTMS. The CSF from patients that underwent 10 Hz rTMS
showed a trend toward an increased kindling rate. These results support
the similarity of ECS and rTMS and suggest that 1 Hz and 10 Hz rTMS
produce distinct physiologic changes.
Clin Neurophysiol. 2003 Oct;114(10):1827-33. |
Suprathreshold 0.3 Hz repetitive TMS prolongs the cortical silent
period: potential implications for therapeutic trials in epilepsy.
Cincotta M, Borgheresi A, Gambetti C, Balestrieri F, Rossi L, Zaccara G, Ulivelli M, Rossi S, Civardi C, Cantello R.
Unita’ Operativa di Neurologia, Azienda Sanitaria di Firenze,
Ospedale S. Maria Nuova, Piazza S. Maria Nuova, 1 50122, Florence,
Italy. cincotta@unifi.it
OBJECTIVE: To investigate the after-effects of 0.3 Hz repetitive
transcranial magnetic stimulation (rTMS) on excitatory and inhibitory
mechanisms at the primary motor cortex level, as tested by single-pulse
TMS variables.
METHODS: In 9 healthy subjects, we studied a wide set of
neurophysiological and behavioral variables from the first dorsal
interosseous before (Baseline), immediately after (Post 1), and 90 min
after (Post 2) the end of a 30 min long train of 0.3 Hz rTMS delivered
at an intensity of 115% resting motor threshold (RMT). Variables under
investigation were: maximal M wave, F wave, and peripheral silent period
after ulnar nerve stimulation; RMT, amplitude and stimulus-response
curve of the motor evoked potential (MEP), and cortical silent period
(CSP) following TMS; finger-tapping speed.
RESULTS: The CSP was consistently lengthened at both Post 1 and Post 2
compared with Baseline. The other variables did not change
significantly.
CONCLUSIONS: These findings suggest that suprathreshold 0.3 Hz rTMS
produces a relatively long-lasting enhancement of the inhibitory
mechanisms responsible for the CSP. These effects differ from those,
previously reported, of 0.9-1 Hz rTMS, which reduces the excitability of
the circuits underlying the MEP and does not affect the CSP. This
provides rationale for sham-controlled trials aiming to assess the
therapeutic potential of 0.3 Hz rTMS in epilepsy.
Seizure. 2003 Sep;12(6):373-8. |
Usefulness of magnetic motor evoke potentials in the surgical treatment of hemiplegic patients with intractable epilepsy.
Kamida T, Baba H, Ono K, Yonekura M, Fujiki M, Kobayashi H.
Department of Neurosurgery, Oita Medical University, 1-1 Idaigaoka, Hasama-machi, Oita 879-55, Japan.
Five hemiplegic patients with intractable epilepsy were studied with
transcranial magnetic stimulation (TMS) before and after various
surgical treatments. These patients had unilateral widespread cerebral
lesions acquired at various times, including congenital, infantile and
childhood injury. Motor evoked potentials (MEPs) of the abductor
pollicis brevis (APB) muscles were simultaneously recorded on both sides
following TMS of the motor cortex in the respective hemisphere using a
figure-8 or circular coil. In all patients with congenital disease, the
abolition of motor function in the affected hemisphere was estimated by
magnetic MEPs, and the hemiplegia did not deteriorate after functional
hemispherectomy (HS) was performed in two of them. In two patients with
acquired disease, HS was not performed because it was shown by magnetic
maps that the motor function in the affected hemisphere remained.
Furthermore, it was shown by electric MEPs using subdural electrodes
that a patient who had had encephalitis in early childhood had a
reorganised motor area in the parietal cortex of the affected
hemisphere. The present findings indicate that magnetic MEPs are a very
useful non-invasive method of assessing whether the motor area in the
affected hemisphere can be resected in hemiplegic patients with
intractable epilepsy.
Nervenarzt. 2003 Aug;74(8):664-76. |
Electric brain stimulation for epilepsy therapy.
[Article in German]
Kellinghaus C, Loddenkemper T, Moddel G, Tergau F, Luders J, Ludemann P, Nair DR, Luders HO.
Department of Neurology, The Cleveland Clinic Foundation, Cleveland, Ohio, USA. kelling@uni-muenster.de
Attempts to control epileptic seizures by electrical brain
stimulation have been performed for 50 years. Many different stimulation
targets and methods have been investigated. Vagal nerve stimulation
(VNS) is now approved for the treatment of refractory epilepsies by
several governmental authorities in Europe and North America. However,
it is mainly used as a palliative method when patients do not respond to
medical treatment and epilepsy surgery is not possible. Numerous
studies of the effect of deep brain stimulation (DBS) on epileptic
seizures have been performed and almost invariably report remarkable
success. However, a limited number of controlled studies failed to show a
significant effect. Repetitive transcranial magnetic stimulation (rTMS)
also was effective in open studies, and controlled studies are now
being carried out. In addition, several uncontrolled reports describe
successful treatment of refractory status epilepticus with
electroconvulsive therapy (ECT). In summary, with the targets and
stimulation parameters investigated so far, the effects of electrical
brain stimulation on seizure frequency have been moderate at best. In
the animal laboratory, we are now testing high-intensity, low-frequency
stimulation of white matter tracts directly connected to the
epileptogenic zone (e.g., fornix, corpus callosum) as a new methodology
to increase the efficacy of DBS (“overdrive method”).
Int J Neurosci, 66(1-2):75-85 1992 Sep
Attenuation of epilepsy with application of external magnetic fields: a case report.
Sandyk R; Anninos PA , Democrition University of Thrace, Department of Medical Physics, Alexandroupolis, Greece.
We have previously demonstrated that magnetoencephalographic (MEG)
brain measurements in patients with seizure disorders show significant
MEG activity often in the absence of conventional EEG abnormalities. We
localized foci of seizure activity using the mapping technique
characterized by the ISO-Spectral Amplitude (ISO-SA) on the scalp
distribution of specified spectral components or frequency bands of the
emitted MEG Fourier power spectrum. In addition, using an electronic
device, we utilized the above recorded activity to emit back the same
intensity and frequency of magnetic field to the presumed epileptic
foci. Using this method we were able, over the past two and one-half
years, successfully to attenuate seizure activity in a cohort of over
150 patients with various forms of epilepsy. We present a patient with
severe epilepsy and behavioral disturbances in whom application of an
external artificial magnetic field of low intensity produced a
substantial attenuation of seizure frequency which coincided with an
improvement in the patient’s behavior. This case demonstrates that
artificial magnetic treatment may be a valuable adjunctive procedure in
the management of epilepsy.