A case of succinic semialdehyde dehydrogenase deficiency with status epilepticus and rapid regression

BACKGROUND

Clinical phenotypic expression of SSADH deficiency is highly heterogeneous, and some infants may develop refractory secondary generalized seizures.

PATIENT

A 9-month-old boy manifested partial seizures, developing severe status epilepticus, and conventional antiepileptic drugs were ineffective. Use of ketamine contributed to the control of status epilepticus, achieving a reduction in frequency of partial seizures, and improving EEG findings without apparent complications. Diffusion-weighted images showed hyperintensities in the bilateral basal ganglia and fornix, and multiple T2 hyperintensity lesions were detected. (123)I-iomazenil (IMZ) SPECT revealed a decrease in binding of (123)I-iomazenil predominantly in the left temporal region by the 18th day of hospitalization. However, repeated IMZ-SPECT on the 46th day of hospitalization demonstrated almost no accumulation across a broad region, sparing the left temporal region. The patient showed rapid regression, refractory myoclonus, and severe progressive brain atrophy.

CONCLUSION

IMZ-SPECT findings demonstrated reduced benzodiazepine receptor binding and its dynamic changes in an SSADH-deficient patient. Considering the down regulation of the GABAA receptor, ketamine should be included in pharmacotherapeutic strategies for treatment of refractory status epilepticus in SSADH-deficient patients.

Autoimmune autonomic ganglionopathy in a pediatric patient presenting with acute encephalitis

Autoimmune autonomic ganglionopathy (AAG) is an acquired immune-mediated disorder that leads to systemic autonomic failure. Autoantibodies to the ganglionic nicotinic acetylcholine receptor (gAChR) are detected in 50% of AAG patients. We report the first pediatric case of AAG presenting with acute encephalitis. The patient was a 13-year-old boy who presented with orthostatic hypotension, followed by rapidly progressing disturbance of consciousness. Cerebrospinal fluid analysis revealed significant pleocytosis and increased neopterin concentration. Head MRI showed hyperintensities in bilateral caudate nuclei, putamen, hippocampus, and insula cortex. Severe autonomic dysfunctions such as severe orthostatic hypotension, bradycardia, dysuria, prolonged constipation and vomiting appeared. These symptoms were successfully controlled by repeated immunomodulating therapy with intravenous methylprednisolone pulse therapy and intravenous immunoglobulin. Autoantibodies to the α3 subunit of gAChR were detected at neurological onset, but were undetectable five months later. This observation indicates that AAG should be suspected in patients manifesting acute encephalitis characterized by preceding and prolonged autonomic symptoms, and immunomodulating therapy from an early stage can be effective.

Early Detection and Treatment of Neuroblastic Tumor with Opsoclonus-Myoclonus Syndrome Improve Neurological Outcome: A Review of Five Cases at a Single Institution in Japan

INTRODUCTION

Opsoclonus-myoclonus syndrome (OMS) is a paraneoplastic neurological disorder associated with neuroblastic tumor (NT) in childhood. Half of patients have neurological sequelae after the neurological and oncological treatment. We reviewed the neurological and oncological outcomes of NT with OMS, and discussed whether the treatment of NT would contribute to improving the neurological prognosis.

METHODS

We retrospectively assessed NT patients with OMS from January 2001 to December 2013 at a single institution in Japan. Demographic data, neurological and oncological status, histopathology, treatments, prognosis, and diagnosis and treatment timing were retrospectively reviewed from the records. The timings assessed were the interval between OMS onset and NT detection, initial NT therapy, and initial OMS therapy, the interval between NT therapy and OMS remission, and duration of OMS.

RESULTS

A total of 73 patients with NT were treated during the study period, and 5 of 73 patients were diagnosed as having NT with OMS. The median age at onset of OMS was 22 months (range, 18-30 months). The median age at detection of NT was 29 months (range, 21-33 months). Three of five cases showed no uptake on meta-iodobenzylguanidine scintigraphy. The tumor histopathology was neuroblastoma in two patients, ganglioneuroblastoma in two patients, and ganglioneuroma in one patient. Primary resection was performed in three cases. All patients survived. Two of five cases presented with atypical neurological symptoms without opsoclonus. The initial neurological therapy was started within a mean of 20 days (range, 3-76 days) from the onset of OMS in all cases. Four patients received intravenous immunoglobulin, and one with persistent neurological problems received rituximab. Neurological symptoms resolved in three cases. The mean interval between the onset of OMS and the detection of NT in case without neurological sequelae was 57 days (range, 25-113 days), while in case with neurological sequelae it was 365 days (range, 271-458 days). The mean interval between onset of OMS and initial therapy for NT in case without neurological sequelae was 88 days (range, 47-145 days), while in case with neurological sequelae it was 389 days (range, 292-486 days).

CONCLUSION

The interval between the onset of OMS and the detection and initial therapy of NT tended to be longer in patients with neurological sequelae than in those without neurological sequelae. This study suggested that early detection and treatment of NT with OMS might improve the neurological outcomes.

Clinical and genetic features of acute encephalopathy in children taking theophylline

BACKGROUND

Theophylline has recently been suspected as a risk factor of acute encephalopathy with biphasic seizures and late reduced diffusion (AESD), although there has been no systematic study on the relationship between acute encephalopathy in children taking theophylline (AET) and AESD.

METHODS

We recruited 16 Japanese patients (11 male and 5 female, median age of 2 years and 7 months) with AET from 2008 to 2013. We evaluated their clinical features, such as the duration of first seizure, biphasic clinical course and cranial CT/MRI imaging and compared them with those of AESD. We analyzed the polymorphisms or mutations of genes which are associated with AESD.

RESULTS

Clinically, 12 patients had neurological and/or radiological features of AESD. Only one patient died, whereas all 15 surviving patients were left with motor and/or intellectual deficits. Genetically, 14 patients had at least one of the following polymorphisms or mutations associated with AESD: thermolabile variation of the carnitine palmitoyltransferase 2 (CPT2) gene, polymorphism causing high expression of the adenosine receptor A2A (ADORA2A) gene, and heterozygous missense mutation of the voltage gated sodium channel 1A (SCN1A) and 2A (SCN2A) gene.

CONCLUSIONS

Our results demonstrate that AET overlaps with AESD, and that AET is a multifactorial disorder sharing a genetic background with AESD.

Characteristic neuroradiologic features in hemorrhagic shock and encephalopathy syndrome

Hemorrhagic shock and encephalopathy syndrome is a devastating disease, but the pathogenesis remains unclear. The aim of this study was to examine the usefulness of neuroimaging in establishing a diagnosis and elucidating the pathogenesis. We analyzed the neuroradiologic features of 22 patients who fulfilled the Levin criteria. All patients underwent brain computed tomography (CT), and 14 patients underwent brain magnetic resonance imaging (MRI) including diffusion-weighted imaging in 10 patients. Initial CT showed normal findings in 14 of 18 (78%) patients, but subsequently hypodensities appeared in bilateral watershed zones and progressed to whole brain edema. MRI revealed cytotoxic edema, showing hyperintensities in bilateral watershed zones on diffusion-weighted imaging with a low apparent diffusion coefficient. Serial neuroimaging showed characteristic features of a widespread brain ischemic event mainly in watershed zones in hemorrhagic shock and encephalopathy syndrome.

[A clinical study on high-dose erythropoietin therapy for acute encephalopathy or encephalitis]

OBJECTIVE

We performed high-dose erythropoietin therapy (hEPO) for acute encephalopathy or encephalitis (AE), and evaluated its safety and efficacy.

METHODS

We performed hEPO in AE patients with widespread lesions demonstrated by diffusion-weighted imaging, and prospectively investigated changes in hemoglobin levels, adverse events, changes in images, and developmental quotients.

RESULTS

All four patients showed neither an increase in the hemoglobin level nor adverse event possibly related to hEPO. One patient with acute encephalitis showed resolution of the lesion and normal developmental quotient. Two patients who had acute encephalopathy with febrile convulsive status epilepticus showed mild cerebral atrophy in the recovery phase;one had a normal developmental quotient. The patient with acute necrotizing encephalopathy including a brainstem lesion avoided acute-phase death.

CONCLUSION

Two patients showed no sequelae despite images indicating widespread abnormality. hEPO could be performed safely in patients with AE, however further trials are necessary concerning its efficacy.

[Clinical evaluation of six patients with anti-NMDAR encephalitis]

OBJECTIVE

We examined the clinical course and the prognosis of patients with anti-NMDAR encephalitis.

METHODS

We retrospectively evaluated the patients who has distinctive clinical features as anti-NMDAR encephalitis based on their medical records.

RESULTS

There were two male and four female patients with anti-NMDAR encephalitis. They were aged between 13 and 16 years. One of the six, 14 years female patient was negative for anti-NMDAR antibody. All four female patients with anti-NMDAR encephalitis had an ovarian tumor. Neurocognitive dysfunction and epilepsy remained in one female patient with right temporal lobe lesion and one male patient with celebellar abnormalities had mild mental impairment. In three patients including two patients who were examined abdominal MRI for the first time after recovery from the encephalitis, overian tumors became apparent during follow-up. In one of other patients, overian tumors had a tendency to increase in size after recovery.

CONCLUSION

Sequellae were seen in two cases that have abnormalities in brain MRI. As to ovarian tumor, it was considered to be necessary to checkup pelvic MRI for at least four years after the onset of encephalitis.

Genotype-phenotype correlations in alternating hemiplegia of childhood

OBJECTIVE

Clinical severity of alternating hemiplegia of childhood (AHC) is extremely variable. To investigate genotype-phenotype correlations in AHC, we analyzed the clinical information and ATP1A3 mutations in patients with AHC.

METHODS

Thirty-five Japanese patients who were clinically diagnosed with AHC participated in this study. ATP1A3 mutations were analyzed using Sanger sequencing. Detailed clinical information was collected from family members of patients with AHC and clinicians responsible for their care.

RESULTS

Gene analysis revealed 33 patients with de novo heterozygous missense mutations of ATP1A3: Glu815Lys in 12 cases (36%), Asp801Asn in 10 cases (30%), and other missense mutations in 11 cases. Clinical information was compared among the Glu815Lys, Asp801Asn, and other mutation groups. Statistical analysis revealed significant differences in the history of neonatal onset, gross motor level, status epilepticus, and respiratory paralysis in the Glu815Lys group compared with the other groups. In addition, 8 patients who did not receive flunarizine had severe motor deteriorations.

CONCLUSIONS

The Glu815Lys genotype appears to be associated with the most severe AHC phenotype. Although AHC is not generally seen as a progressive disorder, it should be considered a disorder that deteriorates abruptly or in a stepwise fashion, particularly in patients with the Glu815Lys mutation.

A case of severe progressive early-onset epileptic encephalopathy: unique GABAergic interneuron distribution and imaging

Early-onset epileptic encephalopathies include various diseases such as early-infantile epileptic encephalopathy with suppression burst. We experimentally investigated the unique clinicopathological features of a 28-month-old girl with early-onset epileptic encephalopathy. Her initial symptom was intractable epilepsy with a suppression-burst pattern of electroencephalography (EEG) from 7 days of age. The suppression-burst pattern was novel, appearing during sleep, but disappearing upon waking and after becoming 2 months old. The EEG showed multifocal spikes and altered with age. Her seizures demonstrated various clinical features and continued until death. She did not show any developmental features, including no social smiling or head control. Head MRI revealed progressive atrophy of the cerebral cortex and white matter after 1 month of age. (123)IMZ-SPECT demonstrated hypo-perfusion of the cerebral cortex, but normo-perfusion of the diencephalon and cerebellum. Such imaging information indicated GABA-A receptor dysfunction of the cerebral cortex. The genetic analyses of major neonatal epilepsies showed no mutation. The neuropathology revealed atrophy and severe edema of the cerebral cortex and white matter. GAD-immunohistochemistry exhibited imbalanced distribution of GABAergic interneurons between the striatum and cerebral cortex. The results were similar to those of focal cortical dysplasia with transmantle sign and X-linked lissencephaly with ARX mutation. We performed various metabolic examinations, detailed pathological investigations and genetic analyses, but could not identify the cause. To our knowledge, her clinical and pathological courses have never been described in the literature.

[Clinical study of patients undergoing paperless electroencephalography in emergency room]

Fifty-eight patients who visited the emergency room of our center with febrile convulsions and impaired consciousness, and underwent paperless electroencephalography soon after arrival. They consisted of 25 male and 33 female children, ranging in age from 5 months to 15 years and 4 months, with a mean age of 4 years and 10 months. The final diagnoses were poor responsiveness associated with fever and febrile delirium in 5 patients, febrile convulsions in 26, encephalitis/encephalopathy in 24, convulsions associated with mild gastroenteritis in 2, and aseptic meningitis in 1. The appearance of spindle wave within 24 hours after admission was considered to be a favorable prognostic factor, whereas generalized high-amplitude delta waves without fast-wave components and dysrhythmic flat basic waves were considered poor prognostic factors. We conclude that bed-side paperless electroencephalography is useful for the evaluation of changes in the brain function and course of treatment.

[Usefulness of 123I-iomazenil SPECT in pediatric patients with neurological disease]

This study examined the usefulness of 123I-iomazenil SPECT (IMZ-SPECT), a type of brain scintigram that focuses on the central benzodiazepine receptor in order to determine its distribution and the function of inhibitory neurons. IMZ-SPECT has been used for the detection of epileptogenic foci, especially when surgical intervention is considered. Interictal study by IMZ-SPECT is widely available at numerous institutions and its usefulness has been confirmed in patients with not only focal cortical dysplasia and hippocampal sclerosis, but also tuberous sclerosis and neuronal migration disorders, even when magnetic resonance image fails to demonstrate any abnormal findings. When interpreting scintigrams, the developmental dynamic change of the central benzodiazepine receptor in childhood and the duration of the benzodiazepine exposure period should be taken into consideration. It is expected that IMZ-SPECT will be used in various neurological disorders other than epilepsy in the future allow medical services to be provided based on findings in the inhibitory synaptic system obtained with IMZ-SPECT.

Progressive leukoencephalopathy with intracranial calcification, congenital deafness, and developmental deterioration

We report on a 12-year-old male with a unique cerebral white matter disease. His initial symptoms were congenital hearing loss and multiple intracranial calcifications on head CT. He developed severe intellectual disability and epilepsy. MRI showed signal abnormalities in the posterior limbs of the internal capsules, thalami, and cerebral white matter. The abnormalities were progressive over time. The neuropathology revealed diffuse and severe disruption of myelin and axons of the cerebral white matter and cerebrospinal tracts. We performed various metabolic examinations, detailed pathological investigations and genetic analyses, but could not identify the cause. To our knowledge his clinical course has not been described in the literature.

[Review of images in children with septo-optic dysplasia based on MRI and SPECT]

We reviewed MRI and SPECT images in 10 patients with septo-optic dysplasia (SOD). MRI was performed in all of them. Six of them had bilateral optic nerve atrophy and abnormality of midline brain structures (e. g., septum pellucidum, corpus callosum). Four cases had one-sided optic nerve atrophy. They have ipsilateral or bilateral cortical dysplasia. It may suggest that one of the pathogenesis of SOD is a disruption of the anterior cerebral artery at embryonic site. SPECT was performed in 3 patients with cortical dysplasia. At cortical dysplasia area, CBF-SPECT and IMZ-SPECT showed the same RI count as the normal cortex. This finding is compatible with the fact that few patients with SOD have epileptic seizures.

[Study of an efficacy and a pharmacokinetics of intranasal midazolam for status epilepticus on childhood epilepsy]

We reviewed the efficacy and a pharmacokinetics of intranasal midazolam (MDL) for status epilepticus in childhood epilepsies. This trial was planned for the patients who developed status epilepticus at least once in the past and had no responses with diazepam. Intranasal midazolam was proved to be effective (complete remission;65%), rapidly (an average time to stop seizures; 5.7 min) and safe with no adverse effects including respiratory depression with this dosage (an average of 0.26 mg/kg). In patients whose longitudinal concentrations of MDL in the blood were measured, MDL level was increased rapidly within five minutes after nasal application. Intranasal MDL is useful as a simple and safe method in the child emergency situation.

[Successful steroid pulse therapy for acute unilateral oculomotor nerve palsy associated with norovirus infection]

We report a 4-year-old boy who developed acute unilateral oculomotor nerve palsy following Norovirus infection. He visited our hospital because of diplopia three weeks after Norovirus gastroenteritis. Physical examination showed only the left oculomotor nerve palsy. Enhanced MRI of the brain and cerebrospinal fluid examination revealed no abnormality. Anti GQlb antibody was negative. Because blepharoptosis and ophthalmoplegia progressed rapidly, we performed three courses of steroid pulse therapy (methylpredonisolone 30 mg/kg x 3 day/course) combined with vitamin B6. Autonomic dysfunction (isocorea, light reflex) began to improve in several days and subsequently extraocular movements (blepharoptosis, infraduction supraduction, adducent in order) resolved completely in one month. Idiopathic oculomotor paralysis is usually believed to be selflimited, but steroid pulse therapy should to be considered in cases ocular paralysis is so severe or progressive that immune-mediated mechanism was presumed.

[Late infantile GM1 gangliosidosis with progressive dilatation of common bile duct and obstructive apnea--an autopsy case]

We report a 5-year-old autopsy case of late infantile type of GM1 gangliosidosis,which developed rare respiratory and intestinal complications. Obstructive apnea by adenoidal hypertrophy was improved by adenoidectomy, but the right bronchus was compressed by hilar lymph node swellings. The lymph nodes could not be treated surgically because of her poor general condition. There was hyperplasia showing foamy histiocyte including mucopolysaccharide which demonstrated a vacuolar formation containing irregular arranged fibrillar material on electron microscopy. Cerebral atrophy progressed gradually, and epileptic apnea developed, which was intractable to all antiepileptic drugs administered. Glycolipid accumulation, showing membranous cytoplasmic body on electron microscopy, seemed to lead to neurodegeneration. Abdominal distension due to hepatosplenomegaly, common bile duct dilatation compressed by lymph node swelling of the caput pancreatis part, and enteroparalysis was uncontrolled. These findings suggest that severe glycolipid deposition in lymphoreticular organs can induce various complications in patients with late infantile type of GM1 gangliosidosis.

Epilepsy and neurological findings in 11 individuals with 1p36 deletion syndrome

The 1p36 deletion syndrome is a newly delineated multiple congenital anomalies/mental retardation syndrome characterized by mental retardation, growth delay, epilepsy, congenital heart defects, characteristic facial appearance, and precocious puberty. We analyzed 11 patients by fluorescence in situ hybridization (FISH) using commercially available bacterial artificial chromosome and P1-derived artificial chromosome genomic clones to define the chromosomal deletion responsible for the 1p36 deletion syndrome. Cytogenetic investigation revealed two cases with a terminal deletion of 1p36. Nine patients had an apparently normal karyotype with standard G-bands by trypsin using Giemsa (GTG), but FISH screening with the highly polymorphic genetic marker D1Z2, which is mapped to 1p36.3 and contains an unusual reiterated 40-bp variable number tandem repeat, revealed a submicroscopic deletion. All patients had severe to profound mental retardation. Based on the University of California Santa Cruz Genome Browser, we constructed a deletion map and analyzed the relationship between neurological findings and chromosomal deletions for the 11 cases. Six cases had intractable epilepsy and three had no seizures. The common deletion interval was about 1 million base pairs (Mbp) located between RP11-82D16 and RP4-785P20 (Rho guanine exchange factor (GEF) 16). The severity of clinical symptoms correlates with the size of the deletion. This is demonstrated by the 3 patients with at least 8Mbp deletions that display profound mental retardation and congenital heart defects. Although haploinsufficiency of the potassium channel beta-subunit (KCNAB2) is thought to be responsible for intractable seizures in the 1p36 deletion syndrome, this was not the case for 3 of the 11 patients in this study. Further investigation of the 1p36 region is necessary to allow identification of genes responsible for the 1p36 deletion syndrome.

[Multicenter study of occipital lobe epilepsy in childhood: clinical characteristics]

We investigated the clinical characteristics of 54 patients with childhood onset occipital lobe epilepsy (OLE). There were 25 patients of symptomatic OLE (cortical dysplasia, post encephalitis or encephalopathy, brain tumor and so on), and 29 cases of cryptogenic OLE. Eighteen patients had positive visual symptoms such as flash light, bright spots and sparks of light, 23 patients had negative ones such as scotoma, hemianopia and amaurosis and 10 patients had other complicated visual symptoms such as change of the shape or colors. Young children complained of simple visual phenomena. The youngest patient who could explain visual symptom was 3 years old. All 3 patients with visual field defects had cortical dysplasia in occipital lobe. Ictal SPECT study showed wide hyperperfusion areas in the temporo-parieto-occipital lobe in most of patients with abnormal MRI findings. CBZ and VPA were prescribed in most cases, and were effective in 65% and 60% of the patients, respectively. Seizure prognosis was relatively good. Seizures disappeared in 56% of the patients with symptomatic OLE and 79% of those with cryptogenic OLE.

Magnetoencephalography in the detection of focal lesions in West syndrome

BACKGROUND

According to the international classification of epilepsy syndromes, West syndrome (WS) is a form of generalized epilepsy. However, it is known that localized lesions can induce WS and that patients with WS often subsequently develop focal seizures. We evaluated such patients using magnetoencephalography (MEG).

METHOD

Fourteen patients of 3 months to 6 years of age who had or who had previously had WS were examined. MEGs were recorded using a laying-type whole-cortex MEG system with a 160-channel first-order gradiometer. Twelve-channel electroencephalography (EEG) and one-channel electrocardiography (ECG) were simultaneously recorded. Equivalent current dipoles were estimated at the point of spikes on the EEG.

RESULTS

Patients were classified by magnetic resonance imaging (MRI) findings into a focal lesion group (group F, n=7) and a non-focal lesion group (group N, n=7). The dipoles estimated from the MEG were classified into three groups: W, with the dipoles distributed over a wide brain area (n=7); WC, dipoles distributed over a wide area along with a dense dipole distribution in a specific cortical area (n=3); and C, closed dipole distribution in a unilateral cerebral focal area (n=4). Patients were also classified by the stage of the disease during which the MEG was recorded, and by the type of seizure they experienced. Those with hypsarrhythmia examined early in the disease all had pattern W regardless of their lesion group, whereas those examined later exhibited more diverse dipole patterns that corresponded to seizure type.

CONCLUSIONS

Dipoles were distributed widely over bilateral cerebral cortex when patients had infantile spasms with hypsarrhythmia whether or not they had focal lesions. The dipole distribution pattern in MEG changed according to changes in seizure type.

[Seizures associated with fever in children of congenital adrenal hyperplasia]

We investigated seizures in 22 children with congenital adrenal hyperplasia (CAH), eight of whom had seizures associated with fever. The follow-up period was 5-18 years. The onset of seizures ranged from 1 to 4 years of age, and the total number of seizures was one to three in all cases. Four cases had seizures twice within 24 hours. None had seizures after 5 years of age. In two of the eight cases, the seizures may have caused by hypoglycemia or hyponatremia, in the remaining six they were considered to be febrile seizures. Three of them had first-degree relatives with febrile seizures. Electroencephalogram was recorded in five cases, with normal results in all of them. One case with febrile status developed localization-related epilepsy later. None showed developmental delay during follow-up. Although seizures in CAH have been ascribed to hypoglycemia and/or metabolic disorders (hyponatremia), our findings implicate unknown factors in the pathogenesis such as excess secretion of corticotropin releasing factor (CRF) under stress, prolonged elevation of CRF during fetus life and linkage between CAH and febrile seizures on the chromosome 6.