The first historically documented pandemic caused by Yersinia pestis began as the Justinianic Plague in 541 within the Roman Empire and continued as the so-called First Pandemic until 750. Although paleogenomic studies have previously identified the causative agent as Y. pestis, little is known about the bacterium’s spread, diversity, and genetic history over the course of the pandemic. To elucidate the microevolution of the bacterium during this time period, we screened human remains from 21 sites in Austria, Britain, Germany, France, and Spain for Y. pestis DNA and reconstructed eight genomes. We present a methodological approach assessing single-nucleotide polymorphisms (SNPs) in ancient bacterial genomes, facilitating qualitative analyses of low coverage genomes from a metagenomic background. Phylogenetic analysis on the eight reconstructed genomes reveals the existence of previously undocumented Y. pestis diversity during the sixth to eighth centuries, and provides evidence for the presence of multiple distinct Y. pestis strains in Europe. We offer genetic evidence for the presence of the Justinianic Plague in the British Isles, previously only hypothesized from ambiguous documentary accounts, as well as the parallel occurrence of multiple derived strains in central and southern France, Spain, and southern Germany. Four of the reported strains form a polytomy similar to others seen across the Y. pestis phylogeny, associated with the Second and Third Pandemics. We identified a deletion of a 45-kb genomic region in the most recent First Pandemic strains affecting two virulence factors, intriguingly overlapping with a deletion found in 17th- to 18th-century genomes of the Second Pandemic.

Focal cortical disturbances are frequent sequelae in West syndrome (WS) even though it is a generalized epileptic syndrome. Functional neuroimaging was used to determine whether focal perfusion abnormalities exist at WS onset and change during evolution. We studied regional cerebral blood flow (rCBF) at different stages of WS. Mean CBF (mCBF) and rCBF were measured using SPECT (single photon emission computed tomography) and 133Xe in 13 WS patients: at onset (20 cases), just after steroids (17 cases), and after a mean follow-up of 2 years (26 cases). At WS onset, interictal mCBF was increased as the result of foci of hyper- and hypoperfusion, which were, respectively, mainly located in the frontal and posterior cortex. Just after steroid therapy, mCBF decreased without any focal predominance. During follow-up, hypoperfused foci remained unchanged whereas the frontal hyperperfused foci decreased after spasm control. Our results show that focal abnormalities are present at WS onset. Focal hypoactivity could reflect a cortical lesion responsible for WS and focal hyperactivity could play a role in the persistence of generalized epilepsy.

Visual behavior is frequently impaired at onset of West syndrome (WS). We studied the neuropsychological outcome of eight children who had cryptogenic WS and moderate to severe visual impairment at the onset of epilepsy. At the last examination, a regional cerebral blood flow study using SPECT (single photon emission computed tomography) was performed. The behavior abnormalities observed initially evolved to various defects of cognitive function. Three patients had severe mental retardation with autistic features. Two had marked speech disorders but one had global cognitive impairment. Three patients had specific visual-spatial deficits. SPECT showed perfusion defects involving the parieto-occipital areas in 6 of 8 patients. These abnormalities were restricted to parieto-occipital regions in the three patients with selective visual-spatial deficits, whereas they were associated with other perfusion defects in the three remaining patients. This study demonstrates that the visual inattention observed at the onset of WS is frequently associated with long-term cognitive and/or perfusion defects involving the parieto-occipital regions.

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