[Clinical and imaging features of acute encephalopathy with biphasic seizures and late reduced diffusion in children]

Objective: To explore the clinical and imaging features of acute encephalopathy with biphasic seizures and late reduced diffusion(AESD) in children. Methods: For the case series study, 21 children with AESD from Peking University First Hospital, Provincial Children's Hospital Affiliated to Anhui Medical University, Children's Hospital of Fudan University, and Shanxi Children's Hospital who were diagnosed and treated from October 2021 to July 2023 were selected. Clinical data were collected to summarize their clinical information, imaging, and laboratory tests, as well as treatment and prognostic characteristics. Descriptive statistical analysis was applicated. Results: Of the 21 cases with AESD, 11 were males and 10 were females, with the age of onset of 2 years and 6 months (1 year and 7 months, 3 years and 6 months). Of the 21 cases, 18 were typical cases with biphasic seizures. All typical cases had early seizures within 24 hours before or after fever onset. Among them, 16 cases had generalized seizures, 2 cases had focal seizures, and 7 cases reached the status epilepticus. Of the 21 cases, 3 atypical cases had late seizures in biphasic only. The late seizures in the 21 cases occurred on days 3 to 9. The types of late seizures included focal seizures in 12 cases, generalized seizures in 6 cases, and both focal and generalized seizures in 3 cases. Diffusion-weighted imaging (DWI) test on days 3 to 11 showed reduced diffusion of subcortical white matter which was named "bright tree sign" in all cases. The diffuse cerebral atrophy predominantly presented in the front-parietal-temporal lobes was found in 19 cases between day 12 and 3 months after the onset of the disease. Among 21 cases, 20 had been misdiagnosed as autoimmune encephalitis, central nervous system infection, febrile convulsions, posterior reversible encephalopathy syndrome, acute disseminated encephalomyelitis, and hemiconvulsion-hemiplegia-epilepsy syndrome. All the cases received high-dose gammaglobulin and methylprednisolone pulse therapy with poor therapeutic effect. By July 2023, 18 cases were under follow-up. Among them, 17 cases were left with varying degrees of neurologic sequelae, including 11 cases with post-encephalopathic epilepsy; 1 recovered completely. Conclusions: AESD is characterized by biphasic seizures clinically and "bright tree sign" on DWI images. Symptomatic and supportive treatments are recommended. The immunotherapy is ineffective. The prognosis of AESD is poor, with a high incidence of neurological sequelae and a low mortality.

Anterior cingulate glutamate levels associate with functional activation and connectivity during sensory integration in schizophrenia: a multimodal 1H-MRS and fMRI study

BACKGROUND

Glutamatergic dysfunction has been implicated in sensory integration deficits in schizophrenia, yet how glutamatergic function contributes to behavioural impairments and neural activities of sensory integration remains unknown.

METHODS

Fifty schizophrenia patients and 43 healthy controls completed behavioural assessments for sensory integration and underwent magnetic resonance spectroscopy (MRS) for measuring the anterior cingulate cortex (ACC) glutamate levels. The correlation between glutamate levels and behavioural sensory integration deficits was examined in each group. A subsample of 20 pairs of patients and controls further completed an audiovisual sensory integration functional magnetic resonance imaging (fMRI) task. Blood Oxygenation Level Dependent (BOLD) activation and task-dependent functional connectivity (FC) were assessed based on fMRI data. Full factorial analyses were performed to examine the Group-by-Glutamate Level interaction effects on fMRI measurements (group differences in correlation between glutamate levels and fMRI measurements) and the correlation between glutamate levels and fMRI measurements within each group.

RESULTS

We found that schizophrenia patients exhibited impaired sensory integration which was positively correlated with ACC glutamate levels. Multimodal analyses showed significantly Group-by-Glutamate Level interaction effects on BOLD activation as well as task-dependent FC in a 'cortico-subcortical-cortical' network (including medial frontal gyrus, precuneus, ACC, middle cingulate gyrus, thalamus and caudate) with positive correlations in patients and negative in controls.

CONCLUSIONS

Our findings indicate that ACC glutamate influences neural activities in a large-scale network during sensory integration, but the effects have opposite directionality between schizophrenia patients and healthy people. This implicates the crucial role of glutamatergic system in sensory integration processing in schizophrenia.

Hub-connected functional connectivity within social brain network weakens the association with real-life social network in schizophrenia patients

Hubs in the brain network are the regions with high centrality and are crucial in the network communication and information integration. Patients with schizophrenia (SCZ) exhibit wide range of abnormality in the hub regions and their connected functional connectivity (FC) at the whole-brain network level. Study of the hubs in the brain networks supporting complex social behavior (social brain network, SBN) would contribute to understand the social dysfunction in patients with SCZ. Forty-nine patients with SCZ and 27 healthy controls (HC) were recruited to undertake the resting-state magnetic resonance imaging scanning and completed a social network (SN) questionnaire. The resting-state SBN was constructed based on the automatic analysis results from the NeuroSynth. Our results showed that the left temporal lobe was the only hub of SBN, and its connected FCs strength was higher than the remaining FCs in both two groups. SCZ patients showed the lower association between the hub-connected FCs (compared to the FCs not connected to the hub regions) with the real-life SN characteristics. These results were replicated in another independent sample (30 SCZ and 28 HC). These preliminary findings suggested that the hub-connected FCs of SBN in SCZ patients exhibit the abnormality in predicting real-life SN characteristics.

Altered empathy-related resting-state functional connectivity in patients with bipolar disorder

Empathy is the ability to generate emotional responses (i.e., cognitive empathy) and to make cognitive inferences (i.e., affective empathy) to other people's emotions. Empirical evidence suggests that patients with bipolar disorder (BD) exhibit impairment in cognitive empathy, but findings on affective empathy are inconsistent. Few studies have examined the neural mechanisms of cognitive and affective empathy in patients with BD. In this study, we examined the empathy-related resting-state functional connectivity (rsFC) in BD patients. Thirty-seven patients with BD and 42 healthy controls completed the self-report Questionnaires of Cognitive and Affective Empathy (QCAE), the Yoni behavioural task, and resting-sate fMRI brain scans. Group comparison of empathic ability was conducted. The interactions between group and empathic ability on seed-based whole brain rsFC were examined. BD patients scored lower on the Online Simulation subscale of the QCAE and showed positive correlations between cognitive empathy and the rsFC of the dorsal Medial Prefrontal Cortex (dmPFC) with the lingual gyrus. The correlations between cognitive empathy and the rsFC of the temporal-parietal junction (TPJ) with the fusiform gyrus, the cerebellum and the parahippocampus were weaker in BD patients than that in healthy controls. These findings highlight the underlying neural mechanisms of empathy impairments in BD patients.

The diagnostic threshold of Cornell assessment of pediatric delirium in detection of postoperative delirium in pediatric surgical patients

Background

Cornell assessment of pediatric delirium (CAPD) showed advantage in diagnosis of pediatric delirium in Chinese critically ill patients. But its performance in surgical patients is still unclear. The present study was designed to validate the diagnostic performance of CAPD in surgical pediatric patients.

Methods

This is a prospective validation study. Pediatric patients who underwent selective surgery and general anesthesia were enrolled. Primary outcome was the incidence of delirium within postoperative three days. CAPD Chinese version was used to evaluate if the patient had delirium one time per day. At the meantime, a psychiatrist employed Diagnostic and Statistical Manual of Mental Disorders fifth edition to diagnose delirium, which was the “gold standard”, and the result was considered as reference standard. Sensitivity, specificity and area under receiver operating characteristic (ROC) curve were calculated to investigate the performance of CAPD.

Results

A total of 170 patients were enrolled. Median age was 4 years old. As diagnosed by psychiatrist, 23 (13.5 %) patients experienced at least one episode of delirium during the follow-up period. When diagnostic threshold was set at 9, CAPD showed the optimal sensitivity (87.0 %, 95 %CI 65.3 %-96.6 %) and specificity (98.0 %, 95 %CI 93.7 %-99.5 %) in comparison with other diagnostic thresholds. ROC analysis showed that CAPD was a good delirium assessment instrument with area under curve of 0.911 (95 % CI 0.812 to 1.000, P < 0.001). Agreement between CAPD and reference standard was 0.849 (Kappa coefficient, P < 0.001).

Conclusions

This study found that Cornell assessment of pediatric delirium could be used as an effective instrument in diagnosis of delirium in pediatric surgical patients.

Trial registration

www.chictr.org.cn Identifier: ChiCTR-DDD-17,012,231, August 3, 2017.

[Investigation on the status of monotherapy for newly diagnosed tic disorders and its comorbidity in children]

Objective: To investigate the status of monotherapy for newly diagnosed tic disorders and its comorbidity in children, so as to provide a reference for clinical medication. Methods: A questionnaire survey was conducted to collect the application experience of monotherapy for newly diagnosed tic disorders and comorbidities in 110 pediatric neurologists and psychiatrists from Chinese Tic Disorders Study Consortium from February to August in 2019. Doctors were asked to rate treatment options based on a rank 5-point scale with "1" least appropriate and "5" most appropriate. The drug evaluation index was based on the comparison of the median score of a single drug with the overall scores of all drugs in this disease (M (Q₁, Q₃)), single drug M ≥ overall Q₃ was recommended as preferred drugs; overall Q₁≤ single drug M < overall Q₃ was considered as secondary drugs; single drug M < overall Q₁ was considered as unsuitable drugs. Results: Among 110 electronic questionnaires, 94 (86%) were availably responded, responding doctors included 37 (39%) males and 57 (61%) females, the age of responding doctors was (48±10) years, and their working year was (17±10) years. In the investigation of the first and second monotherapy for newly diagnosed tic disorders in children without comorbidities, there were no preferred drugs for mild transient tic disorders. The scores of clonidine, aripiprazole and tiapride were 4 (3, 4), 4 (3, 4), 4 (4, 5) scores respectively, and were greater than overall scores (3 (2, 4) scores), so they could be recommended as the preferred drugs for moderate chronic tic disorders, the recommendation for initial mild Tourette syndrome (TS) treatment was the same as preferred drugs for moderate chronic tic disorders. Similarly, clonidine, aripiprazole, tiapride and haloperidol could be recommended as the preferred drugs for other kinds of tic disorders. As for the second monotherapy, the preferred drugs for moderate transient tic disorders, mild chronic tic disorders and severe TS were all aripiprazole, tiapride, haloperidol, sulpiride, clonidine and topiramate. While clonidine, aripiprazole, tiapride could be considered as preferred drugs for severe transient tic disorders, moderate to severe chronic tic disorders and mild to moderate tic disorders. In the investigation of monotherapy for newly diagnosed tic disorders in children with comorbidities, for moderate chronic tic disorders and TS comorbid with obsessive-compulsive disorder, aripiprazole (4 (3, 5) scores) and sertraline (4 (3, 4) scores) were preferred drugs,the median scores of which were all greater than overall scores (3 (3, 4) scores), they were also the preferred treatment for severe transient tic disorders and mild chronic tic disorders. For mild and moderate transient tic disorders, severe chronic tic disorders and TS comorbid with obsessive-compulsive disorder, aripiprazole, fluvoxamine, fluoxetine, haloperidol and sertraline were preferred drugs. When comorbid with attention deficit hyperactivity disorder (ADHD), severe transient tic disorders, moderate chronic tic disorders and TS, tomoxetine and clonidine were recommended as preferred drugs (both 4 (4, 5) scores), and tomoxetine and clonidine were also the preferred treatment for severe TS. For severe chronic tic disorders comorbid with ADHD, clonidine (5(4, 5) scores) was preferred drug, greater than overall scores (4 (3, 5) scores), while for mild and moderate transient tic disorders clonidine, tomoxetine, guanidine and methylphenidate were recommended as preferred drugs. For mild chronic tic disorders and TS comorbid with ADHD tomoxetine was preferred drug. When comorbid with sleep disorders, there were no preferred drugs for mild transient tic disorders; estazolam (3 (2, 3) scores) was the preferred drug for mild chronic tic disorders and TS comorbid with sleep disorders. For othe kind of tic disorders comorbid with sleep disorders, estazolam, melatonin and clonazepam were preferred drugs. When comorbid with anxiety and depressive disorders, for all kinds of tic disorders sertraline was recommended as preferred drugs, the median scores of sertraline were all (4 (3, 5) scores) in severe transient tic disorders, moderate to severe chronic tic disorders and moderate TS, and greater than overall scores (3 (3, 4) scores). While severe chronic tic disorders comorbid with anxiety and depressive disorders, fluvoxamine could also be chosen as preferred drugs. Conclusions: Drug therapy is not recommended for mild transient tic disorders, while tiapride, aripiprazole, clonidine, and haloperidol are mainly preferred drugs for the other kinds of tic disorders. Corresponding drugs should be selected when tic disorders are combined with obsessive-compulsive disorder, ADHD, sleep disorders, anxiety, depression, etc.

[Clinical characteristics and ketogenic diet therapy of glucose transporter type 1 deficiency syndrome in children: a multicenter clinical study]

Objective: To explore the clinical characteristics of pediatric glucose transporter type 1 deficiency syndrome (GLUT1 DS), evaluate the efficacy and safety of ketogenic diet therapy (KDT). Methods: Clinical data of 19 children with GLUT1 DS admitted to Children's Hospital of Fudan University, Tianjin Children's Hospital, Shenzhen Children's Hospital, Children's Hospital of Nanjing Medical University and Jiangxi Provincial Children's Hospital between 2015 and 2019 were collected retrospectively. The first onset symptom, main clinical manifestations, cerebrospinal fluid features and genetic testing results of patients were summarized, the efficacy and safety of ketogenic diet treatment were analyzed. Results: Among the 19 cases, 13 were males and 6 females. The age of onset was 11.0 (1.5-45.0) months,the age of diagnosis was 54.0 (2.8-132.0) months. Epilepsy was the first onset symptom of 13 cases. Different forms of tonic-clonic seizures were the most common types of epilepsy (7 cases with generalized tonic-clonic seizures, 5 cases with focal tonic or clonic seizures, 4 cases with generalized tonic seizures). Antiepileptic drugs were effective in 4 cases. Paroxysmal motor dysfunction was present in 12 cases and ataxia was the most common one. All patients had different degrees of psychomotor retardation. Among 17 patients received cerebrospinal fluid examination, cerebrospinal fluid (CSF) glucose level was lower than 2.2 mmol/L and CSF glucose/glycemic index was<0.45 in 16 cases, only 1 case presented normal CSF glucose level (2.3 mmol/L) and normal CSF glucose/glycemic index(0.47). SLC2A1 gene mutations were found in 16 patients, missense, frameshift and nonsense mutations were the common types with 5 cases, 5 cases and 3 cases respectively. All 19 patients were treated with ketogenic diet, which was effective in 18 cases in seizure control, 11 cases in dyskinesia improvement and 18 cases in cognitive function improvement. No serious side effects were reported in any stage of KDT. Conclusions: The diagnosis of GLUT1 DS is often late. It is necessary to improve the early recognition of the disease and perform CSF glucose detection and genetic testing as early as possible. The KDT is an effective and safe treatment for GLUT1 DS, but a small number of patients have not response to diet therapy.

Validation of the Questionnaire of Cognitive and Affective Empathy in patients with schizophrenia, major depressive disorder and bipolar disorder

INTRODUCTION

Alteration of empathy is common in patients with psychiatric disorders. Reliable and valid assessment tools for measuring empathy of clinical samples is needed. The Questionnaire of Cognitive and Affective Empathy (QCAE) is a newly-developed instrument to capture cognitive and affective components of empathy. This study aimed to validate the QCAE and compared self-reported empathy between clinical groups with varied psychiatric diagnoses and healthy sample.

METHODS

The present study performed factor analysis for the QCAE on clinical samples in the Chinese setting (n = 534), including patients with schizophrenia (n = 158), bipolar disorder (n = 213) and major depressive disorder (n = 163). Internal consistency, internal correlation and convergent validity was examined in the subsample (n = 361). Group comparison among patients with schizophrenia, bipolar disorder, major depressive disorder and healthy controls (n = 107) was conducted to assess the discriminant validity.

RESULTS

Our results indicated acceptable factor model, good reliability and validity of the QCAE. Impaired cognitive empathy was found in clinical samples, especially in patients with schizophrenia, while higher affective empathy was found in patients with bipolar disorder and major depressive disorder.

CONCLUSION

The QCAE is a useful tool in assessing empathy in patients with varied psychiatric diagnoses.

Cross-cultural adaptation and validation of the 3D-CAM Chinese version in surgical ICU patients

BACKGROUND

Accurate diagnosis of delirium is very important for prevention and treatment. Present study was designed to validate the 3-Minute Diagnostic Interview for CAM-defined Delirium Chinese version (3D-CAM-CN) in surgical ICU patients.

METHODS

In this prospective diagnostic study, the 3D-CAM was translated into Chinese with culture adaption. Two interviewers (Roles A and B) independently administrated 3D-CAM-CN assessment in adult patients from postoperative days 1 to day 3. At the meantime, a panel of psychiatrists diagnosed delirium according to the Diagnostic and Statistical Manual of Mental Disorders-fifth edition as the reference standard. The sensitivity and specificity were calculated to analyze the diagnostic character of the 3D-CAM-CN. Kappa coefficient was used to evaluate interrater reliability.

RESULTS

Two hundred forty-five adult patients were assessed for at least 2 days, resulting a total of 647 paired-assessments. When compared with the reference standard, the sensitivity and specificity of the 3D-CAM-CN assessment were 87.2 and 96.7%, respectively, by Role A and 84.6 and 97.4%, respectively, by Role B, with good interrater reliability (Kappa coefficient = 0.82, P < 0.001). It also performed well in patients with mild cognitive impairment, with the sensitivity from 85.7 to 100% and the specificity from 95.7 to 96.4%.

CONCLUSION

Our results showed that the 3D-CAM-CN can be used as a reliable and accurate instrument for delirium assessment in surgical patients.

TRIAL REGISTRATION

This trail was approved by the Clinical Research Ethic Committee of Peking University First Hospital (No. 2017-1321) and registered on Chinese clinical trial registry on July 6, 2017 (ChiCTR-OOC-17011887).

[Detection ofmethylated genes related to allergic rhinitis and establishment of methylation profile]

Objective:The aim of this study is to detect differentially methylated genes to allergic rhinitis (AR) based on methylation chip, and to analyze the relationship between DNA methylation and AR.Method:Illumina methylation chip were made by normal inferior turbinate mucous tissue obtained from patients(n=19) and healthy individuals(n=11). Detection of differential the sites of methylated genes, Gene Ontology enrichment, KEGG pathway enrichment database and literature search were used to analysis.Result:There were 94 aberrant methylation sites in patients with AR, including 51 hypermethylation sites (e.g. ST7,LCE2D,ATRIP genes) and 43 hypomethylation sites (e.g. PIK3CG, TLR6, IL-4 genes). The results of Gene Ontology enrichment and KEGG pathway enrichment indicates the DNA methylation has relative trend with AR, and DNA methylation of ST7, LCE2D, PIK3CG genes may be associated with AR, but the results of GO analysis and KEGG analysis were statistically significant. Moreover, literature search prompts that DNA methylation of TLR6 gene and IL-4 gene may be associated with AR.Conclusion:Varying degrees of methylated genes from inferior turbinate mucous tissue based on high-flux methylation chip hint gene methylation is an important cause of AR. The relationship between them needs further verification.

[Demographic characteristics and canalith repositioning efficacy in 907 patients with typical benign paroxysmal positional vertigo]

AbstractObjective:To review the demographic characteristics and canalith repositioning efficacy in 907 patients with typical benign paroxysmal positional vertigo(BPPV). Method: The demographic characteristics of 907 patients with typical BPPV were statistically analyzed. According to the type of BPPV, patients were treated with the appropriate repositioning maneuver, and the clinical efficacy of repositioning maneuver was analyzed and summarized. Result: Nine hundred and seven patients of BPPV with typical nystagmus were elected in this study. 585 out of 907 were female and 322 out of were male, and the mean age was 53.10±14.25(13 to 89) years. The lesion located to the posterior semiCIrcular canal was 489 patients(53.9%), horizontal semiCIrcular canal was 312 patients(34.4%), anterior semiCIrcular was 63 patients(6.9%), and multiple semiCIrcular was 43 patients(4.8%). According to Kaplan-Meier survival analysis curve, the median cure time for the modified Semont and Epley repositioning maneuver in PC-BPPV groups was 3 days, and there was no significant difference in survival curves between the two repositioning maneuver. Meanwhile, the median cure time for Barbecue and Li horizontal canal quick repositioning maneuver groups was 3 days, and 1 day for Gufoni repositioning maneuver group in HC-BPPV groups. And there was no significant difference in survival curves among the three repositioning maneuver. In the AC-BPPV, 7 cases, 31 cases, 57 cases, 58 cases were cured with the Li anterior canal quick repositioning maneuver in the 1st day, the 3rd day, 1 week later, and 1 month later, and 5 cases lost to be follow-up. According to Kaplan-Meier survival analysis curve, the median cure time for the Li anterior canal quick repositioning maneuver in AC-BPPV groups was 3 days. Conclusion:Repositioning maneuver represents a simple, safe, rapid and effective approach to the treatment of BPPV. Therefore, repositioning maneuver should be choice for the BPPV treatment.

Clinical efficacy, onset time and safety of bright light therapy in acute bipolar depression as an adjunctive therapy: A randomized controlled trial

BACKGROUND

Bright light therapy (BLT) is an effective treatment for seasonal affective disorder and non- seasonal depression. The efficacy of BLT in treating patients with bipolar disorder is still unknown.

AIMS

The aim of this study is to examine the efficacy, onset time and clinical safety of BLT in treating patients with acute bipolar depression as an adjunctive therapy (trial registration at ClinicalTrials.gov: NCT02009371).

METHODS

This was a multi-center, single blind, randomized clinical trial. Seventy-four participants were randomized in one of two treatment conditions: BLT and control (dim red light therapy, dRLT). Sixty-three participants completed the study (33 BLT, 30 dRLT). Light therapy lasted for two weeks, one hour every morning. All participants were required to complete several scales assessments at baseline, and at the end of weeks 1 and 2. The primary outcome measures were the clinical efficacy of BLT which was assessed by the reduction rate of HAMD-17 scores, and the onset time of BLT which was assessed by the reduction rate of QIDS-SR16 scores. The secondary outcome measures were rates of switch into hypomania or mania and adverse events.

RESULTS

1) Clinical efficacy: BLT showed a greater ameliorative effect on bipolar depression than the control, with response rates of 78.19% vs. 43.33% respectively (p < 0.01). 2) Onset day: Median onset day was 4.33 days in BLT group. 3) BLT-emergent hypomania: No participants experienced symptoms of hypomania. 4) Side effects: No serious adverse events were reported.

CONCLUSION

BLT can be considered as an effective and safe adjunctive treatment for patients with acute bipolar depression.

[Analysis of gene mutation of early onset epileptic spasm with unknown reason]

Objective: To summarize the gene mutation of early onset epileptic spasm with unknown reason. Method: In this prospective study, data of patients with early onset epileptic spasm with unknown reason were collected from neurological department of Children's Hospital of Fudan University between March 2016 and December 2016. Patients with known disorders such as infection, metabolic, structural, immunological problems and known genetic mutations were excluded. Patients with genetic disease that can be diagnosed by clinical manifestations and phenotypic characteristics were also excluded. Genetic research methods included nervous system panel containing 1 427 epilepsy genes, whole exome sequencing (WES), analysis of copy number variation (CNV) and karyotype analysis of chromosome. The basic information, phenotypes, genetic results and the antiepileptic treatment of patients were analyzed. Result: Nine of the 17 cases with early onset epileptic spasm were boys and eight were girls. Patients' age at first seizure onset ranged from 1 day after birth to 8 months (median age of 3 months). The first hospital visit age ranged from 1 month to 2 years (median age of 4.5 months). The time of following-up ranged from 8 months to 3 years and 10 months. All the 17 patients had early onset epileptic spasm. Video electroencephalogram was used to monitor the spasm seizure. Five patients had Ohtahara syndrome, 10 had West syndrome, two had unclear classification. In 17 cases, 10 of them had detected pathogenic genes. Nine cases had point mutations, involving SCN2A, ARX, UNC80, KCNQ2, and GABRB3. Except one case of mutations in GABRB3 gene have been reported, all the other cases had new mutations. One patient had deletion mutation in CDKL5 gene. One CNV case had 6q 22.31 5.5MB repeats. Ten cases out of 17 were using 2-3 antiepileptic drugs (AEDs) and the drugs had no effect. Seven cases used adrenocorticotropic hormone (ACTH) and prednisone besides AEDs (a total course for 8 weeks). Among them, five cases had no effect and two cases were seizure free recently. A case with GABRB3 (C.905A>G) had seizure controlled for 3 mouths. A case with ARX (C.700G>A) had seizure controlled for 6 mouths. Conclusion: The early onset epileptic spasm with unknown reason is highly related to genetic disorders. A variety of genetic mutations, especially new mutations were found. Genetic heterogeneity of epileptic spasm is obvious.

[Novel compound heterozygous TBC1D24 mutations in a boy with infantile focal myoclonic epilepsy and literature review]

Objective: To investigate the clinical features and genetic characteristics of patients with TBC1D24 gene mutations. Method: The clinical data of a patient with novel TBC1D24 compound heterozygous mutations from Children's Hospital of Fudan University were collected, the related literature was searched from China National Knowledge Infrastructure, Wanfang Data Knowledge Service Platform, National Center from Biotechnology Information and Pubmed (up to April 2016) by using search terms "TBC1D24" "epilepsy" . The clinical features, electroencephalogram (EEG) and prognosis of the patients with TBC1D24 gene mutations were studied. Result: The patient was a boy with non-consanguineous healthy parents.He had an acute episode of focal continuous myoclonus lasting a few hours with consciousness preserved at the age of 3 months.Myoclonic jerks alternatively affected the eyelids, either the right or left limbs, sometimes triggered by fever or fatigue.The frequency was once 3-7 days.At the age of 6 months he was found to have myoclonus seizures with onset from a unilateral eyes lid and limb lasting 10 more minutes and subsequently affected four extremities or the trunk.They occurred once 3-4 months with perserved consciousness and lasted from several hours to up to ten more hours.They mostly disappeared during sleep.He had ataxia and mild mental retarding.Paroxysmal anomalies were not found on ictal traces.A novel compound heterozygous mutation of TBC1D24 gene, c. 730G>A, p.A244T and c. 1571G>C, p.R524P were found in the patient.Further study showed that c. 730G>A mutation was inherited from his father and c. 1571G>C from his mother. These two were not reported in public databases and predicted deleterious by Mutation Taster and polyphen-2.Literature relevant to TBC1D24 published all around the world was reviewed, no Chinese cases with TBC1D24 gene mutations had been reported. The total of 24 cases including the present case with TBC1D24 gene mutation were reported.Among them, 11 cases had compound heterozygous mutations and 13 cases had homozygous mutations.Ten mutations were identified, including 1 termination mutation, 1 frameshift mutation and 8 missense mutations. Conclusion: TBC1D24 gene mutational analysis should be performed on patients with early-onset focal continuous myoclonus, if the etiology was unclear.

Reduced Penetrance of PRRT2 Mutation in a Chinese Family With Infantile Convulsion and Choreoathetosis Syndrome

Paroxysmal kinesigenic dyskinesia is a rare episodic movement disorder that can be isolated or associated with benign infantile seizures as part of choreoathetosis syndrome. Mutations in the PRRT2 gene have been recently identified as a cause of paroxysmal kinesigenic dyskinesia and infantile convulsion and choreoathetosis (ICCA). We reported a PRRT2 heterozygous mutation (c.604-607delTCAC, p.S202Hfs*25) in a 3-generation Chinese family with infantile convulsion and choreoathetosis and paroxysmal kinesigenic dyskinesia. The mutation was present in 5 family members, of which 4 were clinically affected and 1 was an obligate carrier with reduced penetrance of PRRT2. The affected carriers of this mutation presented with a similar type of infantile convulsion during early childhood and developed additional paroxysmal kinesigenic dyskinesia symptoms later in life. In addition, they all had a dramatic clinical response to oxcarbazepine/phenytoin therapy. Reduced penetrance of the PRRT2 mutation in this family could warrant genetic counseling.

Adeno-associated virus 2-mediated gene transfer in vivo: organ-tropism and expression of transduced sequences in mice

Adeno-associated virus 2 (AAV), a non-pathogenic human parvovirus, is gaining attention as a vector for its potential use in human gene therapy. However, few studies have examined the safety and the efficacy of this vector system in vivo. We report here that recombinant AAV vectors, when directly injected intravenously in mice, accumulated predominantly in liver cells, suggesting that AAV may possess in vivo organ-tropism for liver. The transduced lacZ reporter gene was expressed in hepatocytes in the liver and, at the level examined, did not appear to induce any detectable cytotoxic T lymphocyte response against beta Gal. AAV-mediated transduction of murine hematopoietic progenitor cells ex vivo followed by transplantation into lethally irradiated syngeneic mice also revealed high-efficiency gene transfer into progeny cells without any observable cytotoxicity or deleterious effect. The transduced reporter gene sequences were also expressed in mice in vivo. The AAV-based vectors may thus prove useful as a potentially safe alternative to the more commonly used retrovirus- and adenovirus-based vector systems.

Lack of site-specific integration of the recombinant adeno-associated virus 2 genomes in human cells

The adeno-associated virus 2 (AAV)-based vector system has been suggested for its potential use in human gene therapy because the wild-type (wt) AAV genome appears to integrate into the human chromosomal DNA in a site-specific manner. We systematically investigated the integration patterns of the recombinant AAV genomes lacking one or both the viral coding sequences. Four recombinant AAV genomes were constructed containing the genes for resistance to tetracycline (TcR) and the herpesvirus thymidine kinase (TK) promoter-driven gene for resistance to neomycin (neoR; vTc.Neo), the genes for resistance to ampicillin (ApR) and TK-neoR (vAp.Neo), the genes for AAV replication (rep) genes and TK-neoR (vRep.Neo), and the AAV capsid (cap) genes and TK-neoR (vCap.Neo). The integration pattern of each of the recombinant AAV genomes in individual clonal isolates of the human nasopharyngeal carcinoma cell line (KB) analyzed on Southern blots using a neo-specific DNA probe was distinctly different. In addition, in none of the clones examined was the proviral genome covalently linked to the previously described AAV right-junction (Rt.Jn.) human chromosomal DNA fragment, the putative specific-site of integration for the wt AAV genome. Furthermore, whereas a 276-bp DNA fragment could be readily amplified from each of these clones, using a neo-specific primer-pair by polymerase chain reaction (PCR), no amplified DNA product was obtained using the neo- and the Rt.Jn. primer-pair under identical conditions. Fluorescence in situ hybridization (FISH) analyses further revealed the lack of integration of the recombinant AAV into human chromosome 19, even in the presence of a functional rep gene as determined by rescue of the recombinant AAV genome in the presence of adenovirus. These data suggest that the recombinant AAV genomes integrate at sites that are different from that characterized for the wt AAV genome. These studies may have implications in the development of the AAV-based vector system for its potential use in human gene therapy.

Differential expression in human cells from the p6 promoter of human parvovirus B19 following plasmid transfection and recombinant adeno-associated virus 2 (AAV) infection: human megakaryocytic leukaemia cells are non-permissive for AAV infection

Expression from the human parvovirus B19p6 promoter fused to the firefly luciferase ('Luc') reporter gene was evaluated in a non-erythroid human nasopharyngeal carcinoma cell line, KB, and a human megakaryocytic leukaemia cell line, MB-02, known to become permissive for B19 replication following erythroid-differentiation. The B19p6-Luc construct was introduced into KB and MB-02 cells, both in undifferentiated and differentiated states, either via DNA-mediated transfection, or via infection with recombinant adeno-associated virus 2 (AAV), a non-pathogenic human parvovirus known to possess a broad host-range. Although Luc activity was readily detected in KB cells following transfection of the B19p6-Luc plasmid DNA, no expression from the B19p6 promoter was observed following infection with recombinant virus. In addition, transfection of the reporter plasmid resulted in high-level expression of Luc in differentiated but not in undifferentiated MB-02 cells. However, no Luc activity was detected, even in differentiated MB-02 cells, following infection with recombinant virus. Further studies with an additional recombinant as well as wild-type (wt) AAV revealed that MB-02 cells were non-permissive for AAV infection. A second human megakaryocytic leukaemia cell line, M07e, was likewise resistant to infection by recombinant as well as wt AAV. Taken together, these studies identify the first human cell type that cannot be infected by AAV. They indicate that expression from the B19p6 promoter, in the context of an AAV genome, is restricted to primary human haematopoietic cells, perhaps because parvoviral DNA replication and transcription are intrinsically coupled.

Adeno-associated virus 2-mediated transduction and erythroid cell-specific expression of a human beta-globin gene

Recombinant adeno-associated virus 2 (AAV) virions were constructed that contained the genomic copy of a normal human beta-globin gene marked with a 4-bp Clal linker, and the herpesvirus thymidine kinase (TK) promoter-driven bacterial gene for resistance to neomycin (v beta m-globin), as well as those containing the DNase l-hypersensitive site 2 (HS-2) from the locus control region (LCR) of the human beta-globin gene cluster (vHS2-beta m-globin). These recombinant virions were used to infect a human erythroleukemia cell line which normally does not express the beta-globin gene (K562), or a human nasopharyngeal carcinoma cell line (KB). Cell populations resistant to G418, a neomycin analogue, were obtained following infections with the recombinant virions, indicating high-efficiency transduction of the chimeric gene as well as functional activity of the transduced neo gene in both cell types. Southern blot analysis using a human beta-globin DNA probe substantiated stable integration of the exogenous beta-globin allele in these cells. There was no expression of the transduced beta-globin gene in K562 or KB cells infected with the v beta m-globin virus. High-level expression of the transduced beta-globin gene occurred only in the vHS2-beta m-globin virus-infected K562 cells, but not in KB cells, as determined by Northern blot as well as RNase protection analyses. Expression of the human beta-globin protein could also be detected in approximately 10-20% of the vHS2-beta m-globin virus-infected K562 cells. These studies suggest that the AAV-based vector system may prove useful for high-efficiency globin gene transfer in human hematopoietic cells.

Parvovirus B19 promoter at map unit 6 confers autonomous replication competence and erythroid specificity to adeno-associated virus 2 in primary human hematopoietic progenitor cells

The pathogenic human parvovirus B19 is an autonomously replicating virus with a remarkable tropism for human erythroid progenitor cells. Although the target cell specificity for B19 infection has been suggested to be mediated by the erythrocyte P-antigen receptor (globoside), a number of nonerythroid cells that express this receptor are nonpermissive for B19 replication. To directly test the role of expression from the B19 promoter at map unit 6 (B19p6) in the erythroid cell specificity of B19, we constructed a recombinant adeno-associated virus 2 (AAV), in which the authentic AAV promoter at map unit 5 (AAVp5) was replaced by the B19p6 promoter. Although the wild-type (wt) AAV requires a helper virus for its optimal replication, we hypothesized that inserting the B19p6 promoter in a recombinant AAV would permit autonomous viral replication, but only in erythroid progenitor cells. In this report, we provide evidence that the B19p6 promoter is necessary and sufficient to impart autonomous replication competence and erythroid specificity to AAV in primary human hematopoietic progenitor cells. Thus, expression from the B19p6 promoter plays an important role in post-P-antigen receptor erythroid-cell specificity of parvovirus B19. The AAV-B19 hybrid vector system may also prove to be useful in potential gene therapy of human hemoglobinopathies.

Transcriptional transactivation of parvovirus B19 promoters in nonpermissive human cells by adenovirus type 2

The pathogenic human parvovirus B19 contains a promoter at map unit 6 (B19p6) of the viral genome, expression from which is largely restricted to human cells in the erythroid lineage, whereas a putative promoter at map unit 44 (B19p44) is inactive during a natural viral infection. Although nonerythroid human cells, such as HeLa and KB, allow expression from the B19p6 promoter but not from the B19p44 promoter following DNA-mediated transfection, little expression from the B19p6 promoter occurs following recombinant virus infection (S. Ponnazhagan, X.-S. Wang, M.J. Woody, F. Luo, L.Y. Kang, M.L. Nallari, N.C. Munshi, S.Z. Zhou, and A. Srivastava, submitted for publication). However, significant expression from the B19p6 promoter as well as the B19p44 promoter could be detected in a human 293 cells line that expresses the adenovirus early gene products, suggesting that coinfection with adenovirus might mediate transcriptional transactivation of the B19 promoters in nonpermissive cells. Expression of the firefly luciferase reporter gene from the B19 promoters was evaluated either following plasmid transfection or following infection with the recombinant adeno-associated virus type 2 vectors. Both B19p6 and B19p44 promoters could be transactivated by coinfection with adenovirus in nonpermissive human cells, although the extent of transactivation of the B19p44 promoter was significantly lower than that of the B19p6 promoter. Expression of the adenovirus E1A proteins was necessary and sufficient for the observed transactivation of the B19 promoters. These studies further illustrate that the underlying molecular mechanisms of transactivation of parvovirus promoters in general by the adenovirus early proteins have similarities with those of the well-documented transactivation of the adeno-associated virus type 2 promoters.

Adeno-associated virus 2-mediated gene transfer and functional expression of the human granulocyte-macrophage colony-stimulating factor

It is becoming increasingly clear that the adeno-associated virus 2 (AAV)-based vector system may prove to be useful for high-efficiency gene transfer in human cells as well as for potential gene therapy in humans. A recombinant AAV vector containing the gene for a human hematopoietic growth factor, granulocyte-macrophage colony-stimulating factor (GM-CSF), was constructed and used to infect COS-1 cells, a monkey kidney cell line. COS-1 cells infected with the recombinant virus, but not mock-infected cells, expressed high levels of the human GM-CSF gene transcripts. Furthermore, in co-cultivation experiments with the recombinant virus-infected cells, but not in those with mock-infected cells, active proliferation of a GM-CSF-dependent human megakaryocytic leukemia cell line, M07e, could be obtained in the absence of exogenously added GM-CSF. The recombinant GM-CSF protein released into the supernatant was biologically active in progenitor cell assays carried out with primary human hematopoietic cells, and this activity was specifically abrogated by treatment of the supernatant with anti-GM-CSF antibodies. This recombinant virus may be potentially useful in the management and gene therapy of a variety of malignant disorders in the human hematopoietic system.

Adeno-associated virus 2-mediated high efficiency gene transfer into immature and mature subsets of hematopoietic progenitor cells in human umbilical cord blood

Recombinant adeno-associated virus 2 (AAV) virions were constructed containing a gene for resistance to neomycin (neoR), under the control of either the herpesvirus thymidine kinase (TK) gene promoter (vTK-Neo), or the human parvovirus B19 p6 promoter (vB19-Neo), as well as those containing an upstream erythroid cell-specific enhancer (HS-2) from the locus control region of the human beta-globin gene cluster (vHS2-TK-Neo; vHS2-B19-Neo). These recombinant virions were used to infect either low density or highly enriched populations of CD34+ cells isolated from human umbilical cord blood. In clonogenic assays initiated with cells infected with the different recombinant AAV-Neo virions, equivalent high frequency transduction of the neoR gene into slow-cycling multipotential, erythroid, and granulocyte/macrophage (GM) progenitor cells, including those with high proliferative potential, was obtained without prestimulation with growth factors, indicating that these immature and mature hematopoietic progenitor cells were susceptible to infection by the recombinant AAV virions. Successful transduction did not require and was not enhanced by prestimulation of these cell populations with cytokines. The functional activity of the transduced neo gene was evident by the development of resistance to the drug G418, a neomycin analogue. Individual high and low proliferative colony-forming unit (CFU)-GM, burst-forming unit-erythroid, and CFU-granulocyte erythroid macrophage megakaryocyte colonies from mock-infected, or the recombinant virus-infected cultures were subjected to polymerase chain reaction analysis using a neo-specific synthetic oligonucleotide primer pair. A 276-bp DNA fragment that hybridized with a neo-specific DNA probe on Southern blots was only detected in those colonies cloned from the recombinant virus-infected cells, indicating stable integration of the transduced neo gene. These studies suggest that parvovirus-based vectors may prove to be a useful alternative to the more commonly used retroviral vectors for high efficiency gene transfer into slow or noncycling primitive hematopoietic progenitor cells, without the need for growth factor stimulation, which could potentially lead to differentiation of these cells before transplantation.

[A CT study of the relation between ocular axial biometry and refraction]

Ocular biometry in 255 eyes (131 subjects) with CT scan revealed that the length of the antero-posterior axis was 23.63 +/- 0.92 mm in hyperopia, 24.62 +/- 0.38 mm in emmetropia and 26.68 +/- 0.75 mm in myopia, and the length of the horizontal transverse axis was correspondingly 24.61 +/- 0.53 mm, 24.91 +/- 0.37 mm and 25.12 +/- 0.73 mm. There were significant differences among groups of different refractions, and the axial length increased with the severity of myopia. It was evident that refractive errors were chiefly caused by the varying axial lengths. The authors propose the parameter of the ocular diametrical ratio which is the ratio of the anteroposterior axis to the horizontal transverse axis, and accordingly hyperopia has a ratio under 1, myopia a ratio over 1 and an emmetropic eye is apparently spherical with the ratio in the vicinity of 1. The authors point out that the refractive state is determined by the ocular diametrical ratio.

Adeno-associated virus 2-mediated gene transfer in murine hematopoietic progenitor cells

Recombinant human adeno-associated virus 2 (AAV) virions were constructed containing a gene for resistance to neomycin (neoR), under the control of either the herpesvirus thymidine kinase (TK) promoter (vTK-Neo), the murine colony-stimulating factor-1 (CSF-1) promoter (vCSF1-Neo) or the CSF-1 promoter plus an upstream human erythroid cell-specific enhancer, HS-2 (vHS2-CSF1-Neo). Recombinant virions were used to infect low-density murine primary bone marrow cells. In hematopoietic progenitor cell assays initiated with cells infected with these recombinant virions, myeloid as well as erythroid cell colonies resistant to the drug G418, a neomycin analogue, were readily obtained, indicating that the murine hematopoietic progenitor cells were susceptible to infection by the recombinant AAV virions and that the transduced neo gene was functionally active in these cells. Whereas only approximately 10% of the colony-forming unit-granulocyte/macrophage (CFU-GM) colonies cloned from mock-infected cells survived the G418-selection at a final active concentration of 250 micrograms/mL of the drug, the extent of the CFU-GM colony formation initiated with the recombinant AAV-Neo virions was as follows: 15% with vTK-Neo, 22% with vCSF1-Neo and 49% with vHS2-CSF1-Neo. In addition, only 14% of the burst-forming unit-erythroid (BFU-E) colonies from mock-infected cells were resistant to G418, whereas 82% of the BFU-E colonies initiated with cells infected with vHS2-CSF1-Neo virions survived the drug selection, suggesting that a human erythroid cell-specific enhancer was able to potentiate expression of the transduced neoR gene from a murine promoter. Individual CFU-GM and BFU-E colonies from mock-infected or recombinant AAV-Neo virus-infected cultures were subjected to polymerase chain reaction (PCR) analysis using a neo-specific synthetic oligonucleotide primer-pair. A 276 bp DNA fragment that hybridized with a neo-specific DNA probe on Southern blots was detected only in colonies cloned from the recombinant virus-infected cells, indicating stable integration of the transduced neo gene. These studies suggest the feasibility of using the AAV-based vector system in an animal model as a prelude to evaluating its safety and efficacy in human gene therapy.

[Effect of elevated plasma norepinephrine on electrocardiographic changes in subarachnoid hemorrhage]

We compared electrocardiographic abnormalities and plasma norepinephrine concentration in 40 patients with subarachnoid hemorrhage within the first 24 hours, at 72 hours, and after 1 week. In the 20 patients with high plasma norepinephrine concentrations within the first 24 hours, sinus tachycardia and negative T waves were more frequently seen than in the 20 patients with normal plasma norepinephrine concentrations. After 72 hours, only sinus tachycardia was found with increased frequency in the 26 patients with high plasma norepinephrine concentrations. Although 24 patients had high plasma norepinephrine concentrations after 1 week, we found no difference in the frequency of electrocardiographic abnormalities as compared with patients with normal plasma norepinephrine. QT prolongation, U waves, ST depression, and arrhythmias were found with similar frequency in patients with high and normal plasma norepinephrine concentrations. We conclude that, with the exception of sinus tachycardia and negative T waves, other electrocardiographic changes in patients with subarachnoid hemorrhage do not depend on elevated plasma norepinephrine concentrations.

Versatile adeno-associated virus 2-based vectors for constructing recombinant virions

We have constructed several plasmid vectors with which a more efficient molecular cloning, followed by rescue, replication, and packaging of DNA fragments, can be achieved. The availability of these vectors should facilitate construction of a variety of recombinant adeno-associated virus 2 (AAV)-based virions containing therapeutic genes for potential use in human gene therapy.

Efficacy of recombinant human macrophage colony-stimulating factor in combination with whole-body hyperthermia in the treatment of mice infected with the polycythemia-inducing strain of the Friend virus complex

Macrophage colony-stimulating factor (M-CSF, CSF-1) and whole-body hyperthermia (WBH) were evaluated, alone or in combination, for their capability to influence disease progression in mice inoculated with the polycythemia-inducing strain of the Friend virus complex (FVC-P). DBA/2 mice were injected i.v. with FVC-P and were treated with 20 micrograms/dose M-CSF s.c. twice a day for 5 days beginning 6 days after injection of FVC-P and/or with WBH (between 38.8 degrees C and 40.2 degrees C) given on days 5 and 12 after FVC-P injection. Fourteen days after viral inoculation, mice were sacrificed and spleen cells evaluated for: 1) spleen focus-forming virus (SFFV), by the spleen focus-forming unit assay (SFFU); 2) SFFV mRNA and genomic DNA using, respectively, Northern and Southern analysis with a B-E-SFFV DNA probe; and 3) natural killer (NK) cell activity, by 51Cr-release assay. Treatment with M-CSF or WBH alone had a small effect on SFFU numbers but little or no effect on SFFV mRNA expression and SFFV-specific DNA. However, dramatically decreased levels of SFFU and SFFV mRNA and specific DNA fragments were observed in mice treated with M-CSF in combination with WBH, and NK cell activity was restored to normal. These results suggest the possibility that M-CSF may have a therapeutic effect in combination with WBH in the in vivo treatment of certain hematologic malignancies and/or retroviral infections.

Synergistic effect of human lactoferrin and recombinant murine interferon-gamma on disease progression in mice infected with the polycythemia-inducing strain of the Friend virus complex

Mice infected with the polycythemia-inducing strain of the Friend virus complex (FVC-P) have been used as a leukemic mouse model. In the present study, purified iron-saturated human lactoferrin (LF) and recombinant murine (rmu) interferon-gamma (IFN-gamma), alone or in combination, were used to influence disease progression in virally infected mice. DBA/2 mice were injected i.v. with FVC-P, and were treated s.c. with 100 micrograms LF at day 7, and/or rmuIFN-gamma at 5 x 10(4) units/day for 3 days beginning at day 6 after viral infection. Mice were assessed for survival, and also 14 days after virus inoculation, the mice were killed and spleen extracts were assessed for spleen focus forming virus (SFFV) titers by spleen focus forming unit (SFFU) assay, SFFV mRNA and genomic DNA expression, and natural killer (NK) cell activity. Treatment with LF or rmuIFN-gamma alone had little or no effect on SFFU numbers or SFFV mRNA or genomic DNA expression. However, dramatically decreased SFFV titers and levels of SFFV mRNA and genomic DNA were observed in mice treated with the combination of LF and rmuIFN-gamma. NK cell activity decreased by FVC-P was returned to normal levels by LF and rmuIFN-gamma. The combined treatment also enhanced the survival rates of FVC-P-infected mice. The results suggest synergistic suppressive effects of LF with rmuIFN-gamma on disease progression in FVC-P-infected mice. This information might be of significance as a potential therapy for patients with leukemia and those infected with retroviruses.

Effect of split low dose total body irradiation on SFFV mRNA, genomic DNA and protein expression in mice infected with the Friend virus complex

DBA/2 mice infected with lethal dosages of Friend virus complex (FVC) can be 100% cured by split-dose total body irradiation (TBI) at 150 cGy, an effect associated with the restoration of the cellular immunity which is compromised by the virus. The exact mechanism underlying the curative effect is unknown, but it may involve the interferon (IFN) system and interleukin-2 (IL-2) production. Initial studies indicated that TBI did not directly inactivate the virus, suggesting that irradiation either acted on the target cells for virus replication or on other cells mediating the effect. We have now examined the effect of this relatively low dose TBI on replication, transcription, and protein expression of the Friend virus. Northern blot analysis revealed that in FVC infected mice treated with curative low dose TBI, no spleen focus-forming virus (SFFV)-specific mRNA species were detected. Southern blot analysis revealed that a 6.0 kb SFFV fragment could be detected in infected, untreated spleen cells, but not in cells from FVC-infected mice treated with TBI, or in uninfected spleen cells. Western blot analysis revealed that the SFFV envelope glycoprotein was expressed in the spleen cells from untreated FVC infected mice, but not in the cells from TBI treated FVC infected mice. These results, consistent with our previous findings of greatly reduced spleen focus forming units in mice with FVC which had been treated with this regimen of TBI, suggest the possibility of using such treatments in other retroviral associated disorders.

Spatial patterns underlying population differences in the background EEG

A method is described which can be used to extract common spatial patterns underlying the EEGs from two human populations. These spatial patterns account, in the least-squares sense, maximally for the variance in the EEGs from one population and minimally for the variance in the other population and therefore would seem to be optimal for quantitatively discriminating between the individual EEGs in the two populations. By using this method, it is suggested that the problems associated with the more common approach to discriminating EEGs, significance probability mapping, can be avoided. The method is tested using EEGs from a population of normal subjects and using the EEGs from a population of patients with neurologic disorders. The results in most cases are excellent and the misclassification which occurs in some cases is attributed to the nonhomogeneity of the patient population particularly. The advantages of the method for feature selection, for automatically classifying the clinical EEG, and with respect to the reference-free nature of the selected features are discussed.