Neuronal ceroid lipofuscinoses (NCLs) are hereditary lysosomal storage disorders characterized by progressive neurodegeneration and intracellular accumulation of auto-fluorescent lipopigment. Most NCLs, except for some adult types, present autosomal recessive inheritance patterns with progressive motor development regression, convulsions, and visual impairment, and the prognosis is generally poor with childhood onset. The clinical features are classified into four types : infantile, late infantile, juvenile, and adult. Recently, abnormalities in 13 genes, including genes encoding lysosomal enzymes, have been reported as the cause of the diseases.

  NCLs have allelic heterogeneity with different clinical courses even with the same gene mutation. Various pathogenic mechanisms have been suggested, but many remain unclear. Although there is no underlying therapy for most NCLs, enzyme replacement therapy of cerliponase alfa via the intracerebroventricular route in NCL type 2 (CLN2) significantly reduces the rate of decline in motor and language functions in comparison with that in historical controls. Early diagnosis, including newborn screening and administration of recombinant enzymes, may be important in the management of CLN2.

  Objective: The identification of seizure type is necessary to treat epilepsy. It is usually based on intermittent electroencephalography (EEG) findings and medical interviews conducted in an outpatient clinical setting but is difficult to accurately determine in some cases. We evaluated the usefulness of long-term video-EEG (VEEG) monitoring and examination by a specialist for the precise determination of seizure type. Methods: We retrospectively analyzed data from the medical records of 139 cases who underwent VEEG for more than 12 hours for epileptic seizure assessment at our hospital between April 2015 and March 2019. Results: Seizure was detected in 115 (82.7%) of the 139 cases. The seizure capture rate was high in patients with daily seizures and intellectual disabilities. Seizure types or non-epileptic seizures were identified in 113 of 115 cases (98.3%) which seizures were detected. Among patients treated by a pediatric neurology specialist, the proportion of those with an unchanged seizure type according to the treating specialist's judgment was significantly higher than patients treated by non-specialist (p=0.025) ; therefore, examination by a specialist was considered useful for the identification of seizure type. However, the seizure type was newly revealed in 62.8% of patients who underwent VEEG even after seeing a specialist. Conclusions: The diagnosis of seizure type is highly accurate in cases examined by a specialist, therefore consultation with a specialist is useful for identification of seizure type. On the other hand, even after consultation with a specialist, VEEG is useful for the identification of seizure type and treatment of epilepsy and should be conducted in patients with intractable seizures.

  CAPOS (cerebellar ataxia, areflexia, pes cavus, optic atrophy and sensorineural hearing loss) syndrome is an ATP1A3-related disorder caused by a heterozygous mutation (c.2452G>A) of the ATP1A3 gene. We herein report a male patient with CAPOS syndrome who presented disturbance of consciousness, ataxia, muscular hypotonia and areflexia associated with febrile illness three times during his early childhood. He was suspected of having CAPOS syndrome because of sensorineural hearing loss and an optic nerve disorder found by a detailed examination, although pes cavus was absent. Sanger sequencing revealed a de novo heterozygous mutation (NM_152296.5 : c.2452G>A [p.Glu818Lys]) in exon 18 of the ATP1A3 gene. After acetazolamide treatment was initiated, the patient did not experience any acute episodes for 2 years and 5 months. A detailed family history evaluation, an ophthalmologic work-up, a hearing examination and genetic testing are recommended for patients with repetitive acute encephalopathy, acute cerebellar ataxia or Guillain-Barré syndrome-like episodes.