Epilepsy with auditory features: Contribution of known genes in 112 patients.

Epilepsy with Auditory Features (EAF) is a focal epilepsy syndrome mainly of unknown aetiology. LGI1 and RELN have been identified as the main cause of Autosomal Dominant EAF and anecdotally reported in non-familial cases. Pathogenic variants in SCN1A and DEPDC5 have also been described in a few EAF probands belonging to families with heterogeneous phenotypes and incomplete penetrance. We aimed to estimate the contribution of these genes to the disorder by evaluating the largest cohort of EAF. We included 112 unrelated EAF cases (male/female: 52/60) who underwent genetic analysis by next-generation sequencing (NGS) techniques. Thirty-three (29.5%) were familial cases. We identified a genetic diagnosis for 8% of our cohort, including pathogenic/likely pathogenic variants (4/8 novel) in LGI1 (2.7%, CI: 0.6-7.6); RELN (1.8%; CI: 0.2-6.3); SCN1A (2.7%; CI: 0.6-7.6) and DEPDC5 (0.9%; CI 0-4.9).This study shows that the contribution of each of the known genes to the overall disorder is limited and that the genetic background of EAF is still largely unknown. Our data emphasize the genetic heterogeneity of EAF and will inform the diagnosis and management of individuals with this disorder.

A novel mutation af Cln3 associated with delayed-classic juvenile ceroid lipofuscinois and autophagic vacuolar myopathy.

Juvenile neuronal-ceroid-lipofuscinosis (JNCL) is a lysosomal storage disease caused by mutations in CLN3. The most frequent mutation is a 1.02-kb deletion that, when homozygous, causes the classical clinical presentation. Patients harboring mutations different than the major deletion show a marked clinical heterogeneity, including protracted disease course with possible involvement of extraneuronal tissues. Cardiac involvement is relatively rare in JNCL and it is usually due to myocardial storage of ceroid-lipofuscinin. Only recently, histopathological findings of autophagic vacuolar myopathy (AVM) were detected in JNCL patients with severe cardiomyopathy. We describe a 35-year-old male showing a delayed-classic JNCL with visual loss in childhood and neurological manifestations only appearing in adult life. He had an unusual CLN3 genotype with an unreported deletion (p.Ala349_Leu350del) and the known p.His315Glnfs*67 mutation. Autophagic vacuolar myopathy was shown by muscle biopsy. At clinical follow-up, moderately increased CPK levels were detected whereas periodic cardiac assessments have been normal to date. Adult neurologists should be aware of protracted JNCL as cause of progressive neurological decline in adults. The occurrence of autophagic vacuolar myopathy necessitates periodic cardiac surveillance, which is not usually an issue in classic JNCL due to early neurological death.

Rare mtDNA variants in Leber hereditary optic neuropathy families with recurrence of myoclonus.

OBJECTIVE: To investigate the mechanisms underlying myoclonus in Leber hereditary optic neuropathy (LHON). METHODS: Five patients and one unaffected carrier from two Italian families bearing the homoplasmic 11778/ND4 and 3460/ND1 mutations underwent a uniform investigation including neurophysiologic studies, muscle biopsy, serum lactic acid after exercise, and muscle ((31)P) and cerebral ((1)H) magnetic resonance spectroscopy (MRS). Biochemical investigations on fibroblasts and complete mitochondrial DNA (mtDNA) sequences of both families were also performed. RESULTS: All six individuals had myoclonus. In spite of a normal EEG background and the absence of giant SEPs and C reflex, EEG-EMG back-averaging showed a preceding jerk-locked EEG potential, consistent with a cortical generator of the myoclonus. Specific comorbidities in the 11778/ND4 family included muscular cramps and psychiatric disorders, whereas features common to both families were migraine and cardiologic abnormalities. Signs of mitochondrial proliferation were seen in muscle biopsies and lactic acid elevation was observed in four of six patients. (31)P-MRS was abnormal in five of six patients and (1)H-MRS showed ventricular accumulation of lactic acid in three of six patients. Fibroblast ATP depletion was evident at 48 hours incubation with galactose in LHON/myoclonus patients. Sequence analysis revealed haplogroup T2 (11778/ND4 family) and U4a (3460/ND1 family) mtDNAs. A functional role for the non-synonymous 4136A>G/ND1, 9139G>A/ATPase6, and 15773G>A/cyt b variants was supported by amino acid conservation analysis. CONCLUSIONS: Myoclonus and other comorbidities characterized our Leber hereditary optic neuropathy (LHON) families. Functional investigations disclosed a bioenergetic impairment in all individuals. Our sequence analysis suggests that the LHON plus phenotype in our cases may relate to the synergic role of mtDNA variants.

Unreliability of automatic scoring of MESAM 4 in assessing patients with complicated obstructive sleep apnea syndrome.

BACKGROUND: Portable devices are used for unattended recording of patients with suspected obstructive sleep apnea syndrome (OSAS). The MESAM 4 (MAP; Martinsried, Germany) is a computerized ambulatory polysomnographic system that records four parameters: breathing noise, heart rate, arterial oxygen saturation (SaO(2)), and body position. DESIGN AND METHOD: We evaluated the reliability of the oxygen desaturation index (ODI) automatically calculated by the MESAM 4 device in evaluating patients with "complicated" OSAS. These patients present SaO(2) drops due to apneas associated with a fall in baseline SaO(2) during sleep, as occurs in the "overlap syndrome." Ten patients with complicated OSAS underwent nocturnal MESAM 4 recordings, and we compared the visual and automatic scorings of the ODI. RESULTS: The ODI obtained with visual scoring was significantly higher than ODI automatically calculated by the MESAM 4 in all patients. In some patients, this difference was so significant that it could bias clinical judgment of OSAS severity. We demonstrated that the system did not identify those desaturation events that were superimposed on a fall in baseline SaO(2). The error depends on the algorithm by which the device recognizes the desaturation events and calculates the baseline SaO(2). CONCLUSION: Automatic analysis of MESAM 4 recordings may be misleading in evaluating OSAS patients who have a fall in baseline SaO(2) during sleep. In this case, visual scoring performed by a trained polysomnographer is recommended.

Sleep complaints in periodic paralyses: a web survey.

Neuronal potassium conductance has been shown to influence the sleep-wake cycle and REM sleep homeostasis. The periodic paralyses (PP) are characterized by episodes of muscular weakness associated with changes in serum potassium levels and, therefore, with possible alterations in extracellular neuronal potassium conductance. We submitted a sleep questionnaire to the members of Periodic Paralysis International Listserv, an on-line support and information group for subjects with PP. Three control groups were made up of patients with untreated depression, patients with depression under treatment and healthy subjects. Both subjects with PP and those with untreated depression had a higher frequency of self-reported insufficient sleep quality and a higher number of nocturnal awakenings than patients with depression under treatment and healthy controls. PP subjects had more self-reported daytime sleepiness, sleep-related hallucinations and nightmares/abnormal dreams than the other three groups. Patients affected by PP may have disrupted sleep architecture and homeostasis. In particular, we suggest that the stereotypical abnormal dreams reported by several patients may reflect oneiric elaboration of nocturnal episodes of flaccid paralysis, while the increased frequency of sleep-related hallucinations may be due to enhanced REM sleep expression associated with alterations of neuronal potassium conductance.