Mauro Bergui

Voxel-Based Morphometry Reveals Gray Matter Abnormalities in Migraine: January 2008

Background.— Migraine is generally considered a functional brain disorder lacking structural abnormalities. Recent magnetic resonance imaging (MRI) studies, however, suggested that migraine may be associated with subtle brain lesions.

The corticotrophin-releasing hormone test is the most reliable noninvasive method to differentiate pituitary from ectopic ACTH secretion in Cushing's syndrome.

objective It has been reported previously that the paired interpretation of the corticotrophin‐releasing hormone (CRH) test and the 8‐mg dexamethasone suppression test (HDDST) could have higher diagnostic power than any single test in the differential diagnosis of ACTH‐dependent Cushings syndrome. This finding has not been confirmed thereafter in large series. The aim of the present study has been to assess the operating characteristics of either the CRH test or the overnight HDDST and also to evaluate the potential utility of combining the interpretation of both tests in the differential diagnosis of ACTH‐dependent Cushings syndrome.

Diffusion-weighted images of intracranial cyst-like lesions

Abstract Magnetic resonance sequences may be designed to evaluate the diffusion movements of the protons (diffusion-weighted images, DWI). In these images, a bright signal identifies a region where the diffusion along a spatial axis is restricted. The contents of a cystic lesion frequently have the signal intensities of a generic homogeneous hyperproteinic fluid (hypointensity in T1-, hyperintensity in T2-weighted images). DWI may give further information about the microscopic organisation of these fluids: a hyperintense signal indicates the presence of a restricted diffusion, due to some kind of microscopic organisation, at the cellular or macromolecular level. This may provide additional information useful for clinical purposes. We obtained DWI in 24 consecutive patients with intracranial cystic lesions, (19 intra-axial: five abscesses, five gliomas, six metastases, two demyelinating lesions, one neurocysticercosis; five extra-axial: two arachnoid cysts, two epidermoid cysts, one cholesteatoma). We found a strongly hyperintense signal, indicating restricted diffusion, in brain abscesses, epidermoid cysts and cholesteatoma; all the remaining lesions were hypointense or mildly hyperintense. We found these data useful in critical diagnoses, such as in differentiating abscesses from tumours, and in identifying elusive tumours such as epidermoid cysts.

Neuropsychological assessment after microsurgical clipping or endovascular treatment for anterior communicating artery aneurysm

Summary¶Background. After open surgery for ruptured ACoA aneurysms, several patients who have achieved a favourable neurological outcome still exhibit significant cognitive deficits. The aim of this study was to investigate the cognitive performances in patients with ACoA aneurysms submitted to different therapeutic options such as endovascular treatment and surgical clipping. Methods. We evaluated 37 consecutive patients in WFNS grade I or II, who underwent an early treatment (within 48 hours) of a bleeding ACoA aneurysm: 20 out of 37 were surgically clipped (group A) and 17 were treated with endovascular coiling (group B).These two groups were compared with 16 patients (group C) with subarachnoid haemorrhage and negative cerebral panangiography and with 18 volunteers (group D) without neurological or psychiatric disorders.All patients were neurologically intact at discharge and were in Glasgow Outcome Scale 1 at 6 months follow-up after SAH.All subjects were tested to assess selective attention, verbal, spatial and logical memory, frontal lobe executive functions, language and intelligence. Depressive symptoms and anxiety were also examined. Findings. Selective attention, verbal and spatial memory, and intelligence tests didn’t show any significant difference between the patients and the controls.Surgically treated patients showed a significant worse performance on the logical memory and on the frontal lobe executive functions compared to controls, while the endovascular group and the group C (not treated) showed a significant decrease only in the literal fluency score.Moreover, the surgical group showed a significant impairment in using grammatical and syntactical rules to produce sentences. No significant difference was found between the group B, C and controls. Treated patients were not significantly more depressive or anxious than controls. Interpretation. Investigation of neuropsychological deficits can show an impairment, even in patients classified as good outcome by Glasgow Outcome Scale (GOS).The frontal lobe functions and language are impaired especially in surgically treated in comparison with controls, but no significant difference was found respect to the endovascular and no treated patients (group C).

Progressive multifocal leukoencephalopathy: diffusion-weighted imaging and pathological correlations.

We examined MRI of two patients with progressive multifocal leukoencephalopathy (PML), including diffusion-weighted imaging (DWI), with calculation of apparent diffusion coefficients (ADC). The pathology findings of one patient were compared with those of MRI. The lesions had different ADC and DWI appearances, depending on the stage of the disease. Newer lesions and the advancing edge of large lesions had normal-to-low ADC and gave high signal on DWI. Older lesions and the centre of large lesions had increased ADC and gave low signal. High signal on DWI and low ADC mark the regions of active infection and cell swelling, distinguishing them from areas of reparative gliosis.

Mechanical Thrombolysis in Ischemic Stroke Attributable to Basilar Artery Occlusion as First-Line Treatment

Background and Purpose— To report results of mechanical disruption or retrieval of thrombus as first-line treatment in patients with stroke attributable to occlusion of the basilar artery, in particular regarding efficiency and safety. Methods— In 12 consecutive patients with acute stroke attributable to basilar occlusion, mechanical disruption or thrombus retrieval using various loop-shaped tools was tried before eventually starting local intra-arterial thrombolysis with recombinant tissue plasminogen activator (r-tPA). Main inclusion criteria were: National Institutes of Health Stroke Scale score >8 or Glasgow Coma Scale score <12; onset or worsening of symptoms <8 hours; no hemorrhages or large hypodensities on computed tomography scan; and occlusion of the basilar artery matching clinical symptoms. Efficiency included recanalization, procedure time, and r-tPA dose; safety was defined as rate of procedure-related complications. Outcome was evaluated at 3 months. Results— Mechanical recanalization was successful in 6 patients. A single brain infarction, possibly attributable to distal embolization, occurred. Three patients had good outcomes. In 5 of 6 remaining patients, the artery was recanalized using r-tPA. A single asymptomatic hemorrhage occurred; 3 patients had good outcomes. Procedure time and r-tPA were significantly less in patients with successful mechanical thrombolysis (43.33 minutes and 13.33 mg versus 112.33 minutes and 55.83 mg, respectively). Conclusion— Mechanical recanalization was effective in half of the patients and at least as safe as local intra-arterial thrombolysis. It allowed to save r-tPA and time. Although the low success rate remains a limit, the excellent and quick anatomical recanalization obtained after successful procedures makes this approach promising.

The effect of gender on planning: An fMRI study using the Tower of London task.

Since the introduction of brain mapping, evidences of functional gender differences have been corroborating previous behavioral and neuropsychological results showing a sex-specific brain organization. We investigated gender differences in brain activation during the performance of the Tower of London (TOL) task which is a standardized test to assess executive functions. Eighteen healthy subjects (9 females and 9 males) underwent fMRI scanning while solving a series of TOL problems with different levels of difficulty. Data were analyzed by modeling both genders and difficulty task load. Task-elicited brain activations comprised a bilateral fronto-parietal network, common to both genders; within this network, females activated more than males in dorsolateral prefrontal cortex (DLPFC) and right parietal cortex, whereas males showed higher activity in precuneus. A prominent parietal activity was found at low level of difficulty while, with heavier task demand, several frontal regions and subcortical structures were recruited. Our results suggest peculiar gender strategies, with males relying more on visuospatial abilities and females on executive processing.

Brain lesions due to cerebral venous thrombosis do not correlate with sinus involvement.

Abstract Cerebral venous thrombosis may be well tolerated or lead to a brain lesion; availability of collateral venous pathways may explain the great variability of the lesions. This collateral circulation involves mainly medullary and cortical veins. These are difficult to assess neuroradiologically, particularly if thrombosed. Cerebral venous thrombosis is diagnosed usually based on thrombosis of dural sinuses and of the deep venous system. We tried to correlate the site and extent of dural sinus thrombosis with the location and the size of brain lesions in 26 consecutive patients with cerebral venous thrombosis, to investigate whether a simple causal relationship exists. No significant correlation between the extent and site of thrombosis in dural sinuses and the extent and location of brain lesions was found. In some cases a clear relationship between thrombosis of cortical and medullary veins and the lesions was evident. These data suggest that sinus thrombosis alone may be well tolerated in many cases, while involvement of cortical and medullary veins leads to a worse clinical situation.

Propofol analgesia in central pain: Preliminary clinical observations

Propofol, an intravenous general anaesthetic, has been reported to relieve some forms of pruritus at subhypnotic doses. We assessed its effectiveness in 32 patients with several kinds of non-malignant chronic pain, in a placebo-controlled, double-blind study. We found that central pain, but not neuropathic pain, is at least partially controlled by propofol at subhypnotic doses, without major side-effects. In particular, allodynia associated with central, but no neuropathic, pain has been completely controlled. Propofol analgesia leads to renormalization of brain metabolism as seen on single photon emission computed tomography. We conclude that propofol may help in the diagnosis of central pain, particularly in unclear cases, and also in treatment. Possible mechanisms of action are discussed.

Brain volumetric abnormalities in patients with anorexia and bulimia nervosa: A Voxel-based morphometry study

Recent studies focussing on neuroimaging features of eating disorders have observed that anorexia nervosa (AN) is characterized by significant grey matter (GM) atrophy in many brain regions, especially in the cerebellum and anterior cingulate cortex. To date, no studies have found GM atrophy in bulimia nervosa (BN) or have directly compared patients with AN and BN. We used voxel-based morphometry (VBM) to characterize brain abnormalities in AN and BN patients, comparing them with each other and with a control group, and correlating brain volume with clinical features. We recruited 17 AN, 13 BN and 14 healthy controls. All subjects underwent high-resolution magnetic resonance imaging (MRI) with a T1-weighted 3D image. VBM analysis was carried out with the FSL-VBM 4.1 tool. We found no global atrophy, but regional GM reduction in AN with respect to controls and BN in the cerebellum, fusiform area, supplementary motor area, and occipital cortex, and in the caudate in BN compared to AN and controls. Both groups of patients had a volumetric increase bilaterally in somatosensory regions with respect to controls, in areas that are typically involved in the sensory-motor integration of body stimuli and in mental representation of the body image. Our VBM study documented, for the first time in BN patients, the presence of volumetric alterations and replicated previous findings in AN patients. We evidenced morphological differences between AN and BN, demonstrating in the latter atrophy of the caudate nucleus, a region involved in reward mechanisms and processes of self-regulation, perhaps involved in the genesis of the binge-eating behaviors of this disorder.