The effect of environmental lead exposure on human health and the contribution of inflammatory mechanisms, a review

Lead (Pb) pollution has been considered as a major threat for human health due to induction of inflammatory cascades in various tissues. The aim of present review is to summarize the literature on the effects of lead exposure on respiratory, neurologic, digestive, cardiovascular and urinary disorders and the role of inflammation as an underlying mechanism for these effects. Various databases such as ISI Web of Knowledge, Medline, PubMed, Scopus, Google Scholar and Iran Medex, were searched from 1970 to November 2017 to gather the required articles using appropriate keywords such as lead, respiratory disorders, neurologic disorders, digestive disorders, cardiovascular disorders, urinary disorders and inflammation. Disorders of various body systems and the role of inflammation due to lead exposure has been proven by various studies. These studies indicate that lead exposure may cause respiratory, neurologic, digestive, cardiovascular and urinary diseases. The results were also indicated the increased inflammatory cells and mediators due to lead exposure including cytokines and chemokines due to lead exposure which suggested to be the cause various organ disorders.

A prospective study of long-term outcomes among hospitalized COVID-19 patients with and without neurological complications

BACKGROUND

Little is known regarding long-term outcomes of patients hospitalized with COVID-19.

METHODS

We conducted a prospective study of 6-month outcomes of hospitalized COVID-19 patients. Patients with new neurological complications during hospitalization who survived were propensity score-matched to COVID-19 survivors without neurological complications hospitalized during the same period. The primary 6-month outcome was multivariable ordinal analysis of the modified Rankin Scale(mRS) comparing patients with or without neurological complications. Secondary outcomes included: activities of daily living (ADLs;Barthel Index), telephone Montreal Cognitive Assessment and Neuro-QoL batteries for anxiety, depression, fatigue and sleep.

RESULTS

Of 606 COVID-19 patients with neurological complications, 395 survived hospitalization and were matched to 395 controls; N = 196 neurological patients and N = 186 controls completed follow-up. Overall, 346/382 (91%) patients had at least one abnormal outcome: 56% had limited ADLs, 50% impaired cognition, 47% could not return to work and 62% scored worse than average on ≥1 Neuro-QoL scale (worse anxiety 46%, sleep 38%, fatigue 36%, and depression 25%). In multivariable analysis, patients with neurological complications had worse 6-month mRS (median 4 vs. 3 among controls, adjusted OR 1.98, 95%CI 1.23-3.48, P = 0.02), worse ADLs (aOR 0.38, 95%CI 0.29-0.74, P = 0.01) and were less likely to return to work than controls (41% versus 64%, P = 0.04). Cognitive and Neuro-QOL metrics were similar between groups.

CONCLUSIONS

Abnormalities in functional outcomes, ADLs, anxiety, depression and sleep occurred in over 90% of patients 6-months after hospitalization for COVID-19. In multivariable analysis, patients with neurological complications during index hospitalization had significantly worse 6-month functional outcomes than those without.

Paraneoplastic syndromes associated with lung cancer

Paraneoplastic syndromes are signs or symptoms that occur as a result of organ or tissue damage at locations remote from the site of the primary tumor or metastases. Paraneoplastic syndromes associated with lung cancer can impair various organ functions and include neurologic, endocrine, dermatologic, rheumatologic, hematologic, and ophthalmological syndromes, as well as glomerulopathy and coagulopathy (Trousseau’s syndrome). The histological type of lung cancer is generally dependent on the associated syndrome, the two most common of which are humoral hypercalcemia of malignancy in squamous cell carcinoma and the syndrome of inappropriate antidiuretic hormone secretion in small cell lung cancer. The symptoms often precede the diagnosis of the associated lung cancer, especially when the symptoms are neurologic or dermatologic. The proposed mechanisms of paraneoplastic processes include the aberrant release of humoral mediators, such as hormones and hormone-like peptides, cytokines, and antibodies. Treating the underlying cancer is generally the most effective therapy for paraneoplastic syndromes, and treatment soon after symptom onset appears to offer the best potential for symptom improvement. In this article, we review the diagnosis, potential mechanisms, and treatments of a wide variety of paraneoplastic syndromes associated with lung cancer.

Neurologic complications of COVID-19

BACKGROUND

Much of the focus regarding the global pandemic of coronavirus disease of 2019 (COVID-19) has been on the cardiovascular, pulmonary, and hematologic complications. However, neurologic complications have arisen as an increasingly recognized area of morbidity and mortality.

OBJECTIVE

This brief report summarizes the neurologic complications associated with COVID-19 with an emphasis on the emergency medicine clinician.

DISCUSSION

COVID-19 has infected over 3.5 million people and killed over 240,000 people worldwide. While pulmonary complications are profound, the neurologic system is also significantly impacted, with complications including acute cerebrovascular events, encephalitis, Guillain-Barré syndrome, acute necrotizing hemorrhagic encephalopathy, and hemophagocytic lymphohistiocytosis. Additionally, patients on immunosuppressive medications for pre-existing neurologic issues are at an increased risk for complications with COVID-19 infection, and many of the currently proposed COVID-19 therapies can interact with these medications.

CONCLUSIONS

When caring for COVID-19 patients, emergency medicine clinicians should be aware of the neurologic complications from COVID-19.

Clinical Guide and Update on Porphyrias

Physicians should be aware of porphyrias, which could be responsible for unexplained gastrointestinal, neurologic, or skin disorders. Despite their relative rarity and complexity, most porphyrias can be easily defined and diagnosed. They are caused by well-characterized enzyme defects in the complex heme biosynthetic pathway and are divided into categories of acute vs non-acute or hepatic vs erythropoietic porphyrias. Acute hepatic porphyrias (acute intermittent porphyria, variegate porphyria, hereditary coproporphyria, and aminolevulinic acid dehydratase deficient porphyria) manifest in attacks and are characterized by overproduction of porphyrin precursors, producing often serious abdominal, psychiatric, neurologic, or cardiovascular symptoms. Patients with variegate porphyria and hereditary coproporphyria can present with skin photosensitivity. Diagnosis relies on measurement of increased urinary 5-aminolevulinic acid (in patients with aminolevulinic acid dehydratase deficient porphyria) or increased 5-aminolevulinic acid and porphobilinogen (in patients with other acute porphyrias). Management of attacks requires intensive care, strict avoidance of porphyrinogenic drugs and other precipitating factors, caloric support, and often heme therapy. The non-acute porphyrias are porphyria cutanea tarda, erythropoietic protoporphyria, X-linked protoporphyria, and the rare congenital erythropoietic porphyria. They lead to the accumulation of porphyrins that cause skin photosensitivity and occasionally severe liver damage. Secondary elevated urinary or blood porphyrins can occur in patients without porphyria, for example, in liver diseases, or iron deficiency. Increases in porphyrin precursors and porphyrins are also found in patients with lead intoxication. Patients with porphyria cutanea tarda benefit from iron depletion, hydroxychloroquine therapy, and, if applicable, elimination of the hepatitis C virus. An α-melanocyte-stimulating hormone analogue can reduce sunlight sensitivity in patients with erythropoietic protoporphyria or X-linked protoporphyria. Strategies to address dysregulated or dysfunctional steps within the heme biosynthetic pathway are in development.

Neuropsychiatric comorbidities in adults with phenylketonuria: A retrospective cohort study

Adults with phenylketonuria (PKU) may experience neurologic and psychiatric disorders, including intellectual disability, anxiety, depression, and neurocognitive dysfunction. Identifying the prevalence and prevalence ratios of these conditions will inform clinical treatment. This nested, case-controlled study used International Classification of Diseases, Ninth Revision (ICD-9) codes from the MarketScan® insurance claims databases from 2006 to 2012 and healthcare claims data for US-based employer and government-sponsored health plans. Prevalence and prevalence ratio calculations of neuropsychiatric comorbidities for adults (≥20years old) with PKU were compared with two groups [diabetes mellitus (DM) and general population (GP)] matched by age, gender, geographic location, and insurance type. Age cohorts (i.e., 20-29, 30-39, 40-49, 50-59, 60-69, and 70+years, and a combined subset of 20-39) were used to stratify data. The PKU cohort experienced significantly higher rates of several comorbid neurologic, psychiatric and developmental conditions. Compared to GP, PKU was associated with significantly higher prevalence for numerous neuropsychiatric conditions, most notably for intellectual disability (PR=7.9, 95% CI: 6.4-9.9), autism spectrum disorder (PR=6.1, 95% CI: 3.6-10.4), Tourette/tic disorders (PR=5.4, 95% CI: 2.1-14.1), and eating disorders (4.0, 95% CI: 3.2-5.0). Rates of fatigue/malaise, epilepsy/convulsions, sleep disturbance, personality disorders, phobias, psychosis, and migraines among those with PKU exceeded rates for the GP but were comparable to those with DM, with significantly lower rates of concomitant disorders occurring in younger, compared to older, adults with PKU. Lifelong monitoring and treatment of co-occurring neuropsychiatric conditions are important for effective PKU management.

Diurnal and twenty-four hour patterning of human diseases: acute and chronic common and uncommon medical conditions

The symptom intensity and mortality of human diseases, conditions, and syndromes exhibit diurnal or 24 h patterning, e.g., skin: atopic dermatitis, urticaria, psoriasis, and palmar hyperhidrosis; gastrointestinal: esophageal reflux, peptic ulcer (including perforation and hemorrhage), cyclic vomiting syndrome, biliary colic, hepatic variceal hemorrhage, and proctalgia fugax; infection: susceptibility, fever, and mortality; neural: frontal, parietal, temporal, and occipital lobe seizures, Parkinson's and Alzheimer's disease, hereditary progressive dystonia, and pain (cancer, post-surgical, diabetic neuropathic and foot ulcer, tooth caries, burning mouth and temporomandibular syndromes, fibromyalgia, sciatica, intervertebral vacuum phenomenon, multiple sclerosis muscle spasm, and migraine, tension, cluster, hypnic, and paroxysmal hemicranial headache); renal: colic and nocturnal enuresis and polyuria; ocular: bulbar conjunctival redness, keratoconjunctivitis sicca, intraocular pressure and anterior ischemic optic neuropathy, and recurrent corneal erosion syndrome; psychiatric/behavioral: major and seasonal affective depressive disorders, bipolar disorder, parasuicide and suicide, dementia-associated agitation, and addictive alcohol, tobacco, and heroin cravings and withdrawal phenomena; plus autoimmune and musculoskeletal: rheumatoid arthritis, osteoarthritis, axial spondylarthritis, gout, Sjögren's syndrome, and systemic lupus erythematosus. Knowledge of these and other 24 h patterns of human pathophysiology informs research of their underlying circadian and other endogenous mechanisms, external temporal triggers, and more effective patient care entailing clinical chronopreventive and chronotherapeutic strategies.

Brain abnormalities in COVID-19 acute/subacute phase: A rapid systematic review

OBJECTIVE

This systematic review aimed to synthesize early data on typology and topography of brain abnormalities in adults with COVID-19 in acute/subacute phase.

METHODS

We performed systematic literature search via PubMed, Google Scholar and ScienceDirect on articles published between January 1 and July 05, 2020, using the following strategy and key words: ((covid[Title/Abstract]) OR (sars-cov-2[Title/Abstract]) OR (coronavirus[Title/Abstract])) AND (brain[Title/Abstract]). A total of 286 non-duplicate matches were screened for original contributions reporting brain imaging data related to SARS-Cov-2 presentation in adults.

RESULTS

The selection criteria were met by 26 articles (including 21 case reports, and 5 cohort studies). The data analysis in a total of 361 patients revealed that brain abnormalities were noted in 124/361 (34%) reviewed cases. Neurologic symptoms were the primary reason for referral for neuroimaging across the studies. Modalities included CT (-angiogram, -perfusion, -venogram), EEG, MRI (-angiogram, functional), and PET. The most frequently reported brain abnormalities were brain white matter (WM) hyperintensities on MRI 66/124 (53% affected cases) and hypodensities on CT (additional 23% affected cases), followed by microhemorrhages, hemorrhages and infarcts, while other types were found in <5% affected cases. WM abnormalities were most frequently noted in bilateral anterior and posterior cerebral WM (50% affected cases).

CONCLUSION

About a third of acute/subacute COVID-19 patients referred for neuroimaging show brain abnormalities suggestive of COVID-19-related etiology. The predominant neuroimaging features were diffuse cerebral WM hypodensities / hyperintensities attributable to leukoencephalopathy, leukoaraiosis or rarefield WM.

Cell-free nucleic acid patterns in disease prediction and monitoring-hype or hope?

Interest in the use of cell-free nucleic acids (CFNAs) as clinical non-invasive biomarker panels for prediction and prevention of multiple diseases has greatly increased over the last decade. Indeed, circulating CFNAs are attributable to many physiological and pathological processes such as imbalanced stress conditions, physical activities, extensive apoptosis of different origin, systemic hypoxic-ischemic events and tumour progression, amongst others. This article highlights the involvement of circulating CFNAs in local and systemic processes dealing with the question, whether specific patterns of CFNAs in blood, their detection, quantity and quality (such as their methylation status) might be instrumental to predict a disease development/progression and could be further utilised for accompanying diagnostics, targeted prevention, creation of individualised therapy algorithms, therapy monitoring and prognosis. Presented considerations conform with principles of 3P medicine and serve for improving individual outcomes and cost efficacy of medical services provided to the population.

Potential neurological impact of coronaviruses: implications for the novel SARS-CoV-2

Coronaviruses (CoV) are viruses widely known to cause severe respiratory distress due to the prominent clinical symptoms presented. These symptoms, which include fever and dry cough, are frequently found in individuals with CoV infection. Neurological manifestations of CoV have often been neglected; however, recent studies have reported neurological consequences of CoV infection. Here, we review these literatures and discuss the neurologic impact of CoV while highlighting potential implications of the novel SARS-CoV-2 in the nervous system. We also discuss the possible routes by which these viruses invade the nervous system and the mechanism by which they may induce neurological damage.

Challenges and management of neurological and psychiatric manifestations in SARS-CoV-2 (COVID-19) patients

COVID-19 is a pandemic caused by human coronavirus (HCoV) SARS-CoV-2, which originated in Wuhan, China, at the end of 2019 and spread globally during 2020. Due to the difficulty of clinical decision-making during this period, our study group reviewed current literature focusing on the neurological and psychiatric aspects of COVID-19. Despite the knowledge on this newly discovered virus which is constantly evolving, different pieces of evidence reported an association between COVID-19 and neurological symptoms like headache, dizziness, taste and smell disorders and complications involving the nervous system eventually triggered by the pathologic processes elicited by SARS-CoV-2. It seems that younger patients are less prone to develop severe forms of COVID-19. However, neurological signs have been reported in paediatric patients as well, and in some cases, the infection presented neurological sequelae. Furthermore, children with particular neurological diseases or treated with specific drugs (e.g. immune-suppressant therapies) must be carefully monitored during this pandemic. Neurologists should be aware of the main drug–drug interactions and the neurological side effects of COVID-19 treatments. Notably, adverse mental health impact has been reported in patients with SARS-CoV-2, which could be related either to the social strain or to the eventual neurotropic effects of the virus, which in other infections have been proven to promote the onset of psychiatric symptoms. Further, psychiatric population may be more vulnerable to the infection and at higher risk for adverse outcomes.

Paraneoplastic Neurologic Syndromes

Paraneoplastic neurologic syndromes (PNS) are mostly immune-mediated disorders that occur in patients with cancer. Because the same neurologic syndromes may occur without a cancer association it is important to know the likelihood of PNS, which is based in part on the syndrome and the patient's demographics and risk factors for cancer. The presence of specific antineuronal antibodies can facilitate the diagnosis and suggest treatment strategies. Although some PNS are rarely responsive to therapies, other disorders are highly treatment responsive.

Lysosomal storage disease: gene therapy on both sides of the blood-brain barrier

Most lysosomal storage disorders affect the nervous system as well as other tissues and organs of the body. Previously, the complexities of these diseases, particularly in treating neurologic abnormalities, were too great to surmount. However, based on recent developments there are realistic expectations that effective therapies are coming soon. Gene therapy offers the possibility of affordable, comprehensive treatment associated with these diseases currently not provided by standards of care. With a focus on correction of neurologic disease by systemic gene therapy of mucopolysaccharidoses types I and IIIA, we review some of the major recent advances in viral and non-viral vectors, methods of their delivery and strategies leading to correction of both the nervous and somatic tissues as well as evaluation of functional correction of neurologic manifestations in animal models. We discuss two questions: what systemic gene therapy strategies work best for correction of both somatic and neurologic abnormalities in a lysosomal storage disorder and is there evidence that targeting peripheral tissues (e.g., in the liver) has a future for ameliorating neurologic disease in patients?

Serious central nervous system side effects of cephalosporins: A national analysis of serious reports registered in the French Pharmacovigilance Database

INTRODUCTION

Among antibiotics, Central Nervous System (CNS) adverse drug reactions (ADRs) are often under-suspected and overlooked. Cephalosporins are an important cause of drug-induced CNS ADRs but the characteristics of such ADR have not been fully explored. We aimed to characterize the profile of cephalosporins serious CNS ADRs.

METHOD

We performed an analysis of serious reports recorded in the French Pharmacovigilance database from 1987 to 2017.

RESULTS

A total of 511 serious ADRs reports was analyzed. Patients had a mean age of 67.1 years and were mainly men (52.5%), with a mean creatinine clearance of 32.9 ml/min. The most involved molecules were cefepime (33.1%), ceftriaxone (29.7%), ceftazidime (19.6%), cefotaxime (9%) and cefazoline (2.9%), mostly administered intravenously (87.3%). A CNS history was observed in 25% of the reports (n = 128). Patients exhibited encephalopathy (30.3%), confusional state (19.4%), convulsion (15.1%), myoclonia (9.4%), status epilepticus (9.2%), coma (6.3%) and hallucination (4.3%). The mean time of onset was 7.7 days and the mean duration was 6 days. Cephalosporin plasma levels were recorded for 153 patients (29.9%) and 107 were above the standards including 62 (57.9%) related to renal impairment. Electroencephalograms were performed in 38.2% (n = 195) of the patients and 81% (n = 158) were abnormal.

CONCLUSION

This study characterizes an off-target CNS ADRs of several cephalosporins. Ceftriaxone represented a large part of our reports after cefepime and it would be relevant to warn healthcare professionals. Investigations (EEG, though plasma levels and renal function) can be precious tools for clinicians to make a prompt diagnosis and improve patients' outcomes.

Neurological Complications of Sjögren's Syndrome: Diagnosis and Management

Opinion statement

Purpose of review

Neurologic disease is a common extraglandular manifestation of Sjögren's syndrome (SS), the study of which has been hampered both by the lack of uniform definitions for specific neurologic complications and by the imprecision of the tools used to diagnose SS. There is a great need to develop consensus criteria for classifying these varied neurologic manifestations, as has been done in systemic lupus erythematosus (SLE) "Arthritis and rheumatism 42:599-608, 1999". SS patients with certain forms of neurologic involvement, such as small fiber neuropathy and sensory ataxic ganglionopathy, frequently lack anti-SSA and anti-SSB antibodies and other serologic abnormalities. In these patients, neurologic disease is often their presenting manifestation, triggering a search for underlying SS. Given the frequent seronegativity of such patients, their diagnosis of SS rests heavily on the interpretation of a labial gland biopsy. However, these biopsies are prone to misinterpretation "Vivino etal. J Rheumatol 29:938-44, 2002", and "positive" ones are found in up to 15% of healthy volunteers "Radfar et al. Arthrit Rheumatu 47:520-4, 2002". Better diagnostic tools are needed to determine if the frequent seronegative status of these SS patients may be related to a unique disease pathogenesis.

Recent findings

Recent advances in diagnostic techniques have served to define a likely pathogenetic basis for certain neurologic manifestations of SS. The advent of punch skin biopsies to analyze intraepidermal nerve fiber density and morphology has helped define pure sensory small fiber neuropathy as common in SS and the basis for both length- and non-length-dependent patterns of neuropathic pain. New protocols for magnetic resonance imaging (MRI) have enabled the recognition of dorsal root ganglionitis, a finding originally detected in pathologic studies. The advent of the anti-aquaporin-4 (AQP4) antibody test in 2004 has Led to the appreciation that demyelinating disease in SS is often related to the presence of neuromyelitis optica spectrum disorder. The anti-AQP4 antibody is considered to be directly pathogenic in the brain, targeting the primary water channel proteins in the brain, expressed prominently on astrocytic foot processes.

Summary

There are no clinical trials evaluating the efficacy of systemic immune suppressive therapy for peripheral or central nervous system involvement. With the recent increase in clinical trials of biologic agents for SS, which utilize systemic disease manifestations as standardized outcome measures, there is an urgency to deveLop appropriate definitions of neuroLogic compLications of SS and cLear parameters for clinical improvement.

Challenges in diagnosing normal pressure hydrocephalus: Evaluation of the diagnostic guidelines

Purpose

To evaluate the present diagnostic guidelines of idiopathic normal pressure hydrocephalus (iNPH) in a sample from the general population.

Methods

A total of 168 individuals (93 females, 75 males), mean age 75 years (range 66–92) with and without symptoms of iNPH underwent a CT-scan of the brain, a neurological examination with assessment of the triad symptoms, i.e. gait disturbances, memory impairment and urgency incontinence. The participants were then diagnosed as “unlikely”, “possible” and “probable” iNPH according to the American-European and the Japanese guidelines, respectively. Separately, a senior consultant in neurology diagnosed each patient based on the overall clinical picture.

Results

Obtaining a diagnosis of “probable iNPH” was three times more likely according to the American-European guidelines (n = 35) compared to the Japanese guidelines (n = 11) or the neurologist (n = 11). The concordance was highest (Kappa = 0.69) between the Japanese guidelines and the neurologist.

Conclusions

Considerable discrepancies were found when diagnosing iNPH according to two international guidelines and a neurologist, respectively. The Japanese guidelines, which include a minimum of two triad symptoms, were most concordant with the neurologist. As a step towards widely accepted, standardized diagnostic criteria, we suggest a revision of the current guidelines, preferably into one common diagnostic system.

•

Normal pressure hydrocephalus lacks common, standardized diagnostic criteria.

•

Considerable discrepancies were found between the two current international guidelines.

•

The highest concordance in diagnoses was between the Japanese guidelines and a neurologist.

•

We suggest a revision of the current guidelines into one common diagnostic system.

One-year cognitive and neurologic outcomes in survivors of paediatric extracorporeal cardiopulmonary resuscitation

OBJECTIVE

To describe one-year cognitive and neurologic outcomes among extracorporeal cardiopulmonary resuscitation (ECPR) survivors enrolled in the Therapeutic Hypothermia after Paediatric Cardiac Arrest In-Hospital (THAPCA-IH) trial; and compare outcomes between survivors who received ECPR, later extracorporeal membrane oxygenation (ECMO), or no ECMO.

METHODS

All children recruited to THAPCA-IH were comatose post-arrest. Neurobehavioral function was assessed by caregivers using the Vineland Adaptive Behaviour Scales, 2nd edition (VABS-II) at pre-arrest baseline and 12 months post-arrest. Age-appropriate cognitive performance measures (Mullen Scales of Early Learning or Wechsler Abbreviated Scale of Intelligence) and neurologic examinations were obtained 12 months post-arrest. VABS-II and cognitive performance measures were transformed to standard scores (mean = 100, SD = 15) with higher scores representing better performance. Only children with broadly normal pre-arrest function (VABS-II ≥70) were included in this analysis.

RESULTS

One-year follow-up was attained for 127 survivors with pre-arrest VABS-II ≥70. Of these, 57 received ECPR, 14 received ECMO later in their course, and 56 did not receive ECMO. VABS-II assessments were completed at 12 months for 55 (96.5%) ECPR survivors, cognitive testing for 44 (77.2%) and neurologic examination for 47 (82.5%). At 12 months, 39 (70.9%) ECPR survivors had VABS-II scores ≥70. On cognitive testing, 24 (54.6%) had scores ≥70, and on neurologic examination, 28 (59.5%) had no/minimal to mild impairment. Cognitive and neurologic score distributions were similar between ECPR, later ECMO and no ECMO groups.

CONCLUSIONS

Many ECPR survivors had favourable outcomes although impairments were common. ECPR survivors had similar outcomes to other survivors who were initially comatose post-arrest.

Blood BTEX levels and neurologic symptoms in Gulf states residents

BACKGROUND

The chemicals benzene, toluene, ethylbenzene, and xylenes (BTEX) are neuroactive. Exposures often co-occur because they share common sources. We examined neurologic effects of environmental BTEX exposure among U.S. Gulf coast residents taking into account concomitant exposures.

METHODS

We measured blood concentrations of BTEX in 690 Gulf state residents. Neurologic symptoms were ascertained via telephone interview. We used log-binomial regression to estimate associations between blood BTEX levels and self-reported neurologic symptoms independently for the presence of any neurologic, central (CNS), or peripheral nervous system (PNS) symptoms. We estimated associations in single chemical models mutually adjusted for co-occurring BTEX and used weighted quantile sum regression to model associations between the combined BTEX mixture and neurologic symptoms.

RESULTS

Half (49%) of participants reported at least one neurologic symptom. Each BTEX chemical was associated with increased CNS and PNS symptoms in single-chemical models comparing the highest to lowest quartile of exposure. After adjusting for coexposures, benzene was associated with CNS symptoms among all participants (PR = 2.13, 95% CI: 1.27, 3.57) and among nonsmokers (PR = 2.30, 95% CI: 1.35, 3.91). After adjusting for coexposures, associations with toluene were apparent only for reporting multiple PNS symptoms (PR = 2.00, 95% CI: 0.96, 4.16). In mixture analyses, a one-quartile increase in BTEX exposure was associated with neurologic symptoms (OR = 1.47, 95% CI: 1.11, 1.98). The weighted quantile sum index weighted benzene most heavily, which was consistent with single chemical analyses.

CONCLUSIONS

Increasing blood benzene concentration was associated with increased prevalence of CNS symptoms. In this sample, BTEX-associated neurologic effects are likely driven by exposure to benzene and, to a lesser extent, toluene.

Human herpesvirus 6 can be detected in cerebrospinal fluid without associated symptoms after allogeneic hematopoietic cell transplantation

BACKGROUND

Human herpesvirus 6 (HHV-6) is an opportunistic pathogen after hematopoietic cell transplantation (HCT) that is associated with central nervous system (CNS) dysfunction.

OBJECTIVES

The aim of this study was to determine the frequency and significance of HHV-6 DNA detection in cerebrospinal fluid (CSF) after HCT.

STUDY DESIGN

We identified patients with HHV-6 DNA in CSF using quantitative PCR. Patients with neurologic symptoms and HHV-6 DNA in CSF without identification of an alternative etiology were categorized as having HHV-6 CNS dysfunction.

RESULTS

Among 3902 allogeneic HCT recipients from 1998 to 2012, 51 of 124 tested patients had HHV-6 DNA in CSF; 37 met criteria for HHV-6 CNS dysfunction and 14 (27%) did not. Patients with an alternative diagnosis had longer time to HHV-6 detection and lower viral load in CSF. Six patients without HHV-6 CNS dysfunction were not treated and had no morbidity attributable to HHV-6. Kaplan-Meier analysis demonstrated poor overall survival among all patients. Variables associated with higher all-cause mortality in a multivariable Cox model included alternative diagnosis (adjusted hazard ratio [aHR], 8.4; 95% CI, 1.7-40.9; P = 0.009) and higher peak plasma viral load (log(10) scale) (aHR, 1.4; 95% CI, 1.1-1.9; P = 0.01).

CONCLUSION

We identified a number of allogeneic HCT recipients with HHV-6 DNA in CSF who did not meet criteria for HHV-6 CNS dysfunction. All patients had poor survival. Whether CSF HHV-6 DNA detection in patients without associated CNS dysfunction independently contributes to mortality and warrants treatment is unclear; management of these patients warrants further investigation.

Clinicopathologic Features and Magnetic Resonance Imaging Findings in 24 Cats With Histopathologically Confirmed Neurologic Feline Infectious Peritonitis

BACKGROUND

Feline infectious peritonitis (FIP) is the most common infectious central nervous system (CNS) disease in the cat and is invariably fatal. Improved means of antemortem diagnosis is required to facilitate clinical decision making. Information regarding the magnetic resonance imaging (MRI) findings of neurologic FIP currently is limited, resulting in the need for better descriptions to optimize its use as a diagnostic tool.

OBJECTIVE

To describe the clinicopathologic features and MRI findings in cases of confirmed neurologic FIP.

ANIMALS

Twenty-four client-owned cats with histopathologic confirmation of neurologic FIP.

METHODS

Archived records from 5 institutions were retrospectively reviewed to identify cases with confirmed neurologic FIP that had undergone antemortem MRI of the CNS. Signalment, clinicopathologic, MRI, and histopathologic findings were evaluated.

RESULTS

Three distinct clinical syndromes were identified: T3-L3 myelopathy (3), central vestibular syndrome (7), and multifocal CNS disease (14). Magnetic resonance imaging abnormalities were detected in all cases, including meningeal contrast enhancement (22), ependymal contrast enhancement (20), ventriculomegaly (20), syringomyelia (17), and foramen magnum herniation (14). Cerebrospinal fluid was analysed in 11 cases; all demonstrated a marked increase in total protein concentration and total nucleated cell count. All 24 cats were euthanized with a median survival time of 14 days (range, 2-115) from onset of clinical signs. Histopathologic analysis identified perivascular pyogranulomatous infiltrates, lymphoplasmacytic infiltrates, or both affecting the leptomeninges (16), choroid plexuses (16), and periventricular parenchyma (13).

CONCLUSIONS AND CLINICAL IMPORTANCE

Magnetic resonance imaging is a sensitive means of detecting neurologic FIP, particularly in combination with a compatible signalment, clinical presentation, and CSF analysis.

Zika Virus Disease and Associated Neurologic Complications

PURPOSE OF REVIEW

The purpose of this article is to review what is currently known about Zika virus (ZIKV) disease and associated neurologic complications.

RECENT FINDINGS

ZIKV is a mosquito-borne or sexually transmitted flavivirus rapidly spreading throughout the Americas. While ZIKV infection is usually asymptomatic, it may cause a non-specific illness with fever, rash, myalgia, headache, and/or non-purulent conjunctivitis. Additionally, ZIKV has been associated with a number of neurologic complications including microcephaly and other birth defects, Guillain-Barré syndrome, meningoencephalitis, myelitis, and various ophthalmologic abnormalities. Treatment for ZIKV disease is supportive. Those in ZIKV endemic areas should protect themselves from mosquito bites by wearing insect repellent, wearing long-sleeved shirts and pants when outdoors, and/or using air conditioning or window screens when indoors. Furthermore, unprotected sexual intercourse should be temporarily avoided by those who recently traveled to endemic areas. Suspected ZIKV disease cases should be reported to local, state, or territorial health departments.

Influenza vaccination in children with neurologic or neurodevelopmental disorders

BACKGROUND

Children with neurologic or neurodevelopmental disorders (NNDDs) are at increased risk of complications from influenza. Although the Advisory Committee on Immunization Practices (ACIP) has recognized NNDDs as high-risk conditions for influenza complications since 2005, little is known about influenza vaccination practices in this population.

METHODS

CDC collaborated with Family Voices, a national advocacy group for children with special healthcare needs, to recruit parents of children with chronic medical conditions. Parents were surveyed about their knowledge, attitudes, and practices surrounding influenza vaccination. The primary outcome of interest was parental report of vaccination, or intent to vaccinate, at the time of survey participation. CDC also collaborated with the American Academy of Pediatrics to recruit primary care and specialty physicians who provide care for high-risk children, specifically those with neurologic conditions. The primary outcome was physician recognition of ACIP high-risk influenza conditions.

RESULTS

2138 surveys were completed by parents of children with high-risk conditions, including 1143 with at least one NNDD. Overall, 50% of children with an NNDD were vaccinated, or their parents planned to have them vaccinated against influenza. Among all 2138 children, in multivariable analysis, the presence of a respiratory condition and prior seasonal influenza vaccination was significantly associated with receipt or planned current season influenza vaccination, but the presence of an NNDD was not. 412 pediatricians completed the provider survey. Cerebral palsy was recognized as a high-risk influenza condition by 74% of physician respondents, but epilepsy (51%) and intellectual disability (46%) were less commonly identified.

CONCLUSIONS

Our estimates of influenza vaccination in children with NNDDs are comparable to published reports of vaccination in healthy children, which continue to be suboptimal. Education of parents of children with NNDDs and healthcare providers about influenza and the benefit of annual influenza vaccination is needed.

Neuropsychiatric Adverse Reactions to Mefloquine: a Systematic Comparison of Prescribing and Patient Safety Guidance in the US, UK, Ireland, Australia, New Zealand, and Canada

Introduction

The antimalarial drug mefloquine (MQ) is associated with neuropsychiatric adverse reactions, some of which may predict the development of more serious effects. Although prescribing guidance in the United States drug label (DL) recommends to discontinue MQ at the onset of neuropsychiatric symptoms, only certain reactions are listed in both the DL and the corresponding patient medication guide with a recommendation to discontinue or to consult a physician should they occur. To identify possible prodromal reactions for which there is complete or partial agreement in prescribing and patient recommendations, a systematic comparison of international drug safety labeling was performed.

Methods

The full text of each DL and medication guide (or equivalent) from six primarily English-speaking countries was reviewed to identify specific reactions with corresponding recommendations in drug safety labeling. Percentage agreement across the countries in corresponding recommendations was determined by MedDRA^® high level group term (HLGT).

Results

Recommendations were found for reactions in 22 neuropsychiatric HLGTs. Complete or partial international agreement was found for reactions in 11 (50%) HLGTs.

Conclusion

This analysis suggests opportunities for physicians to improve patient counseling and for international drug regulators to clarify language in MQ safety labeling to reflect national risk–benefit considerations.

Other forms of gastroparesis: postsurgical, Parkinson, other neurologic diseases, connective tissue disorders

Although many surgical procedures originally associated with gastroparesis are less commonly performed nowadays, several more recently developed upper abdominal procedures may be complicated by the development of gastroparesis. Gastroparesis has been described in association with neurologic disorders ranging from Parkinson disease to muscular dystrophy, and its presence may have important implications for patient management and prognosis. Although scleroderma is most frequently linked with gastrointestinal motility disorder, gastroparesis has been linked to several other connective tissue disorders. The management of these patients presents several challenges, and is best conducted in the context of a dedicated and skilled multidisciplinary team.

Phenylketonuria and the brain

Classic phenylketonuria (PKU) is caused by defective activity of phenylalanine hydroxylase (PAH), the enzyme that coverts phenylalanine (Phe) to tyrosine. Toxic accumulation of phenylalanine and its metabolites, left untreated, affects brain development and function depending on the timing of exposure to elevated levels. The specific mechanisms of Phe-induced brain damage are not completely understood, but they correlate to phenylalanine levels and on the stage of brain growth. During fetal life, high levels of phenylalanine such as those seen in maternal PKU can result in microcephaly, neuronal loss and corpus callosum hypoplasia. Elevated phenylalanine levels during the first few years of life can cause acquired microcephaly, severe cognitive impairment and epilepsy, likely due to the impairment of synaptogenesis. During late childhood, elevated phenylalanine can cause alterations in neurological functioning, leading to ADHD, speech delay and mild IQ reduction. In adolescents and adults, executive function and mood are affected, with some of the abnormalities reversed by better control of phenylalanine levels. Altered brain myelination can be present at this stage. In this article, we review the current knowledge about the consequences of high phenylalanine levels in PKU patients and animal models through different stages of brain development and its effect on cognitive, behavioural and neuropsychological function.