Myelin oligodendrocyte glycoprotein antibody (MOG-Ab) seropositivity is being increasingly reported in diverse demyelinating syndromes with monophasic and relapsing presentations. Conus myelitis is described as a typical feature of MOG-Ab seropositivity. However, the association with lumbosacral radiculitis in this disease is not well-recognized. Here, we report a patient with relapsing MOG-Ab disease who presented clinically and radiologically with a relapsing lumbosacral myeloradiculopathy. This presentation raises the diagnostic possibilities of chronic infections, sarcoidosis, and neoplastic infiltration. This case illustrates the need to consider MOG-Ab disease as one of the differential diagnosis for a non-compressive lumbosacral myeloradiculopathy.

Arterial spin labelling is an emerging non-invasive magnetic resonance imaging technique for estimating the cerebral perfusion without the requirement for gadolinium-based intravenous contrast agents. Despite the wide range of applications in epilepsy, dementia, brain tumours, vascular malformations and stroke imaging, obtaining clinically useful arterial spin labelling data is technically challenging and prone to numerous artefacts. The objective of this review is to provide a comprehensive pictorial overview of the various artefacts associated with arterial spin labelling, particularly three-dimensional fast spin echo pseudocontinuous arterial spin labelling with spiral readout. These artefacts could be broadly classified as those occurring during the magnetic labelling, arterial transit or image acquisition. Arterial spin labelling artefacts of clinical diagnostic utility are also elaborated. A thorough knowledge of the basis of these artefacts will avoid diagnostic pitfalls while interpreting arterial spin labelling images. Important tips to reduce or overcome these artefacts are also discussed.

Immune reconstitution inflammatory syndrome (IRIS) is an exaggerated immune response which can occur with various coinfections in human immunodeficiency virus (HIV) infected patients, of which the most commonly implicated in central nervous system (CNS)-IRIS are progressive multifocal leukoencephalopathy (PML), cryptococcosis, and tuberculosis (TB). TB-IRIS is a known complication of pulmonary TB or TB lymphadenitis coinfection in HIV infected patients who are on antituberculosis treatment (ATT) after the initiation of antiretroviral therapy (ART). However, development of IRIS in extrapulmonary TB such as CNS TB is very rare. Our case is that of an isolated CNS-TB-IRIS, presenting as increase in the size and perilesional edema of the ring enhancing lesions in the brain, which was observed in two sequential magnetic resonance imaging done over a period of 2 months in a retropositive patient who presented with clinical deterioration after commencement of ART. As prompt diagnosis was made and specific management aimed at IRIS was started without delay, the patient improved symptomatically.

Craniospinal rachischisis is a rare and severe form of neural tube defects (NTDs), which is always fatal. It is characterized by anencephaly accompanied by a bony defect of the spine and exposure of neural tissue. We describe the two patients with ultrasonographic and magnetic resonance imaging appearance of craniospinal rachischisis totalis, detected antenatally at 22 and 25 weeks of gestation, and confirmed after termination of pregnancy. The multifactorial etiology of NTDs, with specific reference to folate deficiency, is discussed with possible role of folate fortification in the Indian context.