[A case of Miller Fisher syndrome with a false-positive edrophonium test].

A 69-year-old woman presented with acute bilateral ptosis, ophthalmoplegia, ataxia, and hyporeflexia in the extremities following an antecedent upper respiratory infection. We suspected that she had Miller Fisher syndrome (MFS) and performed an edrophonium test (ET) to rule out myasthenia gravis (MG). Edrophonium chloride improved the patient's bilateral ptosis, but not her ophthalmoplegia. Given the absence of the waning phenomenon on electrophysiological examination, the anti-acetylcholine receptor antibody, and a diurnal variation of symptoms, we concluded that the ET result was a false-positive. A diagnosis of MFS was confirmed by the presence of a positive anti-GQ1b antibody. To our knowledge, this is the first case report of MFS with a false-positive ET.

Optimal Doses of H1 Antihistamines Do Not Increase Susceptibility to Febrile Convulsions in Children.

BACKGROUND: The purpose of this study was to elucidate whether H1 antihistamine administration increases susceptibility to febrile convulsions in children. METHODS: A single-center, retrospective observational study was conducted in Japan. The study included 380 children with febrile convulsions between the ages of six months and five years transported via ambulance from 2011 through 2016. They were divided into the preseizure H1 antagonist "use group" and the "nonuse group." The former consisted of children who took H1 antagonists within 24 hours before the seizure onset. The primary outcome (seizure duration) and the secondary outcome (interval from fever to seizure onset) were compared between the two groups. RESULTS: Of the 380 study patients, 70 (18%) were identified as the use group. None of the patients was taking excessive doses of H1 antagonists. The prevalence of seizures lasting 15 minutes or longer was not different between the use group and the nonuse group (11% versus 8%, prevalence ratio 1.47 [95% confidence interval, 0.63 to 3.42], P = 0.37). The prevalence of fever to seizure onset less than six hours was significantly lower in the use group (26% versus 52%, prevalence ratio 0.33 [95% confidence interval 0.19 to 0.60], P < 0.001). Similar results were obtained when analyses were conducted separately by different generations (first and second) of H1 antagonists. CONCLUSIONS: Prolonged seizure duration and shortened interval from fever to seizure were not observed in children who received H1 antagonists. This study provides evidence that H1 antagonists at optimal doses could be safely used in febrile children with allergic symptoms.

Vascular pathomechanism in acute encephalopathy with biphasic seizures and late reduced diffusion.

Acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) is a childhood-onset encephalopathy, but the precise pathophysiology remains unclear. We encountered a child with Moyamoya syndrome and AESD. He exhibited left-predominant stenosis of the middle cerebral artery (MCA), and later developed broad lesions in the left hemisphere, raising the possibility that insufficient blood supply relates to formation of the lesions. To test the hypothesis, we investigated the relationship between MCA volume and lesion extent in seven AESD children without preexisting diseases. The MCA volume and lesion extent were quantified with time of flight images for construction of magnetic resonance angiography and apparent diffusion coefficient maps, respectively. Lateralization indices ([right - left]/[right + left]) of the MCA volume and lesion extent were calculated. We found that the lateralization indices were negatively correlated (r = -0.786, p = .036), that is, when the MCA volume was smaller in one side than the other side, the lesions were likely to develop more extensively in the ipsilateral side than the contralateral side. This indicates the association of insufficient blood supply with the lesions. The present study provides the first observation to suggest the involvement of vascular mechanism in AESD and has potential implications for novel therapeutic approach.