Low-frequency rTMS over right dorsolateral prefrontal cortex in the treatment of resistant depression: cognitive improvement is independent from clinical response, resting motor threshold is related to clinical response.

BACKGROUND: Clinical studies have shown that repetitive transcranial magnetic stimulation (rTMS) is effective in a certain percentage of treatment-resistant depression (TRD). The left dorsolateral prefrontal cortex (DLPFC) 10 Hz rTMS stimulation received FDA approval in 2008, although different rTMS protocols have also shown their effectiveness in reducing depressive symptoms. We investigated the clinical, cognitive and neurophysiologic effects of a 3 weeks' protocol of low-frequency rTMS applied over the right DLPFC in resistant depression. METHODS: Twenty-eight patients with TRD (age range 28-55) received low-frequency rTMS (1 Hz) over the right DLPFC in a 3-week open trial. Hamilton scales for depression and anxiety, Corsi block-tapping test, phonemic verbal fluency, right and left resting motor thresholds were evaluated in each subject over the trial period. RESULTS: At the end of the trial 42.9% of the subjects were considered as responders. A significant reduction of both HAMD (p < 0.001) and HAMA (p < 0.01) total scores was observed. At the 3rd week, the performances in Corsi test (p < 0.02) and phonemic verbal fluency (p = 0.065) were improved independently from depressive symptoms variation. At the end of the rTMS protocol, a significantly decreased left hemisphere resting motor threshold was registered (p < 0.01), while right hemisphere resting motor threshold did not show significant variation. CONCLUSION: Low-frequency rTMS over the right DLPFC appeared effective in 42.9% of depressive resistant subjects in this sample. A significant decrease in left hemisphere resting motor threshold was observed only in responders, while a trend for improvement in cognitive function has been found and appeared independent from clinical response.

Unilateral low frequency versus sequential bilateral repetitive transcranial magnetic stimulation: is simpler better for treatment of resistant depression?

Repetitive transcranial magnetic stimulation (rTMS) efficacy in the treatment of major depression has been shown in both low frequency right-sided and high frequency left-sided stimulation over the dorsolateral prefrontal cortex (DLPFC). The aim of the present investigation was to evaluate the hypothesis of an additive effect of bilateral stimulation compare to sequential to unilateral stimulation. Sixty patients with treatment-resistant depression were assigned to receive either low-frequency rTMS over the right DLPFC (140 s x 1 Hz) followed by controlateral sham (unilateral group, n=20), low frequency right DLPFC rTMS followed by left DLPFC high frequency rTMS (5 s x 10 Hz) (bilateral group, n=20), or bilateral sham (sham group, n=20) in a 3 weeks double-blind, randomized trial. The primary outcome variable was the score on Hamilton Depression Scale (HAM-D). Low frequency right-sided and sequential bilateral stimulation showed different antidepressant efficacy at 3 weeks and across the full duration of the study, only the unilateral method appearing significantly more effective than sham at the end of the trial, and correlated to the higher percent of remitters (30% of the group vs. 10% -bilateral- and 5% -sham). Unilateral stimulation, but not bilateral, showed higher antidepressant efficacy compared to sham stimulation. The data suggest that right-sided low frequency stimulation may be a first line treatment alternative in resistant depression. To confirm and extend these findings further studies require a longer follow-up period, supported by biological observation and replication.

Incidence of RBD and hallucination in patients affected by Parkinson's disease: 8-year follow-up.

We describe the 8-years follow-up of 80 patients affected by idiopathic, L-dopa-responsive Parkinson's disease. All patients were evaluated at baseline and during the follow-up with visual evoked potential, P300 event related potentials and polysomnography. The patients and their relatives compiled sleep and hallucination questionnaires. Statistical analysis was performed to evaluate if visual abnormalities, abnormal P300 recordings or sleep disturbances were linked to the development and hallucinations. Our results show that abnormal vision and abnormal P300 did not correlate with the incidence of hallucinations. However, the presence of REM sleep behavioral disorder (RBD) was significantly related to the development of hallucinations,independently of age, gender or duration of disease but dependent on the amount of dopaminoagonist treatment.