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Acute flaccid myelitis, formerly described as "acute flaccid paralysis with anterior myelitis" or "polio-like syndrome", is an acute neurologic illness in children with focal limb weakness of unknown etiology. Enterovirus 68, which as a member of the enterovirus family is related to polio, is a leading candidate for the cause of the condition. Due to the recent emergence of the condition, the existing literature about it is tentative and should not be taken as established medical opinion. There is no established treatment for the virus. == Clinical description == A summary of the condition was issued by the United States Centers for Disease Control as part of a September 26 2014 health advisory:〔(【引用サイトリンク】title=Acute neurologic illness with focal limb weakness of unknown etiology in children )〕 The CDPHE, Children's Hospital Colorado, and CDC are investigating nine cases of acute neurologic illness among pediatric patients. The cases were identified during August 9–September 17, 2014 among children aged 1–18 years (median age 10 years). Most of the children were from the Denver metropolitan area. All were hospitalized. Common features included acute focal limb weakness and specific findings on magnetic resonance imaging (MRI) of the spinal cord consisting of non-enhancing lesions largely restricted to the gray matter. In most cases, these lesions spanned more than one level of the spinal cord. Some also had acute cranial nerve dysfunction with correlating non-enhancing brainstem lesions on MRI. None of the children experienced altered mental status or seizures. None had any cortical, subcortical, basal ganglia, or thalamic lesions on MRI. Most children reported a febrile respiratory illness in the two weeks preceding development of neurologic symptoms In most cases, cerebrospinal fluid (CSF) analyses demonstrated mild-moderate pleocytosis (increased cell count in the CSF) consistent with an inflammatory or infectious process The CDC requested physicians provide information about cases meeting four criteria: patients diagnosed after August 1, 2014, who are no older than 21 years of age, showing acute onset of focal limb weakness, with a spinal cord lesion largely restricted to gray matter visualized by MRI.〔〔 A group in Texas reported having observed a pattern in 2013 of one to four cases per year with similar polio-like characteristics.〔(【引用サイトリンク】title=An Update on Outbreak of Paralysis in US: Acute Flaccid Myelitis ) (audio)〕 The CDC Morbidity and Mortality Weekly Report〔(【引用サイトリンク】title=Acute neurologic illness of unknown etiology in children — Colorado, August–September 2014 )〕 and a CDC Clinician Outreach and Communication Activity (COCA) conference call,〔(【引用サイトリンク】title=Neurologic Illness with Limb Weakness in Children )〕 noted that many cases had neck, back, or extremity pain, but otherwise those affected generally had normal sensation in their limbs.〔(【引用サイトリンク】title=Neurologic Deficits in Children Preceded by Febrile Illness )〕 A few participants in the conference call discussed whether pain, later abating, might precede the onset of paralysis.〔 An October 21 report in ''Neurology News'' described outbreaks in California and Colorado, suggesting that the number of cases might be 100 or more nationwide. Diagnosis included a good medical history, MRI imaging, and the elimination of transverse myelitis or Guillain-Barré syndrome as potential causes. Physicians were using a listserv online mailing list to communicate about similar cases in Alabama and Kansas. The largest known cluster of cases was in Colorado, with 29 total, 12 of which were reported since August.〔 Three out of four cases treated in Alabama involved a complete inability to move one arm, reminiscent of peripheral nerve injury: The three cases since August really look like each other. They have severe arm flaccidity and no mental status changes. All of them have similar spine MRIs showing gray matter involvement. You could lay all three MRIs on top of each other and they look almost the same. It's pretty striking. ... It you lift the arm up, it literally drops. Sensation is usually intact. There might be slightly decreased sensation in the other arm, but these are younger kids, so they’re not always so cooperative in giving you a good sensory exam.〔 Children’s Mercy Hospital, where three or possibly four cases had occurred since August reports: The sudden onset of flaccid paralysis in single or multiple limbs with absolutely no sensory findings, the MRIs all showing uniformly a signal increase in the ventral horns of the spinal cord — this is exactly the same region of the spinal cord affected in polio ... Almost all of the patients have an increase in their white blood cells in the cerebrospinal fluid. Some of the patients have brainstem findings and cranial-nerve findings. This is all the same as what polio does. None of us has ever seen anything like this before, with few exceptions.〔 An October 23 special session at an annual meeting of the Child Neurology Society, where a show of hands suggested that the 250 participants had collectively treated more than 100 cases. Though a third of the participants raised their hands when asked if they had seen a recent case, only two hands were raised when they were asked if they had seen a complete recovery. A hospital in Philadelphia had seen at least 10 cases. At that time the nationwide CDC count was given as 51. The Stanford University School of Medicine suggested an even higher number: "I was on a conference call a few weeks ago with about 50 doctors from medical centers across North America. Every center had seen cases. That puts the numbers real high, real fast." The number affected was still far less than the tens of thousands affected in polio seasons. Fortunately, as with polio, the number of cases appeared to be decreasing with the onset of cold weather.〔 Of 64 patients meeting the CDC criteria before October 29, 80% had had a preceding respiratory illness and 75% reported fever in the days leading up to limb weakness, the onset of which was generally abrupt.〔(【引用サイトリンク】title=CDC releases guidance on acute flaccid myelitis )〕 By November 20 the number of confirmed cases stood at 88 from 29 states.〔(【引用サイトリンク】title=Investigation of Acute Neurologic Illness with Focal Limb Weakness of Unknown Etiology in Children, Fall 2014 ) Note: despite the URL, this Web document is regularly updated, including the text: "As of November 20, CDC has verified reports of 88 cases in 32 states. We are working with healthcare professionals and state and local officials to investigate all of these cases. We are also in the process of verifying less than half a dozen additional reports."〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「acute flaccid myelitis」の詳細全文を読む スポンサード リンク
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