FLAIR-hyperintense lesions in anti-MOG-associated encephalitis with seizures (FLAMES) unmasked by withdrawal of immunosuppression for Crohn's disease?

A 31-year-old pregnant woman presented with headache, fever and left-sided focal motor seizures, which progressed to bilateral tonic-clonic seizures. Her medical history included Crohn's disease treated with azathioprine and adalimumab, which were discontinued when she became pregnant. Her cerebro-spinal fluid was entirely normal and viral PCR negative. Extensive testing for infectious, autoimmune or malignant causes of encephalitis were non-revealing. MRI head showed unilateral cortical FLAIR-hyperintensity which on interval scans was seen bilaterally. Anti-myelin-oligodendrocyte glycoprotein (MOG)-IgG was positive leading to a diagnosis of cortical FLAIR-hyperintense lesions in Anti-MOG-associated Encephalitis with seizures (FLAMES).

Attention and processing speed performance in multiple sclerosis is mostly related to thalamic volume.

Cognitive impairment (CI), mainly involving attention and processing speed (A-PS), is a common and disabling symptom in multiple sclerosis (MS). Symbol Digit Modalities Test (SDMT) is one of the more sensitive and reliable tests to assess A-PS deficits in MS. Structural MRI correlates of A-PS in MS still need to be clarified. This study aimed to investigate, in a large group of MS patients, the relationship between regional gray matter (GM) atrophy and SDMT performance. 125 relapsing remitting MS patients and 52 healthy controls (HC) underwent a 3 T-MRI protocol including high-resolution 3D-T1 imaging. All subjects underwent a neurological evaluation and SDMT. A Voxel Based Morphometry analysis was performed to assess: 1) correlations between regional GM volume and SDMT performance in MS patients; 2) regional differences in GM volume between MS patients and HC. Thalamic, putamen and cerebellar volumes were also calculated using FIRST tool from the FMRIB Software Library. A linear regression analysis was performed to assess the contribution of each one of these structures to A-PS performance. A significant negative correlation was found between regional GM volume and SDMT score at the level of the thalamus, cerebellum, putamen, and occipital cortex in MS patients. Thalamus, cerebellum and putamen also showed significant GM atrophy in MS patients compared to HC. Thalamic atrophy is also an independent and additional contributor to A-PS deficits in MS patients. These findings support the role of thalamus as the most relevant GM structure subtending A-PS performance in MS, as measured by SDMT.