Proton magnetic resonance spectroscopy in deep cerebral venous thrombosis

Magnetic Resonance Spectroscopy Findings in Patients with Dural Arteriovenous Fistulas: Three Case Reports

BACKGROUND

Magnetic resonance spectroscopy (MRS) is a potentially useful modality for evaluating brain metabolites in patients with dural arteriovenous fistula (dAVF). Here we describe a different pattern of MRS-based cerebral metabolism findings in patients with dAVF.

CASE DESCRIPTIONS

We performed MRS in 3 patients with transverse sigmoid sinus dAVF associated with cortical venous reflux. In case 1, which was associated with vasogenic edema on T2-weighted magnetic resonance imaging (MRI), decreased preoperative N-acetylaspartate (NAA)/creatine (Cr) and myo-inositol (mIns)/Cr and increased lactate (Lac)/Cr ratios improved after treatment. In case 2, a decreased preoperative NAA/Cr ratio improved after treatment. These 2 patients presented with seizures. In case 3, the patient presented with headache and showed no metabolic changes on preoperative or postoperative MRS.

CONCLUSIONS

Our results suggest that patients with dAVF can be classified based on a combination of metabolic and signal changes seen on T2-weighted MRI. MRS may allow significantly expanded evaluation of the metabolic changes associated with dAVF for appropriate classification and management.

Deep Cerebral Venous Thrombosis: An Illustrative Case with Reversible Diencephalic Dysfunction

Objectives:

Meige syndrome is a movement disorder that includes blepharospasm and oromandibular dystonias. Its etiology may be idiopathic (primary) or it may arise secondary to focal brain injury. Acute respiratory distress as a feature of such dystonias occurs infrequently. A review of the literature on Meige syndrome and the relationship between dystonias and respiratory compromise is presented.

Methods:

A 60-year-old woman suffered a cerebral anoxic event secondary to manual strangulation. She developed progressive blepharospasm combined with oromandibular and cervical dystonias. Neuroimaging demonstrated bilateral damage localized to the globus pallidus. Years later, she presented to the emergency department in intermittent respiratory distress associated with facial and cervical muscle spasms.

Results and conclusions:

Increasing frequency and severity of the disorder was noted over years. The acute onset of respiratory involvement required intubation and eventual tracheotomy. A partial therapeutic benefit of tetrabenazine was demonstrated.

Reversible Cerebral Metabolism Changes Using Proton Magnetic Resonance Spectroscopy in a Patient with Intracranial Dural Arteriovenous Fistula: A Case Report

BACKGROUND

Cerebral metabolism can be disrupted by venous congestion in patients with intracranial dural arteriovenous fistula (DAVF), which may lead to adverse neurological outcomes. However, there are no clear indicators to guide cerebral evaluation and treatment selection in cases of DAVF. We describe a patient with a DAVF whose proton magnetic resonance spectroscopy ((1)H-MRS) findings were associated with improvements in clinical status.

CASE DESCRIPTION

An elderly woman with a history of myocardial infarction presented with progressive dementia, aphasia, and a severe headache. We detected a transverse-sigmoid sinus DAVF, as well as abnormal levels of lactate and N-acetylaspartic acid (NAA) in the (1)H-MRS, and successfully treated the patient using surgical sinus skeletonization. However, follow-up (1)H-MRS revealed inconsistent reversals in the levels of lactate and NAA. In addition, we calculated the NAA/creatinine ratios from before and after surgery, which revealed postoperative increases in the ratios for the left temporal, right parietal, and left parietal regions. These increases occurred concurrently with improvements in the patient's cognitive function.

CONCLUSIONS

(1)H-MRS may be useful for pretreatment detection of increased lactate levels, decreased NAA levels, and/or decreased NAA/creatinine ratios. These findings may indicate poorer cerebral metabolism, and show a need for more aggressive treatment. Furthermore, (1)H-MRS may be useful for evaluating the effect of conservative treatment and for indicating conversion to a more aggressive treatment.

Hippocampal modifications in transient global amnesia

Transient global amnesia (TGA) is an acute and transient syndrome with a remarkably stereotypical set of signs and symptoms. It is characterized by the abrupt onset (no forewarning) of massive episodic memory impairment, both anterograde and retrograde. Ever since it was first described, TGA has fascinated neurologists and other memory experts, and in recent years, there has been a surge of neuroimaging studies seeking to pin down the brain dysfunction responsible for it. Several pathophysiological hypotheses have been put forward, including the short-lived suggestion of an epileptic mechanism. All the available data indicate that the brain modifications are reversible, and that the mechanism behind TGA is of a functional nature. However, while diffusion-weighted imaging studies have clearly identified the hippocampus and, more specifically, the CA1 area, as the locus of brain modifications associated with TGA, researchers have yet to determine whether the origin of the mechanism is vascular or neurochemical. Spectroscopy may provide a means of settling this issue once and for all.

Neonatal deep white matter venous infarction and liquefaction: a pseudo-abscess lesion

BACKGROUND

Deep white matter hemorrhagic venous infarction with subsequent cavitation due to necrosis and liquefaction has been described in neonates and may be associated with infection and meningitis. In our experience, the MRI pattern of these lesions is confused with the pattern seen with cerebral abscesses.

OBJECTIVE

The purpose of our study was to characterize the MRI findings of post infarction necrosis and liquefaction after hemorrhagic deep white matter venous infarction in infants and to distinguish these lesions from cerebral abscesses.

MATERIALS AND METHODS

An institutional review board approved a retrospective review of imaging records to identify all patients with cerebral venous infarction at a children's hospital during a 10-year period. Nine infants had deep white matter hemorrhagic venous infarction with white matter fluid signal cavitary lesions. A diagnosis of cerebral abscess was considered in all. The imaging and laboratory findings in these patients are reviewed and compared to descriptions of abscesses found in the literature.

RESULTS

There were six female and three male infants. The mean age at presentation was 20 days (range: 0-90 days), while the corrected age at presentation was less than 30 days for all patients. Seven patients presented with seizures and signs of infection; one infant presented with lethargy and later proved to have protein C deficiency. MRI was performed 0-12 days from presentation in these eight patients. Another patient with known protein C deficiency underwent MRI at 30 days for follow-up of screening US abnormalities. There were a total of 38 deep cerebral white matter fluid signal cavitary lesions: 25 frontal, 9 parietal, 2 temporal, 2 occipital. Larger lesions had dependent debris. All lesions had associated hemorrhage and many lesions had evidence of adjacent small vessel venous thrombosis. Lesions imaged after gadolinium showed peripheral enhancement. Three lesions increased in size on follow-up imaging. Three patients, two with meningitis confirmed via microbiology and one with presumed meningitis by CSF counts, underwent surgical aspiration of a total of six lesions. All specimens were sent for pathology and culture and were negative for microorganisms.

CONCLUSION

Recognizing the MR appearance of cavitary necrosis and liquefaction after deep white matter cerebral venous infarction in neonates can distinguish this entity from cerebral abscess and potentially avoid an unnecessary neurosurgical aspiration procedure.

Diagnosis and management of cerebral venous thrombosis: a statement for healthcare professionals from the American Heart Association/American Stroke Association

BACKGROUND

The purpose of this statement is to provide an overview of cerebral venous sinus thrombosis and to provide recommendations for its diagnosis, management, and treatment. The intended audience is physicians and other healthcare providers who are responsible for the diagnosis and management of patients with cerebral venous sinus thrombosis.

METHODS AND RESULTS

Members of the panel were appointed by the American Heart Association Stroke Council's Scientific Statement Oversight Committee and represent different areas of expertise. The panel reviewed the relevant literature with an emphasis on reports published since 1966 and used the American Heart Association levels-of-evidence grading algorithm to rate the evidence and to make recommendations. After approval of the statement by the panel, it underwent peer review and approval by the American Heart Association Science Advisory and Coordinating Committee.

CONCLUSIONS

Evidence-based recommendations are provided for the diagnosis, management, and prevention of recurrence of cerebral venous thrombosis. Recommendations on the evaluation and management of cerebral venous thrombosis during pregnancy and in the pediatric population are provided. Considerations for the management of clinical complications (seizures, hydrocephalus, intracranial hypertension, and neurological deterioration) are also summarized. An algorithm for diagnosis and management of patients with cerebral venous sinus thrombosis is described.

Imaging of cerebral venous thrombosis: current techniques, spectrum of findings, and diagnostic pitfalls

Cerebral venous thrombosis is a relatively uncommon but serious neurologic disorder that is potentially reversible with prompt diagnosis and appropriate medical care. Because the possible causal factors and clinical manifestations of this disorder are many and varied, imaging plays a primary role in the diagnosis. Magnetic resonance (MR) imaging, un-enhanced computed tomography (CT), unenhanced time-of-flight MR venography, and contrast material-enhanced MR venography and CT venography are particularly useful techniques for detecting cerebral venous and brain parenchymal changes that may be related to thrombosis. To achieve an accurate diagnosis, it is important to have a detailed knowledge of the normal venous anatomy and variants, the spectrum of findings (venous sinus thrombi and recanalization, parenchymal diffusion or perfusion changes or hemorrhage), other potentially relevant conditions (deep venous occlusion, isolated cortical venous thrombosis, idiopathic intracranial hypertension), and potential pitfalls in image interpretation.

Thrombose veineuse cerebrale profonde : à propos de deux observations

We report two cases of cerebral deep venous thrombosis in female adults. The first patient presented with headaches and confusion 20 days postpartum. Deep cerebral internal venous thrombosis was suspected based on the CT scan showing bilateral hypodensity in the thalamus and internal capsules. The diagnosis was confirmed on cerebral angiography. The patient was treated but died within 3 weeks of the onset of symptoms. The second patient had no obvious predisposing factors. She presented with confusion and fever. The diagnosis was strongly suggested by the CT scan, which showed spontaneous high density in the deep venous system associated with bilateral hypodensities in the thalamus and internal capsules. Venous MR angiography revealed obliteration of internal cerebral veins and the great vein of Galen. Ten days after appropriate therapy, the patient recovered completely.

Cerebral Venous Thrombosis

Cerebral venous thrombosis is a rare disorder with highly variable and nonspecific clinical presentations. For these reasons, specific treatment should be given only when the diagnosis has been firmly established. Etiologic diagnosis should begin in the emergency department to identify underlying conditions that require specific treatment. The mainstay of treatment is anticoagulation with heparin, even in the case of cerebral hemorrhage, followed as soon as possible by oral anticoagulant administration. The optimal duration of oral anticoagulation has not been established. By analogy with systemic venous thrombosis, it should be prolonged 3 to 6 months. When a high risk of recurrence is present, treatment should be continued until the risk disappears. In contrast to arterial stroke, complete recovery of prolonged or severe neurologic deficit is possible, justifying initiation of anticoagulation even when the clinical situation seems desperate. For the same reason, aggressive treatment of intracranial hypertension and seizures or status epilepticus is warranted. Screening for extraneurologic venous thrombosis should be done by means of clinical examination and, if necessary, specific imaging procedures. Local thrombolysis is not yet of proven efficacy and safety. It can be used in patients with clinical worsening related to documented extension of the venous thrombosis despite anticoagulation and in the absence of cerebral hematoma. Surgical treatment is limited to external ventricular drainage and suboccipital craniotomy in the very rare cases of cerebellar vein thrombosis with edematous cerebellar infarct.

Diffusion- and perfusion-weighted magnetic resonance imaging in deep cerebral venous thrombosis

BACKGROUND

Diffusion-weighted (DWI) and perfusion-weighted (PI) MRI are highly sensitive techniques for early diagnosis of arterial infarction, but little data on venous cerebral ischemia are available. We describe a case in which DWI, PI, and fast T2-weighted sequences were performed in the acute phase of deep cerebral venous thrombosis (CVT).

CASE DESCRIPTION

An 11-year-old girl with Crohn's disease developed deep CVT in which extensive edema was shown in the deep gray matter on T2-weighted sequence images. Isotropic echo-planar DWI demonstrated a local augmentation of the apparent diffusion coefficient (1.1 to 1.6x10(-3) mm2/s), consistent with vasogenic edema. In dynamic contrast-enhanced PI, the regional cerebral blood volume was increased and the passage time of the contrast bolus was markedly prolonged. Clinically, the patient recovered totally after intravenous full-dose heparinization. T2 abnormalities, apparent diffusion coefficient values (0.8 to 0.92x10(-3) mm2/s), and brain perfusion alterations resolved without damage to brain tissue.

CONCLUSIONS

Unlike arterial infarction, DWI demonstrated vasogenic edema in a patient with deep CVT, which proved to be reversible in follow-up magnetic resonance imaging. PI showed areas with extensive venous congestion, but perfusion deficits were missing. Therefore, we believe that DWI and PI may play a role in detecting venous congestion in CVT and in prospective differentiation of vasogenic edema and venous infarction.

Diffusion-weighted magnetic resonance imaging in a case of cerebral venous thrombosis

BACKGROUND

Diffusion-weighted imaging (DWI) is the most sensitive MR sequence in acute arterial ischemic stroke but has not yet been evaluated in venous cerebral ischemia. We describe a patient with DWI performed at the acute phase of a venous ischemic stroke.

CASE DESCRIPTION

A rapid cerebral MRI including DWI and fast fluid-attenuated inversion recovery (FLAIR) sequences was performed at the acute phase of a venous stroke confirmed by conventional angiography. DWI showed a slight decrease in apparent diffusion coefficient values 3 hours after onset (0.53+/-0.07x10(-3) mm2/s) and was normal 48 hours later (0.064+/-0.15x10(-3) mm2/s). Fast FLAIR sequences showed large left frontoparietal hyperintensities. The lack of a clear decrease in apparent diffusion coefficient values associated with marked FLAIR abnormalities may suggest prominent or early associated vasogenic edema. Physiopathological differences between arterial and venous ischemia may explain the different type of DWI FLAIR abnormalities during the acute phase as well as the better recovery of neurological deficit in venous stroke than in arterial ischemic stroke.

CONCLUSIONS

In the context of an acute stroke, the contrast between marked FLAIR and subtle DWI abnormalities on MRI may reflect the venous mechanism of cerebral ischemia.