HERPES SIMPLEX VIRUS ENCEPHALITIS: PROBLEMS IN DIAGNOSIS

Six children aged 13 days to nine years with herpes simplex encephalitis (HSE) are presented. Institution of appropriate antiviral treatment was later than six days in three cases; original diagnosis in these cases were post-traumatic epilepsy, bacterial meningitis and febrile convulsion. Initially pyrexia was absent in two cases and cranial CT was normal in two cases. Encephalitic changes were observed on the EEGs of five children. Diagnosis was confirmed by paired serological titres, brain biopsy, vesicle culture and CSF titres. The outcome for all six children was poor. HSE should always be considered in children presenting with focal seizures, even when apyrexial and with normal CT findings. In such situations, saving CSF for antibody titres or antigen identification should be routine practice. Treatment with acyclovir is justified before precise virological diagnosis has been established.     

The pharmacokinetics of lignocaine in humans during a computer-controlled infusion.

Several types of chronic pain syndromes are effectively treated with sodium channel blockers such as lignocaine. Further investigation of this therapeutic modality would be facilitated by refinement of the parameters describing lignocaine distribution and elimination. This would allow precise lignocaine infusion by a computer-controlled infusion to attain and maintain stable target lignocaine concentrations. Arterial blood samples were obtained at frequent intervals during a computer-controlled infusion of lignocaine in 12 adult human volunteers. Plasma lignocaine concentrations of 1, 2, 3, 4 and 5 microg/ml were targeted for 15 min at each concentration. A three-compartment mammillary pharmacokinetic model best described the resulting concentration vs time profile. A population pharmacokinetic analysis was performed using three different techniques; the two-stage, pooled and mixed effects modelling. There was marked overshoot of the plasma concentration above the target prior to refinement of the pharmacokinetic parameters. The best parameters of a three-compartment mammillary model fit to the measured concentration using the pooled data approach were: V(1) = 7.44, V(2) =11.5 and V(3) = 97.71; Cl(1) = 0.585, Cl(2) = 2.23 and Cl(3) =1.64 l/min. Similarly calculated parameters using NONMEM were V(1) = 6.99, V(2) =12.2 and V(3) =1341; Cl(1) = 0.703, Cl(2) =1.24 and Cl(3) =1.49 l/min. The addition of age as a covariate of the pharmacokinetic parameters improved the model in both cases. Height, lean body mass and body surface area as covariates of the pharmacokinetic parameters did not improve the predicted value of the model. Prospective testing of the pharmacokinetic parameters will be required to define whether they function well. The refinement of pharmacokinetic parameters for the computer-controlled intravenous infusion of lignocaine will facilitate further research in pain therapy. Published lignocaine pharmacokinetic values have a relatively large central volume of distribution, and hence, when implemented as a computer-controlled infusion, result in dramatic overshoot shortly after targeting a higher plasma concentration. In light of the long-lasting pain relief provided by sodium channel blockade in neuropathic pain states, overshoot of plasma concentrations must be avoided if the concentration vs effect relationship is to be defined.     

Disorders of the pyruvate dehydrogenase complex

Pyruvate dehydrogenase deficiency may be a non-specific consequence of many different neurological degenerative disorders. There are also serious methodological problems in estimating the activity of this enzyme complex.     

Perforation Rates for Nonsterile Examination Gloves in Routine Dermatologic Procedures

BACKGROUND: Low cost, nonsterile examination gloves are used routinely to perform various dermatologic procedures. OBJECTIVE: To evaluate the perforation rate of nonsterile examination gloves in routine dermatologic procedures. METHODS: Three hundred fifty nonsterile latex examination gloves used to perform shave biopsies were evaluated for perforations using an air inflation/water submersion method. Ninety gloves, which were intentionally perforated with a 30-gauge needle, were used as controls to assess our evaluation method. RESULTS: Eight of the 350 gloves were found to have a perforation, which corresponds to a 2.3% perforation rate. Seven of the eight perforations were found in the web space between the second and third finger sleeves, with one being an obvious manufacturing error. All 90 perforations of the control group were correctly identified. CONCLUSION: There appears to be a very low risk of glove perforation when nonsterile examination gloves are used in routine dermatologic procedures.     

Persistent hyperplastic primary vitreous involving the anterior eye.

The imaging features of persistent hyperplastic primary vitreous (PHPV) affecting the posterior eye are well known. We recently encountered a patient with the anterior variant of PHPV who had MR imaging of the orbits. We present the clinical and imaging findings of this unusual entity and discuss the therapeutic options available for its management.     

Active idiopathic systemic lupus erythematosus in a 90-year-old woman requiring corticosteroid therapy.

A woman who developed multisystem systemic lupus erythematosus (SLE) at the age 80 improved with therapy, but after a hip fracture her disease flared necessitating corticosteroid treatment at age 90. This is the oldest case of active lupus ever reported, and points out the importance of not excluding active SLE as a cause of symptoms or signs even in advanced age.