• Metabolic disease

Even experienced neurologists must sometimes step back from a difficult clinical problem, take out the surgical sieve from their metaphorical cupboard, and check they are not missing something. The sieve provides a reminder that alongside the more common explanations we should also consider toxic, environmental and metabolic causes. In this issue, Freddie Vonberg and Peter Blain fill these gaps with a systems-based review of occupational and environmental neurotoxicology (page 357). Neurotoxic syndromes can manifest at all levels of the nervous system, from grey matter encephalopathies and leukodystrophy to myopathies and autonomic neuropathies. They can arise following acute or long-term exposure so may have the full range of clinical time courses. Some have specific treatments, but identifying and removing the exposure is essential for all.

Metabolic conditions are rare and an increasing number are treatable. This is illustrated by a patient with arginine:glycine amidinotransferase deficiency (page 413), …