Effects of Deliberate Ingestion of Organophosphate or Paraquat on Brain Stem Auditory-Evoked Potentials

Organophosphate (OP) and paraquat (PQ) ingestion is a serious health problem. A common pathology behind OP or PQ poisoning is the generation of reactive oxygen species (ROS) which is known to cause ototoxicity. The aim of the study was to identify the effects of deliberate ingestion of OP or PQ on brain stem auditory-evoked potentials (BAEPs). Consecutive patients with deliberate self-poisoning with OP or PQ who were admitted to a secondary and a tertiary care hospital in the Southern province of Sri Lanka and matched controls were recruited. BAEPs were performed at 1 week (first assessment) and 6 weeks (second assessment) after the exposure. Interpeak latencies of I–III, III–V, and I–V were measured. There were 70 and 28 patients in the OP and PQ arms with the mean age of 32 ± 12 and 29 ± 12 years, respectively. There were 70 controls and their mean age was 33 ± 12 years. In OP and PQ poisoning, 53/70 and 18/28 came for the second assessment, respectively. The interpeak latency was not statistically different in the controls vs the first assessment, controls vs the second assessment, and the first vs the second assessment. There were no significant lesions in the auditory pathway in OP or PQ poisoned patients. The generation of ROS within the perilymphatic space following the ingestion of OP or PQ may not be sufficient to cause lesions in the auditory pathway. Further studies with the assessment of auditory threshold are needed

Identifying a Window of Vulnerability during Fetal Development in a Maternal Iron Restriction Model

It is well acknowledged from observations in humans that iron deficiency during pregnancy can be associated with a number of developmental problems in the newborn and developing child. Due to the obvious limitations of human studies, the stage during gestation at which maternal iron deficiency causes an apparent impairment in the offspring remains elusive. In order to begin to understand the time window(s) during pregnancy that is/are especially susceptible to suboptimal iron levels, which may result in negative effects on the development of the fetus, we developed a rat model in which we were able to manipulate and monitor the dietary iron intake during specific stages of pregnancy and analyzed the developing fetuses. We established four different dietary-feeding protocols that were designed to render the fetuses iron deficient at different gestational stages. Based on a functional analysis that employed Auditory Brainstem Response measurements, we found that maternal iron restriction initiated prior to conception and during the first trimester were associated with profound changes in the developing fetus compared to iron restriction initiated later in pregnancy. We also showed that the presence of iron deficiency anemia, low body weight, and changes in core body temperature were not defining factors in the establishment of neural impairment in the rodent offspring

Afasia global sem hemiparesia: relato de caso Global aphasia without hemiparesis: case report

Afasia global geralmente é acompanhada por hemiparesia direita devido à extensão da lesão subjacente. Recentemente têm sido registrados na literatura casos em que tal síndrome ou não se acompanha do déficit motor ou este é apenas transitório, sendo esta condição conhecida como afasia global sem hemiparesia (AGSH). Relatamos caso de AGSH devido a infarto cerebral embólico cardiogênico, corroborando a tese de que esta condição pode ter valor preditivo para o diagnóstico de infartos embólicos.<br>Symptoms and signs of a stroke indicate which areas of the brain are affected and may also suggest the pathophysiology. We report herein a case of global aphasia without hemiparesis due to embolic infarct. Our case suggests that this situation may be an important sign for embolic cerebral infarction, as reported in literature