An unusual variant of the dorsal midbrain syndrome in MS: clinical characteristics and pathophysiologic mechanisms

Three-Dimensional Identification of the Medial Longitudinal Fasciculus in the Human Brain: A Diffusion Tensor Imaging Study

Background: The medial longitudinal fasciculus (MLF) interacts with eye movement control circuits involved in the adjustment of horizontal, vertical, and torsional eye movements. In this study, we attempted to identify and investigate the anatomical characteristics of the MLF in human brain, using probabilistic diffusion tensor imaging (DTI) tractography. Methods: We recruited 31 normal healthy adults and used a 1.5-T scanner for DTI. To reconstruct MLFs, a seed region of interest (ROI) was placed on the interstitial nucleus of Cajal at the midbrain level. A target ROI was located on the MLF of the medulla in the reticular formation of the medulla. Mean values of fractional anisotropy, mean diffusivity, and tract volumes of MLFs were measured. Results: The component of the MLF originated from the midbrain MLF, descended through the posterior side of the medial lemniscus (ML) and terminated on the MLF of medulla on the posterior side of the ML in the medulla midline. DTI parameters of right and left MLFs were not significantly different. Conclusion: The tract of the MLF in healthy brain was identified by probabilistic DTI tractography. We believe this study will provide basic data and aid future comparative research on lesion or age-induced MLF changes.

Parinaud syndrome: Any clinicoradiological correlation?

INTRODUCTION

The significance of MRI findings of patients with Parinaud syndrome (PS) with respect to clinical characteristics is poorly defined. Over the past decades, all patients with PS undergo magnetic resonance imaging which allows a better identification of the lesion localization. We compared the neuro-ophthalmological findings of patients with PS caused by intrinsic (intra-axial) vs extrinsic (pineal gland tumor) brainstem lesions.

METHODS

Medical records of patients with PS evaluated between 2000 and 2016 were retrospectively reviewed.

RESULTS

Twenty-six patients with PS were included. Eight patients had pineal gland tumors and hydrocephalus. Two patients had hydrocephalus due to aqueduct stenosis and fourth ventricle tumor. Sixteen patients suffered from an intrinsic brainstem lesion and seven associated with hydrocephalus. The neuro-ophthalmological findings did not differ between patients with extrinsic and intrinsic brainstem lesions. No correlation was found between the grade of hydrocephalus and number of clinical findings except for more findings in low-grade hydrocephalus in intrinsic (40%) vs extrinsic (0%) lesions (P=.003). Patients with moderate brainstem lesions and hydrocephalus had more clinical findings (65%) than patients with the same grade of brainstem involvement without hydrocephalus (29%) (P=.03). The resolution rate of ophthalmological findings was comparable in all groups of patients.

CONCLUSIONS

Our results did not show differences in neuro-ophthalmological findings between intra- and extra-axial lesions causing PS. However, the presence of hydrocephalus was an important factor influencing clinical findings. The prognosis of PS was less favorable than generally reported.

Visual issues in multiple sclerosis

Multiple sclerosis has several ophthalmic manifestations, including optic neuritis, internuclear ophthalmoplegia, and nystagmus. The presentation, treatment, and prognosis of visual complaints secondary to multiple sclerosis are discussed. Additionally, the use of optical coherence tomography and complications related to the use of fingolimod are considered.

Efferent manifestations of multiple sclerosis

PURPOSE OF REVIEW

To review the various efferent visual system disorders associated with multiple sclerosis (MS).

RECENT FINDINGS

Studies have supported the use of internuclear ophthalmoplegia, a model to study effects of fatigue and heat in MS patients.

SUMMARY

There are a host of efferent ocular manifestations that can present throughout the course of MS. These may manifest as blurred vision, potentially misleading both the patient and clinician to suspect an afferent visual deficit. Other efferent symptoms include diplopia, oscillopsia, and vertigo. The efferent system can be divided into broad categories: supranuclear, internuclear, nuclear, and gaze-holding systems. This review will briefly touch on the anatomy as well as the signs and symptoms associated with MS-related dysfunction involving these systems.

The neuro-ophthalmology of multiple sclerosis

Multiple sclerosis (MS) is a disease marked by focal demyelinating inflammatory plaques throughout the CNS. Neuro-ophthalmologic sequelae are common in MS and may arise from the disease itself or from treatment of the disease. Both afferent and efferent functions may be affected. Despite much progress, our understanding of the pathophysiology of MS, and the efficacy of our available treatments, remain inadequate. Here, we review the chief neuro-ophthalmologic abnormalities associated with MS and discuss the emerging diagnostic and therapeutic advances that are likely to further our understanding of MS and its treatment.

Eye disorders in patients with multiple sclerosis: natural history and management

Multiple sclerosis (MS) is a demyelinating disease of the central nervous system and leading cause of disability in young adults. Vision impairment is a common component of disability for this population of patients. Injury to the optic nerve, brainstem, and cerebellum leads to characteristic syndromes affecting both the afferent and efferent visual pathways. The objective of this review is to summarize the spectrum of eye disorders in patients with MS, their natural history, and current strategies for diagnosis and management. We emphasize the most common disorders including optic neuritis and internuclear ophthalmoparesis and include new techniques, such as optical coherence tomography, which promise to better our understanding of MS and its effects on the visual system.

[Ocular motor disorders in multiple sclerosis]

Multiple sclerosis is the most common disabling neurological disease in young people. Many neuro-ophthalmological manifestations can occur during the course of the illness, and optic neuritis is both the most frequent and the best known. However, some ocular motility disorders can also occur, but since there may be no symptoms, they often remain underdiagnosed. These eye movement disorders are mostly related to brain-stem and cerebellum lesions. They can be acute, indicating a spatial dissemination of the demyelinating disease, and consequently may indicate the need for systemic treatment of multiple sclerosis. More often, they evolve slowly, progressing with the multiple sclerosis. In this case, they could provide a clue to the prognosis of the disease. In this survey, we discuss the two major symptoms of ocular motor disorders likely to occur during multiple sclerosis: oscillopsia and diplopia.

Localizing forms of nystagmus: Symptoms, diagnosis, and treatment

Nystagmus is a rhythmic oscillation of the eyes that may be acquired or congenital. The symptoms of acquired nystagmus include blurred vision and oscillopsia. Most patients with congenital nystagmus do not have oscillopsia symptoms. Several forms of nystagmus have localizing value and any neuroimaging should be directed to the topographic localization suggested by the morphology of the nystagmus and any accompanying localizing signs. Several optical, medical, and surgical treatments have been used with some success in specific forms of nystagmus.