Cannabis for dyskinesia in Parkinson disease: a randomized double-blind crossover study.

BACKGROUND: The long-term treatment of Parkinson disease (PD) may be complicated by the development of levodopa-induced dyskinesia. Clinical and animal model data support the view that modulation of cannabinoid function may exert an antidyskinetic effect. The authors conducted a randomized, double-blind, placebo-controlled crossover trial to examine the hypothesis that cannabis may have a beneficial effect on dyskinesia in PD. METHODS: A 4-week dose escalation study was performed to assess the safety and tolerability of cannabis in six PD patients with levodopa-induced dyskinesia. Then a randomized placebo-controlled crossover study (RCT) was performed, in which 19 PD patients were randomized to receive oral cannabis extract followed by placebo or vice versa. Each treatment phase lasted for 4 weeks with an intervening 2-week washout phase. The primary outcome measure was a change in Unified Parkinson's Disease Rating Scale (UPDRS) (items 32 to 34) dyskinesia score. Secondary outcome measures included the Rush scale, Bain scale, tablet arm drawing task, and total UPDRS score following a levodopa challenge, as well as patient-completed measures of a dyskinesia activities of daily living (ADL) scale, the PDQ-39, on-off diaries, and a range of category rating scales. RESULTS: Seventeen patients completed the RCT. Cannabis was well tolerated, and had no pro- or antiparkinsonian action. There was no evidence for a treatment effect on levodopa-induced dyskinesia as assessed by the UPDRS, or any of the secondary outcome measures. CONCLUSIONS: Orally administered cannabis extract resulted in no objective or subjective improvement in dyskinesias or parkinsonism.

Electrophysiological confirmation of the zona incerta as a target for surgical treatment of disabling involuntary arm movements in multiple sclerosis: use of local field potentials.

Lesioning or chronic deep brain stimulation (DBS) of the nucleus ventralis intermedius results in abolition of tremor in the contralateral limbs in Parkinson's disease (PD) and also in essential tremor. Recently, chronic DBS of the subthalamic nucleus has also proved to be very effective in reducing contralateral limb tremor in PD. These targets have been less effective in controlling the complex limb tremor often seen in multiple sclerosis (MS). Consequently, other targets have been sought in cases of MS with tremor. We describe a patient with MS with disabling proximal and distal involuntary arm movements in whom we were able to obtain sustained control of contralateral arm tremor and achieve functional improvement of the affected arm by chronic DBS of the region of the zona incerta. We also highlight the important role played by local field potentials recorded from the brain, with simultaneous recording of corresponding EMGs, in target localisation.

Bilateral internal globus pallidus stimulation for the treatment of spasmodic torticollis.

Three patients with spasmodic torticollis (ST) obtained substantial benefit from bilateral globus pallidus internus (GPi) stimulation. Progressive improvement in ST occurred over several months but residual cervical dystonia remained. These results corroborate those obtained by Krauss et al. on three patients with ST.

Targeting the subthalamic nucleus.

The small size and surrounding neuronal structures and fibre tracts make the STN a difficult stereotactic target. In this article we present the technique used by us to target the STN. Our combined experience from two centres comprises 18 lesions and 27 stimulator implants in the STN. Our criteria for patient selection and the use of MRI, frame-on CT and volumetric image fusion are presented. The role of a movement disorder specialist neurologist in the operating theatre, local field potential recording, impedance monitoring, macrostimulation, post-operative CT/MRI and test stimulation are detailed.

Localisation of the subthalamic nucleus using Radionics Image Fusion and Stereoplan combined with field potential recording. A technical note.

Subthalamic nucleus stimulation is an effective therapy for alleviating parkinsonian tremor, rigidity and bradykinesia. Although microelectrode recording is said to be essential for accurate targeting, this often prolongs the operation and the multiple recording tracts required may increase the incidence of complications, particularly haemorrhage. We describe a technique for implantation of deep brain electrodes in the subthalamic nucleus using MRI/CT fusion for anatomical localisation followed by bipolar recording of focal field potentials via the implanted stimulating electrode for neurophysiological confirmation of the stimulation site. The technique is effective, safe and requires much less time, and can be used as an alternative method to microelectrode recording.

Histamine H2 receptor antagonist-refractory oesophagitis: the efficacy of long-term omeprazole maintenance treatment.

BACKGROUND: Erosive oesophagitis refractory to high dose histamine H2 receptor antagonists (definition: failure to heal fully after > or = 3 months' treatment with cimetidine 3.2 g or ranitidine 0.9 g) responds well to omeprazole 40 mg daily but frequently relapses when the patients are put back on maintenance H2 receptor antagonists at medium or even high dose (e.g. cimetidine 1.6 g and 3.2 g, respectively). AIM: To investigate the efficacy of maintenance omeprazole 20 mg daily in refractory erosive oesophagitis. PATIENTS & METHODS: In this open, sequential study, patients with H2 receptor antagonist-refractory oesophagitis were healed on omeprazole 40 mg daily and then put on maintenance H2 receptor antagonists (cimetidine 1.6 g or 3.2 g). Relapses were re-treated with omeprazole 40 mg; upon rehealing, patients were put on maintenance omeprazole 20 mg daily for up to 4.5 years. RESULTS: Healing on omeprazole occurred in 38 out of 39 patients (97%) at 12 weeks. Only six of the 38 patients (16%) relapsed (asymptomatic in half) during subsequent maintenance treatment, whereas all had relapsed earlier on high dose H2 receptor antagonists. CONCLUSION: Within the limits of interpretation of an open study, omeprazole 20 mg daily seems effective in maintaining prolonged remission in this group of patients with H2 receptor antagonist-refractory oesophagitis.