Electron-induced ionization and cationic fragmentations of the isolated molecule of 2,4-imidazolidinedione (hydantoin): a study of the relaxing path thresholds.

In this work, our new experimental setup has been used to study the ionization and fragmentation of a prebiotic molecule, hydantoin, by electron impact. Scanning of the incident electron energy allows the determination of the appearance thresholds of the cations. The vertical ionization potential was found to be in good agreement with previous data. Dissociation thresholds for the main fragmentation patterns were also measured. In parallel, thanks to quantum chemical calculations, reaction schemes compatible with the experimental results are given.

Functional Foreign Accent Syndrome in suspected Conversion Disorder: A case study

Background and objectives: We provide a case analysis for a 28-year-old, native Dutch-speaking lady who developed Foreign Accent Syndrome (FAS), a few weeks after falling down the staircase. In addition to FAS, which gave the impression she spoke with a German accent, German(-like) words and structures occurred. Speech symptoms were aggravated by increased stress, fatigue or emotional pressure, and this triggered jargon speech. It was hypothesized her FAS and jargon developed on a functional basis.MethodsIn-depth analyses of the patient’s medical background, neuropsychological and neurolinguistic tests and psychodiagnostic exams were done. The patient participated in an fMRI experiment. In a syllable repetition paradigm, motor speech activations were compared to those of healthy individuals, to see whether they were altered, which would be expected in case of a neurological etiology.ResultsMedical history disclosed prior traumatic experiences for which she sought help, but no neurological incidents. Repeated neuropsychological and neurolinguistic tests showed deficits in recent memory and executive functioning. The patient demonstrated great difficulties with picture naming. Clinically, language switching and mixing as well as recurring jargon speech was found. Formal psychodiagnostic tests did not identify a clear disorder, but psychodiagnostic interviews were consistent with a DSM-5 conversion disorder. The fMRI study demonstrated that speech network activations corresponded to those found in healthy participants.ConclusionThe clinical neurolinguistic characteristics, outcome of the fMRI experiment, together with the clinical psychodiagnostic findings were strongly indicative for an underlying functional etiology for the FAS and jargon speech, presenting as symptoms of conversion disorder. (AU)

Regional cerebral glucose metabolism in epilepsies with continuous spikes and waves during sleep.

BACKGROUND: Epileptic syndromes with continuous spikes and waves during sleep (CSWS) represent a wide spectrum of epileptic conditions associated with cognitive dysfunctions that have the EEG pattern of CSWS as a common feature. Reported are the results of voxel-based analyses of brain glucose metabolism performed in a group of 18 children with CSWS. METHODS: Voxel-based analyses of cerebral glucose metabolism were performed using statistical parametric mapping (SPM). First, each patient was compared with a control group and the influence of age, epileptic activity, and corticosteroid treatment on metabolic abnormalities was studied. Also, disease-related changes in the contribution of a brain area to the level of metabolic activity in another brain area were investigated using pathophysiologic interactions in groups of patients compared with the control group. RESULTS: Individual SPM analyses identified three metabolic patterns: association of hypermetabolic and hypometabolic areas, hypometabolic areas only, and normal pattern. Age and intensity of awake interictal spiking did not significantly differ in patients showing focal hypermetabolism compared with the other ones. Treatment with corticosteroids was associated with absence of focal hypermetabolism. In the group of patients with hypermetabolic areas, analyses of pathophysiologic interactions showed disease-related altered functional connectivity between the parietal and frontal cortices. CONCLUSIONS: Cerebral metabolic patterns are heterogeneous among patients with CSWS. This metabolic heterogeneity could be related to the use of corticosteroid treatment before PET. The parietofrontal altered connectivity observed in patients with hypermetabolism is interpreted as a phenomenon of remote inhibition of the frontal lobes induced by highly epileptogenic and hypermetabolic posterior cortex.

Long-term sequelae in children after cerebellar astrocytoma surgery.

OBJECTIVE: To study long-term effects on neurologic, neuropsychological, and behavioral functioning in children treated for cerebellar pilocytic astrocytoma (CPA) without additional radio- and chemotherapy. METHODS: The authors assessed speech, language, nonverbal intelligence, attention, memory, executive skills, and visual (-spatial) functions in a consecutive series of 23 children. Neurologic and neuropsychological follow-up ranged from 1 year to 8 years and 10 months after resection. RESULTS: Long-term sequelae in the investigated domains were found in all children. Apraxia, motor neglect, and dysarthric features, as well as language, sustained attention, visual-spatial, executive, memory, and behavioral problems, were observed in various combinations and to different degrees. No clear pattern of neurocognitive disturbances could be discerned in this group. In addition, significant relationships were revealed between severity of preoperative hydrocephalus and visual-spatial skills. The high percentage of children who needed special education reflects the severity of the impairments. CONCLUSION: Despite the current opinion of a good quality of life after CPA treatment, careful long-term neurocognitive follow-up is needed in order to inform parents and teachers about the behavioral and cognitive sequelae and to contribute to timely social and educational intervention.

[Cerebellar mutism syndromes with subsequent dysarthria: a study of three children and a review of the literature]. / Syndrome de mutisme cérébelleux et dysarthrie subséquente: étude de trois enfants et revue de la littérature.

Cerebellar mutism and subsequent dysarthria (MSD) is a possible complication of posterior fossa surgery. It is usually seen in children after resection of a cerebellar mass lesion. Most patients become mute after a period of (near)normal postoperative speech, and are dysarthric once speech resumes. The pathophysiological mechanisms underlying MSD are most probably multifactorial, combining neuroanatomical, neurophysiological, neuropsychological, and psychological factors. The aim of the present article is to better define the MSD syndrome. The cerebellum is not only involved in motor control. It is also part of a distributed neural circuitry which underlies higher cognitive functions such as, for instance, those associated with the programming of kinetic parameters before motor initiation of a movement. We hypothesize that it could also be involved in the mental initiation which precedes the programming of any intentional bucco-phonatory movements to be performed in order to express oneself.

The cerebellum may be directly involved in cognitive functions.

Neuropsychological deficits may occur in infratentorial strokes. Only minor cognitive disturbances are reported in unilateral anterior cerebellar lesions. Here, the authors describe a patient with bilateral anterior ponto-cerebellar ischemic lesions associated with major neuropsychological deficits. Cerebral PET and SPECT demonstrated no metabolic defect in supratentorial areas.

[The neurology department]. / Le Service de Neurologie.

The department of neurology is devoted to the diagnosis and medical treatment of organic diseases of central nervous system (brain and spinal cord) and peripheral nervous system (peripheral nerves and muscles). Basic and clinical research in neuroscience constitute an essential activity of the department that defines its academic character. Over the years, the department of neurology has evolved from providing general neurology services to a multifaceted unit that has developed the several subspecialties of clinical neuroscience. Main research areas have included neurooncology, neurophysiology, neuropsychology, cerebrovascular diseases, childhood epilepsy and conditions affecting the psychomotor development of children. Neurogenetics is a recent addition to the areas of the interest of the department; research in neurogenetics includes basic investigations as well as clinical studies and focuses on inherited ataxias and genetic epilepsies.

Clinical evaluation of conversational speech fluency in the acute phase of acquired childhood aphasia: does a fluency/nonfluency dichotomy exist?

Traditional neurologic tenets claim that the clinical picture of acquired childhood aphasia is nonfluent irrespective of lesion location. In the past 20 years, however, several case studies have shown that fluent aphasic patterns can be observed in children with acquired childhood aphasia. But the question remains open as to whether the pattern of their speech characteristics is similar to the one described in adult aphasics as studies addressing spontaneous speech fluency characteristics in larger series of children with acquired childhood aphasia are scarce. The objective of this study was to investigate whether an analysis of spontaneous speech fluency as has previously been performed in adult aphasics by other investigators would also yield two distinct groups of aphasic children and, if so, whether the distribution of the different speech characteristics in both groups would reflect the rank order found in adults, that is, whether nonfluent verbal output characteristics would predominate in one group and fluent features in the other. Audiotaped and videotaped recordings of 24 cooperative children with acute acquired childhood aphasia unselected for age, gender, etiology, and aphasia severity ratings were analyzed according to 10 different speech characteristics. A cluster analysis (two-means clustering) was performed to seek the existence of two distinct groups of aphasic children. Results were confirmed, and exact P values were computed with Mann-Whitney U-tests. A two-means clustering created two distinct classes. Mann-Whitney U-tests ranked the speech characteristics according to their discriminating power between clusters. Comparing this rank order with the one previously found in adults revealed a high correlation (Spearman's rank correlation: r = .915, P << .005), thus indicating that the clusters we found were highly similar to the adult clusters. Thus, the use of the speech variables proposed to evaluate adult aphasic spontaneous speech enabled us to demonstrate a fluent/nonfluent dichotomy in a childhood aphasic population as well. This study shows that the traditional views on the uniformity of the clinical picture of acquired childhood aphasia are obsolete. Our findings corroborate data issued from several case reports of fluent acquired childhood aphasia and from the few studies focusing on speech fluency in acquired childhood aphasia, which all point to the existence of an adultlike heterogeneity of childhood aphasic syndromes. Current clinical evidence no longer supports the hypotheses of equipotentiality and progressive lateralization but favors the notion that the anatomic substrate for language representation in the child is similar to that in adults, even in young subjects.

Anomalous cerebral language organization: acquired crossed aphasia in a dextral child.

Following a dramatic change of its reported incidence, it was only recently recognized that acquired crossed aphasia in dextral children represents a highly exceptional phenomenon. We describe in a three epoch time-frame model the aphasic and neurocognitive manifestations of an additional case and focus briefly on its anatomoclinical configurations. In our patient, a right parietal cortico-subcortical hemorrhagic lesion caused an initially severe aphasia. After remission of the global aphasic symptoms in the acute phase, an adynamic output disorder with relatively severe auditory-verbal comprehension disturbances developed. In addition to the adynamia of self-generated speech, formal language investigations performed 3 weeks postonset, revealed agrammatism, hypertonic dysarthria, and dysprosodia. A substantial improvement of the aphasic disorder was objectified 83 days postonset. Neuropsychological investigations disclosed both dominant and nondominant hemisphere dysfunctions. Reassessment of neurocognitive functions after a 10-year period evidenced discrete residual anomia, confined to visual confrontational naming and a discrete visuo-perceptual syndrome. Given the posterior localization of the lesion, the syndrome shift from global to predominantly adynamic aphasia represents a finding beyond the plausible anatomoclinical expectations holding in general for the uncrossed, classic types of childhood and adult aphasia. As the first representative of crossed aphasia in dextral children with an anomalous lesion-aphasia profile, our case provides evidence to enrich the discussion on lateralization and intrahemispherical organization of language functions in both childhood and adult aphasia.

Acquired crossed aphasia in dextral children revisited.

In contrast to the estimated low incidence of crossed aphasia in dextral adults (among 1%), crossed aphasia in children has been considered a common finding for almost a century. However, reviewing the literature on crossed aphasia in dextrals (CAD) and its related topics from 1975 onward, we encountered only 5 children in a corpus of 180 cases (2.7%). Critical analysis rendered three of the reported cases ambiguous and hence not suitable to draw potentially relevant conclusions. In this review, the neurobehavioral manifestations of the two representative childhood CAD cases are analyzed and compared with adult CAD and acquired childhood aphasia (ACA). In the light of our findings, which support the position of innate cerebral specialization for language, the long-standing controversy as to whether lateralized hemispheric specialization for language is innate or develops progressively during maturation is briefly discussed.

Line bisection performances of 650 normal children.

When bisecting lines, an important number of brain damaged patients tend to place their bisection marks in the hemispace ipsilateral to their lesion. Biases have also been reported in normal adults. In vertical bisection both patients and normal subjects present with upward shifts, although a downward displacement may occur eventually. Surprisingly, little is known on line bisection (LB) in normal or brain damaged children. A total of 650 subjects, aged 7-12 years, performed a horizontal and vertical LB task with their preferred hand. Asymmetry indices (AIs) were used to measure directional bias. Unsigned AIs served to evaluate accuracy and mastery of the LB skill. In vertical bisection a general and significant upward bias was found, whereas in horizontal bisection subject (gender, handedness, utilized hand, age) and stimulus variables (orientation, length, position) yielded significantly different AIs. Although with increasing age significantly increasing accuracy was observed, none of the participating children mastered LB to mathematical precision. Differences in IQ-level and attention test score did not yield significantly different AIs. Impact from reading proficiency could not be demonstrated. It is suggested that stimulus length effect results are compatible with the Halligan and Marshall [Halligan, P., and Marshall, J. Toward a principled explanation of unilateral neglect. Cognitive Neuropsychology, 1994, 11, 167-206] model of hemispatial neglect. Moreover, data may support the hypothesis of greater hemispheric specialization of visuo-spatial skills in boys than in girls.

Tumour type and size are high risk factors for the syndrome of "cerebellar" mutism and subsequent dysarthria.

OBJECTIVE: "Cerebellar mutis" and subsequent dysarthria (MSD) is a documented complication of posterior fossa surgery in children. In this prospective study the following risk factors for MSD were assessed: type, size and site of the tumour; hydrocephalus at presentation and after surgery, cerebellar incision site, postoperative infection, and cerebellar swelling. METHODS: In a consecutive series of 42 children with a cerebellar tumour, speech and neuroradiological studies (CT and MRI) were systematically analysed preoperatively and postoperatively. Speech was assessed using the Mayo Clinic lists and the severity of dysarthria using the Michigan rating scale. RESULTS: Twelve children (29%) developed MSD postoperatively. The type of tumour, midline localisation, and vermal incision were significant single independent risk factors. In addition, an interdependency of possible risk factors (tumour>5 cm, medulloblastoma) was found. CONCLUSION: MSD often occurs after paediatric cerebellar tumour removal and is most likely after removal of a medulloblastoma with a maximum lesion diameter>5 cm.

Clinical utility of the judgment of line orientation test and facial recognition test in children with acquired unilateral cerebral lesions.

In unselected adult patients with brain damage, the Judgment of Line Orientation Test and the Facial Recognition Test are considered valid instruments for detecting right cerebral hemisphere lesions. It is unknown, however, whether this applies to children as well. Performance levels on the Judgment of Line Orientation Test and the Facial Recognition Test of 18 children with acquired left cerebral lesions and 14 children with acquired right cerebral lesions were reviewed. Subjects were unselected for age, sex, or etiology. Age-related norms were obtained in 81 normal controls, aged 7 to 14 years. Judgment of Line Orientation Test and Facial Recognition Test performance levels did not predict the presence of cerebral pathology per se in our unselected groups with demonstrated unilateral cerebral lesions, nor did they contribute to the prediction of the side of the lesion within the two groups with cerebral lesions. These results cast serious doubt on an important aspect of the clinical utility of both tests in children, namely their discriminative validity in the assessment of etiologically unselected populations with brain damage.

Dysarthria in children with cerebellar or brainstem tumors.

Speech features were perceptually analyzed in two groups of children. The first group (n = 6) had undergone cerebellar tumor resection, and the second group (n = 6) included children with brainstem tumors. Children belonging to the first group became dysarthric after a postoperative mute phase. Slow speech rate was a specific feature, but scanning speech and irregular articulatory breakdown (i.e., prominent characteristics in adult ataxic dysarthria) were not observed. In the second group, hypernasality was a prominent characteristic and resembled flaccid dysarthria in adults. These findings suggest that acquired childhood dysarthria needs a proper classification.

Acquired childhood dysarthria: review of its clinical presentation.

The adult classification of dysarthria correlating with the pathophysiology of the motor systems is usually applied to classify acquired childhood dysarthria. However, the validity of this adult model for children has not been studied systematically. All studies pertaining to analysis of speech features in acquired childhood dysarthria published since 1980 were reviewed. Studies were classified on the basis of neuroradiologic evidence of lesion site and associated motor disorder. This review demonstrates that knowledge of acquired childhood dysarthria is based on a limited number of single case studies, most of which pertain to dysarthria occurring after resection of cerebellar tumor. Definite similarities to adult dysarthria were not evident. Some similarity to acquired childhood dysarthria due to basal ganglia lesions was detected. We conclude that acquired childhood dysarthria requires its own classification.

Increased writing activity in neurological conditions: a review and clinical study.

Increased writing activity in a 70 year old, right handed man presenting with a history of alcohol misuse and maturity onset diabetes is reported. Brain CT disclosed corticosubcortical atrophy and 99mTc-HMPAO SPECT disclosed severe bilateral frontal hypoperfusion more prominent on the right. The patient's neuropsychological symptomatology consisted of severe (verbal) aspontaneity, intermittent utilisation behaviour, and pronounced increased writing activity, which mainly consisted of a perseverative, micrographic written reproduction of visually or verbally perceived language fragments. Several neurological causes of increased writing activity and the equivocal terminology met in the medical literature are reviewed. A distinction between hypergraphia and automatic writing behaviour is proposed. It is concluded that our patient's increased writing activity may be characterised as automatic writing behaviour.

Review of research on the clinical presentation of acquired childhood aphasia.

AIMS: The traditional description of the clinical picture of acquired childhood aphasia (ACA) claims that ACA is invariably nonfluent, that recovery of language disorder is rapid and complete, and that ACA commonly occurs after right hemisphere damage. However, since the late 1970s the publication of several case studies has led to reject this longstanding standard doctrine. This review, which concerns the revised insights into ACA, aims at making an inventory of the recently described aphasic symptomatologies and neuroradiological data. MATERIAL: The literature on ACA with emphasis on the studies published since 1978. RESULTS: Recent case studies show a great variety of aphasic symptomatologies including auditory comprehension disorders, paraphasias, neologisms, logorrhoea, jargon, impaired repetition abilities, and a host of linguistic deficits in reading and writing. Not only the typology of the aphasias but also the recently established clinicoradiological correlations appear to resemble those found in adults. Also, recovery from ACA shows to be less complete than previously thought. CONCLUSION: These findings bear consequences as to theories on cerebral organization of language in childhood. It appears that already in infancy the two cerebral hemispheres are no equal substrate for language representation. Therefore, prognosis and final outcome of ACA are not uniformly favourable.

An analysis of spontaneous conversational speech fluency in children with acquired aphasia.

We report on an instrumental analysis of spontaneous conversational speech (SCS) fluency in acquired childhood aphasia (ACA). Tape-recorded SCS samples of 25 children with ACA (clinical judgment: 12 nonfluent and 13 fluent), and of 12 dysarthric and 12 nonaphasic and nondysarthric right hemisphere injured children were analysed in order to: (1) investigate whether a more refined analysis can objectively contribute to the differentiation of patients who were labelled as fluent or nonfluent on the basis of a clinical judgment: (2) verify whether an instrumental analysis of phonation duration does confirm the subjective estimation of verbal rate (i.e. the number of words produced in a unit of time) in groups of children with acquired neurogenic speech/language disorders frequently met in clinical practice. The results are: (1) phonation rate (i.e. the vocalization percentage) seems to represent an adequate variable to distinguish clinically diagnosed nonfluent aphasic children from speech/language impaired children belonging to other clinical groups of acquired neurogenic speech/language disorders; (2) the verbal rate is highly correlated to the phonation rate in all investigated groups except the dysarthric one. We suggest the instrumental method discussed here might contribute to the differential diagnosis between dysarthric and aphasic disturbances in the acute stage of the disease. Concerning the study of ACA, the main issue of the present investigation is that an objective fluency measurement has succeeded in identifying aphasic children who obviously do not fit in with the standard doctrine on ACA, which claims that ACA is invariably nonfluent irrespective of lesion location.