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This study aimed to investigate changes in plasma concentrations of risperidone and 9-hydroxy-risperidone (9-OHR) and the associated clinical effects when switching from oral risperidone to extended-release (ER) paliperidone in patients with schizophrenia. This study included 25 patients with schizophrenia. Following a one-week screening period with a stable dose of risperidone, a six-week open-label switch study from risperidone to extended-release paliperidone (paliperidone ER) was conducted. Efficacy and safety assessments were performed on Day 1 and at Weeks 1, 2, 4, and 6. Plasma levels of the active fractions of oral risperidone and paliperidone ER were measured on Day 1 and at Week 1, respectively. Plasma levels of the active moiety (risperidone plus 9-OHR) while taking risperidone (mean dose: 4.0 mg) were significantly higher than plasma levels of 9-OHR while taking 6 mg of paliperidone ER. For 12 subjects taking only 3 mg of risperidone, plasma concentrations of the active moiety of risperidone were also significantly higher than those of 9-OHR while taking 6 mg of paliperidone ER. The amount of reduction in plasma levels was correlated with a temporal deterioration of clinical symptoms. These findings suggest that for patients with schizophrenia taking 3 mg or more of risperidone, an initial switching dose of 6 mg of paliperidone ER may be relatively low in terms of subsequent plasma concentrations and the associated clinical response. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to investigate the motor recovery mechanism following diffuse axonal injury (DAI) using transcranial magnetic stimulation (TMS) and functional MRI (fMRI). Methods: Twenty-six hands of 13 control subjects and 14 affected hands of 8 patients (two hemiparetics and six quadriparetics) were evaluated. All the patients were initially diagnosedwith DAIand were evaluated after they had reached their maximal motor recovery. fMRI was performed at 1.5 T using a hand grasp-release movement paradigm and TMS was applied with a round coil over the vertex. Results: fMRI revealed that both normal subjects and patients with DAI showed increased contralateral primary sensori-motor cortex activation during affected hand movement.The motor evoked potentials (MEPs) of the patient group was slightly delayed in latency and significantly increased in duration and turns. The relative MEP amplitude, phase, and excitatory threshold were not significantly different between the groups. Conclusions: These findings may indicate the heterogeneity of the axons in the recovery process of the corticospinal tract. It seems that the motor recovery in patients who had suffered DAI was attributable to the recovery of the corticospinal tract. [ABSTRACT FROM AUTHOR]

We demonstrated the recovery of a severely damaged corticospinal tract (CST) in a 45-year-old female patient with intracerebral hemorrhage using diffusion tensor tractography and transcranial magnetic stimulation. Two longitudinal evaluations were conducted. There was no evidence of a CST in the affected hemisphere on the first evaluation. However, we observed evidence of a CST on the second evaluation. It seems that the affected motor function was recovered through the recovery of the damaged CST.