Role of the supplementary motor area in motor deficit following medial frontal lobe surgery.

Objective: Patients undergoing surgical resection of medial frontal lesions may present a transient postoperative deficit that remains largely unpredictable. The authors studied the role of the supplementary motor area (SMA) in the occurrence of this deficit using fMRI.

Methods: Twenty-three patients underwent a preoperative fMRI before resection of medial frontal lesions.

Carotid artery stenosis: prospective comparison of CT, three-dimensional gadolinium-enhanced MR, and conventional angiography.

Purpose: To prospectively compare gadolinium-enhanced magnetic resonance (MR) angiography and computed tomographic (CT) angiography with digital subtraction angiography (DSA) for use in detecting atheromatous stenosis and plaque morphology at the carotid bifurcation.

Materials And Methods: Forty-four carotid arteries (in 22 patients) were analyzed by using CT angiography, enhanced MR angiography, and DSA. CT and enhanced MR angiograms were reconstructed with maximum intensity projection and multiplanar volume reconstruction.

Can diffusion weighted magnetic resonance imaging help differentiate stroke from stroke-like events in MELAS?

The precise mechanism of neurological symptoms in patients with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) is still controversial. The diffusion weighted MR findings at the acute phase of a neurological event in MELAS are described and the pathophysiology of stroke-like lesion in the light of diffusion changes is discussed. Brain MRI was performed 2 days after the sudden onset of cortical blindness in a 25 year old patient with MELAS.

Magnetic resonance-guided stereotactic biopsies: results in 100 consecutive cases.

Background: We present the results of 100 consecutive magnetic resonance (MR)-guided biopsies in cases where computerised tomography (CT) guiding was considered dangerous or impossible.

Method: MR guiding was preferred to CT guiding for cases where lesions were located in the central area, or were not clearly visible on CT scan, or where the visualization of vessels was considered necessary. For most of the patients, calculation of target co-ordinates was performed using dedicated software enabling trajectory previsualization.

[The value of MRI for the diagnosis of meningeal hemorrhage during vasospasm].

Retrospectively, subarachnoidal hemorrhage can be misdiagnosed when the acute event did not bring the patient to medical attention, when clinical history is unclear and the CT scan is normal. Moreover, days after subarachnoid hemorrhage, cerebral vasospasm can result in neurological deficits that are indistinguishable from that produced by other causes of stroke. We report our experience with two patients who presented with symptoms of ischemia due to an arterial vasospasm that followed unrecognized rupture of an intracranial aneurysm.