Search

Epilepsy, ataxia, sensorineural deafness, and tubulopathy (EAST syndrome) is a rare channelopathy due to KCNJ10 mutations. So far, only mild cerebellar hypoplasia and/or dentate nuclei abnormalities have been reported as major neuroimaging findings in these patients. We analyzed the clinical and brain MRI features of two unrelated patients (aged 27 and 23 years) with EAST syndrome carrying novel homozygous frameshift mutations (p.Asn232Glnfs*14and p.Gly275Valfs*7) in KCNJ10, detected by whole exome sequencing. Brain MRI examinations at 8 years in Patient 1 and at 13 years in Patient 2 revealed a peculiar brain and spinal cord involvement characterized by restricted diffusion of globi pallidi, thalami, brainstem, dentate nuclei, and cervical spinal cord in keeping with intramyelinic edema. The follow-up studies, performed, respectively, after 19 and 10 years, showed mild cerebellar atrophy and slight progression of the brain and spinal cord T2 signal abnormalities with increase of the restricted diffusion in the affected regions. The present cases harboring novel homozygous frameshift mutations in KCNJ10 expand the spectrum of brain abnormalities in EAST syndrome, including mild cerebellar atrophy and intramyelinic edema, resulting from abnormal function of the Kir4.1 inwardly rectifying potassium channel at the astrocyte endfeet, with disruption of water-ion homeostasis.

Progressive external ophthalmoplegia (PEO), Kearns–Sayre syndrome (KSS) and Pearson syndrome are the three sporadic clinical syndromes classically associated with single large-scale deletions of mitochondrial DNA (mtDNA). PEO plus is a term frequently utilized in the clinical setting to identify patients with PEO and some degree of multisystem involvement, but a precise definition is not available. The purpose of the present study is to better define the clinical phenotypes associated with a single mtDNA deletion, by a retrospective study on a large cohort of 228 patients from the database of the “Nation-wide Italian Collaborative Network of Mitochondrial Diseases”. In our database, single deletions account for about a third of all patients with mtDNA-related disease, more than previously recognized. We elaborated new criteria for the definition of PEO and “KSS spectrum” (a category of which classic KSS represents the most severe extreme). The criteria for “KSS spectrum” include the resulting multisystem clinical features associated with the KSS features, and which therefore can predict their presence or subsequent development. With the new criteria, we were able to classify nearly all our single-deletion patients: 64.5% PEO, 31.6% KSS spectrum (including classic KSS 6.6%) and 2.6% Pearson syndrome. The deletion length was greater in KSS spectrum than in PEO, whereas heteroplasmy was inversely related with age at onset. We believe that the new phenotype definitions implemented here may contribute to a more homogeneous patient categorization, which will be useful in future cohort studies of natural history and clinical trials. © 2015, Springer-Verlag Berlin Heidelberg.

Monoamine oxidase type B (MAO-B) inhibitors, such as selegiline and rasagiline, can be used as monotherapy or adjuvant therapy to levodopa in Parkinson’s disease (PD). Data on long-term efficacy of MAO-B inhibitors are limited with no head-to-head comparison available to date. The aim of this case–control retrospective study was to analyze data from patients with PD attending the Parkinson Institute (Milan, Italy) over a 6-year period (2009–2015) and compare the effects of selegiline and rasagiline on levodopa treatment outcomes. Patients with PD treated with either selegiline (n = 85) or rasagiline (n = 85) for 3 years as well as a control group of patients (N = 170) who have never received MAO-B inhibitors, were matched for gender, disease duration (±1 year) and age (±1 year) at baseline assessment (ratio 1:1:2). The Unified PD Rating Scale and the Hoehn–Yahr staging system were used for clinical comparisons. At baseline, mean PD duration was 6.5 years and clinical features were comparable across all three groups. After a mean follow-up of approximately 37 months, no differences in clinical progression of motor and non-motor symptoms were observed between the three groups. However, MAO-B inhibitor use was associated with ~2-fold lower change in daily dose of levodopa (p

Ocular myopathy, typically manifesting as progressive external ophthalmoplegia (PEO), is among the most common mitochondrial phenotypes. The purpose of this study is to better define the clinical phenotypes associated with ocular myopathy. This is a retrospective study on a large cohort from the database of the “Nation-wide Italian Collaborative Network of Mitochondrial Diseases”. We distinguished patients with ocular myopathy as part of a multisystem mitochondrial encephalomyopathy (PEO-encephalomyopathy), and then PEO with isolated ocular myopathy from PEO-plus when PEO was associated with additional features of multisystemic involvement. Ocular myopathy was the most common feature in our cohort of mitochondrial patients. Among the 722 patients with a definite genetic diagnosis, ocular myopathy was observed in 399 subjects (55.3%) and was positively associated with mtDNA single deletions and POLG mutations. Ocular myopathy as manifestation of a multisystem mitochondrial encephalomyopathy (PEO-encephalomyopathy, n=131) was linked to the m.3243A>G mutation, whereas the other “PEO” patients (n=268) were associated with mtDNA single deletion and Twinkle mutations. Increased lactate was associated with central neurological involvement. We then defined, among the PEO group, as “pure PEO” the patients with isolated ocular myopathy and “PEO-plus” those with ocular myopathy and other features of neuromuscular and multisystem involvement, excluding central nervous system. The male proportion was significantly lower in pure PEO than PEO-plus. This study reinforces the need for research on the role of gender in mitochondrial diseases. The phenotype definitions here revisited may contribute to a more homogeneous patient categorization, useful in future studies and clinical trials