Gadolinium Deposition in Neurology Clinical Practice.

Background: Magnetic resonance imaging (MRI) enhanced with gadolinium-based contrast agents (GBCAs) is an essential tool in the diagnosis and management of many neurologic diseases, including multiple sclerosis, brain tumors, and infections. The clinical utility of GBCAs is evidenced by their widespread use. GBCAs are produced in macrocyclic and linear forms. Since 2014, evidence has suggested that repeated administration of GBCAs can lead to gadolinium deposition in the brain. Methods: We review the literature on gadolinium deposition, including both animal and human studies, as well as the literature on GBCA-associated health outcomes. Additionally, we summarize and discuss the updated medical society recommendations and perspectives on GBCA use in clinical practice. Results: The first publication reporting gadolinium deposition in the human brain was published in 2014. Since that seminal report, multiple studies have demonstrated that exposure to linear GBCAs is associated with gadolinium deposition in the dentate nucleus and globus pallidus as seen on brain MRI. Macrocyclic GBCA exposure has not convincingly been associated with gadolinium deposition evident on brain MRI. Conclusion: Clear evidence demonstrates that GBCAs lead to gadolinium deposition in the brain in a dose-dependent manner; however, only linear GBCAs have been associated with gadolinium deposition visualized on MRI. To date, no evidence links gadolinium deposition with any adverse health outcome. Updated medical society guidelines emphasize the importance of an individualized risk-benefit analysis with each administration of GBCAs.

Anti-N-Methyl-D-Aspartate Receptor Encephalitis in a Patient With Antithyroid Peroxidase Antibodies and a Parotid Pleomorphic Adenoma.

Background: Anti-N-methyl-D-aspartate receptor (NMDA-R) encephalitis is an autoimmune disorder first described in 2007. It can cause severe neurologic and psychiatric symptoms, and patients often are misdiagnosed with a primary psychiatric disorder. Anti-NMDA-R encephalitis is an important differential diagnosis of psychosis, as the condition can be treated with the appropriate therapy. Case Report: A 42-year-old female with a history of hypothyroidism presented for evaluation of agitation and weakness. Six months prior to her presentation at our hospital, she had complained of headache, and neuroimaging showed a small right frontal hyperintensity on fluid-attenuated inversion recovery imaging. Workup was largely unremarkable, and she improved briefly with steroids at the outside institution. She then developed psychiatric symptoms and had 4 admissions to separate inpatient psychiatric facilities. She was tried on various antipsychotic medications and mood stabilizers with no improvement and lost 30 pounds in 3 months. When the patient was transferred to our facility, her neuroimaging was stable, and serum and cerebrospinal fluid were positive for antithyroid peroxidase and NMDA-R antibodies. She was treated with intravenous immunoglobulin (IVIG), high-dose steroids, and rituximab. Positron emission tomography scan revealed a parotid mass that was resected and determined to be a pleomorphic adenoma. The patient improved remarkably to her baseline and was able to return to full duties at work within 6 months. In the 2 years since her initial admission, she has had minor relapses that have responded well to rituximab and IVIG. Conclusion: This case demonstrates a typical presentation of anti-NMDA-R encephalitis, as well as the challenges that can delay diagnosis. Symptoms vary and are often psychiatric, making these patients difficult to diagnose clinically, and they therefore require thorough investigation. This case illustrates the necessity to be inquisitive and to challenge the diagnosis when a clinical picture is not congruent because an accurate diagnosis is imperative in guiding appropriate treatment.

No cerebral or cervical venous insufficiency in US veterans with multiple sclerosis.

OBJECTIVE: To determine if chronic cerebral venous insufficiency exists in patients with multiple sclerosis (MS) using ultrasonography and 4-dimensional color Doppler ultrasonography examination and unverified criteria proposed by Zamboni et al. DESIGN: Patients with MS and clinically isolated syndrome were matched by age and sex with subjects with migraine or no neurological disease. All subjects underwent gray-scale, color, and spectral Doppler ultrasonography examination of the internal jugular veins (IJVs), vertebral veins, and deep cerebral veins for stenosis, absence of signal, and reflux. SETTING: Academic MS center. PATIENTS: All patients with MS fulfilled revised McDonald criteria for the diagnosis of MS. Patients with clinically isolated syndrome exhibited a typical transient focal neurological deficit and had magnetic resonance imaging lesions typical of MS. Control subjects were recruited from the VA migraine clinic or staff. MAIN OUTCOME MEASURES: Five parameters of venous outflow used by Zamboni et al were examined: (1) IJV or vertebral vein reflux, (2) deep cerebral vein reflux, (3) IJV stenosis, (4) absence of flow in IJVs or vertebral veins, and (5) change in cross-sectional area of the IJV with postural change. RESULTS: There was no significant difference in the number and type of venous outflow abnormalities in patients with MS compared with controls. CONCLUSION: This study does not support the theory that chronic cerebral venous insufficiency exists in MS.

Chronic cerebrospinal venous insufficiency and multiple sclerosis.

Chronic cerebrospinal venous insufficiency has recently been proposed to be etiologic to multiple sclerosis. Independent investigation into this theory during the past 2 years has not succeeded in verifying this relationship. A critical analysis of the scientific methods used in the original studies of chronic cerebrospinal venous insufficiency in multiple sclerosis reveals several methodological problems with regard to potential bias and confounding. The current evidence calls into question whether chronic cerebrospinal venous insufficiency in multiple sclerosis exists at all.

Epstein-Barr virus in multiple sclerosis.

Recent seroepidemiologic and pathologic evidence suggests that prior infection with Epstein-Barr virus (EBV) may be necessary for the development of multiple sclerosis (MS). EBV infects more than 90% of all humans, most of whom remain healthy. In contrast, 99% of MS patients have evidence of prior infection with EBV. EBV infects resting B lymphocytes, immortalizing them into long-lived memory B cells that survive largely undetected by the immune system in the peripheral circulation. MS patients show elevated titers to EBV years before developing any neurologic symptoms. Postmortem pathologic analysis of brains of patients with MS has revealed diffuse EBV-associated B-cell dysregulation in all forms of MS. Theories of pathogenesis of EBV in MS include antigenic mimicry, immortalization of B-cell clones, and cytotoxic T-cell dysfunction against virally infected B cells. This article reviews the existing evidence of the relationship between EBV and MS and considers the therapeutic implication of this evidence.

New oral disease-modifying therapies for multiple sclerosis.

Several promising, oral disease-modifying therapies for multiple sclerosis are currently being evaluated in clinical trials. The arrival of effective oral agents for multiple sclerosis will be a major advance in the global effort to alter the natural history of this chronic disease.

Correlations of Perceived Deficits Questionnaire of Multiple Sclerosis Quality of Life Inventory with Beck Depression Inventory and neuropsychological tests.

The Perceived Deficits Questionnaire (PDQ) is a part of the Multiple Sclerosis (MS) Quality of Life Inventory that assesses self-perceived cognitive difficulties. We used baseline data from 49 MS subjects participating in a clinical trial to evaluate the correlation of the PDQ with two measures of cognitive impairment, the Paced Auditory Serial Addition Test (PASAT) and the California Verbal Learning Test, 2nd edition (CVLT-II), total score, and one measure of depression, the Beck Depression Inventory-Amended (BDI-IA). The PDQ correlated significantly (r = 0.42; 95% confidence interval [CI], 0.15 to 0.62; p = 0.003) with the BDI-IA scores but not with either the PASAT (r = -0.22; 95% CI, -0.48 to 0.06; p = 0.2) or the CVLT-II total (r = -0.17; 95% CI, -0.43 to 0.12; p = 0.25). A subset of 38 of these subjects who scored worse than 0.5 standard deviation below the mean on the PASAT or CVLT-II received a more extensive neuropsychological battery of tests. No significant correlations were found between any of these tests and the PDQ. These results suggest that self-perceived cognitive dysfunction relates more to depression than to objective cognitive dysfunction.

Cognition and fatigue in multiple sclerosis: Potential effects of medications with central nervous system activity.

To evaluate the potential effects of medications with central nervous system (CNS) activity on cognitive function and fatigue in multiple sclerosis (MS), we performed a retrospective analysis of medication use among 70 subjects with MS who were participating in a clinical trial for evaluation of the effects of yoga and exercise programs on cognition and fatigue. Among these MS subjects, 74% were taking at least one potentially CNS-active medication. These 70 subjects were divided into two groups: those taking at least one CNS-active medication (n = 52) and those not on any medications with potential CNS activity (n = 18). We compared assessments of cognitive function and fatigue using an analysis of covariance. MS subjects on CNS-active medication had greater impairment on measures of processing speed, sustained attention, and fatigue than those not on these medications. While these findings do not establish a causal relationship between medication use and cognitive impairment and fatigue, the data indicate that researchers need to control for use of CNS-active medications when conducting studies of cognitive impairment and fatigue in MS subjects.

Cognitive dysfunction in multiple sclerosis: natural history, pathophysiology and management.

Cognitive dysfunction is a major cause of disability in patients with multiple sclerosis (MS). The prevalence of cognitive dysfunction is estimated at 45 to 65%. Natural history studies suggest that once cognitive dysfunction develops in a patient with MS, it is not likely to remit. Unlike physical disability in MS, cognitive disability correlates weakly with T2 lesion burden on brain magnetic resonance imaging (MRI). More robust correlations exist with magnetisation transfer imaging and MRI measures of brain atrophy. Patients with MS who have cognitive impairment most commonly display deficits in the cognitive domains of memory, learning, attention and information processing. In diagnosing cognitive dysfunction in a patient with MS, it is important first to recognise and treat the common comorbidities of fatigue and depression. The first step in the treatment of cognitive dysfunction is to delay disease progression, and there are currently five such disease-modifying agents approved for the treatment of MS (two preparations of interferon-beta-1a, interferon-beta-1b, glatiramer acetate and mitoxantrone). Nonpharmacological measures, such as cognitive rehabilitation, occupational therapy and psychotherapy, are the mainstays of symptomatic treatment. Pharmacological symptomatic therapy centres on the treatment of comorbid fatigue and depression. There are currently no effective pharmacological agents approved as symptomatic therapy of cognitive dysfunction in MS.