Magnetization transfer saturation reveals subclinical optic nerve injury in pediatric-onset multiple sclerosis

Assessment of Trigeminal Nerve Root Demyelination in Patients with Primary Trigeminal Neuralgia Using Macromolecular Proton Fraction Imaging

BACKGROUND AND PURPOSE

Primary trigeminal neuralgia (PTN) is a prevalent chronic pain disorder. This condition is believed to be associated with demyelination of the trigeminal nerve. Previous studies in this field have focused on diffusion tensor imaging, which has limited sensitivity and specificity to myelin. In the present study, we assessed the trigeminal nerve root via the macromolecular proton fraction (MPF) mapping technique. MPF demonstrated strong correlations with myelin histology in a number of earlier animal studies and is currently viewed as a promising clinical myelin biomarker.

MATERIALS AND METHODS

We performed a prospective case-control study. Fifty-six patients with unilateral PTN and 27 healthy controls were included. All participants were evaluated by using high-resolution brain MR imaging, which included the MPF technique. MPF values from different parts of the trigeminal nerve root, such as the root entry zone (REZ) and central and lateral cisternal segments, were extracted. ANCOVAs were performed. Correlations between MPF values and Sindou grade, duration, and intensity of symptoms were also evaluated in patients with PTN.

RESULTS

A statistically significant decrease in the average MPF of the affected trigeminal nerve root was observed in the PTN group compared with the healthy control group (P < .01, false discovery rate [FDR] corrected). Specifically, reductions in the MPF values of the REZ and central cisternal parts of the affected trigeminal nerve root were found in patients with PTN (P < .01 and P < .05, respectively, FDR corrected). Furthermore, we identified a decrease in the average and REZ MPF values on the affected side compared with the contralateral side in patients with PTN (P < .05 and P < .001, respectively, FDR corrected). A negative correlation between MPF values in the REZ and Sindou grade was revealed (R = -0.35, adjusted P < .05).

CONCLUSIONS

Our preliminary results suggest that MPF could serve as a new neuroimaging biomarker of trigeminal nerve root impairment in patients with PTN and enable noninvasive detection of nerve root demyelination.

Pediatric Multiple Sclerosis: Changing the Trajectory of Progression

PURPOSE OF REVIEW

Multiple sclerosis is a chronic inflammatory disease of the central nervous system. When seen in children and adolescents, crucial stages of brain development and maturation may be affected. Prompt recognition of multiple sclerosis in this population is essential, as early intervention with disease-modifying therapies may change developmental trajectories associated with the disease. In this paper, we will review diagnostic criteria for pediatric multiple sclerosis, outcomes, differential diagnosis, and current therapeutic approaches.

RECENT FINDINGS

Recent studies have demonstrated the utility of newer structural and functional metrics in facilitating early recognition and diagnosis of pediatric MS. Knowledge about disease-modifying therapies in pediatric multiple sclerosis has expanded in recent years: important developmental impacts of earlier therapeutic intervention and use of highly effective therapies have been demonstrated. Pediatric MS is characterized by highly active disease and high disease burden. Advances in knowledge have led to early identification, diagnosis, and treatment. Lifestyle-related interventions and higher efficacy therapies are currently undergoing investigation.

The Impact of Neuroimmunologic Disease and Developing Nervous System

Over the last two decades, neuroimmunologic disorders of childhood have been increasingly described, phenotyped, and treated. These disorders remain rare in the general population and while sharing common therapeutic interventions due to their immune pathophysiology, are heterogeneous with regard to presentation and risk of recurrence. As such, the impact of these disorders on the developing brain has come into the forefront of emerging research in pediatric neuroimmunology. Investigations into the singular impact of monophasic disease on long-term development and the impact of early and aggressive disease-modifying therapy in relapsing conditions are quickly becoming areas of ripe investigation as the field's most optimal way to treat and monitor these conditions over time. Although critically important in evaluating the developing brain, research has been heterogeneous among these diseases and limited by small cohort size. This narrative review details the role of common neuroimmunologic disorders in long-term neurological and cognitive outcomes in children as they develop.