We investigated the correlations of deletions of mitochondrial DNA in skeletal muscle with clinical manifestations of mitochondrial myopathies, a group of disorders defined either by biochemical abnormalities of mitochondria or by morphologic changes causing a ragged red appearance of the muscle fibers histochemically. We performed genomic Southern blot analysis of muscle mitochondrial DNA from 123 patients with different mitochondrial myopathies or encephalomyopathies. Deletions were found in the mitochondrial DNA of 32 patients, all of whom had progressive external ophthalmoplegia. Some patients had only ocular myopathy, whereas others had Kearns-Sayre syndrome, a multisystem disorder characterized by ophthalmoplegia, pigmentary retinopathy, heart block, and cerebellar ataxia. The deletions ranged in size from 1.3 to 7.6 kilobases and were mapped to different sites in the mitochondrial DNA, but an identical 4.9-kilobase deletion was found in the same location in 11 patients. Biochemical analysis showed decreased activities of NADH dehydrogenase, rotenone-sensitive NADH-cytochrome c reductase, succinate-cytochrome c reductase, and cytochrome c oxidase, four enzymes of the mitochondrial respiratory chain containing subunits encoded by mitochondrial DNA. We conclude that deletions of muscle mitochondrial DNA are associated with ophthalmoplegia and may result in impaired mitochondrial function. However, the precise relation between clinical and biochemical phenotypes and deletions remains to be defined.

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Results of this study modified our approach in patients with TLE. Interictal epileptiform discharges localized to one temporal lobe on serial routine EEGs or during LTM may be adequate to identify the epileptogenic zone in patients with MRI-identified unilateral medial temporal lobe atrophy.

Summary:Purpose: To determine if using more stringent criteria for cryptogenic Lennox-Gastaut syndrome (LGS) would result in an improved prognosis for that group. Cryptogenic, symptomatic, and non-cryptogenic LGS patients without etiology (indeterminate) were compared with respect to seizure and cognitive outcome.Methods: Retrospective chart review was performed on 245 patients seen at the Mayo Clinic Rochester from 1976 to 1997, with a diagnosis of either LGS or slow spike wave on EEG.LGS was confirmed in 107 (64 male, 43 female) patients. This group was divided into cryptogenic, symptomatic, and indeterminate groups containing 23,47, and 37 patients, respectively. In this study, cryptogenic patients all had normal development before onset of LGS, absence of dysmorphic features, normal neurologic examination, and normal magnetic resonance (MRI) brain imaging. Of the 107 patients, 74 had 2 3 years of follow-up. Results:LGS onset in the 107 patients occurred at a median age of 4.0 years (range, 0.6-28.9 years). When last seen, 63% of those with symptomatic LGS had more than three seizures a day compared with 50% of cryptogenic and 34% of indeterminate patients. The most common seizure types were tonic (77%), atypical absence (61 %), and generalized tonic-clonic (56%). Only three patients, all part of the indeterminate group, were seizure free at last follow-up.Conclusions: Using stringent criteria in defining the cryptogenic subgroup resulted in no significant difference in seizure outcome. Individuals with a normal cognitive outcome did not segregate into one etiologic subgroup, but did have LGS onset at an older age.

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SUMMARYPurpose: Vigabatrin used to treat infantile spasms (IS) has been associated with transient magnetic resonance imaging (MRI) abnormalities. We carried out a retrospective review to better characterize the frequency of those abnormalities in IS and in children and adults treated with vigabatrin for refractory complex partial seizures (CPS). Methods: Medical records and 332 cranial MRIs from 205 infants (aged £24 months) with IS treated at 10 sites in the United States and Canada were collected. Similarly, 2,074 images from 668 children (aged 2-16 years) and adults (aged >16 years) with CPS were re-reviewed. Prespecified MRI abnormalities were defined as any hyperintensity on T 2 -weighted or fluid-attenuated inversion-recovery (FLAIR) sequences with or without diffusion restriction not readily explained by a radiographically well-characterized pathology. MRIs were read by two neuroradiologists blinded to treatment group. The incidence and prevalence of MRI abnormalities associated with vigabatrin were estimated. Results: Among infants with IS, the prevalence of prespecified MRI abnormalities was significantly higher among vigabatrin-treated versus vigabatrin-naive subjects (22% vs. 4%; p < 0.001). Of nine subjects in the prevalence population with at least one subsequent determinate MRI, resolution of MRI abnormalities occurred in six (66.7%)-vigabatrin was discontinued in four. Among adults and children treated with vigabatrin for CPS, there was no statistically significant difference in the incidence or prevalence of prespecified MRI abnormalities between vigabatrin-exposed and vigabatrin-naive subjects. Discussion: Vigabatrin is associated with transient, asymptomatic MRI abnormalities in infants treated for IS. The majority of these MRI abnormalities resolved, even in subjects who remained on vigabatrin therapy.

The child neurologist has a critical role in planning and coordinating the successful transition from the pediatric to adult health care system for youth with neurologic conditions. Leadership in appropriately planning a youth's transition and in care coordination among health care, educational, vocational, and community services providers may assist in preventing gaps in care, delayed entry into the adult care system, and/or health crises for their adolescent patients. Youth whose neurologic conditions result in cognitive or physical disability and their families may need additional support during this transition, given the legal and financial considerations that may be required. Eight common principles that define the child neurologist's role in a successful transition process have been outlined by a multidisciplinary panel convened by the Child Neurology Foundation are introduced and described. The authors of this consensus statement recognize the current paucity of evidence for successful transition models and outline areas for future consideration. Neurology ® 2016;87:835-840 The child neurologist has a critical role in planning and coordinating the successful transition of youth with neurologic conditions from the pediatric to adult health care system. Appropriate leadership and planning of a youth's transition, and care coordination among health care, educational, vocational, and community services providers, may assist in preventing gaps in care, which otherwise may result in a youth running out of medication or delaying entry into the adult medical system through failure to make or keep appointments. Preventable health crises may develop, for which no clear medical specialist has been identified to provide care. Youth whose neurologic conditions result in cognitive or physical disability and their families may need additional support to address the particular legal and financial considerations of the transition they face.Barriers to successful transition have been identified 1-3 and ample evidence demonstrates that many youth, particularly those with special needs, continue to receive insufficient transition planning.4-7 Several models of transition support have been developed and are beginning to be tested, although the available evidence remains insufficient to identify the best models. 5,[8][9][10][11][12] In acknowledgment of this clinical reality, and in response to the 2011 clinical guideline of the American Academy of Pediatrics/American Academy of Family Physicians/American College of Physicians "supporting the healthcare transition from adolescence to adulthood in the medical home," in which specialty providers were called to develop a framework for their population's unique needs, 13 the Child Neurology Foundation convened a multidisciplinary panel of experts in 2014 to develop this guideline. The authors of this consensus statement recognize the current paucity of evidence for successful transition models, and so propose 8 common principles that should be incorporated in any transi...

Both estrogen and progesterone influence seizure activity in women with epilepsy, with estrogen generally demonstrating proconvulsant and progesterone anticonvulsant effects. Women with epilepsy exhibit a variety of endocrine disturbances, probably due to a combination of factors, including the epilepsy syndrome and the effect of interictal and ictal epileptic discharges in the brain. The direct effects of some antiepileptic drugs (AEDs) further increase this risk, apparently related to a specific drug's effect on hepatic microsomal enzymes of the cytochrome P-450 system. AEDs that induce hepatic microsomal enzymes also interact with hormonal contraception to increase estrogen's metabolism and progesterone's protein binding, decreasing concentrations of both hormones and thus reducing contraceptive efficacy. Some evidence indicates that concurrent use of hormonal contraceptives and lamotrigine significantly decreases the plasma concentration of lamotrigine, suggesting that close monitoring is warranted. Nevertheless, hormonal contraception confers comparable or superior efficacy compared with such other contraceptives as the intrauterine device and barrier methods and remains an appropriate option in women with epilepsy. Importantly, concurrent use of hormonal contraception and AEDs does not adversely affect seizure control. Careful patient management, including the use of increased estrogen doses (> or =50 microg) in patients receiving enzyme-inducing AEDs, may further minimize the risk for unintended pregnancy. Special considerations in women of childbearing age include decreased compliance and disease prevention. Although adequate seizure control is the critical requirement of an AED, the potential for interactions with hormonal contraception and the increased risk for endocrine disturbances caused by drugs that alter hepatic microsomal enzymes suggest additional potential advantages for AED treatment that does not affect these enzymes. Both the constellation of physicians treating women with epilepsy and the patients themselves have a poor understanding of the spectrum of reproductive health issues involved, and increased awareness is needed to improve patient management.