Spotlight on Arsenic neuropathy

Arsenic toxicity has predominately been the result of suicidal or homicidal ingestion of massive quantities of arsenic. However, in India and Taiwan, presence of arsenic in drinking water has made the problem endemic. In this article, Dr. Michael Pulley of the University of Florida, Jacksonville discusses the clinical manifestations, diagnosis, and management of acute and chronic arsenic poisoning. The focus of the article is on the effects of arsenic on the peripheral nervous system.

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Spotlight on Eyelid myoclonia with and without absences

Eyelid myoclonia with or without absences is a form of epileptic seizure manifesting with myoclonic jerks of the eyelids, often with brief absences. These seizures are mainly precipitated by lights and closing of the eyes. They occur in symptomatic, possibly symptomatic, and idiopathic generalized epilepsies. Most authors support the view that eyelid myoclonia with absences is the defining seizure type of an idiopathic syndrome (Jeavons syndrome) of reflex epilepsy, which is genetically determined, has age-related onset, and affects otherwise normal children, with a female preponderance. Jeavons syndrome is probably lifelong with continuing seizures in adult life. Eyelid myoclonia is often confused with facial tics or self-induction of seizures.

In this article, Dr. C P Panayiotopoulos of St. Thomas’ Hospital details developments in the clinical manifestations, pathophysiology, genetics, and pharmacological treatment of eyelid myoclonia with absences.

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Spotlight on Stroke associated with sickle cell disease

In this article, Dr. Fenwick Nichols of the Medical College of Georgia reviews the risk of stroke in children with sickle cell anemia (HbSS). Stroke occurs in 11% of children with the disease by 20 years of age. The author reviews the pathophysiology of stroke in sickle cell disease and discusses ways to identify those at high risk for stroke.

Transcranial Doppler (TCD) measurement of the time-averaged mean of the maximum blood flow velocities in the distal internal carotid and proximal middle cerebral artery has proven to be the best predictor of stroke risk in this population. The author discusses the TCD technique used in the examination of children with sickle cell disease for both initial examination as well as follow-up examinations. He also reviews the effectiveness of transfusion therapy for prevention of stroke in this population and discusses possible alternative therapies, including hydroxyurea and bone marrow transplantation, for stroke prevention in this high-risk population. Finally, the author reviews publications on the risk associated with elevated anterior cerebral artery velocities, reports on encephalo-arterio-duro-synangiosis in patients with homozygous sickle cell anemia with moyamoya, and reviews the parameters that affect TCD velocity and potentially impact stroke risk in this population. Recent trials in HbSS, including SWITCH, TWITCH, and a controlled trial of transfusions for silent cerebral infarcts in sickle cell anemia are reviewed, and a report of successful implantation of an antisickling beta-globin gene into autologous hematopoietic stem cells in a 13-year-old with HbSS is discussed.

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Spotlight on Autonomic dysfunction in sleep disorders

Sleep and the autonomic nervous system are closely related from an anatomical, physiological, and neurochemical point of view. In this article, Dr. Pietro Cortelli and Dr. Giovanna Calandra-Buonaura of the University of Bologna describe the clinically relevant dysfunctions of cardiovascular and respiratory autonomic control caused by or associated with sleep disorders. In particular, the authors discuss the association between sleep-wake cycle derangement and autonomic sympathetic overactivity in fatal familial insomnia; the autonomic dysfunctions and the genetic discoveries in congenital central alveolar hypoventilation syndrome; the abnormalities of cardiovascular autonomic control in obstructive sleep apnea and narcolepsy type 1; and the relationship among REM sleep behavior disorder, cardiovascular autonomic dysfunction, and neurodegenerative disease. The autonomic dysfunction, particularly when involving cardiovascular or respiratory control, has a negative impact on prognosis of the associated sleep disorder and may represent a risk factor for the development of other chronic diseases or for life-threatening events. A prompt diagnosis of these autonomic dysfunctions is, therefore, of crucial importance to choose the proper therapeutic approach and treat the risk factors that could severely influence the prognosis.

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Spotlight on Primary systemic amyloidosis: neurologic complications

Amyloidosis is a generic term and refers to the extracellular deposition of fibrils composed of low weight chain of a variety of normal serum proteins.

Amyloid neuropathy remains a serious, usually rapidly fatal disease. However, in this updated article, Dr. John Kelly and Dr. Elham Bayat of George Washington University discuss evidence indicating that peripheral blood stem cell transplantation has proven to be effective treatment in carefully chosen patients. Patients with limited organ involvement have shown a good response to autologous hematopoietic cell transplantation with prolongation of survival. Early hematopoietic cell transplantation in well-selected patients is the current treatment of choice for amyloid neuropathy. Thus, early diagnosis and referral for treatment is essential before the disease spreads to multiple organs. Prognosis has improved with the use of early mortality risk scores to recognize those patients most at risk for early death. Diagnosis is still based on discovery of amyloid deposits in tissue biopsy identified by immunohistochemistry, but new techniques, such as mass spectrometry, show promise in determining amyloid types. Neurologists, who are most likely to see patients with neuropathy only, are in a favorable position to make an early diagnosis. The discussion of the clinical presentation and laboratory findings in this article can aid in early recognition of this disease.

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Spotlight on Tetanus

Despite an effective immunization method, tetanus is still a threat in developing countries worldwide. In developed countries, this condition affects certain population groups, especially the elderly. In this article, Dr. Anan Srikiatkhachorn of King Mongkut’s Institute of Technology Ladkrabang, and Dr. Wanakorn Rattanawong of Chulalongkorn University in Bangkok, and Dr. Thiravat Hemachudha of Chulalongkorn University Hospital in Bangkok describe the clinical features of tetanus, which is characterized by sustained muscle rigidity and reflex spasm. Tetanospasmin, a toxin of Clostridium tetani, is responsible for these clinical symptoms.

Besides symptomatic treatment, neutralization of this toxin is a mainstay for treating this condition. The beneficial effect of intrathecal immunoglobulin in conjunction with intramuscular administration has been proven in a randomized controlled clinical trial, and tetanus toxoid is considered very safe, even for immunodeficient individuals.

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Spotlight on Headache in children: overview and treatment approaches

Primary headaches, particularly those that are recurrent or chronic, in childhood are increasingly being recognized as a significant neurologic health problem. The high incidence and prevalence of headaches in the pediatric population has a significant impact on children and their families. Migraine remains under-recognized, under-diagnosed, and ultimately under- or inappropriately treated in this population; this has potential long-term consequences with regards to disease progression.

In this article, Dr. Nina Schor of the National Institute of Neurological Disorders and Stroke has addressed the key issues of: (1) using practical diagnostic criteria for clinical practice, (2) which acute medication should be chosen, (3) when to use preventive therapy in childhood, and (4) which preventive therapies have the best therapeutic index. This article serves as a quick reference for the diagnosis and management of primary headache disorders in children and adolescents. Effective intervention may prevent progression and lifelong consequences, including the development of comorbidities. Early diagnosis and an integrative treatment approach are essential to minimize the impact on a child’s quality of life.

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Spotlight on Vaccines for neurologic disorders

Vaccines for neurologic disorders are not only developed for prevention of infectious diseases but also for the treatment of cancer involving the nervous system, autoimmune disorders such as multiple sclerosis, and degenerative disorders such as Alzheimer disease. Alzheimer disease and stroke have important inflammatory and immune components and may be amenable to treatment by antiinflammatory and immunotherapeutic approaches.

In this article, Dr. K K Jain reviews various types of vaccines relevant to the nervous system, including adverse reaction of vaccines on the nervous system. An example is the vaccine for Alzheimer disease where the objective is to generate antibodies against amyloid beta. The earlier clinical trials, although effective in halting the progression of the disease, produced encephalitis as an adverse effect in some patients. Improved vaccines are now under development.

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Spotlight on Urinary dysfunction in neurologic disease

Urinary dysfunction accompanies many neurologic conditions. In this article, Dr. Pinky Agarwal of the University of Washington and Dr. Sudeshna Ray of Evergreen Health review the neurophysiology of bladder control. They summarize how it is disturbed by diseases of the nervous system. With an improved understanding of this complex problem, neurologists can be more effective in their approach to patients with urinary dysfunction. This article includes updated information on diagnosis and management of lower urinary tract dysfunction in various neurologic diseases.

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Spotlight on Congenital cytomegalovirus

Cytomegalovirus is a ubiquitous agent responsible for most intrauterine infections. Besides well-known symptoms and findings such as hearing loss and microcephaly, congenital cytomegalovirus infection can also underlie certain cerebral anomalies and static leukodystrophies.

In this article, Dr.Elena Grebenciucova of Northwestern University Feinberg School of Medicine and Dr. Raymond Roos of the University of Chicago Medical Center discuss uncommon presentations of asymptomatic congenital cytomegalovirus, predicted outcomes of congenital multi-strain cytomegalovirus infection, and updates on potential cytomegalovirus vaccines.

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