Spotlight on Labyrinthine infarction

In this article, Dr. Douglas Lanska of the Great Lakes VA Healthcare System and the University of Wisconsin School of Medicine and Public Health explains the clinical presentation, pathophysiology, prevention, diagnostic work-up, and management of labyrinthine infarction.

Although a variety of conditions can cause labyrinthine ischemia, labyrinthine infarction most commonly occurs in the setting of thromboembolic disease of the anterior inferior cerebellar artery or the basilar artery, and almost all of these cases present with acute prolonged vertigo and vestibular dysfunction of peripheral, central, or combined origin. Unlike labyrinthine dysfunction from a viral cause, the most common pattern of dysfunction with labyrinthine infarction includes a combined loss of auditory and vestibular function. Canal paresis associated with posterior circulation ischemic stroke, usually within the territory of the anterior inferior cerebellar artery, typically normalizes within 5 years.

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Spotlight on Pregnancy and epilepsy

Approximately 20,000 to 25,000 children are born in the United States each year to mothers with epilepsy, and between 0.3% and 0.5% of all pregnancies occur among women with epilepsy. Most of these women need to continue taking medication during pregnancy because uncontrolled convulsive seizures may be harmful to the women as well as to their fetuses. The challenge to physicians is to prescribe a treatment that is effective in controlling seizures but has minimal associated risks.

Overall, 95% of women with epilepsy have uncomplicated pregnancies and deliver normal babies. This rate can be significantly improved with proper management; any serious harm to the baby or mother, particularly if it is avoidable, is too much for the family that is affected. The highest risks for major congenital malformations and adverse cognitive outcomes are associated with polytherapy (mainly combination of valproate and lamotrigine). With monotherapy, the highest risk is found with valproate followed by topiramate. In utero exposure to monotherapy with lamotrigine, carbamazepine, and levetiracetam have a low risk of major congenital malformations, near 2.5%. Furthermore, the concentration of antiepileptic drugs may change significantly during pregnancy and the puerperium, resulting in an increase in seizures (mainly with lamotrigine and oxcarbazepine) or toxicity. Women should be made fully aware of all aspects of antiepileptic drug treatment and be able to make informed decisions.

In this article, Dr. C P Panayiotopoulos of St. Thomas’ Hospital details the various issues that women with epilepsy face before, during, and after pregnancy.

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Spotlight on CLIPPERS

In this article, Dr. Morten Blaabjerg of Odense University and Dr. Daniel Kondziella of Copenhagen University Hospital discuss chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS). CLIPPERS is an inflammatory condition of unknown etiology, primarily involving the brainstem and cerebellum. Symptoms of CLIPPERS include subacute onset of brainstem symptoms–most prominently, ataxia, diplopia, dysarthria, and altered facial sensation. The core radiological features are punctate or curvilinear perivascular gadolinium enhancement, typically in the pons and adjacent cerebellum. Neuropathological examination of affected areas reveals a perivascular lymphocytic inflammation with predominant CD4+ T cells. Clinical and radiological features respond to high-dose corticosteroid treatment, but continuous oral corticosteroid treatment and steroid-sparing agents are needed to prevent relapses and to reduce the risk for subsequent parenchymal atrophy and chronic ataxia. The differential diagnosis for CLIPPERS is broad, and a careful workup is needed.

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Spotlight on Congenital rubella

Congenital rubella infection classically causes a severe syndrome with multi-organ manifestations encompassing visual, hearing, and neurologic disabilities; it may, however, also present with more subtle findings that can lead to significant diagnostic delays if the treating physician is not familiar with the consequences of maternal rubella infection. Although widespread vaccination programs have significantly reduced the global burden of rubella, rubella remains an important pathogen that remains endemic in many regions of the world, and its varied presentation requires vigilance on behalf of health providers.

In this article Dr. William Tyor and Dr. Taylor Harrison of Emory University School of Medicine discuss the clinical manifestations, biology, diagnosis, and management of congenital rubella.

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Spotlight on Congenital myasthenic syndromes

Congenital myasthenic syndromes are inherited disorders in which the safety margin of neuromuscular transmission is compromised by 1 or more specific mechanisms. Because they are relatively infrequent, they often go undiagnosed or misdiagnosed. Some congenital myasthenic syndromes can be diagnosed by clinical clues; others require special laboratory studies that define parameters of neuromuscular transmission and analyze the structure of the endplate. The genetic basis of no fewer than 30 congenital myasthenic disorders has now been identified, with 4 novel syndromes recognized since the last review. Most congenital myasthenic syndromes are treatable but therapy has to be tailored for the underlying molecular defect because therapies beneficial in some congenital myasthenic syndromes can be harmful in another type.

In this article, Dr. Andrew Engel of the Mayo Clinic College of Medicine provides an overview of the clinical aspects of the congenital myasthenic syndromes, describes their historical aspects and current classification, summarizes general and specific features of the different disorders, and considers their pathophysiology, pathogenesis, and prognosis.

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Spotlight on Electroconvulsive therapy (ECT)

Although seizures typically indicate a state of brain dysfunction, there are circumstances in which the biological effects of a seizure may exert therapeutic benefits. In this article, Dr. Justin Coffey of the Menninger Clinic and Baylor College of Medicine discusses the standard technique for inducing controlled therapeutic seizures in humans: electroconvulsive therapy (ECT), a safe and remarkably effective treatment that involves the application of an electrical stimulus to the scalp of a patient under general anesthesia and muscle relaxation. ECT remains a cornerstone of treatment for severe mood disorders and certain other neuropsychiatric conditions, including those in patients with neurologic disorders. In addition, the neurobiological effects of ECT may have beneficial effects on a number of neurologic disorders, including Parkinson disease, epilepsy, and delirium. As with any procedure in medicine, the safety and efficacy of ECT depend critically on appropriate technique and proper patient selection and preparation.

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Spotlight on Acute headache: diagnosis

Headache is a common chief complaint in acute settings. The diagnosis of acute headache can be challenging and should proceed in an orderly fashion. An important first step is to distinguish primary from secondary headaches. The approach is to seek “red flags” that suggest the possibility of secondary headache. If one of these features is identified, the physician must conduct the workup indcated by the red flag and, thereby, diagnose any secondary headache disorder that is present. In the absence of secondary headache, the clinician proceeds to diagnosing a primary headache disorder.

In this article, Dr. Stephanie Nahas of Thomas Jefferson University follows this approach to discuss the differential diagnosis of acute headaches.

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Spotlight on Ethical issues in neurology

Neuroethics is a distinct content field that is concerned with “the ethics of neuroscience and the neuroscience of ethics.” In clinical specialties like neurology, neurosurgery, and neuropsychology, neuroethics focuses on the ethics of neurotechnology research and application as well as social and policy issues associated with their use. A young and rapidly growing field, neuroethics has had a substantial impact on scientific research and clinical practice. Neuroethics has been emphasized by the Presidential Commission for the Study of Bioethical Issues and has become an integral part of major national-level funded neuroscience initiatives across the globe.

In this article, Dr. Karen Rommelfanger and Ms. Kelsey Drewry of Emory University discuss why, as neuroscience continues to evolve and the nature of possible clinical interventions changes, neurologists must begin to consider the implications of interventions to the brain on personhood and identity, autonomy and agency, as well as for informed consent.

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Spotlight on Spasmodic dysphonia

Spasmodic dysphonia is a focal laryngeal dystonia. The more common adductor type typically results in strained effortful speech with breaks in phonation. Abductor spasmodic dysphonia generally causes breathy speech with voiceless pauses. The task-specific nature of this condition means that it may normalize with changes in pitch or volume or with other activities, such as laughing or yawning. Several causative genes have been identified in spasmodic dysphonia. In this article, Dr. Ainhi Ha of Westmead Hospital discusses risk factors, clinical features, pathophysiology, treatment, and updates on genetic causes.

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Spotlight on Sleep and cerebral degenerative disorders

In this article, Dr. Raman Malhotra, Co-Director of the SLUCare Sleep Disorders Center at Saint Louis University School of Medicine and Dr. Alon Avidan of the University of California, Los Angeles discuss the connections between sleep and cerebral degenerative disorders. Degenerative diseases of the central nervous system are a large and varied group of disorders that affect a range of neurologic function. Sleep disorders are commonly seen in patients with cerebral degenerative diseases. Much of this may be related to the underlying central nervous system damage to sleep regulatory centers of the brain. Research has shown that sleep disorders may serve as a biomarker to predict development of a future neurodegenerative disorder. Increasing new data has suggested that disrupted sleep may accelerate the degenerative process in conditions such as Alzheimer dementia and Parkinson disease. One potential mechanism is emerging evidence of the role of sleep in glymphatic clearance of metabolic waste products from the brain. Prompt attention to and treatment of sleep symptoms can result in significant improvement in quality of life or possibly delay in progression of disease.

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