Frontal Parietal Areas Research Articles

869b Simeprevir (TMC435) With Peginterferon/Ribavirin for Treatment of Chronic HCV Genotype 1 Infection in Patients Who Relapsed After Previous Interferon-Based Therapy: Results From PROMISE, a Phase III Trial

connectivity and negative correlations with right frontal parietal ICN precentral gyrus connectivity. Sex x disease related differences were observed in the default mode network (DMN), right frontal parietal areas, and left frontal parietal areas with increasing levels of EALs. Conclusions: Intrinsic connectivity networks are altered in IBS compared to HC in the context of early adverse life trauma, and these differences are further evident in the pain and emotion regions for females compared to the somatosensory and cognitive regions for males. Consistent with other research, these results suggest that an increased sensitivity to emotion and pain in female IBS compared to male IBS may be associated with altered connectivity integrity with increasing levels of early life adversity.

A stray bullet in the brain

In 2003, after the second Gulf War, the authors were medical doctors at the humanitarian Mission of the Red Cross Field Hospital in Baghdad, Iraq. Our experience in the fi eld indicated that civilians were at a high risk for injuries caused by stray bullets. Whilst we were attending an out-patient activity, we saw a 10-year old boy with a deep lesion of the skin in the left frontal-parietal area of his head caused by a stray bullet 2 months earlier. The bullet had entered the upper parietal portion of the skull (fi gures A, B). Clinical and neurological examination showed no defi cit of power, cognition, sense of touch, or speech. Blood test results were unremarkable. The scalp A stray bullet in the brain

Evaluation of an acute focal epidural mass model to characterize the intracranial pressure-volume relationship in healthy Beagles

To characterize the intracranial pressure-volume relationship (ICPVR) in dogs by use of an acute frontal-parietal mass lesion model. 7 healthy adult female Beagles. Dogs were anesthetized with isoflurane to achieve a surgical plane of anesthesia. A fiberoptic intracranial pressure (ICP) monitor was inserted to a depth of 1 cm in the parenchyma of the right frontal-parietal region of the brain. A Foley balloon-tipped catheter was placed in the epidural space of the left frontal-parietal area through a separate 1-cm burr hole. Baseline measurements were obtained with the balloon deflated. The balloon was then inflated incrementally with 0.5 mL of 0.9% NaCl solution every 10 minutes until ICP exceeded mean arterial blood pressure. Nonlinear regression analysis with 2-factor and 3-factor exponential equations was used to characterize the ICPVR. The mean baseline ICP was 11 mm Hg, with a 95% confidence interval of 2 to 20 mm Hg. The ICPVR was well characterized by 2-factor or 3-factor exponential equations for all dogs (R² > 0.93). Balloon volumes of > 1. 2 mL were associated with ICP > 20 mm Hg. Characterization of the ICPVR may provide clinically useful information regarding the safety of obtaining CSF from the atlanto-occipital space or implantation of brachytherapy catheters and for determining the need for decompressive craniectomy in dogs with acute intracranial disease. High ICP should be suspected in dogs that have an acute frontal-parietal mass lesion estimated to exceed 2% of the brain volume.

Novel influenza A (H1N1)-associated encephalopathy/encephalitis with severe neurological sequelae and unique Image features — A case report

Since the outbreak of novel influenza A (H1N1) in 2009, various neurological complications have been cited. We described a male patient with H1N1-associated encephalopathy/encephalitis presenting with severe neurological symptoms and signs. Residual neurological sequelae were dominant. This is the first report of extensive cortical–subcortical necroses over the bilateral frontal–parietal areas based on an MRI study.

Learning sculpts the spontaneous activity of the resting human brain

The brain is not a passive sensory-motor analyzer driven by environmental stimuli, but actively maintains ongoing representations that may be involved in the coding of expected sensory stimuli, prospective motor responses, and prior experience. Spontaneous cortical activity has been proposed to play an important part in maintaining these ongoing, internal representations, although its functional role is not well understood. One spontaneous signal being intensely investigated in the human brain is the interregional temporal correlation of the blood-oxygen level-dependent (BOLD) signal recorded at rest by functional MRI (functional connectivity-by-MRI, fcMRI, or BOLD connectivity). This signal is intrinsic and coherent within a number of distributed networks whose topography closely resembles that of functional networks recruited during tasks. While it is apparent that fcMRI networks reflect anatomical connectivity, it is less clear whether they have any dynamic functional importance. Here, we demonstrate that visual perceptual learning, an example of adult neural plasticity, modifies the resting covariance structure of spontaneous activity between networks engaged by the task. Specifically, after intense training on a shape-identification task constrained to one visual quadrant, resting BOLD functional connectivity and directed mutual interaction between trained visual cortex and frontal-parietal areas involved in the control of spatial attention were significantly modified. Critically, these changes correlated with the degree of perceptual learning. We conclude that functional connectivity serves a dynamic role in brain function, supporting the consolidation of previous experience.

Auditory Oddball Deficits in Schizophrenia: An Independent Component Analysis of the fMRI Multisite Function BIRN Study

Deficits in the connectivity between brain regions have been suggested to play a major role in the pathophysiology of schizophrenia. A functional magnetic resonance imaging (fMRI) analysis of schizophrenia was implemented using independent component analysis (ICA) to identify multiple temporally cohesive, spatially distributed regions of brain activity that represent functionally connected networks. We hypothesized that functional connectivity differences would be seen in auditory networks comprised of regions such as superior temporal gyrus as well as executive networks that consisted of frontal-parietal areas. Eight networks were found to be implicated in schizophrenia during the auditory oddball paradigm. These included a bilateral temporal network containing the superior and middle temporal gyrus; a default-mode network comprised of the posterior cingulate, precuneus, and middle frontal gyrus; and multiple dorsal lateral prefrontal cortex networks that constituted various levels of between-group differences. Highly task-related sensory networks were also found. These results indicate that patients with schizophrenia show functional connectivity differences in networks related to auditory processing, executive control, and baseline functional activity. Overall, these findings support the idea that the cognitive deficits associated with schizophrenia are widespread and that a functional connectivity approach can help elucidate the neural correlates of this disorder.

Voluntary and involuntary attention affect face discrimination differently

Do voluntary (endogenous) and involuntary (exogenous) attention have the same perceptual consequences? Here we used fMRI to examine activity in the fusiform face area (FFA—a region in ventral visual cortex responsive to faces) and frontal–parietal areas (dorsal regions involved in spatial attention) under voluntary and involuntary spatial cueing conditions. The trial and stimulus parameters were identical for both cueing conditions. However, the cue predicted the location of an upcoming target face in the voluntary condition but was nonpredictive in the involuntary condition. The predictable cue condition led to increased activity in the FFA compared to the nonpredictable cue condition. These results show that voluntary attention leads to more activity in areas of the brain associated with face processing than involuntary attention, and they are consistent with differential behavioral effects of attention on recognition-related processes.

Striking response to intrathecal liposomal cytarabine in a patient with meningeal myelomatosis

A 63-year-old woman presented with right retro-orbital plasmacytoma. Magnetic resonance imaging (MRI; Fig 1A) confirmed a large, solid, well-delineated mass in the right orbit that was displacing the eyeball and upper extrinsic muscles downwards, without cerebral parenchyma involvement. Linear pachy-meningeal thickening extended to the right supraorbital and frontal dura, suggesting dural infiltration. The patient underwent fronto-temporal craniotomy. Histology and immunohistochemistry of the mass showed massive immunoglobulin (Ig) G-j plasma cell infiltration with 20% Ki-67 plasma cells. Bone marrow biopsy indicated 35% infiltration of monoclonal IgG-j plasma cells. Cerebral spinal fluid (CSF) was normal. Blood tests, including b2-microglobulin, were normal except for total protein (62 g/l), hypogammaglobulinaemia (4 g/l) and the presence of an IgG-j monoclonal component by serum immunofixation. Bence Jones protein was undetectable. A skeletal X-ray showed small osteolytic areas in the cranial vault and frontal–parietal area. Multiple myeloma (MM) was diagnosed. The patient underwent three cycles of Cy-VAD (cyclophosphamide, vincristine, adriamycin, dexamethasone) chemotherapy but, before the fourth, presented with a persistent headache. A MRI scan showed MM dural involvement. The CSF cell count was 18/mm with plasma cells and plasmablasts. Polymerase chain reaction amplification of IGH showed a monoclonal rearrangement in CSF. Meningeal myelomatosis was diagnosed. The patient received two intrathecal pushes of 50 mg liposomal cytarabine (SkyePharma, London, UK) at a 14-d interval, and dexamethasone (8 mg twice daily for 14 d). Her fever and headache rapidly disappeared. One month after encephalic radiotherapy (total dose 30 Gy), two more pushes of liposomal cytarabine were administered. Dexamethasone, radiotherapy and four injections of liposomal cytarabine were well tolerated. 18 months after diagnosis, disease assessment showed no serum monoclonal component, rare plasma cells in the bone marrow and no mass on cranial MRI (Fig 1B). Multiple myeloma involvement of the central nervous system is rare (Damaj et al, 2004; Fassas et al, 2004) and the outcome is extremely poor despite aggressive local and systemic treatment including high-dose chemotherapy (Pizzuti et al, 1997; Patriarca et al, 2001). As our patient had already been treated with dexamethasone in first-line treatment, intrathecal liposomal cytarabine alone seemed to ensure successful eradication of meningeal myelomatosis.

Functional Anatomy in Relation to Myelin Maturation

Neural organization of cerebral activity in adult and child can be investigated by means of MRI with fMRI and DTI: MRI with fMRI analyses cortical haemodynamic responses correlated to neuronal activity, whereas DTI describes the spatial orientations of the white matter fibres. The fMRI patterns of cortical activity in children more than eight years old overlap the anatomical localization in adults except for the frontal and posterior parietal cortical areas, where BOLD responses in children are often difficult to arouse. This confirms what is currently known: myelin maturation is complete in these areas only in young adulthood. In neonates and young children, depending on the higher cortical cell concentration than adults and the increase in synaptic density up to the age of four-eight years, signal changes detected by BOLD may vary drastically. BOLD signal amplitude may be lower than that found in adults due to the reduced dynamic range during haemodynamic responses, or negative due to the local increase in HbR not fully compensated by the rise in CBF. The administration of sedatives or anaesthesia in children to perform MR scans can influence the BOLD signal: signal amplitude could decrease dramatically and the activated areas could be smaller in extension, indicating a fundamental role of the level of consciousness. BOLD signal analysis can supply useful data on the maturation processes of myelin and the cerebral cortex.

Basal ganglia and supplementary motor area subtend duration perception: an fMRI study

Brain imaging studies on duration perception usually report the activation of a network that includes the frontal and mesiofrontal cortex (supplementary motor area, SMA), parietal cortex, and subcortical areas (basal ganglia, thalamus, and cerebellum). To address the question of the specific involvement of these structures in temporal processing, we contrasted two visual discrimination tasks in which the relevant stimulus dimension was either its intensity or its duration. Eleven adults had to indicate (by pressing one of two keys) whether they thought the duration or the intensity of a light (LED) was equal to (right hand) or different from (left hand) that of a previously presented standard. In a control task, subjects had to press one of the two keys at random. A similar broad network was observed in both the duration-minus-control and intensity-minus-control comparisons. The intensity-minus-duration comparison pointed out activation in areas known to participate in cognitive operations on visual stimuli: right occipital gyrus, fusiform gyri, hippocampus, precuneus, and intraparietal sulcus. In contrast, the duration-minus-intensity comparison indicated activation of a complex network that included the basal ganglia, SMA, ventrolateral prefrontal cortex, inferior parietal cortex, and temporal cortex. These structures form several subnetworks, each possibly in charge of specific time-coding operations in humans. The SMA and basal ganglia may be implicated in the time-keeping mechanism, and the frontal-parietal areas may be involved in the attentional and mnemonic operations required for encoding and retrieving duration information.

Interaction between the Frontal and Left Parietotemporal Areas in Verbal Thinking

The synchronization of the rhythmical components of evoked potentials (EP) was studied during verbal-task solving. A novel method of the calculation of Wavelet curve correlation was used to reveal synchronization between the evoked rhythmical components in short time intervals. This method was applied to earlier EP records, which were conducted during the search for verbal associations and revealed the successive activation of the frontal and left parietal cortical areas. Two stages of task solving were identified. Independently of the task type, the first stage was characterized by a diffuse synchronization in a broad frequency band below 22 Hz immediately after the stimulus presentation. This stage results in a realization of the verbal stimulus. The second stage was manifested in a localized synchronization between the frontal and left temporal (Wernicke's) areas in the narrow frequency band about 17 Hz only during search for associations. This specific and local synchronization took place earlier than the diffuse activation of the left temporal cortex. This stage appears to reflect the information transmission from the frontal cortex to the left parietotemporal area.

Effect hypokinesia on the ultrastructure of rat neocortex

The effect of 40, 90, and 120-day hypokinesia and nonstressful hypokinesia on the ultrastructure of cingular convolution, motor and frontal-parietal areas of rat cortex were investigated. Differences were found only in the ultrastructure of cingular convolution after hypokinesic stress. In each area both procedures led to a decrease in the number and variety of spike and axospike synapses.

Projections from fetal neocortical transplants placed in the frontal neocortex of newborn rats. A Phaseolus vulgaris-leucoagglutinin tracing study

Fetal rat neocortex grafted into lesion cavities made in the newborn rat neocortex can exchange multiple axonal connections with the host brain. Most previous studies demonstrating efferent transplant-to-host brain connections have used fluorescent retrograde tracers injected into the host brain (Castro et al. 1985, 1987; Floeter and Jones 1984; O'Leary and Stanfield 1989). Other studies have used anterograde axonal tracing with either tritium-labelled amino acids impregnating the transplant and its efferents (Floeter and Jones 1985) or horseradish peroxidase injected into the transplants (Chang et al. 1984, 1986). In the present study we used the anterograde axonal tracer Phaseolus vulgaris-leucoagglutinin (PHA-L) to examine in detail the course and termination of the efferent neocortical graft fibers. Twenty-six newborn rats had the right frontal cortex forepaw area removed by vacuum aspiration, while anesthetized by hypothermia. A piece of fetal frontal cortex 14-16 embryonic days old (E14-16) was immediately thereafter placed in the lesion, and the recipient rats allowed to survive for 5-7 months. At this time the rats were reoperated under sodium pentobarbital (Nembutal) anesthesia and the transplants iontophoretically injected with PHA-L. Two weeks later the animals were again anesthetized, perfused, and processed for PHA-L immunocytochemistry and routine histology. Analysis of acetylcholinesterase- (AChE) and Nissl-stained sections showed graft survival in 19 of the 26 animals used in this study. When these 19 brains were processed for PHA-L immunocytochemistry, 5 of them were found with certainty to have the PHA-L injection confined to the transplant. Based on these cases PHA-L-reactive fibers arising from labelled transplant neurons were traced into the ipsilateral host neocortex adjacent to the transplant and found to project through the subcortical white matter to the ipsilateral parietal neocortical area 1, and claustrum. Callosal fibers were traced to the contralateral frontal neocortical forelimb and parietal areas. Transplant fibers were also observed to descend through the caudate putamen in the dispersed fiber bundles of the internal capsule to distribute as terminal branches and varicose fibers within the mesencephalic periaqueductal gray, red nucleus, deep mesencephalic nucleus, and intermediate gray of the superior colliculus, as well as in the pontine gray. Similar fibers and terminations were present in the caudate putamen, the reticular, ventrobasal, centrolateral, posterior, and parafascicular thalamic nuclei.(ABSTRACT TRUNCATED AT 400 WORDS)

PERIVENTRICULAR LEUKOMALACIA OF THE PRETERM INFANT AND NEURODEVELOPMENTAL OUTCOME AT 18 MONTHS

Periventricular leukomalacia(PVL) can be accurately identified in the neonatal period by means of ultrasonography and the use of high-frequency transducer. In order to establish its pronostic value, a prospective neurological and developmental assessment(Griffith's development quotient [DQ]) at 18 months corrected for prematurity was per formed on 82 infants of 34 weeks'gestation or less, alloca ted in 4 groups : 41 with normal scans(group I), 13 with isolated haemorrhage(group II), 4 with post-haemorrhagic ventricular dilatation(group III) and 24 with PVL associated or not with haemorrhage or dilatation(group IV). The outcome was good and similar in group I,II and III.By contrast, the outcome of group IV was worse and seemed to depend on the extent and site of PVL: 1)Frontal areas(n=13): all babies developed normally. 2)Frontal-parietal areas (n=6): 3 had major handicap. 3)Frontal-parietal-Occipital areas(n=5): all had major handicap. Our study indicate that major sequelae are more closely related to the extent and localisation of PVL than to haemorrhage or ventricular dilatation as previously reported.

Letter: Cerebral arteriovenous fistula in hereditary hemorrhagic telangiectasia.

To the Editor.—Recently, Boynton and Morgan1described an infant with a positive family history of hereditary hemorrhagic telangiectasia (HHT) who died of congestive heart failure secondary to a large cerebral arteriovenous (AV) malformation. The authors believed their case was a unique instance of large cerebral AV malformation associated with HHT. However, other such cases have been reported previously2-4and we have seen an additional example in a 46-year-old man with typical HHT, whose angiogram revealed a large AV malformation in the left frontal-parietal area and a smaller one in the right frontal pole. Cerebral vascular malformations of smaller and unspecified size have also been described in patients with HHT.5-10In its relation to HHT, Boynton and Morgan's case was unusual only with respect to the early age at which the cerebral AV malformation manifested. In view of the high frequency of neurological symptoms in HHT, such