Driving restrictions following deep brain stimulation surgery

Background

There are currently no Australian guidelines to assist clinicians performing deep brain stimulation (DBS) procedures in setting postoperative driving restrictions.

Purpose

We aimed to provide recommendations for post-DBS driving restrictions to guide practice in Australia.

Methods

A review of current Australian and international driving guidelines, literature regarding the adverse effects of DBS and literature regarding the long-term effect of neurostimulation on driving was conducted using Elton B Stephens Company discovery service-linked databases. Australian neurologists and neurosurgeons who perform DBS were surveyed to gain insight into existing practice.

Results

No guidance on driving restrictions following DBS surgery was found, either in existing driving guidelines or in the literature. There was a wide difference seen in the rates of reported adverse effects from DBS surgery. The most serious adverse events (haemorrhage, seizure and neurological dysfunction) were uncommon. Longer term, there does not appear to be any adverse effect of DBS on driving ability. Survey of Australian practitioners revealed a universal acceptance of the need for and use of driving restrictions after DBS but significant heterogeneity in how return to driving is managed.

Conclusion

We propose a 6-week driving restriction for private licences and 6-month driving restriction for commercial licences in uncomplicated DBS. We also highlight some of the potential pitfalls and pearls to assist clinicians to modify these recommendations where needed. Ultimately, we hope this will stimulate further examination of this issue in research and by regulatory bodies to provide more robust direction for practitioners performing DBS implantation.

Sodium selenate as a disease-modifying treatment for progressive supranuclear palsy: protocol for a phase 2, randomised, double-blind, placebo-controlled trial

INTRODUCTION

Progressive supranuclear palsy (PSP) is a neurodegenerative disorder for which there are currently no disease-modifying therapies. The neuropathology of PSP is associated with the accumulation of hyperphosphorylated tau in the brain. We have previously shown that protein phosphatase 2 activity in the brain is upregulated by sodium selenate, which enhances dephosphorylation. Therefore, the objective of this study is to evaluate the efficacy and safety of sodium selenate as a disease-modifying therapy for PSP.

METHODS AND ANALYSIS

This will be a multi-site, phase 2b, double-blind, placebo-controlled trial of sodium selenate. 70 patients will be recruited at six Australian academic hospitals and research institutes. Following the confirmation of eligibility at screening, participants will be randomised (1:1) to receive 52 weeks of active treatment (sodium selenate; 15 mg three times a day) or matching placebo. Regular safety and efficacy visits will be completed throughout the study period. The primary study outcome is change in an MRI volume composite (frontal lobe+midbrain-3rd ventricle) over the treatment period. Analysis will be with a general linear model (GLM) with the MRI composite at 52 weeks as the dependent variable, treatment group as an independent variable and baseline MRI composite as a covariate. Secondary outcomes are change in PSP rating scale, clinical global impression of change (clinician) and change in midbrain mean diffusivity. These outcomes will also be analysed with a GLM as above, with the corresponding baseline measure entered as a covariate. Secondary safety and tolerability outcomes are frequency of serious adverse events, frequency of down-titration occurrences and frequency of study discontinuation. Additional, as yet unplanned, exploratory outcomes will include analyses of other imaging, cognitive and biospecimen measures.

ETHICS AND DISSEMINATION

The study was approved by the Alfred Health Ethics Committee (594/20). Each participant or their legally authorised representative and their study partner will provide written informed consent at trial commencement. The results of the study will be presented at national and international conferences and published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

Australian New Zealand Clinical Trials Registry (ACTRN12620001254987).

Progressive cranial neuropathy and uterine involvement in myeloid sarcoma

A rare extramedullary manifestation of haematological malignancy, myeloid sarcoma is most commonly seen in patients with acute myeloid leukaemia. We report on an adult patient who presented with an atypical phenotype of progressive cranial neuropathy without blood or bone marrow involvement, and in whom obtaining material for pathological diagnosis was made challenging by unusual findings of absent fluorodeoxyglucose-positron emission tomography avidity and involvement of sites not readily accessible to biopsy (orbital apex and cauda equina). The eventual diagnosis was obtained through biopsy of the uterine cervix before being verified on repeat lymph node and cerebrospinal fluid sampling prior to initiation of chemotherapy.

Practical approaches to commencing device-assisted therapies for Parkinson disease in Australia

In Australia 1% of individuals aged over 50 years have Parkinson disease (PD). Guidance for commencing device-assisted therapies (DAT) for PD in Australia was developed based on a review of European recommendations and their relevance to the local clinical setting. An online survey and teleconference discussions were held by a group of eight local movement disorder experts to develop consensus. Referral to a movement disorder specialist and consideration of DAT is appropriate when motor fluctuations cause disability or reduced quality of life, response to treatment is inconsistent or motor fluctuations and dyskinesias require frequent treatment adjustment without apparent benefit and levodopa is required four or more times daily. Three types of DAT are available in Australia for patients with PD: continuous subcutaneous apomorphine; continuous levodopa-carbidopa intestinal gel infusion; and deep brain stimulation. All improve consistency of motor response. The most important aspects when considering which DAT to use are the preferences of the patient and their carers, patient comorbidities, age, cognitive function and neuropsychiatric status. Patients and their families need to be provided with treatment options that are suitable to them, with adequate explanations regarding the recommendations and comparison of potential device-related complications. DAT are best managed, where possible, in a specialist centre with experience in all three types of therapy. Proactive and early management of symptoms during disease progression is essential to maintain optimally motor responses and quality of life in patients with PD.

Refining the perfusion-diffusion mismatch hypothesis

BACKGROUND AND PURPOSE

The Echoplanar Imaging Thrombolysis Evaluation Trial (EPITHET) tests the hypothesis that perfusion-weighted imaging (PWI)-diffusion-weighted imaging (DWI) mismatch predicts the response to thrombolysis. There is no accepted standardized definition of PWI-DWI mismatch. We compared common mismatch definitions in the initial 40 EPITHET patients.

METHODS

Raw perfusion images were used to generate maps of time to peak (TTP), mean transit time (MTT), time to peak of the impulse response (Tmax) and first moment transit time (FMT). DWI, apparent diffusion coefficient (ADC), and PWI volumes were measured with planimetric and thresholding techniques. Correlations between mismatch volume (PWIvol-DWIvol) and DWI expansion (T2(Day 90-vol)-DWI(Acute-vol)) were also assessed.

RESULTS

Mean age was 68+/-11, time to MRI 4.5+/-0.7 hours, and median National Institutes of Health Stroke Scale (NIHSS) score 11 (range 4 to 23). Tmax and MTT hypoperfusion volumes were significantly lower than those calculated with TTP and FMT maps (P<0.001). Mismatch > or =20% was observed in 89% (Tmax) to 92% (TTP/FMT/MTT) of patients. Application of a +4s (relative to the contralateral hemisphere) PWI threshold reduced the frequency of positive mismatch volumes (TTP 73%/FMT 68%/Tmax 54%/MTT 43%). Mismatch was not significantly different when assessed with ADC maps. Mismatch volume, calculated with all parameters and thresholds, was not significantly correlated with DWI expansion. In contrast, reperfusion was correlated inversely with infarct growth (R=-0.51; P=0.009).

CONCLUSIONS

Deconvolution and application of PWI thresholds provide more conservative estimates of tissue at risk and decrease the frequency of mismatch accordingly. The precise definition may not be critical; however, because reperfusion alters tissue fate irrespective of mismatch.

Intrastriatal injection of GDNF attenuates the effects of 6-hydroxydopamine

Our study was designed to determine whether intrastriatal administration of glial cell line-derived neurotrophic factor (GDNF) can attenuate the behavioral effects and injury to the mesostriatal dopaminergic system caused by 6-hydroxydopamine (6-OHDA). Four groups of rats received a series of four intrastriatal injections of vehicle or one of three doses of GDNF (0.1, 1 or 10 micrograms per injection) on days 1,3,5 and 8. On day 4 the animals received a single, intrastriatal injection of 25 micrograms 6-OHDA. Treatment with GDNF significantly reduced the development of amphetamine-induced rotation, and the dose of 1 microgram per injection appeared to be the most effective. The group treated with this dose had significantly greater preservation of tyrosine hydroxylase-immunoreactive (TH-IR) fibers adjacent to the injection site in the striatum and significantly greater preservation of Nissl-stained and TH-IR neurons in the substantia nigra pars compacta (SNpc).

BDNF attenuates the effects of intrastriatal injection of 6-hydroxydopamine

Groups of eight rats received unilateral, intrastriatal injections of 22.5 micrograms brain-derived neurotrophic factor (BDNF) or cytochrome c on 3 consecutive days. Following the injection of BDNF or cytochrome c on the second day, each animal received an intrastriatal injection of 25 micrograms of 6-hydroxydopamine (6-OHDA). During the second week following treatment and thereafter, the animals that received BDNF had significantly fewer apomorphine-induced, contraversive rotations than did the animals that received cytochrome c. The animals that received BDNF but not those that received cytochrome c had a halo of dopaminergic axons around the injection site. Our data indicate that BDNF can attenuate the loss of dopaminergic axons and rotational asymmetry that result from an intrastriatal injection of 6-OHDA.