[Brain stimulation procedures. Transcranial magnetic stimulation, magnetic seizure therapy and deep brain stimulation]

["Even electricity cannot work wonders!". Neglected achievements by German psychiatrists around 1880 in the treatment of depressions and psychoses]

Parallel to the recent reneurobiologization of psychiatry as a subject, therapies based on electricity and elektrcomagnetism are returning to mental health care. Around 1880, the application of brain stimulating treatment on patients was particularly popular among German psychiatrists. This fact has largely been ignored in historical psychiatric research as present day practices, in particular deep brain stimulation (DBS), have frequently been seen solely within the tradition of brain surgery. Against this background the present study aims to revive the first trials of non-surgical electrical brain stimulation on depressive and psychotic patients, highlighting a 2-part study published by Wilhelm Tigges. It was Tigges along with Rudolph Gottfried Arndt and Wilhelm Erb who tried to establish clear rules on the most beneficial application methods and doses. Interestingly, Tigges's therapy was successful in cases of severe depression with chronification potential, i.e. precisely the clinical picture for which brain stimulation therapies are reserved today as a last option and ascribed an easing and even curing potential. Trigges also found that electricity produced almost no positive effect whatsoever with madly insane patients and hence anticipated the current non-application of DBS on these patients. After 1890 electrotherapeutic approaches in psychiatry were marginalized, first and foremost as no clear and reliable rules could be verified for their application, nor could their mode of action be fully explained. The success of electrotherapy in psychiatry was also restricted due to limitations of the time, namely (1) electrophysiology only emerging as a discipline, (2) the electrophysical medical apparatus industry only beginning to be established and (3) the lack of generally accepted guidelines and electrotherapy restriction to individual, barely generalizable experience (eclecticism). Present day applications of electricity, mainly DBS, have overcome these problems.

Can transcranial electrical stimulation improve learning difficulties in atypical brain development? A future possibility for cognitive training

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Transcranial electrical stimulation (TES) can improve cognitive training effects in adults.

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TES can enhance neuroplasticity from the molecular level to the system level.

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We discuss the usage of TES with cognitive training in atypically developing children.

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We discuss the possible cognitive and physical side effects of TES.

Learning difficulties in atypical brain development represent serious obstacles to an individual's future achievements and can have broad societal consequences. Cognitive training can improve learning impairments only to a certain degree. Recent evidence from normal and clinical adult populations suggests that transcranial electrical stimulation (TES), a portable, painless, inexpensive, and relatively safe neuroenhancement tool, applied in conjunction with cognitive training can enhance cognitive intervention outcomes. This includes, for instance, numerical processing, language skills and response inhibition deficits commonly associated with profound learning difficulties and attention-deficit hyperactivity disorder (ADHD). The current review introduces the functional principles, current applications and promising results, and potential pitfalls of TES. Unfortunately, research in child populations is limited at present. We suggest that TES has considerable promise as a tool for increasing neuroplasticity in atypically developing children and may be an effective adjunct to cognitive training in clinical settings if it proves safe. The efficacy and both short- and long-term effects of TES on the developing brain need to be critically assessed before it can be recommended for clinical settings.