Peripheral neuropathy (PN) is a significant concern and potential cause of withdrawal in patients with Parkinson's disease (PD) treated with Levodopa/Carbidopa Intestinal Gel (LCIG) infusion. Vitamin B deficiency and/or hyperhomocysteinemia levodopa‐related are considered possible causative factors. In this study, we evaluated PN incidence in LCIG‐PD patients treated since the beginning of infusion with vitamins B supplementation.

Background and purpose: For many years deep brain stimulation (DBS) devices relied only on voltage-controlled stimulation (CV), but recently current-controlled devices have been developed and approved for new implants as well as for replacement of CV devices after battery drain. Constant-current (CC) stimulation has been demonstrated to be effective in new implanted parkinsonian and dystonic patients, but the effect of switching to CC therapy in patients chronically stimulated with CV implantable pulse generators (IPGs) has not been assessed. This report shows the results of a consecutive retrospective data collection performed at five Italian centers before and after replacement of constant-voltage with constant-current DBS devices, in order to verify the clinical efficacy and safety of this procedure.Methods: Nineteen patients with Parkinson's disease or dystonic syndrome underwent DBS IPG CV/CC replacement. Clinical features and therapy satisfaction were assessed before surgery, 1 week after and 3 and 6 months after replacement. Programming settings and impedances were recorded before removing the CV device and when the CC IPGs were switched on.Results: The clinical outcome of CC stimulation was similar to that obtained with CV devices and remained stable at 3 and 6 months of follow-up. Impedance values recorded for CV and CC IPGs were similar. Ninety-five percent of patients and physicians were satisfied with mixed implants. No adverse events occurred after IPG replacement.Conclusion: Replacing CV with CC IPGs is a safe and effective procedure. Longer follow-up is necessary to better clarify the impact of CC stimulation on clinical outcome after chronic stimulation in CV mode.

Subacute and chronic peripheral neuropathies (PN) have been reported in Parkinson’s disease (PD) patients treated with levodopa/carbidopa intestinal gel infusion (Duodopa), but only one study evaluated a long term follow up. We performed a retrospective electrophysiological study of 23 PD patients treated with Duodopa with a follow up period of 18 months. The electrophysiological assessments of 23 patients have been retrospectically collected and evaluated at baseline (before Duodopa infusion) and at 6, 12 and 18 months. Nerve conduction studies were obtained for the bilateral median, ulnar, tibial and peroneal motor nerves and for the bilateral median, ulnar and sural sensory nerves. During a follow-up period of 18 months, a statistically significant decrease in mean sural SAP amplitude was recorded. At baseline 5/23 patients showed PN. During the follow up, one patient developed a subacute PN and two patients developed a sensory-motor PN. Duodopa infusion was immediately halted in the subacute case, while the infusion therapy was not interrupted in chronic forms. All patients were supplemented with vitamin B12 and folate. Serial electrophysiological evaluations are mandatory in patients treated with Duodopa, given the possible risk of PN.

Many studies confirmed the efficacy and safety of continuous infusion of intrajejunal levodopa/carbidopa gel (CIILG) for advanced Parkinson’s disease (PD). Although this treatment is widely used, definite inclusion/exclusion criteria do not exist. In this prospective open-label study, we evaluated the long-term outcome in 28 consecutive patients and sought to detect any predictive factor to identify the best candidates for CIILG therapy. The assessment was carried out routinely at baseline, after 6 months and every year with UPDRS III–IV, FOG Questionnaire, non-motor symptoms scale, PD questionnaire (PDQ-8), cognitive and psychiatric status evaluation (MMSE, FAB, NPI) and caregiver’s quality of life. 17/28 patients reached the 24-month follow-up. A statistically significant beneficial effect was shown on motor complications in short- and long-term follow-up, also on axial symptoms like gait disturbances. A concomitant improvement in PDQ8 score was observed, with a parallel mild amelioration, but not significant, on Caregivers QoL. When classified according to their outcome on QoL, the only predictive positive factor was less severe at Neuropsychiatric Inventory (NPI) score at baseline. Considering the improvement in motor scores (duration of “off” period), the more advanced age was associated with a poorer outcome. Our results confirmed a sustained efficacy and safety in long-term follow-up and suggest that younger age at operation and absence or mild presence of psychiatric/behavioural symptoms could be considered valid predicting factors in selecting the best candidates for this efficacious therapy.