Background-Varicella zoster virus (VZV) vasculopathy produces stroke secondary to viral infection of cerebral arteries. Not all patients have rash before cerebral ischemia or stroke. Furthermore, other vasculitides produce similar clinical features and comparable imaging, angiographic, and CSF abnormalities.

We describe members of 4 kindreds with a previously unrecognized syndrome characterized by seizures, sensorineural deafness, ataxia, mental retardation, and electrolyte imbalance (hypokalemia, metabolic alkalosis, and hypomagnesemia). By analysis of linkage we localize the putative causative gene to a 2.5-Mb segment of chromosome 1q23.2-23.3. Direct DNA sequencing of KCNJ10, which encodes an inwardly rectifying K ؉ channel, identifies previously unidentified missense or nonsense mutations on both alleles in all affected subjects. These mutations alter highly conserved amino acids and are absent among control chromosomes. Many of these mutations have been shown to cause loss of function in related K ؉ channels. These findings demonstrate that loss-of-function mutations in KCNJ10 cause this syndrome, which we name SeSAME. KCNJ10 is expressed in glia in the brain and spinal cord, where it is believed to take up K ؉ released by neuronal repolarization, in cochlea, where it is involved in the generation of endolymph, and on the basolateral membrane in the distal nephron. We propose that KCNJ10 is required in the kidney for normal salt reabsorption in the distal convoluted tubule because of the need for K ؉ recycling across the basolateral membrane to enable normal activity of the Na ؉ -K ؉ -ATPase; loss of this function accounts for the observed electrolyte defects. Mice deficient for KCNJ10 show a related phenotype with seizures, ataxia, and hearing loss, further supporting KCNJ10's role in this syndrome. These findings define a unique human syndrome, and establish the essential role of basolateral K ؉ channels in renal electrolyte homeostasis.Gitelman syndrome ͉ hypokalemia ͉ hypomagnesemia ͉ inwardly rectifying K ϩ channel ͉ renal salt wasting

Our results show that the presence of MOG-abs strongly depends on the age at disease onset and that high MOG-ab titers were associated with a recurrent non-MS disease course.

SUMMARYEncephalitis is generally presumed, even when seizures follow banal febrile infection, and pathogen detection in cerebrospinal fluid fails. This retrospective multicenter case series reports on 22 previously healthy children aged 3-15 years (median 6.5 years) with prolonged or recurrent seizures occurring 2-14 days (median 5 days) after fever onset (19 children with respiratory or nonspecific infections). Cerebrospinal fluid studies revealed 2-42 cells/ll (median 5 cells/ll) and no pathogens. Electroencephalography showed diffuse slowing or multifocal discharges. Neuroimaging demonstrated normal findings in 10 children. Brain biopsies were performed in seven children showing gliosis but no inflammation. Anesthetic barbiturates were used in 14 children with refractory status epilepticus, and immunotherapy in 9. Two children died, eight remained in a state of impaired consciousness, eight developed therapy-refractory epilepsies, two had behavioral disturbances, and two recovered. The lack of evidence for encephalitis suggests another infectionrelated pathogenesis of this disastrous epileptic encephalopathy. Therefore, we propose the term ''febrile infection-related epilepsy syndrome'' (FIRES).

Results MOG antibodies (median 1:2560; range 1:160-1:20 480) were detected in 19 children with ADEM. The majority of children showed a decline of serum MOG-IgG titres over time. Children with MOG antibodies did not differ in their age at presentation, sex ratio, the presence of oligoclonal bands, clinical symptoms or initial severity, apart from a higher CSF cell count ( p=0.038), compared with children without MOG antibodies. In addition, further relapsing demyelinating episodes associated with MOG antibodies were observed only in children with MOG antibodies. All 19 children with MOG antibodies had a uniform MRI pattern, characterised by large, hazy and bilateral lesions and the absence of atypical MRI features (eg, mainly small lesions, well-defined lesions), which was significantly different compared to that of children without MOG antibodies ( p=0.003; and p=0.032, respectively). In addition, children with MOG antibodies had involvement of more anatomical areas ( p=0.035) including the myelon characterised by a longitudinally extensive transverse myelitis ( p=0.003), more often a complete resolution of lesions ( p=0.036) and a better outcome ( p=0.038). Conclusions Patients with ADEM with MOG antibodies in our cohort had a uniform MRI characterised by large, bilateral and widespread lesions with an increased frequency of longitudinal extensive transverse myelitis and a favourable clinical outcome in contrast to children lacking MOG antibodies.