The role of time-resolved imaging of contrast kinetics (TRICKS) magnetic resonance angiography (MRA) in the evaluation of head-neck vascular anomalies: a preliminary experience.

OBJECTIVES: In this preliminary report, we describe our experience with time-resolved imaging of contrast kinetics-MR angiography (TRICKS-MRA) in the assessment of head-neck vascular anomalies (HNVAs). METHODS: We prospectively studied six consecutive patients with clinically suspected or diagnosed HNVAs. All of them underwent TRICKS-MRA of the head and neck as part of the routine for treatment planning. A digital subtraction angiography (DSA) was also performed. RESULTS: TRICKS-MRA could be achieved in all cases. Three subjects were treated based on TRICKS-MRA imaging findings and subsequent DSA examination. In all of them, DSA confirmed the vascular architecture of HNVAs shown by TRICKS-MRA. In the other three patients, a close follow up to assess the evolution of the suspected haemangioma was preferred. CONCLUSIONS: TRICKS sequences add important diagnostic information in cases of HNVAs, helpful for therapeutic decisions and post-treatment follow up. We recommend TRICKS-MRA use (if technically possible) as part of routine MRI protocol for HNVAs, representing a possible alternative imaging tool to conventional DSA.

Clinical applications of dynamic susceptibility contrast perfusion-weighted MR imaging in brain tumours.

Magnetic resonance imaging (MRI) with a dynamic susceptibility contrast perfusion-weighted imaging (DSC-PWI) sequence to study brain tumours provides information on the haemodynamic characteristics of the neoplastic tissue. Brain perfusion maps and calculation of perfusion parameters, such as relative cerebral blood flow (rCBF), relative cerebral blood volume (rCBV) and mean transit time (MTT) allow assessment of vascularity and angiogenesis within tumours of the central nervous system (CNS), thus providing additional information to conventional MRI sequences. Although DSC-PWI has long been used, its clinical use in the study of brain tumours in daily clinical practice is still to be defined. The aim of this review was to analyse the application of perfusion MRI in the study of brain tumours by summarising our personal experience and the main results reported in the literature.

Intracranial hypotension and PRES: case report.

We report a case of a woman presenting, 7 days after epidural analgesia for a caesarean section, to the emergency room for a worsening of the headache and tonico-clonic seizures. MRI showed alterations suggestive of the presence of intracranial hypotension (IH) as well as evidence of posterior reversible encephalopathy syndrome (PRES). She was treated with a blood patch which leads to the prompt regression of the clinical symptoms and follow-up MRI, after 15 days, showed complete resolution of radiological alterations. The possible pathogenetic relationship between IH, secondary to the inadvertent dural puncture, and PRES is discussed. We suggest that venous stagnation and hydrostatic edema, secondary to intracranial hypotension, probably played a crucial role in the pathogenesis of PRES.

Neurovascular headache and occipital neuralgia secondary to bleeding of bulbocervical cavernoma.

It has recently been suggested that the trigeminocervical complex plays a crucial role in the pathophysiology of neck discomfort that accompanies migraine attacks. Clinical and neurophysiological data have shown that pain within the occipital area may be transmitted by the first trigeminal branch, which supports an anatomical and functional link between cervical and trigeminal modulation of peripheral afferents. We describe a patient with an acute symptomatic migraine attack and chronic occipital neuralgia, both due to bleeding of a bulbocervical cavernoma. The clinical presentation is also discussed and related to recent scientific data on the role of the trigeminocervical complex in both the clinical picture and underlying pathophysiological mechanisms of cervical and head pain.

Sporadic Creutzfeldt-Jakob disease without dementia at onset: clinical features, laboratory tests and sequential diffusion MRI (in an autopsy-proven case).

A rapidly progressing dementia, followed by focal neurological signs, and evidence of periodic sharp wave complexes (PSWC) in the EEG may lead to the clinical suspicion of Creutzfeldt-Jakob disease (CJD). Different clinical variants of CJD have been described in the past, with prominent extrapyramidal or occipital lobe involvement, all included in the sporadic form of CJD (sCJD). Familiar and iatrogenic forms of CJD are also known. More recently a new variant has been described, vCJD, casually linked to bovine spongiform encephalopathy (BSE) and it has attracted increasing attention toward each form of rapidly progressing dementia; likewise the differential diagnosis between sCJD vs. vCJD is not always easy. Magnetic resonance imaging (MRI) too seems to have a peculiar role in differentiating sCJD from vCJD, even if the role of MRI in the diagnosis of CJD is still debated. Diffusion MRI is expected to play an important role in the clinical setting of CJD, contributing to formulation of an early diagnosis, especially in cases with unusual clinical presentation. In fact, the sensitivity of diffusion MRI is superior to that of conventional MRI (T1, T2, FLAIR) in detecting specific basal ganglia and cortical abnormalities early in the course of CJD and these abnormalities correlate well with areas of the most severe and characteristic neuropathological changes. We describe a case of autopsy-proven sCJD, with an unusual clinical course without dementia as a presenting symptom and discuss the role of diffusion MRI and laboratory tests in making an early diagnosis.

beta2-microglobulin serum level is not a marker of disease activity in multiple sclerosis.

Beta2-microglobulin (beta2-MG) is a pharmacodynamic marker of interferon-beta activity in multiple sclerosis (MS). Its role in the natural course of the disease is not fully known. We analyzed the spontaneous fluctuation of beta2-MG in free-treatment MS patients during a short-time course to quantify beta2-MG as a marker of disease activity/progression. Thirty MS patients were clinically assessed and imaged monthly over a 3-month period. Sera were collected concomitantly for the evaluation of beta2-MG, by means of an enzyme-linked immunosorbent assay. Sera from 20 healthy individuals (HI) were drawn and used as controls. The Mann-Whitney test was used when appropriate and time effect on radiological and biological measures was assessed by means of the random effect models. Eight (26.7%) patients experienced a clinical relapse but three (10%) required steroid treatment. A reduction in the contrast-enhancing lesion load (P = 0.02) and a trend (P = 0.07) toward a decrease in brain parenchyma fraction were observed. Baseline levels of beta2-MG were similar in patients and HI. Patients' beta2-MG values increased over the 3-month time period (P = 0.05) but did not exceed those detected in HI at any time point. These results failed to demonstrate the validity of beta2-MG as a surrogate marker of disease in MS.

Reversible diffusion MRI abnormalities and transient mutism after liver transplantation.

Transient mutism was observed in a liver transplant patient under immunosuppressant therapy with cyclosporine A and antifungal prophylaxis with amphotericin B. Fluid-attenuated inversion recovery and diffusion-weighted images revealed reversible bilateral symmetric hyperintensity located in the frontal motor cortex and corticospinal tracts. These MRI abnormalities may be caused by acute edema, possibly a combination of cytotoxic and vasogenic edema, which resolved with a prompt change in therapy.

Clinical and genetic studies in hereditary spastic paraplegia with thin corpus callosum.

BACKGROUND: A complicated form of recessive hereditary spastic paraplegias (HSPs) with thin corpus callosum (TCC) was first described in Japan, and most of the Japanese families showed linkage to chromosome 15q13-15. A recessive HSP locus (SPG11) has also been mapped to chromosome 15q13-15 in Italian and North American families with and without TCC, and it overlaps the region identified in the Japanese families. OBJECTIVE: To study clinically and genetically 12 Italian families with HSP and TCC. METHODS: The authors investigated 18 affected and 30 healthy individuals from 12 unrelated Italian families with recessive HSP-TCC. Clinical, neurophysiologic, and neuroradiologic studies were undertaken. All patients were negative for SPG7 mutations. Genetic linkage analyses were carried out with polymorphic DNA markers on 15q13-15. RESULTS: Five families were consistent with linkage, thus defining a 19.8-cM region between markers D15S1007 and D15S978, encompassing the SPG11 interval. In one consanguineous family, linkage could be firmly excluded, confirming genetic heterogeneity. Two families appeared not linked to the region, but this could not be firmly proved because of the small family size. The remaining four families were uninformative for linkage purposes. CONCLUSION: HSP-TCC is common in Italy. The phenotype is fairly homogeneous and is associated with impaired cognition. There are at least two loci for HSP-TCC, one of which is on chromosome 15q13-15.

Novel SACS mutations in autosomal recessive spastic ataxia of Charlevoix-Saguenay type.

Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is an early-onset familial disease with prominent myelinated fibers in the optic fundus. ARSACS is frequent in the Charlevoix-Saguenay region of Quebec but rare elsewhere. Mutations in SACS, encoding sacsin, a protein of unknown function, are associated with ARSACS. The authors identified three new SACS mutations in two Italian patients whose phenotype closely matches that of Quebec cases, but without retinal striation.

Cerebral hemodynamics on MR perfusion images before and after bypass surgery in patients with giant intracranial aneurysms.

BACKGROUND AND PURPOSE: Preoperative assessment of the anatomy and dynamics of cerebral circulation for patients with giant intracranial aneurysm can improve both outcome prediction and therapeutic approach. The aim of our study was to use perfusion MR imaging to evaluate cerebral hemodynamics in such patients before and after extraintracranial high-flow bypass surgery. METHODS: Five patients with a giant aneurysm of the intracranial internal carotid artery underwent MR studies before, 1 week after, and 1 month after high-flow bypass surgery. We performed MR and digital subtraction angiography, and conventional and functional MR sequences (diffusion and perfusion). Surgery consisted of middle cerebral artery (MCA)-internal carotid artery bypass with saphenous vein grafts (n = 4) or MCA-external carotid artery bypass (n = 1). RESULTS: In four patients, MR perfusion study showed impaired hemodynamics in the vascular territory supplied by the MCA of the aneurysm side, characterized by significantly reduced mean cerebral blood flow (CBF), whereas mean transit time (MTT) and regional cerebral blood volume (rCBV) were either preserved, reduced, or increased. After surgery, angiography showed good canalization of the bypass graft. MR perfusion data obtained after surgery showed improved cerebral hemodynamics in all cases, with a return of CBF index (CBFi), MTT, and rCBV to nearly normal values. CONCLUSION: Increased MTT with increased or preserved rCBV can be interpreted as a compensatory vasodilatory response to reduced perfusion pressure, presumably from compression and disturbed flow in the giant aneurysmal sac. When maximal vasodilation has occurred, however, the brain can no longer compensate for diminished perfusion by vasodilation, and rCBV and CBFi diminish. Bypass surgery improves hemodynamics, increasing perfusion pressure and, thus, CBFi. Perfusion MR imaging can be used to evaluate cerebral hemodynamics in patients with intracranial giant aneurysm.

Mitochondrial myopathy, parkinsonism, and multiple mtDNA deletions in a Sephardic Jewish family.

The authors describe a family of Sephardic Jews with progressive external ophthalmoparesis, skeletal muscle weakness, and parkinsonism. Autosomal recessive inheritance was suggested by many consanguineous marriages, although a dominant disorder could not be excluded. No linkage to known progressive external ophthalmoparesis locus was found. The presence of cytochrome c oxidase-negative ragged-red fibers, biochemically reduced respiratory chain complexes, and multiple mitochondrial DNA deletions in muscle biopsies from four patients suggested a new mitochondrial disorder of intergenomic communication.

Intrafamilial variability in hereditary spastic paraplegia associated with an SPG4 gene mutation.

The authors studied a family with pure autosomal dominant spastic paraplegia (ADHSP) that showed a marked intrafamilial variability in both age at onset and clinical severity, ranging from severe congenital presentation to mild involvement after age 55. They found a novel mutation in the SPG4 gene, which segregates with the disease in six patients. The mutation affects the consensus donor splice site of SPG4 intron 16, resulting in a premature termination codon at amino acid 578. The data confirm the pathologic significance of SPG4 mutations in pure ADHSP and add to the list of known SPG4 allelic variants.

Correlation between MRI findings and long-term outcome in patients with severe brain trauma.

Our aim was to relate MRI findings in patients with severe traumatic brain injury (TBI) to clinical severity and long-term outcome. We studied 37 patients with severe TBI, who were submitted to clinical assessment for disability and cognition and to MRI 60-90 days after trauma. Clinical assessment was also performed 3, 6 and 12 months later. The number and volume of lesions in various cerebral structures were calculated semiautomatically from FLAIR and fast field-echo images. Possible correlations between total and regional lesion volume and clinical deficits were then investigated. The frontal and temporal lobes were most frequently involved. Total lesion volume on FLAIR images correlated significantly with clinical outcome, whereas that on FFE images did not. Regional analysis showed that FLAIR lesion volume in the corpus callosum correlated significantly with scores on disability and cognition scales at the first clinical assessment. FLAIR lesion volume in the frontal lobes correlated significantly with clinical scores 1 year later.

[Usefulness of selective partial inversion recover (SPIR) sequences in optic nerve diseases]. / Utilità delle sequenze "Selective Partial Inversion Recover" (SPIR) nelle malattie del nervo ottico.

PURPOSE: To evaluate the yield of SPIR sequences with fat suppression in the diagnosis of optic nerve lesions. MATERIAL AND METHODS: Ten patients with suspected optic nerve involvement on the basis of clinical data and abnormalities of visual evoked potentials were examined. MRI was performed with a 1.5 T unit (Philips NT 15) using T1 weighted conventional spin-echo and T1- and T2 weighted SPIR sequences with fat suppression. Axial images were obtained along the optic nerve course, while coronal images throughout the optic nerve axis; slices were 3 mm thick. Axial T2 weighted SPIR sequences were also performed with the volumetric technique (1.5 mm thickness); coronal and parasagittal reconstructions along the nerve axis were obtained too. After paramagnetic contrast medium injection, conventional T1 weighted and SPIR sequences were performed on axial and coronal planes. RESULTS: Optic nerve lesions consistent with the diagnosis of neuritis were demonstrated with T2 weighted images in 4 of 10 patients. No abnormalities and/or nerve enlargement were found on T1 weighted images. An enhancement area was seen after contrast medium injection in only one case. MRI showed a pilocytic astrocytoma in one patient and selective atrophy of the right optic nerve in another. MRI showed normal findings in 4 patients. CONCLUSIONS: T1 and T2 weighted fat-suppressed SPIR imaging of the optic nerve improves anatomical definition, lesion detection and characterization in optic nerve conditions.

Pleomorphic xanthoastrocytoma with CT and MRI appearance of meningioma.

We describe a pleomorphic xanthoastrocytoma (PXA) in a young girls whose frontal lobe location, solid structure, dural tail and MRI signal characteristics led to a preoperative diagnosis of meningioma. PXA should be considered in differential diagnosis of tumours affecting young patients with neuroradiological characteristics suggestive of meningioma.

The role of MRI in dementia.

Neuroimaging techniques aimed at studying structural changes of the brain may provide useful information for the diagnosis and the clinical management of patients with dementia. Magnetic resonance imaging (MRI) may show abnormalities amenable to surgical treatment in a significant percentage of patients with cognitive impairment. MRI may also assist the differential diagnosis in dementia associated with metabolic or inflammatory diseases.MRI has the potential to detect focal signal abnormalities which may assist the clinical differentiation between Alzheimer's disease (AD) and vascular dementia (VaD). Severe temporal atrophy, hyperintensities involving the hippocampal or insular cortex, and gyral hypointense bands are more frequently noted in AD. Basal ganglionic/thalamic hyperintense foci, thromboembolic infarctions, confluent white matter and irregular periventricular hyperintensities are more common in VaD. The high sensitivity of MRI in detecting T2 hyperintense lesions and the low specificity off white matter lesions have resulted in a poor correlation between MRI findings and both neuropathological and clinical manifestations. In particular, MRI has disclosed a series of white matter focal changes in the elderly population, which are not necessarily associated with cognitive dysfunction. The recent advent of a new MRI method sensitive to the microstructural changes of white matter, the so-called diffusion tensor imaging, may be helpful in correlating clinical manifestations with white matter abnormalities.