Adalimumab-induced sensory vasculitic neuropathy.

Vasculitis and other autoimmune conditions are known complications of tumour necrosis factor alpha (TNF-α) inhibitor use. By definition, TNF-α inhibitor induced vasculitis is a secondary systemic vasculitis. However, its phenotype is varied and can present as an isolated vasculitic neuropathy. This presents a diagnostic challenge as the gold standard for diagnosis of a vasculitic neuropathy is a peripheral nerve biopsy that meets predefined histopathological criteria. Given the poor sensitivity of the peripheral nerve biopsy, it is important that clinicians take a good history and maintain a high index of suspicion, as this is a treatable iatrogenic condition. Here we present a case of adalimumab-induced sensory vasculitic neuropathy, treated according to the Peripheral Nerve Society guideline for non-systemic vasculitic neuropathy, given her disease phenotype.

Lesson of the month 2: Transient reversible amnesia in multiple sclerosis.

Transient amnestic syndromes are fascinating clinical entities and there are several subtypes. Transient global amnesia (TGA) is characterised by sudden onset of anterograde amnesia with repetitive questioning, lasting less than 24 hours. The pathophysiology of TGA involves the medial temporal lobes and hippocampi. Episodes of TGA are thought to involve venous congestion with Valsalva-like activities, vascular or migrainous mechanisms. In contrast, transient epileptic amnesia manifests as brief and frequent episodes of amnesia due to seizure activity in the temporal lobes. Transient memory disturbances can also be caused by transient ischaemic attack. We describe the first reported case of transient reversible amnesia directly attributable to acute demyelination. This case reminds us that multiple sclerosis relapses may present with acute cognitive impairment rather than the more classical physical symptoms. This is an important learning point in terms of appropriate management and eligibility for disease-modifying drugs.