Increased functional connectivity within mesocortical networks in open people.

Openness is a personality trait reflecting absorption in sensory experience, preference for novelty, and creativity, and is thus considered a driving force of human evolution. At the brain level, a relation between openness and dopaminergic circuits has been proposed, although evidence to support this hypothesis is lacking. Recent behavioral research has also found that people with mania, a psychopathological condition linked to dopaminergic dysfunctions, may display high levels of openness. However, whether openness is related to dopaminergic circuits has not been determined thus far. We addressed this issue via three functional magnetic resonance imaging (fMRI) experiments in n=46 healthy volunteers. In the first experiment participants lied at rest in the scanner while in the other two experiments they performed active tasks that included the presentation of pleasant odors and pictures of food. Individual differences in openness and other personality traits were assessed via the NEO-PI-R questionnaire (NEO-Personality Inventory-Revised), a widely employed measure of the five-factor model personality traits. Correlation between fMRI and personality data was analyzed via state-of-art methods assessing resting-state and task-related functional connectivity within specific brain networks. Openness was positively associated with the functional connectivity between the right substantia nigra/ventral tegmental area, the major source of dopaminergic inputs in the brain, and the ipsilateral dorsolateral prefrontal cortex (DLPFC), a key region in encoding, maintaining, and updating information that is relevant for adaptive behaviors. Of note, the same connectivity pattern was consistently found across all of the three fMRI experiments. Given the critical role of dopaminergic signal in gating information in DLPFC, the increased functional connectivity within mesocortical networks in open people may explain why these individuals display a wide "mental permeability" to salient stimuli and an increased absorption in sensory experience.

Abnormal pressure waves in headache sufferers with bilateral transverse sinus stenosis.

INTRODUCTION: Bilateral transverse sinus stenosis (BTSS) has been reported to be associated with idiopathic intracranial hypertension without papilloedema in headache sufferers. SUBJECTS AND METHODS: To test the accuracy of short-term cerebrospinal fluid (CSF) pressure monitoring through a lumbar needle for detection of elevated intracranial pressure in headache sufferers with BTSS, we prospectively performed lumbar puncture in order to measure lumbar CSF opening pressures and to monitor, for 1 h, the CSF pressure in 48 consecutive headache sufferers with BTSS and in 50 consecutive headache sufferers with normal appearance of transverse sinuses or stenosis of one transverse sinus. RESULTS: Of the 48 headache sufferers with BTSS, 18 (37.5%) had elevated CSF opening pressure and abnormal pressure waveforms, but short-term CSF pressure monitoring revealed abnormal pressure waves associated with elevated mean CSF pressure also in 26 (86.6%) out of 30 patients who had normal opening pressures. None of the 50 headache sufferers with normal appearance of transverse sinuses or stenosis of one transverse sinus had abnormal pressure waves and elevated CSF pressures. CONCLUSIONS: In this study, short-term CSF pressure monitoring through a lumbar needle revealed abnormal pressure waves and elevated mean CSF pressures in the majority of headache sufferers with BTSS who had normal CSF opening pressures. These findings demonstrate the accuracy of short-term CSF pressure monitoring through a lumbar needle in estimating CSF pressure; they also highlight that a single-spot opening pressure measurement has a low accuracy for recognition of increased intracranial pressure in headache sufferers with BTSS.

The upper limit of normal CSF opening pressure is related to bilateral transverse sinus stenosis in headache sufferers.

There are limited data on the relationship between normal cerebrospinal fluid (CSF) opening pressure and bilateral transverse sinus stenosis (BTSS); there are also several conflicting reports about the upper limit of normal CSF opening pressure. To evaluate the influence of BTSS on the upper limit of normal CSF opening pressure, we prospectively recorded lumbar CSF opening pressures in 217 adult patients with neurological symptoms who underwent cerebral magnetic resonance venography (MRV). The CSF opening pressures ranged between 65 and 286 mmH(2)O (mean = 149.3, s.d. = 47.5). The upper limit of opening pressure in patients with both normal appearance of transverse sinuses and unilateral transverse sinus stenosis on MRV (n = 167) was 195 mmH(2)O with a range of 65-195 mmH(2)O. All patients with BTSS were headache sufferers, and the upper limit of opening pressure in patients with BTSS (n = 50) was 286 mmH(2)O with a range of 91-286 mmH(2)O. All patients with opening pressures > 200 mmH(2)O displayed BTSS, whereas only 13% of patients with a pressure < 200 mmH(2)O displayed BTSS. Our findings demonstrate that the upper limit of normal CSF opening pressure is related to BTSS, and they also highlight that headache sufferers with opening pressures > 200 mmH(2)O should be tested for BTSS by MRV.

Bilateral transverse sinus stenosis and idiopathic intracranial hypertension without papilledema in chronic tension-type headache.

Previous MR studies have established that bilateral transverse sinus stenosis (BTSS) predicts idiopathic intracranial hypertension without papilledema (IIHWOP) in migraine. However, it is uncertain whether BTSS identifies IIHWOP in patients with chronic tension-type headache (CTTH): using cerebral MR venography this study aimed to address this question.In a prospective study from February 2002 to December 2006, 198 consecutive patients with CTTH underwent MR venography. Of these patients, 58 underwent lumbar puncture to measure cerebrospinal fluid (CSF) pressure. MR venography and lumbar puncture were also performed in 45 age-matched control subjects. BTSS was considered present when the signal flow was poor or lacking (flow gap) in the mid-lateral portion of both transverse sinuses. IIHWOP was diagnosed if the patient met the diagnostic criteria for idiopathic intracranial hypertension and did not have papilledema. Among the 198 patients with CTTH who underwent MR venography, 18 (9%) had BTSS. Thirteen of these 18 patients with BTSS underwent lumbar puncture, and nine (69.2%) had IIHWOP. CSF opening pressure was normal in all 45 patients as well as in all 45 controls with normal MR venography.These data suggest that BTSS on MR venography is associated with increased intracranial pressure in the absence of papilledema in patients with headache mimicking CTTH.

Investigating the role of brain-derived neurotrophic factor in relapsing-remitting multiple sclerosis.

Multiple sclerosis (MS) is a common, heterogeneous disorder of the central nervous system with a complex trait composed of both genetic and environmental factors. Recently, scientific interest has increased in defining factors that possibly contribute to brain functional plasticity; the results might be useful to assess the relationship between MS lesion burden and clinical events, as well as explaining the well-known phenotypic heterogeneity of the disease. In this study, we explored the effect of the Val66Met brain-derived neurotrophic factor (BDNF) functional polymorphism on cognitive performances and volumetric measurements obtained by magnetic resonance imaging of the brain in a selected population of relapsing-remitting MS (RRMS) patients, with relatively short disease duration and minimal clinical disability, compared to gender, age and educational-level matched healthy subjects. We found that in the RRMS group, the BDNF Met-allele was significantly associated with the lower volume of cerebral grey matter (GM) (P = 0.005). Furthermore, a significant (P = 0.013) interaction effect between 'MS-status' and the BDNF genotype was found for GM volumes, with the result that patients carrying the BDNF Met-allele showed a higher risk of developing global GM atrophy than the homozygous Val/Val. No BDNF-related impact on global neuropsychological functions resulted in either RRMS patients or controls. Our data seem to be consistent with the reported influence of BDNF in neuronal plasticity, thus suggesting that the Met-allele might have a negative prognostic effect on cortical morphometry in RRMS patients.

Bilateral transverse sinus stenosis predicts IIH without papilledema in patients with migraine.

BACKGROUND: The headache profile of patients with idiopathic intracranial hypertension without papilledema (IIHWOP) may be indistinguishable from that of migraine. Bilateral transverse sinus stenosis (BTSS) has been found in the majority of patients with IIHWOP. The frequency of BTSS associated with IIHWOP in patients with migraine is unknown. OBJECTIVE: To detect the frequency of BTSS in adult patients with migraine and to investigate whether the presence of BTSS identifies patients with IIHWOP. METHODS: In a prospective study from December 2000 to November 2005, 724 consecutive patients with recurrent headaches who fulfilled International Headache Society diagnostic criteria for migraine underwent cerebral MR venography (MRV). A portion of these patients underwent a lumbar puncture (LP) to measure CSF pressure. MRV and LP were also performed in 70 age-matched control subjects. RESULTS: Six hundred seventy-five of the 724 patients with migraines had normal MRV. Seventy of these 675 patients underwent LP, and all of them had normal CSF pressure. Forty-nine (6.7%) of the 724 patients with migraine had BTSS. Twenty-eight of these 49 patients with BTSS underwent LP, and 19 (67.8%) had IIHWOP. The headache profiles of patients with BTSS and IIHWOP did not differ from those of patients with normal MRVs and CSF pressures within normal limits. CSF pressure was normal in both patients and controls with normal MRV. CONCLUSIONS: Of patients with migraine, 6.7% had bilateral transverse sinus stenosis; 67.8% of these patients had idiopathic intracranial hypertension without papilledema (IIHWOP). These results suggest that patients with migraine who present bilateral transverse sinus stenosis on cerebral MR venography should undergo lumbar puncture to exclude IIHWOP.

Transverse sinus stenoses persist after normalization of the CSF pressure in IIH.

BACKGROUND: Bilateral transverse sinus (TS) stenosis has been found in more than 90% of patients with idiopathic intracranial hypertension (IIH). OBJECTIVE: To evaluate whether TS stenosis changed after normalization of CSF pressure in patients with IIH during medical treatment. METHODS: Fourteen consecutive patients with IIH with bilateral TS stenosis on cerebral MR venography (MRV) during the medical treatment were studied. Patients were followed for over a 6-year period. During the follow-up, patients underwent repeated lumbar punctures (LPs) and cerebral MRV. MRV was always performed before each LP. RESULTS: TS stenosis persisted in all the patients during the follow-up. In 9 of 14 (64%) patients with IIH, CSF pressure normalized during medical treatment. CONCLUSIONS: Transverse sinus (TS) stenoses, as revealed by MR venography, persist in patients with idiopathic intracranial hypertension after normalization of CSF pressure, suggesting the lack of a direct relationship between the caliber of TS and CSF pressure.

A novel Notch3 gene mutation not involving a cysteine residue in an Italian family with CADASIL.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a hereditary cerebrovascular disease leading to accumulating neurologic deficits and dementia. CADASIL has been linked to nucleotide substitutions and deletions in the Notch3 gene. All the mutations described until now lead to unpaired cysteine residue in the epidermal growth factor-like repeats. The authors report a family with CADASIL carrying a deletion in the Notch3 gene that did not involve a cysteine residue.

Gross morphology and morphometric sequelae in the hippocampus, fornix, and corpus callosum of patients with severe non-missile traumatic brain injury without macroscopically detectable lesions: a T1 weighted MRI study.

OBJECTIVE: The gross morphology and morphometry of the hippocampus, fornix, and corpus callosum in patients with severe non-missile traumatic brain injury (nmTBI) without obvious neuroradiological lesions was examined and the volumes of these structures were correlated with performance on memory tests. In addition, the predictability of the length of coma from the selected anatomical volumes was examined. METHOD: High spatial resolution T1 weighted MRI scans of the brain (1 mm3) and neuropsychological evaluations with standardised tests were performed at least 3 months after trauma in 19 patients. RESULTS: In comparison with control subjects matched in terms of gender and age, volume reduction in the hippocampus, fornix, and corpus callosum of the nmTBI patients was quantitatively significant. The length of coma correlated with the volume reduction in the corpus callosum. Immediate free recall of word lists correlated with the volume of the fornix and the corpus callosum. Delayed recall of word lists and immediate recall of the Rey figure both correlated with the volume of the fornix. Delayed recall of the Rey figure correlated with the volume of the fornix and the right hippocampus. CONCLUSION: These findings demonstrate that in severe nmTBI without obvious neuroradiological lesions there is a clear hippocampal, fornix, and callosal volume reduction. The length of coma predicts the callosal volume reduction, which could be considered a marker of the severity of axonal loss. A few memory test scores correlated with the volumes of the selected anatomical structures. This relationship with memory performance may reflect the diffuse nature of the damage, leading to the disruption of neural circuits at multiple levels and the progressive neural degeneration occurring in TBI.

Cerebral MR venography of transverse sinuses in subjects with normal CSF pressure.

Flow artifacts or anatomic variants of venous sinuses often make MR venography (MRV) interpretation difficult. The authors investigated cerebral MRV in 111 subjects with normal CSF pressure to identify the most common flow abnormalities of transverse sinuses (TS). Disturbance of venous outflow in one transverse sinus was commonly observed in 30% of subjects whereas flow abnormalities of both TS occurred in 2 of 111 individuals. Subjects with flow gaps in both TS should undergo lumbar puncture to exclude increased CSF pressure.

Obesity does not induce abnormal CSF pressure in subjects with normal cerebral MR venography.

Obesity has been shown to increase lumbar CSF pressure in healthy subjects. The authors studied lumbar CSF opening pressure in 18 obese, 33 overweight, and 49 nonoverweight subjects with normal MRI and MR venography (MRV) of the brain. No subject had a CSF pressure above 200 mm H2O. Obesity does not cause abnormal CSF pressure in subjects with normal MRV. Individuals with a CSF pressure higher than 200 mm H2O should undergo MRV to exclude cerebral venous thrombosis.

Neurophysiological correlates of age-related changes in human motor function.

BACKGROUND: There are well-defined and characteristic age-related deficits in motor abilities that may reflect structural and chemical changes in the aging brain. OBJECTIVE: To delineate age-related changes in the physiology of brain systems subserving simple motor behavior. METHODS: Ten strongly right-handed young (<35 years of age) and 12 strongly right-handed elderly (>50 years of age) subjects with no evidence of cognitive or motor deficits participated in the study. Whole-brain functional imaging was performed on a 1.5-T MRI scanner using a spiral pulse sequence while the subjects performed a visually paced "button-press" motor task with their dominant right hand alternating with a rest state. RESULTS: Although the groups did not differ in accuracy, there was an increase in reaction time in the elderly subjects (mean score plus minus SD, young subjects = 547 +/- 97 ms, elderly subjects = 794 +/- 280 ms, p < 0.03). There was a greater extent of activation in the contralateral sensorimotor cortex, lateral premotor area, supplementary motor area, and ipsilateral cerebellum in the elderly subjects relative to the young subjects (p < 0.001). Additional areas of activation, absent in the young subjects, were seen in the ipsilateral sensorimotor cortex, putamen (left > right), and contralateral cerebellum of the elderly subjects. CONCLUSIONS: The results of this study show that elderly subjects recruit additional cortical and subcortical areas even for the performance of a simple motor task. These changes may represent compensatory mechanisms invoked by the aging brain, such as reorganization and redistribution of functional networks to compensate for age-related structural and neurochemical changes.

Cerebral venous thrombosis and isolated intracranial hypertension without papilledema in CDH.

BACKGROUND: There is evidence that patients with chronic daily headache (CDH) may have isolated intracranial hypertension without papilledema (IHWOP). Recent studies have emphasized that isolated IH may be due to cerebral venous thrombosis (CVT). OBJECTIVE: To detect the occurrence of CVT in patients with CDH. METHODS: The authors investigated the occurrence of CVT in 114 consecutive patients with CDH by using MR venography (MRV). A portion of these patients underwent a lumbar puncture (LP) to measure CSF pressure. MRV and LP were also performed in 28 age-matched control subjects. RESULTS: In all the control subjects, both MRV and CSF pressure were normal. One hundred three of the 114 patients with CDH had normal MRV. Twenty-seven (Group 1) of these 103 patients underwent LP, and all of them had normal CSF pressure. Eleven (9.6%) of the 114 patients with CDH had CVT of one or both transverse sinuses. Six of these 11 patients had flowing abnormalities of one transverse sinus (Group 2), whereas the remaining five patients showed involvement of both transverse sinuses (Group 3). The CSF pressure of Group 2 was higher than that of either Group 1 or the control subjects, and one of the six patients showed isolated IHWOP. Patients of Group 3 displayed the highest CSF pressure, and four of five had isolated IHWOP. The headache profiles of patients with CDH and CVT did not differ from those of patients with CDH but normal MRV. CONCLUSIONS: CVT, as detected by MRV, occurred in 9.6% of patients who presented with CDH. Almost half of the patients with CVT had isolated IHWOP. These results suggest that MRV may be a useful tool for selecting patients with CDH who should have LP to exclude isolated IHWOP.

Simultaneous BOLD/perfusion measurement using dual-echo FAIR and UNFAIR: sequence comparison at 1.5T and 3.0T.

Functional MRI (fMRI) studies designed for simultaneously measuring Blood Oxygenation Level Dependent (BOLD) and Cerebral Blood Flow (CBF) signal often employ the standard Flow Alternating Inversion Recovery (FAIR) technique. However, some sensitivity is lost in the BOLD data due to inherent T1 relaxation. We sought to minimize the preceding problem by employing a modified UN-inverted FAIR (UNFAIR) technique, which (in theory) should provide identical CBF signal as FAIR with minimal degradation of the BOLD signal. UNFAIR BOLD maps acquired from human subjects (n = 8) showed significantly higher mean z-score of approximately 17% (p < 0.001), and number of activated voxels at 1.5T. On the other hand, the corresponding FAIR perfusion maps were superior to the UNFAIR perfusion maps as reflected in a higher mean z-score of approximately 8% (p = 0.013), and number of activated voxels. The reduction in UNFAIR sensitivity for perfusion is attributed to increased motion sensitivity related to its higher background signal, and, T2 related losses from the use of an extra inversion pulse. Data acquired at 3.0T demonstrating similar trends are also presented.

Randomized trial comparing two different high doses of methylprednisolone in MS: a clinical and MRI study.

OBJECTIVE: To assess the efficacy of two different high doses of intravenous methylprednisolone (IVMP) for the treatment of relapses in MS. BACKGROUND: IVMP is the treatment of choice for MS relapses, but it is unknown whether its effects are dose related. METHODS: We conducted a double-blind, randomized study. Follow-up included serial clinical and MRI recordings at baseline and at 7, 15, 30, and 60 days after the beginning of treatment. Outcome measures were the number of brain and cervical spinal cord MRI contrast-enhancing lesions, and the Expanded Disability Status Scale score. RESULTS: Both treatment regimens improved clinical scores and reduced the number of MRI enhancing lesions during the follow-up period. The higher dose of IVMP was significantly more effective than the lower dose in reducing the number of MRI contrast-enhanced lesions at 30 and 60 days, mainly by decreasing the rate of new lesion formation. CONCLUSIONS: The higher dosage of IVMP has a more powerful and prolonged action in maintaining blood-brain barrier integrity after a clinical relapse.

Action palatal tremor in a patient with primary intestinal lymphoma.

We report the case of a 59-year-old man with primary intestinal T-cell non-Hodgkin's lymphoma who developed abnormal facial twitching synchronous with small palatal movements induced by attempts at speaking or swallowing. At rest, the electromyogram (EMG) showed no spontaneous muscular activity. Phonation triggered trains of synchronous, rhythmic EMG bursts at a frequency of 3-4 Hz lasting 10-20 s, with an average burst of 150 ms, which simultaneously involved palatal, facial, and neck muscles bilaterally with left-sided predominance. An enhanced blink reflex recovery curve was observed after stimulation of either side. Backaveraging electroencephalographic study revealed no activity that was time locked with the jerks. Axial T2-weighted magnetic resonance imaging showed an increased signal intensity and bilateral enlargement of the inferior olives. No antineuronal-specific antibodies were found in the blood or in the cerebrospinal fluid. All of these clinical findings were consistent with a symptomatic palatal tremor (PT). Because it was triggered by activation of cranial muscles, we termed this movement disorder action PT. To our knowledge, this is the first report of symptomatic PT displaying these features.