Each patient partially preserved restricted sensory representations, as evidenced by slow evoked magnetic fields and gamma band activity. In two patients, these activations correlate with isolated behavioral patterns and metabolic activity. Remaining active regions identified in the three PVS patients with behavioral fragments appear to consist of segregated corticothalamic networks that retain connectivity and partial functional integrity. A single patient who sustained severe injury to the tegmental mesencephalon and paramedian thalamus showed widely preserved cortical metabolism, and a global average metabolic rate of 65% of normal. The relatively high preservation of cortical metabolism in this patient defines the first functional correlate of clinical–pathological reports associating permanent unconsciousness with structural damage to these regions. The specific patterns of preserved metabolic activity identified in these patients reflect novel evidence of the modular nature of individual functional networks that underlie conscious brain function. The variations in cerebral metabolism in chronic PVS patients indicate that some cerebral regions can retain partial function in catastrophically injured brains. Misdiagnoses
Statistical PVS misdiagnosis is common. An example study with 40 patients in the United Kingdom reported 43% of their patients classified as PVS were believed so and another 33% had recovered whilst the study was underway. Some PVS cases may actually be a misdiagnosis of patients being in an undiagnosed minimally conscious state. Since the exact diagnostic criteria of the minimally conscious state were only formulated in 2002, there may be chronic patients diagnosed as PVS before the secondary notion of the minimally conscious state became known.
New world arena viruses are further broken down into three clades, A, B, and C. The Guanarito arena virus belongs to clade B and is the cause of VHF. On the biosafety level scale of one to four, with four causing the most risk, the viruses causing hemorrhagic fevers have been assigned a four by the CDC. Host
The short-tailed cane mouse, the main host of GTOV, is native to western Venezuela and resides in large numbers in tall grass, cultivated agricultural fields, human homes, and outbuildings. It is speculated that demographic and ecological changes in the rural areas increased the frequency of contact between humans and infected rodents such that VHF emerged. History
From September 1989 through December 2006, the State of Portuguesa recorded 618 cases of VHF. Nearly all of the cases were individuals who worked or lived in Guanarito during the time they became infected. The case fatality rate was 23.1%.Because the virus is contracted by aerosol dissemination, concern arose shortly after the first cases emerged in 1989 due to fear of biological warfare. Potential biological terrorism agents were identified and categorized in 1999 by the Centers for Disease Control and Prevention (CDC) as part of the Congressional initiative to further response capabilities to biological weapons. Arenaviruses causing hemorrhagic fevers, along with a genus of virus called filoviruses, were categorized in Category A; these are pathogens with the highest potential impact on public health safety.