Cervical Spinal Cord Stimulation for Failed Neck Surgery Syndrome.

PURPOSE OF REVIEW: Cervical spine pain with or without radicular symptoms is a common condition leading to high utilization of the healthcare system with over 10 million medical visits per year. Many patients undergo surgical interventions and unfortunately are still left with neck and upper extremity pain, sometimes referred to as "Failed Neck Surgery Syndrome." When these options fail, cervical spinal cord stimulation can be a useful tool to decrease pain and suffering as well as reduce prescription medication use. RECENT FINDINGS: Spinal cord stimulation is a well-established therapy for chronic back and leg pain and is becoming more popular for neck and upper extremity pain. Recent studies have explored cervical spinal cord stimulation with successful outcomes regarding improved pain scores, functional outcomes, and reduction of prescription medication use. Continued research into cervical spinal cord stimulation is essential for maximizing its therapeutic potential for patients with chronic neck and upper extremity pain. This review highlights the importance of cervical spinal cord stimulation as an option for patients with failed neck surgery syndrome.

Current Review of Regenerative Medicine Therapies for Spine-Related Pain.

PURPOSE OF REVIEW: Persistent spinal pain syndromes are pervasive and lead to functional impairment, increased healthcare utilization, potential disability, and high societal costs. Spinal (cervical, thoracic, lumbar, and sacroiliac joint) pain includes mechanical, degenerative, inflammatory, oncologic, and infectious etiologies. Regenerative medicine is a novel biotechnology targeting mechanical, degenerative, and inflammatory conditions believed to cause pain. Preparations including platelet-rich plasma, mesenchymal stem cells (adipose tissue and bone marrow aspirate concentrates), and growth factors are derived from an autologous donor. The goal of intervention through guided injection of the regenerative media is to reduce inflammation and reverse the degenerative cascade in hopes of restoring normal cellular composition (physiologic homeostasis) and anatomical function to improve pain and function. The authors review limited research supporting the use of platelet-rich plasma injections for facet joint arthropathy and sacroiliac joint pain compared to traditional steroid treatments, as well as the use of platelet rich plasma or mesenchymal stem cells for lumbar discogenic and radicular pain. RECENT FINDINGS: Current evidence to support regenerative medicine for spine-related pain is limited. Although several studies demonstrated a reduction in pain, many of these studies had a small number of participants and were case series or prospective trials. Regenerative medicine treatments lack evidence for the treatment of spine-related pain. Large randomized controlled trials are needed with consistent study protocols to make further recommendations.

Pilot study of sunlight exposure and vitamin D status in Arab women of childbearing age.

Vitamin D deficiency is common in Arab women. In a pilot study we investigated the effect of sun exposure at recommended levels on the vitamin D status of Arab women. Eight healthy Arab women of childbearing age consented to expose their face, arms and hands for 15 minutes per day twice a week for 4 weeks within the privacy of their courtyard and to avoid changes in dietary vitamin D intake. Serum 25-hydroxyvitamin D [25(OH)] levels were measured pre- and post-intervention. Although vitamin D levels remained sub-optimal median serum 25(OH)D levels were significantly higher post-intervention (23.0 nmol/L) than pre-intervention (17.6 nmol/L). Extending sun exposure for more than 4 weeks should be investigated as part of strategies to improve vitamin D status in high-risk Arab women who lack outdoor sun exposure to the skin.

Current maternal-infant micronutrient status and the effects on birth weight in the United Arab Emirates.

Micronutrient deficiencies exist among women of childbearing age in the United Arab Emirates but the effects of maternal micronutrient deficiency on fetal growth are not well documented. To investigate the association between micronutrients and birth weight, we measured maternal and cord blood micronutrients (vitamin A, C, D, and E) and ferritin in 84 term, singleton infants born to healthy Arab and South Asian women at Al-Ain hospital. Median serum ascorbic acid and 25-hydroxyvitamin D (25-OHD) concentrations were low in mothers and infants. In multivariate analysis, maternal serum 25-OHD correlated positively with birth weight while serum ferritin showed a negative correlation.

Size at birth in a rapidly developing economy: intrauterine growth pattern of UAE infants.

BACKGROUND: Despite rapid economic growth and the recognition of intrauterine growth pattern as an important indicator of neonatal morbidity and mortality, the size at birth relative to gestation for UAE (United Arab Emirates) live births has not been investigated. AIM: The present study evaluated the intrauterine growth pattern of UAE infants and compared the data with the currently used reference standard. SUBJECTS AND METHODS: A total of 2497 singleton hospital live births to UAE mothers without pregnancy complications were studied. Anthropometric measurements and gestational age assessment of each infant were carried out according to standard procedures. The LMS computer program was used to construct perentile curves. RESULTS: The mean birth weight, length and head circumference of 1113 male term infants were 3298 g, 50.6 cm and 34.5 cm, respectively, and the same parameters for 1118 female term infants were 3201 g, 49.9 cm and 34.0 cm, respectively. These growth parameters were higher in males than females. Mean birth weight data were similar to those reported previously from a study from an economically developed community. The 10th percentile values were higher than in the currently used reference chart. CONCLUSION: Data on size at birth for UAE infants indicate that continuing use of the current reference chart may underestimate the prevalence of fetal growth failure in the population. Data from larger numbers of very preterm infants are needed to generate percentiles charts for very preterm infants.

Racial disparities in cord blood vitamin D levels and its association with small-for-gestational-age infants.

OBJECTIVE: To examine the relationship of race and maternal characteristics and their association with cord blood vitamin D levels and small-for-gestational-age (SGA) status. STUDY DESIGN: Cord blood vitamin D levels were measured in 438 infants (276 black and 162 white). Multivariable logistic regression models were used to evaluate associations between maternal characteristics, vitamin D status and SGA. RESULTS: Black race, Medicaid status, mean body mass index at delivery and lack of prenatal vitamin use were associated with vitamin D deficiency. Black infants had 3.6 greater adjusted odds (95% confidence interval (CI): 2.4, 5.6) of vitamin D deficiency when compared with white infants. Black infants with vitamin D deficiency had 2.4 greater adjusted odds (95% CI: 1.0, 5.8) of SGA. Vitamin D deficiency was not significantly associated with SGA in white infants. CONCLUSION: Identification of risk factors (black race, Medicaid status, obesity and lack of prenatal vitamin use) can lead to opportunities for targeted prenatal vitamin supplementation to reduce the risk of neonatal vitamin D deficiency and SGA status.

[Risk of nasopharyngeal cancer, Leukemia and other tumors in a cohort of employees and students potentially exposed to (FA) formaldehyde in University laboratories].

FA was recently classified as carcinogen of second class (category 1B). A retrospective cohort study was conducted for the evaluation of the association between exposure to FA and cancer in professionally potentially exposed in a University setting. The cohort was composed of 140 exposed to FA and 364 not exposed in the period 1999-2015. The results showed no cancers of naso-pharynx and leukemias or lymphomas both among exposed and not exposed. Moreover, the exposure to FA is not significantly associated to an increase of other types of tumors.

Neonatal outcome in the United Arab Emirates: the effect of changes in resources and practices.

Selective improvements in neonatal care resources and practices were instituted between 1992/1994 (period 1) and 1995/1998 (period 2) following a neonatal audit in the United Arab Emirates. We evaluated the effect of these changes on neonatal mortality rate (NNMR), birth-weight-specific mortality rates and causes of mortality. Overall there was a 17% decline in the NNMR from periods 1 to 2. Mortality rates in infants with birth weight < 1000 g and > 2500 g decreased by 36% and 35% respectively from periods 1 to 2. Modest declines in deaths from asphyxia, sepsis and complications of preterm births occurred from periods 1 to 2 but the differences were not statistically significant.

Agyria-pachygyria and agenesis of the corpus callosum: autosomal recessive inheritance with neonatal death.

We report three neonates, one boy and two girls, born to an inbred Arab family who had cortical dysplasia, probably agyria-pachygyria, and agenesis of the corpus callosum. All had asphyxia, intractable seizures, and increased muscle tone at birth and died in the neonatal period. Congenital microcephaly or dysmorphic features were absent. Cytogenetic abnormality, metabolic disorder, and intrauterine infection were excluded. These cases suggest a new cerebral dysgenesis syndrome with autosomal recessive inheritance.

Neonatal mortality: effects of selective pediatric interventions.

A previous prospective study of neonatal mortality in babies receiving special care at the University College Hospital, Ibadan, revealed that respiratory failure associated with prematurity, perinatal asphyxia, sepsis, and congenital malformations were the major causes of high neonatal mortality. To improve survival, selective measures were taken to improve care of low-birth-weight infants and prevent or treat intrapartum and postnatal hypoxia, metabolic acidosis, hypoglycemia, and hypothermia. A change in the initial antibiotic management of suspected septicemia to the use of cloxacillin and an aminoglycoside was also introduced, based on the current knowledge of etiologic agents and their antimicrobial sensitivities. In the 5-year period (1976 to 1980), the neonatal mortality in babies weighing 2,500 g and more at birth dropped significantly from 1.2% to 0.7% (P less than .02). The case fatality rates from birth asphyxia and neonatal sepsis dropped by 48% and 32%, respectively. Despite therapeutic interventions, however, the neonatal mortality in babies with birth weight of 1,000 g or less, 1,001 to 1,500 g, 1,501 to 2,000 g, and 2,001 to 2,499 g remained unchanged at about 82%, 25%, 9%, and 3%, respectively. These results suggest that early identification of infants at risk of developing birth asphyxia or neonatal septicemia and institution of prompt and appropriate management could produce a significant reduction in mortality in infants of normal birth weight. Survival of low-birth-weight infants requires additional high technical, financial, and manpower resources, which most centers in developing countries cannot afford at the present time. Therefore, efforts are probably better concentrated on decreasing the incidence of low birth weight.

Severe facial clefting, limbic dermoid, hypoplasia of the corpus callosum, and multiple skin appendages: severe frontofacionasal "dysplasia" or newly recognised syndrome?

We report on a child with severe midline facial cleft, bilateral cleft lip and palate, telecanthus, S-shaped palpebral fissures, limbic dermoid, midface hypoplasia, hypoplastic corpus callosum, and multiple skin appendages. This case may be an example of severe frontofacionasal "dysplasia" or a newly recognised syndrome.

Abnormal folate metabolism and genetic polymorphism of the folate pathway in a child with Down syndrome and neural tube defect.

The association of neural tube defects (NTDs) with Down syndrome (trisomy 21) and altered folate metabolism in both mother and affected offspring provide a unique opportunity for insight into the etiologic role of folate deficiency in these congenital anomalies. We describe here the case of a male child with trisomy 21, cervical meningomyelocele, agenesis of corpus callosum, hydrocephaly, cerebellar herniation into the foramen magnum, and shallow posterior cranial fossa. Molecular analysis of the methylenetetrahydrofolate (MTHFR) gene revealed homozygosity for the mutant 677C-->T polymorphism in both the mother and child. The plasma homocysteine of the mother was highly elevated at 25.0 micromol/L and was associated with a low methionine level of 22.1 micromol/L. Her S-adenosylhomocysteine (SAH) level was three times that of reference normal women, resulting in a markedly reduced ratio of S-adenosylmethionine (SAM) to SAH and significant DNA hypomethylation in lymphocytes. The child had low plasma levels of both homocysteine and methionine and a reduced SAM/SAH ratio that was also associated with lymphocyte DNA hypomethylation. In addition, the child had a five-fold increase in cystathionine level relative to normal children, consistent with over-expression of the cystathionine beta synthase gene present on chromosome 21. We suggest that altered folate status plus homozygous mutation in the MTHFR gene in the mother could promote chromosomal instability and meiotic non-disjunction resulting in trisomy 21. Altered folate status and homozygous TT mutation in the MTHFR gene in both mother and child would be expected to increase the risk of neural tube defects. The presence of both trisomy 21 and postclosure NTD in the same child supports the need for an extended periconceptional period of maternal folate supplementation to achieve greater preventive effects for both NTD and trisomy 21.

Cicletanine prevents the excitation-conduction blocks induced by terfenadine in ischemic myocardium.

Terfenadine, a histamine H(1) receptor antagonist, has been associated with clinical ventricular arrhythmias and in vitro excitation-conduction blocks, whereas anti-ischemic and antiarrhythmic effects have been shown with cicletanine, a prostacyclin generation stimulator. We aimed at determining in vitro if cicletanine can protect the ischemic myocardium from excitation-conduction blocks and specifically those induced by terfenadine. In a double-chamber bath, isolated guinea pig ventricular strips were partly exposed to normoxia and partly to ischemic, then reperfused, conditions, in the presence of 10 microM terfenadine, 10 microM indomethacin (prostacyclin generation blocker) or the solvent (dimethylsulfoxide 1:100, control) randomly allocated, and thus either in the absence (n=20) or presence (n=21) of 10 microM cicletanine during the total protocol duration. The multivariate Cox's model was used to predict the excitation-conduction block events and to assess the estimated survival of preparations (excitation-conduction block-free rate). Cicletanine protected the preparations (relative risk=0.08, t=-3.28) from the ischemia-induced excitation-conduction blocks (estimated survival=0.83 versus 0.30 in control), and this effect was abolished by indomethacin (estimated survival=0.35). Terfenadine enhanced 3. 58-fold the risk of occurrence of excitation-conduction blocks during ischemia (t=2.10) and this effect was inhibited by cicletanine pretreatment (estimated survival=0.40 versus 0.10 in untreated preparations). In conclusion, these in vitro findings have provided evidence for (1) protective effects of cicletanine against ischemia-induced excitation-conduction blocks, possibly related to its stimulating activity on local prostacyclin generation, and (2) efficacy of cicletanine to prevent excitation-conduction blocks induced by terfenadine in ischemic cardiac tissue.

The risk of myocardial stunning is decreased concentration-dependently by KATP channel activation with nicorandil before high K+ cardioplegia.

BACKGROUND: Drug-induced opening of the adenosine triphosphate-sensitive potassium channel (KATP) during hypoxia and/or ischemia, achieved significant myocardial protection in several in vitro and in vivo models. Pretreatment with KATP openers simulated preconditioning and thus enhanced recovery from ischemia. We have demonstrated that the risk of hypoxia-induced myocardial stunning is reversed by KATP activation with 1 mmol/l nicorandil before cold cardioplegic arrest. Whether lower concentrations were effective is not known. METHODS: In guinea pig papillary muscle preparations contracting isometrically (driven at 1600 ms cycle), nicorandil was superfused (15 min) either 1 mumol/l (n = 4), 30 mumol/l (n = 4), 100 mumol/l (n = 4), or 1 mmol/l (n = 8) in Tyrode's solution (oxygen content 16 ml/l, 37 degrees C, 5 ml/min). Controls were superfused with saline (Tyrode's solution: n = 8). A group containing vehicle (DMSO 1%, n = 8) was also studied. In four preparations the KATP channel blocker glibenclamide 1 mumol/l was given before nicorandil 1 mmol/l. Then, long-lasting (120 min) but moderately hypoxic (oxygen content 5 ml/l: 31% of Tyrode's solution) superfusion with hypothermic (20 degrees C) high K+ (16 mmol/l) cardioplegic solution (5 ml/min) was performed. Recovery of contractility was evaluated after further 60 min of reoxygenation with Tyrode's solution based on DT/TPT (developed tension divided by time to peak tension) as percent of prehypoxia basal values (%DT/TPT60). DT/TPT was also studied following 15 min of inotropic stimulation with dobutamine 10 mumol/l (%DT/TPT75). To assess the risk of stunning, we used a multivariate linear model by all possible subsets analysis (BMDP-9R) aimed at predicting both %DT/TPT60 and %DT/TPT75 (as continuous dependent variables). RESULTS: During cardioplegia induction, time to arrest (TTA) was (mean +/- S.D.) 103 +/- 48s in control preparations which had poor recovery of contractility (stunning) after reoxygenation (%DT/TPT60: 71 +/- 20%; %DT/TPT75: 443 +/- 272%). Nicorandil (1 mumol/l-1 mmol/l) abbreviated TTA concentration-dependently (163 +/- 74, 149 +/- 103, 82 +/- 20, and 56 +/- 27s) and improved both %DT/TPT60 (63 +/- 9, 78 +/- 17, 87 +/- 13, and 98 +/- 11%) and %DT/TPT75 (587 +/- 333, 619 +/- 107, 971 +/- 301, and 666 +/- 400%). Glibenclamide reversed the effects of nicorandil 1 mmol/l (TTA: 165 +/- 30 s, P < 0.01; %DT/TPT60: 43 +/- 12, P < 0.01; %DT/TPT75: 272 +/- 147, P < 0.05). Multivariate prediction of myocardial stunning at both 60 and 75 min reoxygenation showed that nicorandil (30 mumol/l-1 mmol/l) was a significant (P < 0.001) protectant whereas glibenclamide was a significant risk factor (P = 0.009). It is unclear whether negative inotropic effects of nicorandil (%DT/TPT at the end of pretreatment) was mechanistically related to reduced risk of stunning since contribution was seen only to predict %DT/TPT75 (t = 3.24, P = 0.003) whereas a positive association was observed with %DT/TPT60 (t = 1.89, P = 0.068). CONCLUSION: Pretreatment with nicorandil concentration-dependently enhanced the cardioprotective effect of hypothermic high K+ cardioplegia. The risk of myocardial stunning was decreased by KATP opening with nicorandil and increased by KATP block with glibenclamide. Inotropic stimulation with dobutamine might unravel the role of negative inotropic effect of KATP opening as a contributory factor to explain the efficacy of nicorandil in our model.

The shape of human atrial action potential accounts for different frequency-related changes in vitro.

We aimed at investigating frequency-related changes of human atrial action potential (AP) in vitro to see whether baseline AP shape might account for different responses to increasing stimulation rates. Human right atrial trabeculae (n = 48) obtained from adult (n = 38, mean age 59 +/- 8, range 45-72 years) consecutive patients (approximately equal to 30% of those operated upon by a single surgeon; 1.26 preparations per patient, range 1-2) were superfused in an organ bath with oxygenated (O2 content 16 ml/l) and modified (NaHCO3 25.7 mmol/l) Tyrode's solution at 31 degrees C. Baseline electrophysiology (pacing: 1 ms duration, 2-4 mA current intensity) at cycle length (CL) of 1000 ms was recorded in 90% (43 out of 48) of the preparations. The frequency-related protocol (CL from 1600 to 300 ms) was, however, undertaken in 23 (48%) preparations because 20 (42%) became pacing unresponsive immediately after baseline recordings. No statistical differences were seen when baseline electrophysiological parameters (mean +/- SD) were grouped according to late pacing responsiveness (n = 43 vs. n = 23): respectively, resting membrane potential (RMP) was -74 +/- 6 vs. -75 +/- 4 mV, maximal upstroke velocity (Vmax) 172 +/- 60 vs. 173 +/- 39 V/s, AP amplitude (APA) 89 +/- 11 vs. 91 +/- 8 mV and AP durations were at 30% (APD30%) 10 +/- 13 vs. 13 +/- 18 ms, 50% (APD50%) 45 +/- 79 vs. 62 +/- 91 ms and 90% (APD90%) 383 +/- 103 vs. 407 +/- 108 ms. To classify baseline AP shape, two criteria were adopted: criterion 1 ("objective"), based on APA (cut-off 90 mV) and APD90% (cut-off 500 ms) computed values and criterion 2 ("visual") derived from the literature. These criteria enabled us to differentiate three AP shape types: type 1 (spike and dome), type 3 (no dome) and type 4 (extremely prolonged). At baseline, the two criteria diagnosed different proportions of AP shape types. There were, however, no intra-type statistical differences among electrophysiological parameters. By criterion 1, analysis of variance (ANOVA) showed significant inter-type differences of RMP,Vmax, APA, APD50 and 90% and by criterion 2 of APA, APD30, 50 and 90%, respectively. To facilitate comparisons with previous published data, criterion 2 was selected to analyse frequency-related changes of AP shape types. At low stimulation rate, ANOVA for repeated measures (with Greenhouse-Geisser epsilon correction) showed inter-type differences for APD30, 50 and 90% (P = 0.00005). RMP, Vmax, APA and APD90% were overall frequency-related (P = 0.00005). Inter-type frequency-related differences were however seen only for APD90%. Human atrial AP durations (30, 50 and 90%) enable differentiation among AP shape types (1, 3 and 4). By a standardized use-dependent protocol overall RMP, Vmax, APA and APD90% are frequency-related. AP shape accounts for frequency-related changes of APD90% only. A type 4 AP shape with much prolonged AP duration had a flat frequency dependence. At high stimulation rates, adult type 1 and 3 AP shapes are indistinguishable. Use-dependent and pharmacological investigations in human atrial myocytes need to take AP shape into account.

Felodipine protects human atrial muscle from hypoxia-reoxygenation dysfunction: a force-frequency relationship study in an in vitro model of stunning.

AIMS: We aimed at investigating contractile changes after hypoxia-reoxygenation and dobutamine challenge in superfused human atrial pectinate muscle to see whether high versus low stimulation rate during hypoxia might account for outcome differences compatible with the definition of an in vitro model of myocardial stunning and whether pretreatment with the dihydropyridine Ca2+ entry blocker felodipine might afford protection. METHODS: Human right atrial trabeculae obtained from adult patients were superfused in an organ bath with oxygenated (O2 content 16 ml/l) and modified (NaHCO3 25.7 mmol/l) Tyrode's solution at 37 degrees C. Dobutamine (1 nmol/l to 10 micromol/l) was superfused in 10 oxygenated preparations to select the optimal drug concentration to be used in another 22 which were randomized. Group (A) consisted of time-related controls (Tyrodes's solution for 225 min at cycle length (CL) 1600 ms and no dobutamine). There were two test groups, respectively: (B) low (1600 ms CL) and (C) high (400 ms CL) stimulation rate. After 60 min of stabilization, in groups B and C, hypoxic superfusion (O2 content 5 ml/l) lasted 60 min, then reoxygenation (60 min) and dobutamine challenge (1 micromol/l, 15 min) were performed. Analysis of variance for repeated measures with the Greenhouse-Geisser correction, and a repeated measures model with structured covariance (preparation mass, length, width and time-varying time to peak tension) matrices were used whereby grouping (G), time (T) and G x T interaction were weighted. Force-frequency relationship and post-pausal potentiation were studied after each phase. Electrophysiology, histomorphometry and electron microscopy were carried out (n=6). Felodipine (0.1 micromol/l, n=5) pretreatment (15 min before hypoxia) was given in parallel experiments. RESULTS: Time-related controls showed approximately 10% per hour decrease of developed tension and the Paradise test provided approximately 80% of control values. In test groups (as compared to baseline values) contractility was decreased approximately 65% after hypoxia-reoxygenation and it increased approximately 25% after dobutamine (G, 0.0065

Epilepsy in children with cerebral palsy.

OBJECTIVES: To study the occurrence, associated factors, nature and prognosis of seizures in children with cerebral palsy (CP). DESIGN: A prospective, descriptive, hospital-based, case-control study. SETTING: Tertiary level University Teaching Hospitals in the Al Ain Medical District, United Arab Emirates. PATIENTS: Fifty-six children with CP and seizures seen in the neurodevelopmental clinics at Al Ain and Tawam University Hospitals during the period of 1997-1999 were studied (group 1). Two control groups of 35 children with CP without seizures (group 2) and 50 children with seizures but no CP (group 3) were also studied. RESULTS: Spastic tetraplegia was the commonest type of CP associated with seizures whereas spastic diplegia was the commonest variety of CP in group 2. Most children with CP had an early onset of seizures within the first year of life as against those without CP. The children in group 1 had a higher incidence of neonatal seizures (42.9% vs. 29.4% in group 2 and 0% in group 3), presence of significant developmental delay (98.2% vs. 20.0% in group 3), occurrence of significant abnormalities on brain imaging (94.6% vs. 19.6% in group 3) and a need for use of more than 1 antiepileptic drug (66.1% vs. 30.0% in group 3). Over half of children in the study group presented with generalized tonic clonic seizures; the electroencephalogram (EEG) showed focal epileptic discharges with or without secondary generalization in 39.3%. The overall outcome of seizures in children with CP was poor needing prolonged course of anticonvulsant medications, polytherapy and higher incidence of refractory seizures and admissions for status epilepticus compared to the control group. CONCLUSIONS: Cerebral palsy is associated with a higher incidence of seizure disorders, which, in a majority, has its onset in the neonatal period; brain imaging showed abnormal pathology in most affected children, which possibly accounts for the tendency to more refractory seizures in these children.

Tecto-cerebellar dysraphia with occipital encephalocele.

We report four cases with the rare syndrome of tecto-cerebellar dysraphia with occipital encephalocele. The clinical features seen in these patients included episodic tachypnea and irregular breathing, opsoclonus, ataxia, marked hypotonia of the limbs, coloboma, and polydactyly. All four patients had midline occipital encephalocele. The cranial computed tomography scan showed partial to total agenesis of the vermis with a large communication between cisterna magna and the fourth ventricle. The computed tomography scan also showed partial deficiency of the midbrain tectum. We discuss the clinical and radiological findings and review the literature.

Congenital intrinsic duodenal obstruction: problems in the diagnosis and management.

Nineteen infants with intrinsic duodenal obstruction are analyzed. Atresia was the most common lesion. An exceptionally high rate of associated anomalies (73.7%) were present; Down's syndrome, the single most common anomaly, was seen in 47% of the infants. In seven infants, the diagnosis was delayed and in another three it was made intraoperatively while establishing a gastrostomy for esophageal atresia. Three infants died without operation because of gross prematurity and multiple anomalies. Of the 16 operated on, three died, one due to peritonitis and the other two because of metabolic derangements. Of the various operative procedures used, no significant difference was found in the final outcome of treatment. A schematic approach to the diagnosis and management is proposed.

A cluster of choanal atresia.

During a 5-month period in 1991 four infants with choanal atresia or stenosis were born at one hospital. We therefore reviewed our experience of this condition during the past 6 years and compared the patients who presented before with the four clustered cases. No definite explanation has been ascertained for this cluster of cases of choanal obstruction but a viral or other environmental teratogen could not be excluded.