Post-operative tension spinal subdural extra-arachnoid hygroma of the lumbar spine: case series, literature review, and recommendations for clinical management

OBJECTIVE

Case series presentation and literature review of patient group suffering from symptomatic tension subdural extra-arachnoid hygroma following decompressive surgery for degenerative lumbar stenosis or disc disease. The purpose was to better understand this rare post-operative complication with a pathognomic radiological sign to help recommend optimal strategies for clinical management.

METHODS

Retrospective case series comprising seven cases from one tertiary Neurosurgical centre spanning a 10-year period from 2011 to 2021. Patients included were those known to have undergone a spinal procedure and subsequently to have developed a symptomatic spinal subdural extra-arachnoid hygroma (SSEH). A literature review was conducted using PubMed, MEDLINE and EMBASE (keywords 'subdural hygroma', 'lumbar CSF hygroma', 'extra arachnoid hygroma', 'extra-arachnoid CSF collection', 'CSF tension hygroma', 'lumbar extra arachnoid hygroma', 'lumbar spinal hygroma', 'post-operating spinal hygroma', 'post-operative spinal CSF collection') and through reading references cited in relevant articles. Articles involving post-operative SSEH following lumbar spinal surgery were included.

RESULTS

Rare complication with only five other cases in the literature. Dural breach described intra-operatively in only 5 of 12 total cases from our series and the literature. 5 patients in our series were managed surgically with 2 being managed conservatively. All patients in our series improved symptomatically and radiologically following surgical or conservative management.

CONCLUSIONS

This is a rare post-lumbar surgery complication that can cause rapidly deteriorating lower limb and sphincteric function. Surgical management with wide durotomy and arachnoid marsupialisation can lead to reversal of neurological deterioration and excellent clinical results. A delayed presentation with pseudomeningocele formation may be managed conservatively if neurology is stable or improving. It is a condition that it is important for the clinician to recognise in order to instigate appropriate management in a time-dependent fashion.

Casemix, management, and mortality of patients rreseceiving emergency neurosurgery for traumatic brain injury in the Global Neurotrauma Outcomes Study: a prospective observational cohort study

BACKGROUND

Traumatic brain injury (TBI) is increasingly recognised as being responsible for a substantial proportion of the global burden of disease. Neurosurgical interventions are an important aspect of care for patients with TBI, but there is little epidemiological data available on this patient population. We aimed to characterise differences in casemix, management, and mortality of patients receiving emergency neurosurgery for TBI across different levels of human development.

METHODS

We did a prospective observational cohort study of consecutive patients with TBI undergoing emergency neurosurgery, in a convenience sample of hospitals identified by open invitation, through international and regional scientific societies and meetings, individual contacts, and social media. Patients receiving emergency neurosurgery for TBI in each hospital's 30-day study period were all eligible for inclusion, with the exception of patients undergoing insertion of an intracranial pressure monitor only, ventriculostomy placement only, or a procedure for drainage of a chronic subdural haematoma. The primary outcome was mortality at 14 days postoperatively (or last point of observation if the patient was discharged before this time point). Countries were stratified according to their Human Development Index (HDI)-a composite of life expectancy, education, and income measures-into very high HDI, high HDI, medium HDI, and low HDI tiers. Mixed effects logistic regression was used to examine the effect of HDI on mortality while accounting for and quantifying between-hospital and between-country variation.

FINDINGS

Our study included 1635 records from 159 hospitals in 57 countries, collected between Nov 1, 2018, and Jan 31, 2020. 328 (20%) records were from countries in the very high HDI tier, 539 (33%) from countries in the high HDI tier, 614 (38%) from countries in the medium HDI tier, and 154 (9%) from countries in the low HDI tier. The median age was 35 years (IQR 24-51), with the oldest patients in the very high HDI tier (median 54 years, IQR 34-69) and the youngest in the low HDI tier (median 28 years, IQR 20-38). The most common procedures were elevation of a depressed skull fracture in the low HDI tier (69 [45%]), evacuation of a supratentorial extradural haematoma in the medium HDI tier (189 [31%]) and high HDI tier (173 [32%]), and evacuation of a supratentorial acute subdural haematoma in the very high HDI tier (155 [47%]). Median time from injury to surgery was 13 h (IQR 6-32). Overall mortality was 18% (299 of 1635). After adjustment for casemix, the odds of mortality were greater in the medium HDI tier (odds ratio [OR] 2·84, 95% CI 1·55-5·2) and high HDI tier (2·26, 1·23-4·15), but not the low HDI tier (1·66, 0·61-4·46), relative to the very high HDI tier. There was significant between-hospital variation in mortality (median OR 2·04, 95% CI 1·17-2·49).

INTERPRETATION

Patients receiving emergency neurosurgery for TBI differed considerably in their admission characteristics and management across human development settings. Level of human development was associated with mortality. Substantial opportunities to improve care globally were identified, including reducing delays to surgery. Between-hospital variation in mortality suggests changes at an institutional level could influence outcome and comparative effectiveness research could identify best practices.

FUNDING

National Institute for Health Research Global Health Research Group.

Thrombus formation in a dilated torcula following aneurysmal subarachnoid haemorrhage

A case of thrombus formation occurring within a dilation of the dural venous sinuses following aneurysmal sub-arachnoid haemorrhage is presented. Acute neurological deterioration accompanied propagation of the thrombus. The patient was anticoagulated on day 5 post-SAH with no haemorrhagic complications and made a full recovery. The optimum time to commence anticoagulation is not clear and is discussed.

Economic impact of additional radiographic studies after registered diagnostic medical sonographer (RDMS)-certified emergency physician-performed identification of cholecystitis by ultrasound

BACKGROUND

The standard evaluation of patients with right upper quadrant (RUQ) abdominal pain consists of a history and physical examination, laboratory analysis, and radiological investigation. Given the increasing availability of bedside ultrasound in the Emergency Department (ED), a growing proportion of Emergency Physicians are now performing their own ultrasound examinations in patients with RUQ abdominal pain to circumvent diagnostic delays and improve patient care.

OBJECTIVE

To determine the economic "opportunity" costs of additional radiographic testing after identification of acute cholecystitis by focused ED ultrasound performed by registered diagnostic medical sonographer (RDMS)-certified personnel.

METHODS

A retrospective analysis of a consecutive sample of patients with "positive" focused ED ultrasounds of the RUQ that were significant for cholecystitis, who presented from June 1, 2005 through February 30, 2006. Cost analysis was performed using standard Medicare compensation indices for radiological examinations of the abdomen/hepatobiliary system.

RESULTS

There were 37 patients enrolled; 32 patients exhibited RUQ pain with a focused ED ultrasound significant for cholecystitis. Eight (25%) patients received no further radiographic tests and exhibited positive pathology. Twenty-four (75%) patients had additional diagnostic examinations; 22 (92%) showed positive pathology. Based upon Medicare compensation indices, an opportunity cost of $6885.34 was incurred at our institution over 9 months due to additional examinations. Using nationally comparable indices, this was extrapolated to an opportunity cost of $63 million (95% confidence interval $48.3-$78.9 million) per year across the nation, assuming that 50% of patients with cholecystitis present to the ED and receive an ultrasound examination by an RDMS-certified Emergency Physician.

CONCLUSIONS

In this small sample, additional radiological testing after ED ultrasounds significant for acute cholecystitis led to sizable economic costs on a local and national level. Formal cost-benefit analyses are needed to evaluate the full economic and patient care implications of ED ultrasound use in this setting.

The pandemic of Salmonella enteritidis phage type 4 reaches Utah: a complex investigation confirms the need for continuing rigorous control measures

In 1995, Salmonella Enteritidis (SE) cases in the state of Utah increased fivefold. Isolates were identified as phage type 4 (PT4). Risk factors and sources of infection were investigated in two case-control studies, a traceback of implicated foods, and environmental testing. Forty-three patients with sporadic infections and 86 controls were included in a case-control study of risk factors for infection. A follow-up case-control study of 25 case and 19 control restaurants patronized by case and control patients examined risks associated with restaurant practices. In the first case-control study, restaurant dining was associated with illness (P = 0.002). In the follow-up case-control study, case restaurants were likelier to use > 2000 eggs per week (P < 0.02), to pool eggs (P < 0.05), and to use eggs from cooperative 'A' (P < 0.009). Eggs implicated in separately investigated SE PT4 outbreaks were traced to cooperative 'A', and SE PT4 was cultured from one of the cooperative's five local farms. We conclude that SE PT4 transmitted by infected eggs from a single farm caused a fivefold increase in human infections in Utah.

Spatio-logical processes in intracellular signalling

Classical models of intracellular signalling describe how small changes in a cell's external environment can bring about major changes in cellular activity. Recent findings from experimental biology indicate that many intracellular signalling systems show a high level of spatial organisation. This permits the modification, by protein kinase or protein phosphatase action, of specific subsets of intracellular proteins - an attribute that is not addressed in classical signalling models. Here we use ideas and concepts from computer science to describe the information processing nature of intracellular signalling pathways and the impact of spatial heterogeneity of their components (e.g. protein kinases and protein phosphatases) on signalling activity. We argue that it is useful to view the signalling ecology as a vast parallel distributed processing network of agents operating in heterogeneous microenvironments, and we conclude with an overview of the mathematical and semantic methodologies that might help clarify this analogy between biological and computational systems.

Identification of Bartonella species directly in clinical specimens by PCR-restriction fragment length polymorphism analysis of a 16S rRNA gene fragment

It is now established that two species of Bartonella, namely, Bartonella henselae and B. quintana, cause bacillary angiomatosis in human immunodeficiency virus-infected patients. In addition, B. henselae causes cat scratch disease and B. quintana, B. henselae, and B. elizabethae can cause bacteremia and endocarditis in immunocompetent persons. We have developed a PCR-restriction fragment length polymorphism-based assay for direct detection and identification to species level of Bartonella in clinical specimens. This is accomplished by PCR amplification of Bartonella DNA using primers derived from conserved regions of the gene carrying the 16S ribosomal DNA, followed by restriction analysis using DdeI and MseI restriction endonucleases. We amplified a Bartonella genus-specific 296-bp fragment from 25 clinical samples obtained from 25 different individuals. Restriction analysis of amplicons showed that identical patterns were seen from digestion of B. henselae and B. quintana amplicons with DdeI, whereas a different unique pattern was seen by using the same enzyme with B. vinsonii and B. elizabethae. With MseI digestion, B. henselae and B. vinsonii gave nearly identical patterns while B. quintana and B. elizabethae gave a different pattern. By combining the restriction analysis data generated with MseI and DdeI, unique "signature" restriction patterns characteristic for each species were obtained. These patterns were useful in identifying the Bartonella species associated with each tissue specimen.

Platinum distribution in malignant glioma following intraoperative intravenous infusion of carboplatin

The objective of this paper was to determine the time course and extent of platinum uptake into human malignant glioma tissue. An intraoperative, intravenous infusion of carboplatin was given to nine patients (seven glioblastoma and two anaplastic glioma) undergoing tumour excision. Carboplatin dosage was calculated individually to achieve a target systemic free carboplatin exposure. Tumour and peritumoural tissue was harvested at timed intervals following carboplatin administration. Plasma and tumour platinum concentrations were measured by graphite furnace flameless atomic absorption spectrophotometry. Histological examination was also performed on a piece of each tissue sample. The mean carboplatin dose administered was 783, SEM 56 mg (range 485-903). Plasma pharmacokinetics showed a typical elimination curve. The mean peak plasma platinum concentration was 44, SEM 5 micrograms/ml (range 27-74). The mean total elemental plasma platinum area under the curve (AUC) was 9.0, SEM 1.4 mg/ml/min. Platinum was detected in 61 tumour samples, the mean peak concentration being 13 SEM 2 micrograms/g (range 5-21). Platinum was also detected in peritumoural brain and necrotic tumour. No correlation was apparent between the degree of necrosis in each tumour specimen and tumour platinum concentration. Platinum concentrations achieved in tumour were similar to levels that would be cytotoxic for glioma cells in vitro. The results of this study have implications for future studies using capillary permeability modifying agents as adjuncts to brain tumour chemotherapy.

An outbreak of salmonellosis among children attending a reptile exhibit at a zoo

OBJECTIVE

In January 1996, an outbreak of diarrhea caused by Salmonella Enteritidis occurred in children attending a Komodo dragon exhibit at a metropolitan zoo. We sought to determine the extent of the outbreak and mode of transmission.

STUDY DESIGN

A case-control study was conducted. Controls were randomly selected from zoo membership lists and matched to patients by age group and date of exhibit visit.

RESULTS

Of 65 patients identified, 39 had confirmed and 26 had suspected cases. The median age was 7 years (range, 3 months to 48 years); 55% were enrolled in the case-control study. No patients and two (4%) controls reported touching a dragon; however, 83% of patients but only 52% of controls touched the wooden barrier that surrounded the dragon pen (odds ratio = 4.0, 95% CI 1.2 to 13.9). Washing hands at the zoo after visiting the dragons was highly protective (OR = 0.14, 95% CI 0.03 to 0.7). Cultures from the patients, one dragon, and the exhibit barriers yielded Salmonella Enteritidis, phage type 8. On the basis of an attack rate of 4.3% among exhibit attendees under 13 years old on whom data were collected, we estimate that 315 additional cases of salmonellosis occurred among visitors in this age group.

CONCLUSION

This large outbreak demonstrates the importance of environmental contamination in the transmission of Salmonella from reptiles, and the protective value of hand washing. Recommendations regarding reptile exhibits and reptilian pets should emphasize this indirect route.

Middle cranial fossa arachnoid cysts: not always a benign entity

Arachnoid cysts are often discovered as incidental findings on cranial imaging. A rare manifestation is described in a child presenting acutely with symptoms and signs of raised intracranial pressure.

Ventilatory response of the newborn infant to mild hypoxia

The transition from an immature (biphasic) to a mature (sustained hyperpneic) response to a brief period of sustained hypoxia is believed to be well advanced by postnatal day 10 for newborn infants. However, a review of the supporting evidence convinced us that this issue warranted further, more systematic investigation. Seven healthy term infants aged 2 days to 8 weeks were studied. The ventilatory response (VR) elicited by 5 min breathing of 15% O2 was measured during quiet sleep. Arterial SaO2 (pulse oximeter) and minute ventilation (expressed as a change from control, delta V'i) were measured continuously. Infants were wrapped in their usual bedding and slept in open cots at room temperature (23 degrees-25 degrees). Infants aged 2-3 days exhibited predominantely a sustained hypopnea during the period of hypoxia (delta V'i = -2% at 1 min, -13% at 5 min). At 8 weeks of age, the mean response was typically biphasic (delta V'i = +9% at 1 min, -4% at 5 min). This age-related difference between responses was statistically significant (two-way ANOVA by time and age-group; interaction P < 0.05). These data reveal that term infants studied under ambient conditions during defined quiet sleep may exhibit an immature VR to mild, sustained hypoxia for at least 2 months after birth. This suggests that postnatal development of the O2 chemoreflex is slower than previously thought.

A comparison of the ventilatory response of sleeping newborn lambs to step and progressive hypoxaemia

1. Slight variations in the rate at which hypoxaemia develops may significantly alter the ventilatory response (VR) elicited. Here we have developed a technique to compare the VRs elicited from sleeping newborn lambs by specific (step versus progressive), short-duration (< or = 5 min) episodes of hypoxaemia. The results may help us understand the limitations of using tests which deliver poorly defined stimuli to evaluate the postnatal development of the oxygen chemoreflex. 2. The VRs of five lambs elicited by a 5 min step or progressive reduction in the arterial oxygen saturation (Sa,O2) during quiet sleep were compared. Minute ventilation (V1, face mask) and Sa,O2 (pulse oximeter) were measured continuously. Alternate step (Sa,O2 reduced to 80-85% within 60 s and maintained for a further 4 min) and progressive tests (progressive reduction in Sa,O2 to 80% over 5 min) were administered daily between postnatal days 2-14. 3. There was a significant difference between the mean VR to step versus progressive hypoxaemia. The VR to a step challenge was biphasic (delta Vi = +32 +/- 5% at 1 min and -1 +/- 4% at 5 min; mean +/- S.E.M.). Progressive hypoxaemia elicited a more subdued but sustained hyperpnoea (delta Vi = +11 +/- 2% at 1 min and +11 +/- 4% at 5 min). The difference between these two response profiles was statistically significant (P < 0.001). 4. Mean responses of lambs aged < or = 5 days (4 +/- 0.2 days) and > or = 9 days (10 +/- 0.3 days) were also compared. There was an upward shift in the position of step and progressive response curves of older lambs, reflecting primarily the increased vigour of the initial hyperpnoea elicited by step (delta Vi at 1 min = +20 +/- 4% at 4 days vs. +40 +/- 11% at 10 days) as well as progressive (delta Vi at 1 min = +6 +/- 2% at 4 days vs. +17 +/- 5% at 10 days) hypoxaemia. 5. Qualitatively different VRs may be elicited from the newborn, depending upon the specific hypoxaemic profile administered. Therefore, to evaluate the significance of VRs elicited in response to classical, steady-state hypoxia at different postnatal ages properly, the stimulus must be accurately described.

Carbon dioxide concentrations in the environment of sleeping infants

In 22 infants continuous measurements were made of the concentration of carbon dioxide (CO2) in inspired air during sleep. Evidence was found of CO2 enrichment of inspired air in certain environmental conditions. The levels achieved were not sufficiently high to acutely endanger an infant. Carbon dioxide concentrations as high as 2-3% were observed in the prone position when the infant's head was under a blanket and when the lower face was obscured by bedding. Sleeping prone on a sheepskin also resulted in an increased concentration of CO2 but to a lesser extent than being under a blanket. In awake infants the presence of a pacifier also promoted an excess of CO2 in the inspired air, both in the prone and supine positions. The physiological and clinical implications of these findings, in relation to the Sudden Infant Death Syndrome (SIDS), are unknown and warrant investigation.

Amniocentesis in the management of preterm premature rupture of the membranes

A retrospective analysis has been performed of perinatal outcome in 81 pregnancies in which preterm premature rupture of membranes (PPROM) was managed using amniocentesis to diagnose intrauterine infection and lung maturity. Ten patients (13%) had a positive Gram stain on microscopy whilst 29 (37%) had a positive culture. Forty-one patients (58%) had a mature lecithin:sphingomyelin ratio. There was evidence of sepsis in 13 neonates (16%), with a further 16 (20%) being colonized. Both Gram stain and amniotic fluid culture were relatively poor predictors of neonatal sepsis. For Gram stain the sensitivity was low at only 15%. Although the sensitivity for culture was higher (69%), the specificity (71%) was too low to be clinically useful. It is recommended that a randomized controlled trial of amniocentesis in PPROM is needed to define the role of this diagnostic test.

Absent or reversed end diastolic flow velocity in the umbilical artery and necrotising enterocolitis

Absent or reversed end diastolic flow (AREDF) velocities in the umbilical artery were identified in 25 high risk pregnancies. In six pregnancies the fetus was abnormal and all but one of these ended in perinatal death. Of the 19 morphologically normal fetuses, three died in utero and there were four neonatal or infant deaths. The mortality rate was 48% for all pregnancies and 37% for those with morphologically normal fetuses. There was a highly significant increased risk for the development of necrotising enterocolitis in these morphologically normal fetuses with AREDF (53%) compared with controls (6%) who did have umbilical artery end diastolic flow velocities in fetal life. There were no significant differences between the matched pairs for parameters of neonatal outcome chosen to reflect neonatal morbidity. These findings demonstrate the close association between AREDF and necrotising enterocolitis that appears to be independent of other variables such as degree of growth retardation, prematurity, and perinatal asphyxia.