A recent surge of nitrous oxide misuse around London which merits a public health warning.

Background: Use of nitrous oxide (N2O) gas for recreational purposes by young people is increasingly recognized as a public health hazard in the UK.

Methods: We looked at the hospital records of patients admitted over the last 4 years to a single neurological centre in Essex to determine the demographics, presentation, and management of patients presenting with symptoms of N2O toxicity from its recreational use.

Results: Of the 17 patients (mean age = 22.

Comparison of posterior subthalamic area deep brain stimulation for tremor using conventional landmarks versus directly targeting the dentatorubrothalamic tract with tractography.

Objective: To compare posterior subthalamic area deep brain stimulation (PSA-DBS) performed in the conventional manner against diffusion tensor imaging and tractography (DTIT)-guided lead implantation into the dentatorubrothalamic tract (DRTT).

Patients And Methods: Double-blind, randomised study involving 34 patients with either tremor-dominant Parkinson's disease or essential tremor. Patients were randomised to Group A (DBS leads inserted using conventional landmarks) or Group B (leads guided into the DRTT using DTIT).

Assessing neuromuscular junction stability from stimulated EMG in children.

Objective: We present our 9-year experience of stimulated EMG potential analysis using concentric electrodes (SPACE) to evaluate neuromuscular junction (NMJ) disorders in awake children. The technique uses high frequency filtration of stimulated motor unit potentials and applies peak detection software to estimate mean consecutive difference (MCD).

Methods: SPACE was carried out in orbicularis oculi of 878 children (377 girls; median age 47months) between 2007 and 2015, stimulating the facial nerve with a monopolar cathode.

E-norms: a method to extrapolate reference values from a laboratory population.

Purpose: Collecting reference values in subpopulations such as infants and children can pose a daunting challenge to gather through epidemiologic studies. The authors propose to evaluate a method the authors refer to as extrapolated norms (e-norms) to derive Stimulated Single Fiber EMG jitter reference values from the laboratory data of pediatric and adult cohorts. Single Fiber EMG studies are considered the gold standard test for evaluation of neuromuscular transmission disorders.

Voltage-gated potassium channelopathy: an expanding spectrum of clinical phenotypes.

Autoimmune voltage-gated potassium channelopathies represent a wide and expanding spectrum of neurological conditions. We present a case demonstrating the phenotypic heterogeneity of antivoltage-gated potassium channels (VGKC)-associated disorders. Such cases may easily be dismissed as functional disorders at first presentation.

Abnormality of taste and smell in Parkinson's disease.

Background: Smell sense is impaired in classic Parkinson's disease (PD). An initial study found no change in taste threshold in non-demented PD subjects and pathological studies suggest that the first relay for taste, the nucleus of the solitary tract, is spared. We wished to determine if taste is abnormal in PD and whether it is associated with smell dysfunction.