Summary:Purpose: In temporal lobe epilepsy, it remains to be clarified whether hippocampal sclerosis is the cause or the consequence of epilepsy. We studied the temporal evolution of the lesions in the lithium-pilocarpine model of epilepsy in the rat with magnetic resonance imaging (MRI) to determine the progressive morphologic changes occurring before the appearance of chronic epilepsy.Methods: MRI was performed on an MR scanner operating at 4.7 T. We followed the evolution of lesions using T 2 -and T 1 -weighted sequences before and after the injection of gadolinium from 2 h to 9 weeks.Results: At 2 h after status epilepticus (SE), a blood-brain barrier breakdown could be observed only in the thalamus; it had disappeared by 6 h. At 24 h after SE, edema was present in the amygdala and the piriform and entorhinal cortices together with extensive neuronal loss; it disappeared progressively over a 5-day period. During the chronic phase, a cortical signal reappeared in all animals; this signal corresponded to gliosis, which appeared on glial fibrillary acidic protein (GFAP) immunohistochemically stained sections as hypertrophic astrocytes with thickened processes. In the hippocampus, the correlation between histopathology and T 2 -weighted signal underscored the progressive constitution of atrophy and sclerosis, starting 2 days after SE.Conclusions: These data show the reactivity of the cortex that characterizes the initial step leading to the development of epilepsy and the late gliosis that could result from the spontaneous seizures. Moreover, it appears that hippocampal sclerosis progressively worsened and could be both the cause and the consequence of epileptic activity.

We conducted a French multicentric cross-sectional study to describe in detail the demographic, neurological and behavioural characteristics of the frontal variant of frontotemporal dementia (fvFTD) and to characterize the pattern of brain perfusion SPECT in comparison to a healthy control group. A total of 68 fvFTD patients had technetium-99m-ECD brain perfusion SPECT at inclusion, 61 of which also underwent an in-depth evaluation including 70 items assessing behaviour, language and affect/emotion at onset and at inclusion. The mean age-at-onset was 60.4 +/- 7.8 years (35-75). Twenty-six per cent of the patients were older than 65 at onset. A positive familial history consistent with an autosomal dominant inheritance was found in 18% of the patients. At onset, the behavioural profile was predominantly inert in 25% of the patients, disinhibited in 18% and mixed in others. The behavioural features progressed to predominantly mixed or inert forms. Although, inertia was associated with predominant medial frontal and cingulate hypoperfusion, and patients with disinhibition exhibited predominant ventromedial prefrontal and temporal hypoperfusion, there were no major clinical differences between disinhibited and inert patients. Forty-five per cent of the deceased patients survived <6 years (short survival), and 34% of the patients survived >8 years (long survival). This shows that the final outcome of fvFTD is highly variable. No clinical factors predictive of short or long survival were identified. Unexpected, however, was the finding that brainstem hypoperfusion distinguished patients with a short survival from patients with long survival. In conclusion, this study shows that fvFTD is clinically a rather homogeneous entity. It also provides evidence that different behavioural presentations at onset are related to different anatomical localizations of degenerative damage. Finally, it demonstrates the prognostic value of brainstem hypoperfusion in a subgroup of patients with a short survival.

SUMMARY:CS is an autosomal recessive multisystem disorder, which is mainly characterized by neurologic and sensory impairment, cachectic dwarfism, and photosensitivity. We describe the neuroimaging features (MR imaging, 1 H-MR spectroscopy, and CT) in the various clinical subtypes of CS from a cohort of genetically and biochemically proved cases. Hypomyelination, calcifications, and brain atrophy were the main imaging features. Calcifications were typically found in the putamen and less often in the cortex and dentate nuclei. Severe progressive atrophy was seen in the supratentorial white matter, the cerebellum, the corpus callosum, and the brain stem. Patients with early-onset disease displayed more severe hypomyelination and prominent calcifications in the sulcal depth of the cerebral cortex, but atrophy was less severe in late-onset patients. On proton MR spectroscopy, lactate was detected and Cho and NAA values were decreased. These combined neuroradiologic findings can help in the differential diagnosis of CS, distinguishing it from other leukoencephalopathies and/or cerebral calcifications in childhood., ABBREVIATIONS: Cho ϭ choline; Cr ϭ creatine; CS ϭ Cockayne syndrome; COFS ϭ cerebro-oculofacio-skeletal syndrome; FLAIR ϭ fluid-attenuated inversion recovery; NAA ϭ N-acetylaspartate

No abstract