From the background to the spotlight: TASK channels in pathological conditions

TWIK-related acid-sensitive potassium channels (TASK1-3) belong to the family of two-pore domain (K(2P) ) potassium channels. Emerging knowledge about an involvement of TASK channels in cancer development, inflammation, ischemia and epilepsy puts the spotlight on a leading role of TASK channels under these conditions. TASK3 has been especially linked to cancer development. The pro-oncogenic potential of TASK3 could be shown in cell lines and in various tumor entities. Pathophysiological hallmarks in solid tumors (e.g. low pH and oxygen deprivation) regulate TASK3 channels. These conditions can also be found in (autoimmune) inflammation. Inhibition of TASK1,2,3 leads to a reduction of T cell effector function. It could be demonstrated that TASK1(-/-) mice are protected from experimental autoimmune inflammation while the same animals display increased infarct volumes after cerebral ischemia. Furthermore, TASK channels have both an anti-epileptic as well as a pro-epileptic potential. The relative contribution of these opposing influences depends on their cell type-specific expression and the conditions of the cellular environment. This indicates that TASK channels are per se neither protective nor detrimental but their functional impact depends on the "pathophysiological" scenario. Based on these findings TASK channels have evolved from "mere background" channels to key modulators in pathophysiological conditions.

[Clinical re-evaluation of pediatric inflammatory disorders of the central nervous system:a study based on the new classification criteria proposed by the International Pediatric MS Study Group]

A retrospective analysis of the clinical and MRI features in 20 Japanese children diagnosed with central nervous system inflammatory demyelinating disorders was performed. Using the new criteria proposed by International Pediatric MS Study Group, half of children were reclassified into clinical isolated demyelinating syndrome (CIS). Presence of seizures and a pattern of diffuse bilateral lesions on brain MRIs are more frequent in children with ADEM than in CIS. However we suggest these features and encephalopathy may be associated with the age of patients. Furthermore, though persistence of abnormal MRI lesions is significantly more likely in the group of CIS, none of these patients had a subsequent recurrence or developed MS during the follow-up period. The prediction of patient prognosis seems to be difficult even based on the new criteria, and the nationwide multicenter analysis may be necessary in Japan for acquiring the definite conclusion.

[Trigeminal autonomic cephalgias. After initial diagnosis, consider secondary causes]

Trigeminal autonomic cephalgias (TAC) are classified as primary headache syndromes. The use of instrumental procedures including neuroimaging in the diagnostic workup of the TACs is controversially discussed in the literature. Several case reports have been previously published, reporting trigeminal autonomic cephalgias related to structural lesions. We contribute two of our own cases of symptomatic TACs and demonstrate that a "classic" clinical presentation does not preclude a symptomatic etiology. Thus, we advocate a systematic diagnostic evaluation including neuroimaging in every patient presenting with symptoms indicative of TAC for the first time.

Development of the Korean Academy of Medical Sciences Guideline for rating the impairment in the brain injured and brain diseased persons with motor dysfunction

To develop an objective and scientific method to evaluate the brain injured and brain diseased persons with motor dysfunction, American Medical Association's Guides to the Evaluation of Permanent Impairment was used as an exemplar. After the motor dysfunction due to brain injury or brain disease was confirmed, active range of motion and muscle strength of affected extremities were measured. Also, the total function of extremities was evaluated through the assessment of activities of daily living, fine coordination of hand, balance and gait. Then, the total score of manual muscle test and functional assessment of impaired upper and lower extremity were added, respectively. Spasticity of upper and lower extremity was used as minus factors. Patients with movement disorder such as Parkinson's disease were assessed based on the degree of dysfunction in response to medication. We develop a new rating system based on the concept of total score.

Lesion mapping of cognitive abilities linked to intelligence

The Wechsler Adult Intelligence Scale (WAIS) assesses a wide range of cognitive abilities and impairments. Factor analyses have documented four underlying indices that jointly comprise intelligence as assessed with the WAIS: verbal comprehension (VCI), perceptual organization (POI), working memory (WMI), and processing speed (PSI). We used nonparametric voxel-based lesion-symptom mapping in 241 patients with focal brain damage to investigate their neural underpinnings. Statistically significant lesion-deficit relationships were found in left inferior frontal cortex for VCI, in left frontal and parietal cortex for WMI, and in right parietal cortex for POI. There was no reliable single localization for PSI. Statistical power maps and cross-validation analyses quantified specificity and sensitivity of the index scores in predicting lesion locations. Our findings provide comprehensive lesion maps of intelligence factors, and make specific recommendations for interpretation and application of the WAIS to the study of intelligence in health and disease.

Complications during the Wada test

OBJECTIVE

The intracarotid amobarbital procedure (IAP) is routinely used in the preoperative workup of patients with epilepsy. We previously reported dissections and seizures as complications of this procedure and now have reviewed our cohort for additional complications associated with the IAP.

METHODS

Charts of 677 consecutive patients were reviewed for complications during the IAP.

RESULTS

Complications were observed in 74 patients (10.9%) and included encephalopathy (7.2%), seizures (1.2%), strokes (0.6%), transient ischemic attacks (0.6%), localized hemorrhage at the catheter insertion site (0.6%), carotid artery dissections (0.4%), allergic reaction to contrast (0.3%), bleeding from the catheter insertion site (0.1%), and infection (0.1%). Older patients were more prone to strokes and dissections, whereas younger patients more frequently experienced seizures. Use of amobarbital was associated with encephalopathy, whereas methohexital was related to seizures.

CONCLUSION

The IAP bears the risk of minor and major complications in up to 11% of patients. Risks, benefits, and possible alternative options have to be considered when a patient is to undergo the IAP.

[PET/CT-based classification of delayed radiation encephalopathy following radiotherapy for nasopharyngeal carcinoma]

OBJECTIVE

To investigate positron-emission tomography-computed tomography (PET/CT) findings of radiation encephalopathy (RE) following radiotherapy for nasopharyngeal carcinoma (NPC), observe the metabolic changes of the compromised brain tissues, and postulate the clinical classification of RE to provide reference for its diagnosis.

METHODS

This study included 53 pathologically confirmed NPC patients who received previous radical radiotherapy, and the diagnosis of RE was established according to the clinical manifestations and CT/PET findings. All the patients underwent PET/CT whole-body and head scans, and the image data were evaluated along with the clinical data of the patients.

RESULTS

RE most frequently involved the lateral or bilateral inferior temporal lobes. PET identified hypometabolic changes in the bilateral temporal lobes of 35 patients (70 lobes) and in the lateral temporal lobe of 18 patients (18 lobes). According to the PET/CT findings, the lesions were classified into 3 types, namely the oedema type (56 temporal lobes), liquefactive necrosis type (10 temporal lobes), and atrophic calcification type (22 temporal lobes). One patient with oedema type lesion received neurotrophic treatment and recovered completely with normal brain tissue density and metabolism, but the oedema type lesions in 2 patients progressed into to atrophic calcification type; the liquefactive necrotic lesions in another 2 patients also progressed into atrophic calcification type.

CONCLUSION

RE patients exhibit significant hypometabolic changes in the inferior temporal lobe on PET. According to the findings by PET/CT, RE can be classified into the oedema type, liquefactive necrosis type, and atrophic calcification type, and lesions of the former two types may progress into the third type.

Diagnosis of brain abnormality using both structural and functional MR images

A number of neurological diseases are associated with structural and functional alterations in the brain. This paper presents a method of using both structural and functional MR images for brain disease diagnosis, by machine learning and high-dimensional template warping. First, a high-dimensional template warping technique is used to complete morphological and functional representation for each individual brain in a template space, within a mass preserving framework. Then, statistical regional features are extracted to reduce the dimensionality of morphological and functional representation , as well as to achieve the robustness to registration errors and inter-subject variations. Finally, the most discriminative regional features are selected by a hybrid feature method for brain classification, using a nonlinear support vector machine. The proposed method has been applied to classifying the brain images of prenatally cocaine-exposed young adults from those of socioeconomically matched controls, resulting in 91.8% correct classification rate using a leave-one-out cross-validation. Comparison results show the effectiveness of our method and also the importance of simultaneously using both structural and functional images for brain classification.

[Prevalence of dementia or other form of organic brain disorder on a geriatric psychiatry ward]

INTRODUCTION

The prevalence of dementia in various geriatric psychiatry settings has previously been investigated and been found to lie between 15.2% and 61%. The present study investigated the percentage of patients with "organic brain disorder" [OBD] (dementia, acquired brain injury or other brain disease) in one geriatric psychiatric department in Copenhagen, Denmark.

MATERIALS AND METHODS

The journals of all patients admitted to the geriatric psychiatric department (locked ward, open ward, and day hospital) in 2002 were studied in order to find evidence of (a) psychiatric discharge diagnosis of OBD in 2002 (b) previous diagnosis of OBD (c) the basis of these diagnoses.

RESULTS

130 patients were admitted at least once in 2002. 33.1% had an OBD diagnosis at discharge, whilst a further 18.4% had documented evidence of previously diagnosed OBD and/or assessments supporting the presence of OBD. Effects of gender and age at first admission were found on discharge diagnosis.

CONCLUSION

There is evidence that over half of the patients admitted to the geriatric psychiatry department in this study had an OBD, which is higher than the percentage of patients who were discharged with this diagnosis. The possible consequences of findings and the drawbacks of the study are discussed.

Neonatal Encephalopathy and Socioeconomic Status

OBJECTIVE

To investigate the association between maternal socioeconomic status and the risk of encephalopathy in full-term newborns.

DESIGN

Population-based case-control study.

SETTING

Washington State births from 1994 through 2002 recorded in the linked Washington State Birth Registry and Comprehensive Hospital Abstract Reporting System.

PARTICIPANTS

Cases (n = 1060) were singleton full-term newborns with Comprehensive Hospital Abstract Reporting System International Classification of Diseases, Ninth Revision diagnoses of seizures, birth asphyxia, central nervous system dysfunction, or cerebral irritability. Control cases (n = 5330) were singleton full-term newborns selected from the same database. Main Exposures Socioeconomic status was defined by median income of the census tract of the mother's residence, number of years of maternal educational achievement, or maternal insurance status.

MAIN OUTCOME MEASURES

Odds ratios estimating the risk of encephalopathy associated with disadvantaged socioeconomic status were calculated in 3 separate analyses using multivariate adjusted logistic regression.

RESULTS

Newborns of mothers living in neighborhoods in which residents have a low median income were at increased risk of encephalopathy compared with newborns in neighborhoods in which residents have a median income more than 3 times the poverty level (adjusted odds ratio, 1.9; 95% confidence interval, 1.5-2.3). There was also a trend for increasing risk of encephalopathy associated with decreasing neighborhood income (P<.001). Newborns of mothers with less than 12 years of educational achievement had a higher risk of encephalopathy compared with newborns of mothers with more than 16 years of educational achievement (adjusted odds ratio, 1.7; 95% confidence interval, 1.3-2.3). Newborns of mothers receiving public insurance also had a higher risk of encephalopathy compared with newborns of mothers who have commercial insurance (adjusted odds ratio, 1.4; 95% confidence interval, 1.2-1.7).

CONCLUSION

Disadvantaged socioeconomic status was independently associated with an increased risk of encephalopathy in full-term newborns. These findings suggest that a mother's socioeconomic status may influence the risk of encephalopathy for her full-term newborn.

Diagnosis of dementia in primary care: a representative survey of family physicians and neuropsychiatrists in Germany

AIM

To measure the diagnostic competence of family physicians (FP) and neuropsychiatrists (NP) for moderate dementia.

METHODS

Written case vignettes describing moderate dementia either of Alzheimer type or vascular type were randomized to a representative sample of 122 FP and 68 NP, corresponding to response rates of 71.8 and 67.3%, respectively. They served as the basis for a structured face-to-face interview.

RESULTS

NP and FP did not differ with regard to their diagnostic considerations, however, concerning diagnostic workup. Vascular dementia was much better recognized than dementia of Alzheimer type. Neuropsychological tests and brain imaging would be done by 14.8 and 32.8% of the FP in the case of vascular dementia. In Alzheimer dementia they would apply these methods in 24.6 and 19.7%, respectively. The corresponding numbers for NP were about 60% in both cases for testing and more than 80% for brain imaging.

CONCLUSIONS

There is still a wide gap between guidelines and practice in primary care. The apparent overdiagnosis of vascular dementia may be one reason for the low drug treatment rates.

Trinucleotide repeat disorders

DNA trinucleotide repeat expansion diseases represent an interesting group of disorders that include a common cause of mental retardation and autism as well as neurodegenerative and other diseases. Many of these disorders have expression in the pediatric age group. The varied molecular mechanisms of these disorders make them model diseases for the study of mitochondrial dysfunction induced apoptosis, abnormal axonal transport induced apoptosis and disrupted transcription of neighboring genes. Clinical variation in the pathogenesis, severity, onset and inheritance of these disorders make them models for clinical study and research.

Atypical patterns of inheritance

The incomplete prediction of clinical phenotype from genotype in monogenic disorders assumes other complex mechanisms are responsible. Recent examples derived from well-known human diseases will be discussed in this review in the context of the roles of modifier genes, digenic and triallelic inheritance, and the consequence of imprinting and opposite transcripts in known human genetic disorders. Specifically, this review will focus on cystic fibrosis, Huntington's disease, sensory neural deafness due to Connexin gene mutations, Bardet-Biedl syndrome, and the Beckwith-Wiedemann syndrome as there is evidence that complex inheritance is responsible for at least part of the phenotypic variability that is not explainable by the genotype alone. This review is meant to extend and complement the other topics in this issue as the concept of atypical inheritance is explored in more detail.

Validity of the Children's Category Test-Level 1 in a clinical sample with heterogeneous forms of brain dysfunction

Validity of the Children's Category Test-Level 1 (CCT-1) was evaluated in 123 children with various forms of brain dysfunction. Confirmatory factor analyses indicated that the CCT-1 is composed of two factors. The first factor was composed of subtests II and III, and was named "Conceptual Discrimination", while the second was composed of subtests IV and V, and was named "Conceptual Memory". Both factors were more highly correlated with mathematical achievement than with reading or writing achievement. Comparisons between traumatic brain injury (TBI) and Attention-Deficit/Hyperactivity Disorder (ADHD) groups indicated that the Conceptual Discrimination factor was more sensitive to TBI than the Conceptual Memory factor. Also, the total error composite T-score was not particularly sensitive to ADHD. Findings indicate that the composite T-score should be interpreted with caution because it does not appear sensitive to milder forms of brain dysfunction and because the CCT-1 is a multidimensional procedure.

Prefrontal modulation of working memory performance in brain injury and disease

The inter-related cognitive constructs of working memory (WM) and processing speed are fundamental components to general intellectual functioning in humans. Importantly, both WM and processing speed are highly susceptible to disruption in cases of brain injury, neurologic illness, and even in normal aging. A goal of this article is to summarize and critique the functional imaging studies of speeded working memory in neurologically impaired populations. This review focuses specifically on the role of the lateral prefrontal cortex in mediating WM performance and integrates the relevant WM literature in healthy adults with the current findings in the clinical literature. One important finding emerging from a summary of this literature is the dissociable contributions made by ventrolateral and dorsolateral prefrontal cortex (VLPFC and DLPFC) in guiding performance on tasks of WM. Throughout this review, it is shown that when cerebral resources are challenged, it is DLPFC, and often right DLPFC specifically, that plays a critical role in modulating WM functioning. In addition, this article will examine the relationship between task performance and brain activation across studies to clarify the role of increased DLPFC activity in clinical samples. Finally, explanations are offered for the observed increased DLPFC activation and the potentially unique role of right DLPFC in mediating WM performance during periods of cerebral challenge.

Cost estimates of brain disorders in Belgium

This article presents the data on cost of the major brain disorders in Belgium which were retrieved from "Cost of Disorders of the Brain in Europe" study sponsored by the European Brain Council and performed by Stockholm Health Economics. The disorders selected were: addiction, depression, anxiety disorders, brain tumours, dementia, epilepsy, migraine and other headaches, multiple sclerosis, Parkinson's disease, psychotic disorders, stroke and trauma. Figures for prevalence of disorders and direct medical, direct non-medical and indirect costs are based on data coming from available electronic data bases, or when missing for Belgium, best possible estimates or extrapolated data were used. All economic data were transformed to Euro's for 2004 and adjusted for purchasing power parity (PPP). The results show that the total number of people with any brain disorder in Belgium amounts to 2.9 million in 2004, the most prevalent being anxiety disorders 1.1 million, migraine 860000, addiction (any) 800,000 and depression 500,000 cases. The total cost of all included brain disorders in Belgium was estimated at 10.6 billion Euros. Most costly per case are brain tumours, multiple sclerosis, stroke and dementia. Because of their higher prevalence, however depression, dementia, addiction, anxiety disorders and migraine have the highest total costs. Taken together brain disorders consume 4% of the gross national product and cost each citizen of Belgium 1029 Euros per year. The drug costs for brain disorders constitute only 10% of the total drug market in Belgium, and only 4% of the total cost of brain disorders in Belgium. This should be compared to the cost estimates and to a previous study which showed that brain disorders are responsible for 35% of the total burden of all disorders in Europe. This study suggests therefore that the direct healthcare resources, including expenses for drug therapies, allocated to brain disorders in Belgium are not leveled to the indirect costs and burden of these disorders. A comparison with data available from a direct prospective study in demented Belgian patients suggests that the mathematical estimates presented here reflect quite accurately the real average cost for dementia, although there are large variations depending on disease severity. As, in addition, subjects with brain disorders face collateral costs which have not been taken into associations, a complementary survey in the Belgian ecosystem to establish the cost profile of representative patients for the major brain disorders. Such a survey is being organized by a task force of the Belgian Brain Council.

Clinical characteristics of acute encephalopathy of obscure origin: a biphasic clinical course is a common feature

OBJECTIVE

To evaluate the clinical characteristics of acute encephalopathy of obscure origin (AE).

STUDY DESIGN

We examined clinical, imaging, and laboratory findings in children with AE. Specific subtypes of AE such as Reye's syndrome (RS), acute necrotizing encephalopathy (ANE), hemorrhagic shock and encephalopathy (HSE), acute encephalitis with refractory, repetitive partial seizures (AERRPS), and hemiconvulsion-hemiplegia syndrome (HH) were diagnosed. Other AE patients were regarded as non-specific subtype.

RESULTS

Nineteen patients were identified; specific AEs in 14 and non-specific AE in 5. Patients with RS, ANE, HSE frequently showed neuroimaging abnormalities (9/9) and significant elevation of liver enzymes (7/9) within 2 days after onset. Prognoses were extremely poor; early death in 6 and severe neurological sequelae in 3. Two of the 3 HH patients and 4 of the 5 non-specific AE patients showed biphasic clinical courses (AEBC); consciousness levels transiently improved following initial seizures and were exacerbated at the fourth to sixth days. In AEBC, neuroimaging abnormalities were rarely observed during the acute phase (1/5) but were detectable at clinical exacerbation. They rarely showed severely abnormal elevation in liver enzymes (1/6) and resulted in mild to moderate neurological sequelae (6/6).

CONCLUSION

A biphasic clinical course is a common feature in HH and non-specific AE.

Test performance and classification statistics for the Rey Auditory Verbal Learning Test in selected clinical samples

The Rey Auditory Verbal Learning Test [RAVLT; Rey, A. (1941). L'examen psychologique dans les cas d'encéphalopathie traumatique. Archives de Psychologie, 28, 21] is a commonly used neuropsychological measure that assesses verbal learning and memory. Normative data have been compiled [Schmidt, M. (1996). Rey Auditory and Verbal Learning Test: A handbook. Los Angeles, CA: Western Psychological Services]. When assessing an individual suspected of neurological dysfunction, useful comparisons include the extent that the patient deviates from healthy peers and also how closely the subject's performance matches those with known brain injury. This study provides the means and S.D.'s of 392 individuals with documented neurological dysfunction [closed head TBI (n=68), neoplasms (n=57), stroke (n=47), Dementia of the Alzheimer's type (n=158), and presurgical epilepsy left seizure focus (n=28), presurgical epilepsy right seizure focus (n=34)] and 122 patients with no known neurological dysfunction and psychiatric complaints. Patients were stratified into three age groups, 16-35, 36-59, and 60-88. Data were provided for trials I-V, List B, immediate recall, 30-min delayed recall, and recognition. Classification characteristics of the RAVLT using [Schmidt, M. (1996). Rey Auditory and Verbal Learning Test: A handbook. Los Angeles, CA: Western Psychological Services] meta-norms found the RAVLT to best distinguish patients suspected of Alzheimer's disease from the psychiatric comparison group.

Evolution of stimulus-induced rhythmic EEG discharges in three patients with encephalopathy

Stimulus-induced rhythmic EEG discharges (SIRDs) is a recently reported phenomenon in critically ill patients and little is known about their evolution. We found SIRDs in three patients with encephalopathy and followed them with serial EEGs. SIRDs appeared between 4 and 13 days after the onset of illness and persisted for 2-3 days. The discharges were elicited by tactile or nociceptive stimuli and lasted for 20-120 s. They were detected in 2/6, 1/3 and 2/11 EEGs performed between 9 and 32, 2 and 4 and 3 and 15 days, respectively, after the onset of illness. Their morphology varied: blunt triphasic waves, rhythmic delta activity and rhythmic sharp wave complexes. The background EEG activity was slowed or suppressed in all. One patient had acute disseminated encephalomyelitis (ADEM) with good recovery and the other two had fatal hypoxic ischemic encephalopathy. SIRDs appear to be a transient phenomena occurring in patients with encephalopathy, appearing hours to few days after the onset of illness. This is the first report of SIRDs in ADEM. Serial EEGs and repeated testing of EEG response to tactile and nociceptive stimuli is required for their detection. Larger number of patients with SIRDs need to be studied to assess their prognostic significance.

PRES: posterior or potentially reversible encephalopathy syndrome?

Posterior reversible encephalopathy syndrome (PRES) is an acronym that identifies a new clinico-neuroradiologic entity occurring in association with different conditions. We report a patient with eclamptic encephalopathy whose clinico-radiological picture normalised after prompt treatment. We suggest defining this condition as potentially RES, to emphasise that reversibility is not spontaneous but is usually related to an adequate treatment, and that the posterior localisation of the lesions, even if constant, may not represent the most relevant finding in some patients.