Shape and volume changes of the superior lateral ventricle after electroconvulsive therapy measured with ultra-high field MRI.

The subventricular zone (SVZ) of the lateral ventricles harbors neuronal stem cells in adult mammals. Rodent studies report neurogenic effects in the SVZ of electroconvulsive stimulation. We hypothesize that if this finding translates to depressed patients undergoing electroconvulsive therapy (ECT), this would be reflected in shape changes at the SVZ. Using T1-weighted MR images acquired at ultra-high field strength (7T), the shape and volume of the ventricles were compared from pre to post ECT after 10 ECT sessions (in patients twice weekly) or 5 weeks apart (controls) using linear mixed models with age and gender as covariates. Ventricle shape significantly changed and volume significantly decreased over time in patients for the left ventricle, but not in controls. The decrease in volume of the ventricles was associated to a decrease in depression scores, and an increase in the left dentate gyrus, However, the shape changes of the ventricles were not restricted to the neurogenic niche in the lateral walls of the ventricles, providing no clear evidence for neurogenesis as sole explanation of volume changes in the ventricles after ECT.

Vasogenic edema versus neuroplasticity as neural correlates of hippocampal volume increase following electroconvulsive therapy.

BACKGROUND: Volume increases of the hippocampus after electroconvulsive therapy (ECT) are a robust finding, pointing into the direction of neurogenesis. However, such volumetric increases could also be explained by edema and/or neuroplastic changes (such as angiogenesis). OBJECTIVES: If edema explains the volume increase of the hippocampus we hypothesize it would lead to increased mean diffusivity (MD). If neuroplastic would explain the volume increase, it would lead to decreased MD. To investigate angiogenesis as explanation we studied the perfusion fraction f and the pseudodiffusion component D∗ obtained from intravoxel incoherent motion (IVIM) data, and relative perfusion changes obtained from arterial spin labelling (ASL) data. METHODS: Using ultra-high field (7 tesla) MRI we acquired IVIM and ASL data. We compared MD, f, D∗ and ASL values for both hippocampi in 21 patients (before and after 10 ECT sessions) and 8 healthy controls (without ECT) in a linear mixed model adjusting for age and gender. RESULTS: We found a significant decrease in MD (which was absent in the healthy controls) in the left and right hippocampus (t = -3.98, p < 0.001). In addition, a decrease in f (t = -4.61, p < 0.001, but not in controls) and no differences in D∗ or ASL perfusion values (both p > 0.05) were found. CONCLUSIONS: The decrease in MD in perfusion fraction f suggest that formation of edema nor angiogenesis are responsible for the ECT-induced volume increases in the hippocampus. Also, it supports the hypothesis that hippocampal volume increases might be due to neuroplastic changes.

Volume increase in the dentate gyrus after electroconvulsive therapy in depressed patients as measured with 7T.

Electroconvulsive therapy (ECT) is the most effective treatment for depression, yet its working mechanism remains unclear. In the animal analog of ECT, neurogenesis in the dentate gyrus (DG) of the hippocampus is observed. In humans, volume increase of the hippocampus has been reported, but accurately measuring the volume of subfields is limited with common MRI protocols. If the volume increase of the hippocampus in humans is attributable to neurogenesis, it is expected to be exclusively present in the DG, whereas other processes (angiogenesis, synaptogenesis) also affect other subfields. Therefore, we acquired an optimized MRI scan at 7-tesla field strength allowing sensitive investigation of hippocampal subfields. A further increase in sensitivity of the within-subjects measurements is gained by automatic placement of the field of view. Patients receive two MRI scans: at baseline and after ten bilateral ECT sessions (corresponding to a 5-week interval). Matched controls are also scanned twice, with a similar 5-week interval. A total of 31 participants (23 patients, 8 controls) completed the study. A large and significant increase in DG volume was observed after ECT (M = 75.44 mm3, std error = 9.65, p < 0.001), while other hippocampal subfields were unaffected. We note that possible type II errors may be present due to the small sample size. In controls no changes in volume were found. Furthermore, an increase in DG volume was related to a decrease in depression scores, and baseline DG volume predicted clinical response. These findings suggest that the volume change of the DG is related to the antidepressant properties of ECT, and may reflect neurogenesis.

Immediate and long-term effects of bilateral electroconvulsive therapy on cognitive functioning in patients with a depressive disorder.

BACKGROUND: Electroconvulsive therapy (ECT) is the most effective treatment for patients suffering from major depression. However, its use is limited due to concerns about negative effects on cognition. Unilateral ECT is associated with transient cognitive side-effects, while case-controlled studies investigating the effect of bilateral ECT on cognition remain scarce. We investigate the effects of bilateral ECT on cognition in depression in a longitudinal case-controlled study. We hypothesize that adverse cognitive effects of bilateral ECT are transient rather than long-term. METHODS: A total of 48 depressed patients and 19 controls were included in the study and assessed with a battery of cognitive tests, including tests of: working memory, verbal fluency, visuospatial abilities, verbal/visual memory and learning, processing speed, inhibition, attention and task-switching, and premorbid IQ. Patients underwent three cognitive assessments: at baseline (n = 43), after ten ECT sessions (post-treatment; n = 39) and six months after the tenth ECT session (follow-up; n = 25). Healthy controls underwent the same cognitive assessment at baseline and after five-weeks. RESULTS: Within the patient group, transient adverse cognitive side-effects were observed for verbal memory and learning, and verbal fluency. None of the cognitive domains tested in this study showed persisting impairments. LIMITATIONS: A relatively high attrition rate is observed and autobiographical memory was not assessed. CONCLUSION: This study shows that bilateral ECT has negative cognitive effects on short-term. These effects could be explained by a decrease in cognitive performance, a lack of learning effects or a combination. However, the decrease in cognitive functioning appears to recover after six months.

Theta Burst Transcranial Magnetic Stimulation for Auditory Verbal Hallucinations: Negative Findings From a Double-Blind-Randomized Trial.

BACKGROUND: Auditory verbal hallucinations (AVH) in schizophrenia are resistant to antipsychotic medication in approximately 25% of patients. Treatment with repetitive transcranial magnetic stimulation (rTMS) for refractory AVH has shown varying results. A stimulation protocol using continuous theta burst rTMS (TB-rTMS) showed high efficacy in open label studies. We tested TB-rTMS as a treatment strategy for refractory AVH in a double-blind, placebo-controlled trial. METHODS: Seventy-one patients with AVH were randomly allocated to TB-rTMS or placebo treatment. They received 10 TB-rTMS or sham treatments over the left temporoparietal cortex in consecutive days. AVH severity was assessed at baseline, end of treatment and follow-up using the Psychotic Symptom Rating Scale (PSYRATS) and the Auditory Hallucinations Rating Scale (AHRS). Other schizophrenia-related symptoms were assessed with the Positive and Negative Syndrome Scale (PANSS). RESULTS: Seven patients dropped out before completing the study. In the remaining 64, AVH improved significantly after treatment in both groups as measured with both PSYRATS and AHRS. PANSS positive and general subscores also decreased, but the negative subscores did not. However, improvement did not differ significantly between the TB-rTMS and the placebo group on any outcome measure. CONCLUSIONS: Symptom reduction could be achieved in patients with medication-resistant hallucinations, even within 1 week time. However, as both groups showed similar improvement, effects were general (ie, placebo-effects) rather than specific to treatment with continuous TB-rTMS. Our findings highlight the importance of double-blind trials including a sham-control condition to assess efficacy of new treatments such as TMS.

Transcranial magnetic stimulation, transcranial direct current stimulation and electroconvulsive therapy for medication-resistant psychosis of schizophrenia.

PURPOSE OF REVIEW: Despite adequate antipsychotic treatment, 20-30% of patients with schizophrenia fail to obtain remission from psychosis. Physical stimulation treatments may provide an alternative therapy. In this review, we summarize the most recent studies regarding repetitive transcranial magnetic stimulation (rTMS), transcranial direct current stimulation (tDCS) and electroconvulsive therapy (ECT) for medication-resistant psychosis in schizophrenia. RECENT FINDINGS: Stimulation techniques in the treatment of medication-resistant psychosis have shown inconsistent results. Initial results of rTMS for auditory verbal hallucinations (AVH) were promising, but three recent large randomized controlled trials (RCTs) show similar results of rTMS as placebo. tDCS has shown initial promise as a treatment for AVH, but only in case studies and in two small RCTs. Larger studies are needed to define its efficacy. Although psychotic symptoms generally decrease after ECT, its efficacy has not been demonstrated in comparison with placebo. SUMMARY: Although previous meta-analyses indicate significant mean effect sizes for rTMS for intractable AVH, three recent large RCTs indicate no effect compared with placebo. The use of tDCS for resistant AVH and ECT for intractable psychosis has shown some initial promise, but adequately sized placebo-controlled RCTs are now needed. Taken together, the evidence for physical stimulation techniques to relieve medication-resistant psychosis is currently weak.