[Transcranial electrical brain stimulation methods for treatment of negative symptoms in schizophrenia]. / Transkranielle elektrische Hirnstimulationsverfahren zur Behandlung der Negativsymptomatik bei Schizophrenie.

In recent years noninvasive brain stimulation (NIBS) applications have emerged as a third and novel treatment option alongside psychopharmacology and psychotherapy in the treatment of mental diseases. It is assumed that NIBS could represent a supplement or (in some indications) even replacement to established therapeutic strategies, e.g. in disorders with high resistance to current treatment regimens, such as negative symptoms or cognitive impairments in schizophrenia. Although positive symptoms in schizophrenia can be treated sufficiently with antipsychotic drugs, patients with negative symptoms frequently suffer from persistent lack of impetus, cognitive decline, social withdrawal and loss of global functioning in the activities of daily life; however, in these cases, current treatment strategies exert only moderate effects, and new treatment options are urgently needed. This review article provides a summary of the clinical effects of new electrical NIBS methods, e.g. transcranial direct current stimulation (tDCS), transcranial alternating current stimulation (tACS), and transcranial random noise stimulation (tRNS) for the treatment of negative symptoms in schizophrenia. These new NIBS methods could help restore the disrupted neuronal networks and improve disturbed connectivity, especially of the left dorsolateral prefrontal cortex and left temporoparietal junction. Promising results are reported for the treatment of negative symptoms with tDCS, tACS and tRNS and could thus represent new therapeutic options in the treatment of schizophrenia.

Gamma transcranial alternating current stimulation (γtACS) in obsessive-compulsive disorder: a case report

Die Zwangsstörung hat oftmals einen chronischen Verlauf mit Therapieresistenz gegenüber Psychopharmakotherapie und Psychotherapie. Neue nichtinvasive Hirnstimulationsverfahren könnten helfen, Zwangssymptome zu vermindern. In diesem Fallbericht wird die Behandlung einer Patientin mit Zwangsstörung dargestellt, die mit 10 transkraniellen Wechselstromstimulationen in Gamma-Frequenz (40 Hz) im Rahmen eines Heilversuchs behandelt wurde. Die Yale-Brown Obsessive-Compulsive Scale verminderte sich von 70 auf 59 Punkte, und die Hamilton Depression Rating Scale sank von 25 auf 12 Punkte. Daneben konnte eine Verbesserung des Regensburger Wortflüssigkeitstests, des Pfadfindertests und eines computergestützten n-back-Tests verzeichnet werden. Eine Hypothese für die Verbesserung der Zwangsstörung durch Gamma-Wechselstromstimulation könnte eine Auswirkung auf die bei psychischen Erkrankungen (Depression, Zwangsstörung) veränderte alpha-Frequenz sein. Der hier vorgestellte Fall bestätigt die Ergebnisse einer früheren Fallserie und gibt Anlass zur weiteren Untersuchung dieses Verfahrens.

Gamma transcranial alternating current stimulation improves mood and cognition in patients with major depression.

Major depression is one of the most common psychiatric disorders with a high rate of treatment resistance where new treatment options are urgently warranted. One of these new options are non-invasive brain stimulation techniques like transcranial magnetic or electric stimulation. One of the latter is transcranial Alternating Current Stimulation (tACS) in various frequencies. Here, we report a case series of six patients suffering from major depression treated with tACS in gamma (40 Hz) frequency. Patients were randomized to two groups, receiving either two 10-min stimulations (group 1) or a 20-min stimulation or per day (group 2) over ten days. Hamilton Depression Rating Scale and Beck Depression Inventory decreased during treatment in both study groups by 85% and 78% (group 1), or 62% and 24% respectively (group 2). Results also showed an improvement in cognitive functions assessed by word fluency and n-back test. It is hypothesized that gamma tACS could help to synchronize disturbed frequency bands in frontal and prefrontal cortex areas and thus restore dysbalanced neural connectivity in psychiatric disorders.

Gamma transcranial alternating current stimulation in patients with negative symptoms in schizophrenia: A case series.

Non-invasive transcranial brain stimulation therapies, such as transcranial direct current stimulation, have been found to improve negative symptoms in schizophrenia. Another new technique is transcranial alternating current stimulation (tACS). Here we report a series of three patient treated with twice-daily 10min prefrontal 40Hz tACS stimulation over ten days. Patients showed an improvement in the Positive and Negative Syndrome Scale, Scale for the Assessment of Negative Symptoms, and subjective well-being. Furthermore, there was an improvement in the Trail Making Test and word fluency. ytACS merits further investigation in the treatment of schizophrenia symptoms.