Spotlight on Patent foramen ovale

In this article, Dr. Shadi Yaghi and Dr. Shawna Cutting of the Warren Alpert Medical School of Brown University discuss patent foramen ovale, a highly prevalent anomaly occurring in 25% to 30% of the general population.

Patent foramen ovale represents the postnatal persistence of the normally present foramen ovale, a flap valve structure formed by the septum primum and septum secundum in the fetus. Although it is generally asymptomatic, studies have found associations with ischemic stroke and migraine. The best treatment strategy for patent foramen ovale in the setting of ischemic stroke or migraine remains unclear. Randomized controlled trials on patent foramen ovale closure showed no benefit for secondary stroke prevention or migraine improvement.

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Spotlight on Impact of sleep on epileptic manifestations

The circadian, homeostatic, ultradian, and microstructural processes that regulate the sleep-wake cycle are endowed with modulatory properties on epileptic events. In particular, sleep is a powerful trigger of both ictal and interictal manifestations. Non-REM sleep and cyclic alternating pattern promote strong activating effects, although REM sleep tends to exert a more inhibitory action. These characteristics are highly expressed in nocturnal frontal lobe epilepsy.

In this article, Dr. Parrino of the University of Parma discusses the impact of sleep on epileptic manifestations.

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Spotlight on Status migrainosus

In this article, Dr. Shuhan Zhu of Jefferson Headache Center discusses status migrainosus, an attack of severe migraine lasting more than 72 hours accompanied by debilitating symptoms that is not attributable to another disorder.

Status migrainosus may occur in migraineurs with or without aura. For patients presenting with the first or worst prolonged headache, a thorough neurologic evaluation with collateral imaging and/or spinal fluid sampling is indicated to assess for secondary causes of pain. In a patient with underlying diagnosis of migraine and without a secondary attributable cause of prolonged headaches, focus should be on swift and effective treatment with the primary aim of aborting the migraine.

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Spotlight on Nodding syndrome

Nodding syndrome is a neurologic disorder with poorly understood etiology and is clinically characterized by nodding of the head and, in some children, global developmental delay and neuropsychiatric dysfunction. It affects previously healthy children between 3 and 18 years of age. It was first documented in the United Republic of Tanzania in the 1960s but mainly came to public attention when epidemic outbreaks were reported in what is now the Republic of South Sudan in the 1990s and in northern Uganda in the late 2000s.

In this article, Dr. Rajarshi Mazumder of the University of California, Los Angeles reviews available data from different case series and case-control studies.

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Spotlight on Toxic and nutritional deficiency optic neuropathies

Toxic and nutritional deficiency optic neuropathies are fairly uncommon in the United States. They are usually the result of drug toxicity. Due to the effects of these conditions on mitochondria and cellular energy production, these entities share many signs and symptoms. Awareness of the hallmark findings of these entities as well as an increased index of suspicion in patients with chronic disease will assist the clinician with diagnosis.

In this article, Dr. Michelle Wang of the Southern California Permanente Medical Group and Dr. Peter Quiros of the Doheny Eye Center UCLA and the David Geffen School of Medicine discuss manifestations, etiology, diagnosis, and management of toxic and nutritional deficiency optic neuropathies.

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Spotlight on Chronic subdural hematoma

Chronic subdural hematoma is one of the most frequent neurosurgical conditions. It is frequently encountered in elderly people (usually, after minor head trauma) and in patients on long-term anticoagulation and long-term hemodialysis. Bilateral chronic subdural hematoma tends to occur more frequently in patients with anticoagulant or antiplatelet therapy.

Innate immune responses play an important role in the pathogenesis of chronic subdural hematoma. The most frequent presenting symptoms are headache, cognitive decline, and focal neurologic deficit. Cognitive decline includes confusional state, psychomotor slowing, gait abnormalities, and subacute dementia. Chronic subdural hematomas often present with atypical and unusual manifestations and can be difficult to diagnose. A high index of suspicion is needed to make the early diagnosis.

Patients require surgical hematoma evacuation. The common surgical procedures for chronic subdural hematoma include twist drill craniostomy, burr hole evacuation, or craniotomy. Endoscopic hematoma evacuation is a safe and effective alternative for clot removal in the elderly. Eighty percent of patients recover completely. Infrequently, hematoma may recur. Tranexamic acid, angiotensin-converting enzyme inhibitors, mannitol, a platelet-activating factor receptor antagonist, and atorvastatin are tried medical treatment options for chronic subdural hematoma; evidence regarding use is limited.

Common predictors of recurrence are male sex, older age, alcohol addiction, surgical treatment, trauma diagnoses, and diabetes mellitus.

In this article, Dr. Ravindra Kumar Garg of King George’s Medical University in Lucknow, India discusses the pathophysiology, clinical presentation, impact on outcome, and available treatments for chronic subdural hematoma.

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Spotlight on Sensory ganglionopathy

Sensory ganglionitis, variably called ganglionopathy, is a disease of sensory neurons in dorsal root ganglia. Major forms of these diseases are associated with neoplasm, Sjögren syndrome, and paraproteinemia or polyclonal gammopathy with or without known autoantibodies. Most cases follow subacute courses, but there are forms that develop chronically and acutely as well. Clinical signs include sensory ataxia exhibited by gait unsteadiness, a positive Romberg sign, reduced deep tendon reflexes, poor coordination, and pseudo-athetoid movements in the hands. Axonal degeneration warrants treatment as early as possible. Early cases of immunologic origin that are immune-mediated may respond to plasmapheresis and immunosuppression. Differential diagnoses include environmental and industrial intoxication and adverse effects of antineoplastic and antibiotic drugs.

The term “sensory neuronopathy” or “ganglionitis” refers to disorders of small neurons, larger neurons, and/or neurons of both sizes in the sensory ganglia. In this article, Dr. Kyoko Saida of Kyoto Hakuaikai Hospital in Kyoto, Japan focuses on the ganglionopathy involving larger neurons.

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Spotlight on Bell palsy

In this article, Dr. James Russell of the University of Maryland reviews the clinical presentation, diagnosis, pathogenesis, and management of Bell palsy. Bell palsy is an acute, usually unilateral mononeuropathy of the seventh cranial nerve. The disorder is presumed to be inflammatory and associated with 1 of several different viral etiologies, usually herpes simplex virus-1. The disorder is usually self-limiting, with up to 90% of affected subjects showing full recovery. Recovery occurs primarily within 4 to 6 months of onset of the disorder. The differential diagnosis is outlined in this clinical article, and specific tests may be indicated for certain patients depending on the clinical evaluation. Early treatment with steroids is recommended. Several large randomized studies clearly show that prednisone (prednisolone), given within 48 hours of onset of the palsy, improves recovery rate and promotes early recovery in affected patients. Combination therapy with antivirals is not recommended based on current clinical trial and metaanalysis data. In addition, supportive care and eye care are critical.

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Spotlight on Carbon monoxide poisoning: neurologic aspects

In this article, Dr. K K Jain discusses the neurologic aspects of carbon monoxide poisoning. Carbon monoxide can produce several nonspecific symptoms and can mimic several diseases. Most of the signs and symptoms are due to hypoxia, which affects mainly the brain. The most significant neurologic and psychiatric manifestations of carbon monoxide poisoning are seen as subacute or late sequelae, often following a period of complete recovery from an acute episode. There is a possible interaction between nitric oxide, a ubiquitous molecule in the human body, and carbon monoxide. Carbon monoxide exposure initiates processes including oxidative stress that triggers activation of N-methyl-D-aspartate neuronal nitric oxide synthase, and these events are necessary for the progression of carbon monoxide–mediated neuropathology.

The most important diagnostic test for carbon monoxide poisoning is the direct spectroscopic measurement of carboxyhemoglobin level in the blood. Brain imaging findings frequently correlate with clinical manifestations. Hyperbaric oxygen plays an important role in the management of carbon monoxide poisoning.

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Spotlight on Parasomnias

Parasomnias are undesirable but not always pathological events. Abnormal behaviors during sleep are due to the inappropriate activation of the cognitive process or physiological systems, such as the motor and/or autonomic nervous system. For this reason, parasomnias are conditions constituting a window into brain function during sleep.

Parasomnias are common in the general population, occurring more frequently in children. When episodes are frequent they can result in sleep disruption and injuries with adverse health or psychosocial consequences for the patients, bed-partners, or both. It is, thus, necessary for clinicians to recognize, evaluate, and manage these sleep disorders. Many problems hamper a differential diagnosis between non-REM parasomnias and epileptic seizures occurring during sleep.

In this article, Dr. Federica Provini and Dr. Giuseppe Loddo of the University of Bologna describe the characteristics of the most frequent parasomnias, suggesting the key points for a decisive diagnostic workup.

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