Supranormal electroretinogram in a 10-year-old girl with lead toxicity.

PURPOSE: To report a case of lead exposure in a 10-year-old girl which resulted in a supranormal ERG and clinical findings of decreased visual acuity, color vision, and stereopsis. METHOD: Case report. RESULTS: A 10-year-old girl was exposed to unknown levels of lead, with peak recorded blood levels of 19 mcg/dl 5 years prior to presentation. Lead levels had since normalized. Uncorrected visual acuity was 20/200-OU, improving to 20/80-OU with a refractive correction of +1.50 + 0.75 x 90 degrees OD, +2.50 sphere OS. Color vision was tested with Ishihara plates, and appeared markedly impaired. Stereopsis was grossly impaired, as the patient could not perceive stereoscopic depth with the Titmus "fly" target. Her cognitive function appeared to be slowed and her reaction time also delayed. ERG waveforms were supranormal under photopic and scotopic conditions. Implicit times were normal. CONCLUSION: Lead toxicity with significant visual and cognitive dysfunction, and supranormal ERG, can persist at lead levels below those recognized for lead poisoning.

Negative allesthesia and decreased endogenous opiate system activity in anorexia nervosa.

The combined effects of an intragastric load of glucose compared to water and of naltrexone compared to placebo were tested on preference for sucrose in six anorectic patients. While in normal subjects, glucose-induced negative allesthesia is known to disappear upon loss of weight, it persisted in anorexia nervosa (AN) despite a major weight loss; furthermore, in contrast with its effects in normoponderal subjects, naltrexone at the dose of 25 mg did not decrease the preference for sucrose nor did it enhance glucose-induced allesthesia. Basal plasma beta endorphin level determined by radioimmunoassay was higher in AN than in normal subjects (75 +/- 6.1 pmoles/l vs. 13 +/- 3.8 pmoles/l) (p less than 0.001). It is suggested that a decrease in endogenous system opiate activity might be associated with food refusal and body weight loss in anorexia nervosa.

Plasma cholesterol levels and Irlen syndrome: preliminary study of 10- to 17-yr.-old students.

The preliminary study investigated metabolic anomalies in children and teenagers with Irlen Syndrome, particularly in relation to the levels of n-3 and n-6 essential fatty acids, plasma cholesterol levels, and the relative abundance of plasma saturated fatty acids. The experimental group involved 13 subjects with Irlen Syndrome (M=13.3 yr., SD=2.5 yr.), with a comparison group of 16 age- and sex-matched controls (M=13.8 yr., SD=2.4 yr.). The Irlen Syndrome group were selected from people referred for help with reading and writing problems. The control group were primarily recruited from the general public. All subjects were screened for symptoms of the syndrome using the Scotopic Sensitivity Syndrome Screening Manual. Samples of whole blood were collected and plasma extracted. Metabolites were compared using the Student t test. There were no differences in n-3 and n-6 essential fatty acids between Irlen Syndrome and control groups, although the former group had lower mean levels in most of these essential fatty acids. Total plasma cholesterol level was significantly decreased for the Irlen Syndrome group, and there was a significant increase in the relative abundance of the odd-chain fatty acid, heptadecanoic acid. The differences in heptadecanoic acid may have implications for altered membrane function and neurotransmission. The differences in plasma cholesterol levels, as well as heptadecanoic acid, may also point to the presence of viral or bacterial infection.

Low haemoglobin levels increase unilateral spatial neglect in acute phase of stroke.

OBJECTIVE: The objective of this study was to evaluate the relationship between unilateral spatial neglect (USN) and haemoglobin (Hb) level in acute phase of stroke. METHOD: Cross-sectional study was performed after right hemisphere ischemic stroke. INDEPENDENT VARIABLE: Hb level (mg/dL); OUTCOME: USN; Potential confounding factors: Age, National Institutes of Health Stroke Scale (NIHSS), and glycaemia (mg/dL); Characterization variables were obtained from electronic medical records, Hb, mean corpuscular volume (MCV) and glycaemia by laboratory exams, and USN by cancellation and bisection tasks. The relationship between Hb and USN was assessed by Spearman correlation and linear regression model. RESULTS: 40 individuals were evaluated; it was observed that the higher the Hb level, the better the USN test performance, with the two being negatively correlated. There was no significant correlation between VCM level and USN performance. CONCLUSION: Low hemoglobin levels may indicate a worse performance in USN cancellation and bissection tests in acute phase of stroke.

Is reduced ornithine-δ-aminotransferase activity the cause of vigabatrin-associated visual field defects?

BACKGROUND: A gabaergic antiepileptic drug, vigabatrin (VGB), is known to induce bilateral concentric visual field defects (VFD) in 30-40% of treated patients. Although the clinical and electrophysiological features of VFDs are well documented, the mechanism of retinal toxicity is still unclear. PURPOSE: To determine if low basal ornithine-δ-aminotranspherase (OAT) activity is implicated in the etiology of VGB retinotoxicity, resulting in a phenotype of a mild form of gyrate atrophy. METHODS: Assays of OAT activity in lymphocytes and GABA-transaminase activity in platelets were performed, and plasma levels of GABA, ornithine, lysine, glutamic acid and glutamine were measured, and visual fields were examined. A total of 47 subjects, aged 14-78 years, were examined. Twenty-one epileptic patients were off VGB more than 1 year; 11 patients with VGB-induced VFD and 10 with normal visual fields. Ten epileptic patients were on current VGB therapy more than 1 year; four patients with VGB-induced VFD and six with normal visual fields. The results were compared with those of 10 epilepsy patients taking tiagabine and six patients who suffered from gyrate atrophy (GA) or were obligate carriers of the disease. RESULTS: In patients who had stopped VGB and who had VFDs, OAT activity was significantly reduced as compared with those who had normal visual fields (77.4pmol P5C/min/mgPro vs. 181.9pmol P5C/min/mgPro, p=0.002). In patients with ongoing VGB therapy, no difference was found between the patients with and without VFDs (149.4pmol P5C/min/mgPro vs. 159.1pmol P5C/min/mgPro). CONCLUSIONS: : The results suggest that VGB retinotoxicity might be associated with elevated retinal ornithine mediated by low basal OAT activity.

Low haemoglobin levels increase unilateral spatial neglect in acute phase of stroke / Níveis baixos de hemoglobina aumentam a negligência espacial unilateral na fase aguda do acidente vascular cerebral

Objective The objective of this study was to evaluate the relationship between unilateral spatial neglect (USN) and haemoglobin (Hb) level in acute phase of stroke. Method Cross-sectional study was performed after right hemisphere ischemic stroke. Independent variable: Hb level (mg/dL); Outcome: USN; Potential confounding factors: Age, National Institutes of Health Stroke Scale (NIHSS), and glycaemia (mg/dL); Characterization variables were obtained from electronic medical records, Hb, mean corpuscular volume (MCV) and glycaemia by laboratory exams, and USN by cancellation and bisection tasks. The relationship between Hb and USN was assessed by Spearman correlation and linear regression model. Results 40 individuals were evaluated; it was observed that the higher the Hb level, the better the USN test performance, with the two being negatively correlated. There was no significant correlation between VCM level and USN performance. Conclusion Low hemoglobin levels may indicate a worse performance in USN cancellation and bissection tests in acute phase of stroke. .

Objetivo O objetivo do estudo foi avaliar a relação entre a negligência espacial unilateral (NEU) e hemoglobina (Hb) na fase aguda do acidente vascular cerebral (AVC). Método Foi realizado estudo transversal em pacientes com AVC de hemisfério direito dentro das primeiras 48 horas do ictus. Variáveis independentes: nível de Hb (mg/dL); Desfecho: NEU; Fatores potenciais de confundimento: Idade, National Institutes of Health Stroke Scale (NIHSS) e glicemia (mg/dL); A caracterização das variáveis foram obtidas por meio de prontuários eletrônicos, Hb e glicemia por exames laboratoriais, e NEU por meio do Line Cancellation (LCT), Star Cancelation (SCT), e Line Bisection Tasks (LBT). Resultados 40 indivíduos foram avaliados e foi observado que quanto maior os níveis de Hb, melhor o desempenho nos testes de NEU, demonstrando correlação negativa entre eles. Conclusão Níveis baixos de hemoglobina podem indicar pior desempenho nos testes de NEU na fase aguda do AVC. .