Primary diffuse leptomeningeal melanomatosis (PDLM) is an exceptionally rare and aggressive central nervous system melanocytic tumour, often masquerading as inflammatory or infective leptomeningeal disease. A woman in her early 60s presented with hydrocephalus and diffuse leptomeningeal enhancement, initially treated as neurosarcoidosis. This progressed, despite immunosuppression, and repeated lumbar punctures yielded no cerebrospinal fluid (CSF) ('dry taps'). Intradural biopsy identified a melanocytic neoplasm with a GNA11 mutation. Fewer than 25 cases of isolated PDLM have been reported, and misdiagnosis is common. MRI typically shows T1-hyperintense leptomeningeal lesions but CSF is often non-diagnostic. Repeated failure to obtain CSF is a potential clinical clue to extensive leptomeningeal tumour infiltration. PDLM should be considered in atypical, treatment-refractory leptomeningeal disease. Recognising its characteristic imaging features and obtaining early biopsy are important to avoiding diagnostic delay.

Personality traits and disorders are frequently encountered in outpatient neurology. This can significantly influence the clinical consultation and the patient's neurological presentation and management. We offer practical guidance for neurologists to understand personality-related presentations better, along with clinical pointers to distinguish lifelong traits from changes secondary to neurological disease and advice on managing structured consultations with empathy. Recognising this interplay between personality and neurological care will support neurologists to deliver targeted, compassionate and higher quality care, improving patient engagement, safety and overall therapeutic experience.

We describe a 54-year-old woman living with HIV who presented with a tonic-clonic seizure and rapidly progressive encephalitis. Despite an undetectable plasma viral load while taking Biktarvy, initial investigations revealed cerebrospinal fluid escape with an HIV viral load of 474 copies/mL. Extensive testing for opportunistic infections and autoantibodies was negative. Brain biopsy and metagenomic next-generation sequencing identified frequent CD8+ T-cell infiltration and human pegivirus, though the latter was deemed a bystander. The patient's condition improved significantly, notably without the high-dose corticosteroids typically required for CD8+ encephalitis. This recovery suggests a moderate, self-limiting phenotype of the disease. The case highlights the diagnostic utility of metagenomics in complex presentations while cautioning against the misinterpretation of non-pathogenic commensals.

A 70-year-old woman presented with slowly progressive mobility difficulty and involuntary jerking movements, which had started at age 55 years. On examination, she had generalised action-induced myoclonus and gait ataxia. Extensive investigation over 10 years had not given a diagnosis. Genetic testing was re-visited and she was found to carry a likely pathogenic variant and a variant of unknown significance in the neuraminidase gene. Dermal fibroblast culture identified significantly reduced neuraminidase activity in keeping with a diagnosis of late-onset sialidosis. Taking into account biochemical evidence and the clinical phenotype, the identified variants have been reclassified as pathogenic and likely pathogenic. This case shows the value in revisiting genetic testing in unresolved cases and the need to be aware of the presentation of inherited rare metabolic disorders in later life.

The clinical presentation of juvenile-onset Huntington's disease differs from the adult-onset variant which adult neurologists are familiar. We report how we eventually arrived at this diagnosis in a patient whose clinical presentation was marked by numerous confounders and distractors for several years. Only when new clinical signs were elicited, in particular oculomotor apraxia, and a detailed timeline of events was reconstituted, was genetic testing performed to confirm the diagnosis of Huntington's disease. We reflect on several of the difficulties we experienced in securing this diagnosis.

People with acquired brain injury, including stroke and traumatic brain injury, are at increased risk of developing oral health problems, which can occur at any stage from acute admission through rehabilitation and longer-term care. Contributing factors include dysphagia, cognitive impairment, reduced awareness, reliance on others for oral care, altered salivation and oro-motor impairments such as limited mouth opening. Individuals are susceptible to oral disease, including fungal infections, caries and periodontal disease, which can cause pain, infection and reduced quality of life. Poor oral hygiene is also associated with healthcare-associated pneumonia, a significant risk following acquired brain injury. Oral health should remain a clinical priority for neurologists and healthcare teams across rehabilitation and community settings. Oral health management is, therefore, a shared multidisciplinary responsibility to promote recovery and rehabilitation. We provide practical guidance on assessing oral health risks, supporting daily mouth care, managing common oral problems and ensuring timely referral to dental services.

Exercise has a complex and paradoxical relationship with headache disorders. Physical activity may act as a trigger or an exacerbating factor for an acute migraine attack while it is also recognised as an evidence-based preventive strategy. Primary exercise headache is a distinct clinical entity and requires careful assessment and exclusion of sinister pathology but may respond to specific management. Imprecise nomenclature and miscommunication can lead both patients and clinicians to become frustrated. In this narrative review, we summarise the epidemiology, phenotype, differential diagnosis and management of primary exercise headache and briefly discuss the relationship between exercise and migraine.