Mitsutaka Komatsu

Efficacy of bacterial ribosomal RNA-targeted reverse transcription-quantitative PCR for detecting neonatal sepsis: a case control study

BackgroundNeonatal sepsis is difficult to diagnose and pathogens cannot be detected from blood cultures in many cases. Development of a rapid and accurate method for detecting pathogens is thus essential. The main purpose of this study was to identify etiological agents in clinically diagnosed neonatal sepsis using bacterial ribosomal RNA-targeted reverse transcription-quantitative PCR (BrRNA-RT-qPCR) and to conduct comparisons with the results of conventional blood culture. Since BrRNA-RT-qPCR targets bacterial ribosomal RNA, detection rates using this approach may exceed those using conventional PCR.MethodsSubjects comprised 36 patients with 39 episodes of suspected neonatal sepsis who underwent BrRNA-RT-qPCR and conventional blood culture to diagnose sepsis. Blood samples were collected aseptically for BrRNA-RT-qPCR and blood culture at the time of initial sepsis evaluation by arterial puncture. BrRNA-RT-qPCR and blood culture were undertaken using identical blood samples, and BrRNA-RT-qPCR was performed using 12 primer sets.ResultsPositive rate was significantly higher for BrRNA-RT-qPCR (15/39, 38.5%) than for blood culture (6/39, 15.4%; p = 0.0039). BrRNA-RT-qPCR was able to identify all pathogens detected by blood culture. Furthermore, this method detected pathogens from neonates with clinical sepsis in whom pathogens was not detected by culture methods.ConclusionsThis RT-PCR technique is useful for sensitive detection of pathogens causing neonatal sepsis, even in cases with negative results by blood culture.

Differences of Clinical Manifestations According to the Patterns of Brain Lesions in Acute Encephalopathy with Reduced Diffusion in the Bilateral Hemispheres

BACKGROUND AND PURPOSE: The precise clinical characteristics of acute encephalopathy with bilateral reduced diffusion are not fully understood. We compared clinical, laboratory, and neuroimaging findings according to the patterns of brain lesions among children with reduced diffusion in the bilateral hemispheres. MATERIALS AND METHODS: Nine patients were analyzed. The patterns of brain lesions were divided into diffuse lesions and central-sparing lesions. Diffuse lesions were defined as reduced diffusion in the whole cortex and/or subcortical white matter. Central-sparing lesions were defined as the lack of reduced diffusion in the areas around the bilateral Sylvian fissures. Clinical, laboratory, and neuroimaging findings were compared between groups. RESULTS: Five patients showed diffuse lesions and 4 showed central-sparing lesions. Coma was significantly more common in patients with diffuse lesions, whereas a biphasic clinical course was more common in those with central-sparing lesions. Outcome was worse in patients with diffuse lesions. Maximal aspartate aminotransferase, alanine aminotransferase, and kinase levels were also significantly higher in patients with diffuse lesions. In 2 patients with diffuse lesions, diffusion-weighted images during the acute phase revealed reduced diffusion in the bilateral frontal and occipital areas, followed by diffuse lesions. No patient with central-sparing lesions showed MR imaging abnormalities during the acute phase. CONCLUSIONS: Clinical manifestations in patients with diffuse lesions were severe, whereas those in patients with central-sparing lesions were relatively mild.

Clustered subclinical seizures in a patient with acute encephalopathy with biphasic seizures and late reduced diffusion

Using single-channel amplitude-integrated electroencephalography (aEEG), we monitored clustered seizures in a 12-month-old boy suffering from acute encephalopathy with biphasic seizures and late reduced diffusion (AESD). He was admitted to our hospital after losing consciousness and experiencing repeated seizures in association with fever. Although the patients state of consciousness improved the next day, it declined on the fifth day of illness, and clinical seizures were observed. Diffusion-weighted images revealed abnormal high intensities in the frontal area bilaterally. On the same day, aEEG monitoring revealed an unexpected cluster of subclinical seizures. Attending pediatricians, nurses, and other caregivers did not recognize the presence of these frequent subclinical seizures. The efficacy of antiepileptic drugs could also be objectively assessed from aEEG findings. aEEG is useful for continuous monitoring in children with acute encephalopathy, may disclose subclinical seizures, and can contribute to an objective evaluation of the efficacy of antiepileptic drugs.

The spectrum of acute encephalopathy with reduced diffusion in the unilateral hemisphere

We describe the clinical, EEG, and MRI features of children with reduced diffusion in the unilateral hemispheres. Seven patients with reduced diffusion in the subcortical white matter of the unilateral hemisphere alone were identified. Their median age was 32 months. Human herpesvirus 6 infection was virologically proven in 2 patients and human herpesvirus 7 in 1. The initial neurological symptom was a prolonged seizure in 4, a brief seizure in 2, and delirious behavior in 1. Three patients had biphasic clinical course. Laboratory tests were unremarkable in most patients. MRI showed no abnormal findings during the acute phase, whereas reduced diffusivity in the unilateral hemisphere was seen during the subacute phase. EEG during the acute phase demonstrated marked slowing in the affected hemisphere in 1 patient, mild slowing in 4, and relatively low voltage in 1. No patients died, but 6 patients had various degrees of neurological sequelae. Acute encephalopathy with reduced diffusion in the unilateral hemisphere may be one of the representative phenotypes of acute encephalopathy.

A boy with a severe phenotype of succinic semialdehyde dehydrogenase deficiency

Succinic semialdehyde dehydrogenase (SSADH) deficiency is a rare autosomal recessive disorder affecting γ-aminobutyric acid degradation. We describe here a boy with a severe phenotype of SSADH deficiency. He was referred because of a developmental delay at 4 months of age. At the age of 8 months, severe seizures developed. The diagnosis of SSADH deficiency was confirmed by an increase in 4-hydroxybutyric acid and heteroallelic mutation in the ALDH5A1 gene. His seizures were successfully treated with high-dose phenobarbital, and the electroencephalogram (EEG) abnormalities were ameliorated. However, the patient showed a degenerative clinical course with severe neurological deficits. A magnetic resonance imaging (MRI) scan revealed abnormal high intensities in the putamina and caudate nuclei on T2-weighted images, followed by marked atrophic changes. The clinical manifestation of our patient indicates the wide variety of SSADH deficiency phenotypes.

Clinical trial of minimal treatment for clustering seizures in cases of convulsions with mild gastroenteritis

UNLABELLED The aim of this study was to identify means of shortening the treatment period for clustering seizures in patients with convulsions with mild gastroenteritis (CwG). METHODS Sixty-two episodes in 61 patients who presented with CwG managed with carbamazepine (CBZ) or Lidocaine (Lidocaine tape (LDT) or intravenous infusion (Lid-iv)) between November 2005 and October 2008 were studied. The subjects were divided into the following groups: 33 episodes treated with CBZ-1 (5mg/kg/day, 1 day), 7 with CBZ-3 (5mg/kg/day, 3 days), 11 with LDT-1 (LDT 2 sheets in 24h), 4 with LDT-2 (LDT 2 sheets in 48 h), and 7 with Lid-iv (1mg/kg/h, continuous infusion). RESULTS One to seven seizures were recognized before starting CBZ or Lidocaine therapy, followed by complete cessation in 57 episodes and one or two recurrent seizures in five. Efficacy rates were 97% for CBZ-1, 100% for CBZ-3, 72.7% for LDT-1, 75% for LID-2, and 100% for Lid-iv. Efficacy was significantly higher in the CBZ groups than the Lidocaine groups (p=0.019), while the differences between treatment periods (CBZ-1 vs. CBZ-3, and Lid-1 vs. Lid-2) did not reach statistical significance (p>0.999). CONCLUSIONS CBZ and Lidocaine were effective for treating clustering seizures of CwG. We confirmed that the treatment period can be shortened without loss of efficacy. Therefore, we consider 1 day therapy with CBZ or Lidocaine to be sufficient.

Amplitude-integrated electroencephalography in patients with acute encephalopathy with refractory, repetitive partial seizures

We report amplitude-integrated EEG findings in two children with acute encephalopathy with refractory, repetitive partial seizures. Both patients had a febrile illness one week before the onset of seizure. They had reduction of consciousness and repetitive seizures refractory to first-line antiepileptic drugs. Seizure frequency rapidly increased and evolved into status epilepticus. Continuous seizure monitoring with amplitude-integrated EEG revealed frequent subclinical seizures which were missed by direct observation. In addition, the site of origin of seizures was multifocal, and seizure foci shifted from one hemisphere to the other. Their seizures were controlled after an administration of high-dose phenobarbital. Continuous seizure monitoring with amplitude-integrated EEG will contribute to correct estimation of seizure burden and efficacy of antiepileptic drugs in children with acute encephalopathy with refractory, repetitive partial seizures.

The clinical utility of a near patient care rapid microarray-based diagnostic test for influenza and respiratory syncytial virus infections in the pediatric setting.

We evaluated the potential clinical utility of an automated near patient molecular assay Verigene Respiratory Virus Plus (RV+) and rapid immunochromatographic antigen tests (RIAT) in the pediatric setting for diagnosis of influenza and respiratory syncytial virus infections when testing was performed by the pediatrician seeing the patient. Overall, with respect to influenza virus, sensitivity and specificity for RIAT were 70.8% and 100%, respectively, compared to 100% and 96.2%, respectively, for RV+. For respiratory syncytial virus, sensitivity and specificity for RIAT were 78.9% and 100%, respectively, compared to 100% and 100%, respectively, for RV+. When RIAT and RV+ sensitivity for influenza virus was compared based on the time the patient presented after onset of fever, the sensitivity of RIAT at 6 hours was 37.5% compared to 100% for RV+. At 12 hours, RIAT improved to 60.9%. This study confirms the clinical utility of RV+ in the pediatric setting.

Usefulness of single-channel amplitude-integrated electroencephalography for continuous seizure monitoring in infancy: a case report.

We continuously monitored clustered seizures using single-channel amplitude-integrated electroencephalography (aEEG) in a 6-month-old girl with probable benign partial epilepsy in infancy (BPEI). The patient was admitted with clustered seizures, and aEEG using three disposable electrodes was started by a non-expert pediatrician. During the recording, seven seizures were detected. The last seizure was nearly overlooked on clinical observation, but was later confirmed on the basis of aEEG findings. The efficacy of antiepileptic drugs could also be objectively assessed from aEEG findings. Our results show that aEEG is useful for the continuous monitoring of seizures even in older children.

Amplitude-integrated EEG revealed nonconvulsive status epilepticus in children with non-accidental head injury

OBJECTIVE We describe the clinical course and amplitude-integrated EEG findings in three children with non-accidental head injury and discuss on the importance of continuous aEEG monitoring in infants. METHODS NCSE was defined as a continuous 30-min seizure or briefer seizures occurring consecutively comprising at least 30 min of any 1-h period. Non-accidental head injury was diagnosed on the basis of neuroimaging findings such as subdural hemorrhage. Antiepileptic treatment was performed with continuous amplitude-integrated EEG monitoring. RESULTS The age of the patients ranged from 48 days to nine months. All of them had loss of consciousness and seizures on presentation. Nonconvulsive status epilepticus without clinical symptoms were recognized in all patients. Vigorous antiepileptic treatment against nonconvulsive status epilepticus was made in two patients, whereas nonconvulsive status epilepticus disappeared within one hour without additional treatment in one. CONCLUSIONS Our experience indicates that nonconvulsive status epilepticus were not uncommon in children with non-accidental head injury. Continuous amplitude-integrated EEG monitoring will be one of the useful methods in encephalopathic children in order to estimate seizure burden objectively and to treat seizures appropriately.