Spinal Epidural Abscess: A Review of Presentation, Management, and Medicolegal Implications

Spinal epidural abscess (SEA) is a rare condition associated with significant morbidity and mortality. Despite advances in diagnostic medicine, early recognition of SEAs remains elusive. The vague presentation of the disease, coupled with its numerous risk factors, the diagnostic requirement for obtaining advanced imaging, and the necessity of specialized care constitute extraordinary challenges to both diagnosis and treatment of SEA. Once diagnosed, SEAs require urgent or emergent medical and/or surgical management. As SEAs are a relatively rare pathology, high-quality data are limited and there is no consensus on their optimal management. This paper focuses on presenting the treatment modalities that have been successful in the management of SEAs and providing a critical assessment of how specific SEA characteristics may render one infection more amenable to primary surgical or medical interventions. This paper reviews the relevant history, epidemiology, clinical presentation, radiology, microbiology, and treatment of SEAs and concludes by addressing the medicolegal implications of delayed treatment of the disease.

Ocular aberrations after wavefront optimized LASIK for myopia.

Purpose: To study the change in ocular aberrations after wavefront optimized (WFO) laser in situ keratomileusis (LASIK) for correction of myopia and to analyze causative factors that may influence them. Materials and Methods: This was a prospective case series. WFO LASIK was performed for the correction of myopia, using the hansatome (Bausch and Lomb) microkeratome to create the flap and the Allegretto laser (Wavelight Technologie) to perform the ablation. The Allegretto wave analyser (Tscherning-type) measured the ocular aberrations prior to LASIK , one month and six months postoperatively. Results: The mean age of the 59 patients included in the study was 25±5.64 years and the mean spherical equivalent of the 117 eyes that underwent LASIK was ‒5.33±1.22 preoperatively and ‒0.21±0.38 postoperatively. Hundred and two eyes of 117 (87%) achieved uncorrected visual acuity (UCVA) of 20/20 or better after WFO LASIK and 104 of 117 eyes (89%) were within ±0.5D of the attempted refractive correction. There was a 1.96-fold increase in total root-mean-square of higher order aberrations. Induced changes in seven of the 22 higher order Zernike terms showed a significant linear correlation with the refractive correction attempted. Larger ablation zones induced less spherical aberration. Conclusion: In spite of an excellent visual outcome, WFO LASIK induces significant higher order aberrations. Large ablation zones reduce the induction of spherical aberration.

Detection through screening of maternal thyrotoxicosis induced central hypothyroidism in newborns.

Use of a third generation TSH assay enabled extremely low values of TSH to be detected through newborn screening. The use of a supplemental free thyroxine improved testing specificity. The hypothyroidism observed is believed to be secondary to suppression of the hypothalamic-pituitary-thyroid axis by placentally transferred maternal thyroxine.

Mass newborn screening in Singapore.

Births in Singapore are almost exclusively in hospitals and this is conducive to mass newborn screening. Mass newborn screeningbegan in 1965 for G6PD deficiency and has led to successful eradication of the complicating kernicterus. Screening has also identified the distinct ethnic and sex linked variations in incidence. The predominant molecular abnormality is the Canton variant. Congenital hypothyroidism screening was started as a pilot project in 1981, then became institution-based in 1985 and nationwide in 1990. The screening is carried out on the cord blood and is now a primary TSH screen. Anincidence of about 1 in 3000 is being obtained and treatment has been started within 2 weeks of birth in almost all babies. A pilot Newborn Screening for hearing impairment started in 1999. Ituses the measurement of Transient Evoked Oto-Acoustic Emissions, is hospital based andcovers about 10% of the newborn population. The program has identified hearing impairment requiring intervention at a rate of about 1:1000 births. A program covering about 50% of the national births has been commissioned by the Ministry of Health to establish epidemiologic data and to document the outcome of early intervention. Mass newborn screening for inborn errors of metabolism is being considered.

Mass newborn screening for hearing impairment.

Significant hearing impairment is common and impairs communication potential if not detected early. Babies born at the National University Hospital from March 1999 to February 2001 were screened at birth using the strategy of measuring Transient Evoked Oto Acoustic Emissions with the ILO 88 Otodynamics Echoport. The screening was conducted within 24 hours of birth in the majority of patients. Those testing positive were re-screened at about 2 weeks and at 6 weeks if still testing positive. Those who tested positive at 6 weeks were referred to Otolaryngology for formal evaluation of hearing. A total screening rate of 97.2% (4,387 out of 4,514 livebirths) was achieved. Of the 312 testing positive at 6 weeks, 8 were subsequently proven to have significant hearing impairment. Four of them required binaural amplification, giving a 1 in 1,096 incidence of severe hearing impairment. A specificity, positive predictive value and sensitivity of 93%, 26% and 100% respectively were obtained. In all but one, the diagnosis was made by 7 months of age and interventions set in place within 2 months of diagnosis. The screening strategy was reliable and sensitive. A strategy to reduce the high false positive rate needs to be developed.