European Federation of Neurological Societies
Philip Scheltens, MD, PhD
At this year's European
Federation of Neurological Societies (EFNS) meeting (the 5th congress),
only 1 session, a workshop led by Jean Claude Baron, was dedicated solely
to neuroimaging. This could reflect either the European view that imaging
is performed uniquely by radiologists or a different focus of interest
on the part of this year's program committee.
Research into dementia was likewise relatively underrepresented this year. Nonetheless, there were several bright spots among the workshops and symposia.
Two industry-supported sessions were among the exceptions: an excellent teaching course on dementia was organized by Jean Marc Orgogozo, from Bordeaux, France, in which Martin Rossor, from London, United Kingdom, gave an overview of the imaging options in dementia diagnosis and follow up; and a satellite symposium was held, at which participants discussed the role of the neurologist in dementia, including the contributions that registration and functional MRI (fMRI) offer to longitudinal follow up and for assessing treatment effects (see also Imaging Alzheimer's Disease). A teaching course on new imaging methods would have been timely. In the regular scientific program, one had to look carefully to find presentations that focused on imaging.
Amyotropic Lateral Sclerosis
On Monday, Dr. Karlsborg and colleagues, from Copenhagen, Denmark, presented data on diffusion tensor MRI in patients with amyotropic lateral sclerosis (ALS). Only patients with definite upper motor neuron signs displayed elevated diffusion coefficients, which did not change during follow up, and probably reflected neuronal degeneration of the corticospinal tract that occurs in the cerebrum of patients with ALS. This finding, in itself, is an interesting observation that was corroborated by Hecht and colleagues, from Erlangen, Germany, who showed changes of this tract on Fluid-attenuated inversion-recovery (FLAIR) images. Unfortunately, the Danish study involved small groups and did not apply the El Escorial ALS criteria.
In a focused workshop, Dr. Kappos, from Basel, Switzerland, gave an overview of the enormous advances being made by MRI in measuring treatment effects in multiple sclerosis (MS). Particularly promising are the new measures of T1 black holes, magnetization transfer, and spectroscopy, which all seem to have a good correlation with the actual pathologic process in the brain.
Kappos also chaired a poster session on MS at which Dr. Filippi, from Milan, Italy, presented new data on the use of fMRI of the central motor system. He and collaborators from Milan and Munich employed 3 paradigms (flexion/extension of the right hand and/or foot) to study 9 patients with progressive MS. All 3 tasks produced ipsilateral cerebellar activation, but only stimulated contralateral primary motor activation in the hand task and both hand/foot tasks, but not in the foot-only task. These investigators concluded that this absence was evidence of the plasticity of the cortical pathways responsible for the foot movements.
An important clue for the diagnosis of some patients with MS are the T2 lesions present at the onset of optic neuritis (ON). Frederiksen and colleagues, from Copenhagen, Denmark, found them to be present in 79% of ON patients who were later diagnosed with MS. They studied whether gadolinium administration could increase the sensitivity of MRI. However, they found enhancing lesions in only 5% of the patients with ON who did not progress to MS as opposed to 21% of the ON patients who were eventually diagnosed with MS.
At a Main Topic lecture, Filippi pointed out that, when using the newer techniques, pathologic heterogeneity in MS lesions is reflected by different MRI patterns. In particular, the normal-appearing white matter (NAWM) that surrounds the lesions deserves further attention in this respect. In primary progressive MS, microscopic lesions in brain and spinal cord NAWM may be responsible for the disability. This suggestion was further corroborated by Parry and coworkers, from Oxford, United Kingdom, in a short communication on Wednesday. They showed that T1 maps of the total white matter on a 3T scanner in patients with MS correlated very well with disability as measured by the Expanded Disability Status Scale (r = 0.92, P = .01).
The most surprising presentation, in my view, came from Scheuer and colleagues, in Copenhagen, Denmark, who used PET and found lower regional cerebral blood flow values in the parietal and frontal areas of patients with autosomal dominant hereditary spastic paraplegia (Strumpell's disease), a disease thought to be present uniquely in the spinal cord, as compared with controls. These findings may indicate supraspinal (cerebral) involvement in these patients.
In the field of dementia, Hasselbalch and collaborators, from Copenhagen, Denmark, presented data on neuroimaging studies performed on all patients between 1995 and 1999 in their Memory Clinic. Potentially reversible pathologies were found in 3.7% of the sample (n = 704), a figure higher than usually reported. In one third of the patients, they found cerebrovascular pathology relevant to the diagnosis, underscoring the need for imaging studies in such a setting.
The remainder of
the presentations associated with imaging were either too poor in quality
or not new in the sense that they were worth reporting here. I sincerely
hope that future EFNS and other neurology meetings will focus more on imaging,
given the huge interest from clinical practice and research and the rapid
developments in this field.