The impact and opportunities of large language models like ChatGPT in oral and maxillofacial surgery: a narrative review

Since its release at the end of 2022, the social response to ChatGPT, a large language model (LLM), has been huge, as it has revolutionized the way we communicate with computers. This review was performed to describe the technical background of LLMs and to provide a review of the current literature on LLMs in the field of oral and maxillofacial surgery (OMS). The PubMed, Scopus, and Web of Science databases were searched for LLMs and OMS. Adjacent surgical disciplines were included to cover the entire literature, and records from Google Scholar and medRxiv were added. Out of the 57 records identified, 37 were included; 31 (84%) were related to GPT-3.5, four (11%) to GPT-4, and two (5%) to both. Current research on LLMs is mainly limited to research and scientific writing, patient information/communication, and medical education. Classic OMS diseases are underrepresented. The current literature related to LLMs in OMS has a limited evidence level. There is a need to investigate the use of LLMs scientifically and systematically in the core areas of OMS. Although LLMs are likely to add value outside the operating room, the use of LLMs raises ethical and medical regulatory issues that must first be addressed.

[Evaluation of cancelled emergency physician missions and patient handovers in the area of Innsbruck : Retrospective assessment of physician-staffed emergency medical service cancellations and handovers from the emergency physician to the emergency medical service in 2017 and 2018]

BACKGROUND

Human and vehicle resource management indicates a good emergency medical system (EMS). Frequently, an emergency medical technician (EMT) is the first responder to the emergency, which negates the necessity for an emergency physician (EP) and is just as sensible as handing over a stable patient to the EMT for transport to the hospital. The Austrian EMS is utilized by EMTs, in cases of potential life-threatening emergencies the dispatch center dispatches an additional team with an on-board EP. During the years 2017-2018 nearly every fifth EP mission in Innsbruck (including surrounding areas) ended in a cancellation. The numbers of patient handovers from EP to EMT are slightly lower with mission cancellations resulting in every fourth patient. Therefore, due to the high number of cancellations and handovers evaluated in this study, the findings suggest that there is a potential need to re-evaluate procedures. The re-evaluation of these procedures could determine whether these cancellations/handovers were justified or if an over hasty decision making was at fault. All cases considered in this study were from the Innsbruck and Telfs EP bases between 1 January 2017 and 13 December 2018.

METHODS

Out of a total of 96,908 emergency dispatches, there were 2470 cancellation/handover occurrences. These occurrences consisted of 1190 cancellations and 1280 patient handovers from the EP to the EMT. Patients who were transferred to the University Hospital Innsbruck were included in these figures. The protocols of the emergency dispatches have been filtered from the so-called CarPC. They have subsequently been grouped into cancellation and handover categories. The clinical diagnoses of the patients with inpatient treatment were evaluated from the hospital information system (KIS) of the University Hospital Innsbruck. This was done with the help of the so-called emergency physician indications catalogue of the German Medical Council. The diagnosis was documented in the hospital information system. The emergency protocols from the EMTs were also evaluated retrospectively. The Innsbruck based EP patients are hospitalized in the Innsbruck Hospital due their geographical position. When there is no need for a specific intervention the patients of the EPs based in Telfs are transferred to a local hospital. When a specific intervention is necessary, patient care must be provided by the University Hospital Innsbruck. Due to the privacy practices of the Innsbruck Medical University "vote of ethics" only the data of patients transferred to the Innsbruck Clinic can be evaluated. The information provided from the EPs based in Innsbruck was exclusively from the University Hospital Innsbruck's anesthesiologists. The physicians from the Telfs EP base are of mixed medical specialities. All of them, however, have an emergency medical physician diploma, in addition to the ius practicandi. Lastly, there are no EPs in Innsbruck or Telfs, who have any special obligations during their duty.

RESULTS

The results show that in 210 cases (8.5%) the indications for the EP, based on the emergency physician indications catalogue of the German Medical Council were given. Also, 8.7% of all cancellations and 8.4% of patient handovers were not justified. Patients with emergency indications had a longer hospitalization. The EP base EMS Innsbruck had more cancellations than the EP base EMS Telfs. The EMS Innsbruck also had more cancellations than patient handovers. Conversely, the EMS Telfs had more patient handovers than cancellations. On the weekends between 6:00 pm and 6:00 am there were less cancellations and handovers from both EP bases. The documentation from the EMT protocols was incomplete in 284 cancellations (23.9% of the cancellations) and 339 handovers (26.5% of the handovers), 35 patients after cancellations (2.9%), 35 patients after handovers (2.7%) needed intensive care treatment, 20 patients after cancellations (1.7% of all cancellations), and 24 patients after handovers (1.9% of all handovers) who needed intensive care treatment had a critical diagnosis. In 40 cases of patient handovers, the EP was alerted to another emergency follow-up within 10 min.

CONCLUSION

In Austria, the introduction of a standardized emergency indication checklist might help dispatch centers to provide a more accurate dispatch as well as all EMS team members. Furthermore, a better traceability system (according to EP cancellations and patient handovers from the EP to the EMT) could be achieved. The documentation requirements should be more precise by all members of the EMT staff, not only for the legal aspects but also for improving the overall management quality. Intense education and training as well as diagnosis feedbacks could help to reduce the number of risky cancellations/patient handovers.

Kleefstra syndrome: Considerations about treatment strategy in 2 patients with a causative Ehmt1 mutation and apathy

Introduction

Kleefstra syndrome [OMIM: 610253] is caused by a 9q34.3 micro-deletion or an intragenic mutation in the EHMT1 gene. Its core phenotype comprises intellectual disability, childhood hypotonia and distinct dysmorphisms. The syndrome can be associated with congenital anomalies, epilepsy, cardiac arrhythmias and a typical sleep pattern. Starting from adult age, a regressive phenotype may develop.

Objectives

Further delineation of the neuropsychiatric phenotype.

Aims

Formulating a comprehensive treatment approach.

Methods

Detailed examination of two patients with EHMT1 mutation.

Results

Patient 1, male aged 34 years, showed recurrent behavioral problems with aggression and self-injuries as well as obstipation. Elsewhere, a diagnosis of autism was established. Aged 24, he suffered from some epileptic seizures. Recently, paroxysmal atrial fibrillation was diagnosed. Neither treatment with pipamperone and risperidone nor with valproate was effective for behavioral control. Array analysis and metabolic screening did not reveal abnormalities. Whole exome sequencing revealed an intragenic EHMT1 mutation. Patient 2, female aged 53 years, was known with childhood epilepsy and developed gradual decline of general functioning with motor slowing from her third decade. In her thirties, a mood/anxiety disorder was suspected for which several antidepressants were given without any effect. Array analysis was normal. A pathogenic nucleotide deletion was identified resulting in a frame-shift in exon 21 of the EHMT1 gene. In both patients marked apathy was observed (AES = 62 and 64, respectively).

Conclusions

Apathy syndrome in Kleefstra syndrome should be differentiated from depression and autism. Apart from treatment with selected psychotropics, individually targeted contextual measures should always be implemented.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Improvement in advanced pancreatic cancer survival with novel chemotherapeutic strategies - experience of a community based hospital

Background: New chemotherapeutic strategies for locally advanced or metastatic pancreatic ductal adenocarcinoma (PDAC) have been shown to improve survival in randomized clinical trials. Little is known about the use of such chemotherapies and their benefit in community-based hospitals. This retrospective study analyzes the overall survival of these patients under "real life conditions" before and after the introduction of FOLFIRINOX in 2011. Methods: We retrospectively identified consecutive patients with PDAC who were treated at our hospital from 2011 to June 2014 (2011+ cohort) and 2004 to 2010 (historical cohort). Patients were included if PDAC was diagnosed in a locally advanced or metastatic state and at least 1 cycle of chemotherapy was given. Survival was assessed until April 2016. Patients with FOLFIRINOX were further analyzed regarding drug administration and side effects. Results: 128 patients met the inclusion criteria. Of the 74 patients in the historical cohort, 62 patients received Gemcitabine. Of the 54 patients diagnosed between 2011 and June 2014, 28 patients received FOLFIRINOX and 22 Gemcitabine as the first-line chemotherapy. Only 34 % of the patients in the historical cohort received a second-line chemotherapy in comparison to 69 % in the 2011+ cohort. Median overall survival (OS) showed a survival of 13.1 months (95 % CI; 11.6 - 14.5) for the 2011+ cohort compared to 9.6 months (95 % CI; 6.1 - 13.1) in the historical group. Conclusion: This study shows a marked improvement in survival of patients diagnosed with locally advanced or metastatic PDAC in a community-based hospital during the past 4 years. The most likely reasons are the use of new polychemotherapies like FOLFIRINOX and the use of second-line chemotherapy.

A randomized, double-blind, placebo-controlled phase II study to assess the efficacy and safety of mapatumumab with sorafenib in patients with advanced hepatocellular carcinoma

BACKGROUND

This randomized, double-blind, placebo-controlled, phase II study evaluated the efficacy and safety of mapatumumab (a human agonistic monoclonal antibody against tumor necrosis factor-related apoptosis-inducing ligand receptor 1) in combination with sorafenib in patients with advanced hepatocellular carcinoma (HCC).

PATIENTS AND METHODS

Patients with advanced HCC (stratified by Barcelona Clinic Liver Cancer stage and Eastern Cooperative Oncology Group performance status) were randomized 1:1 to receive sorafenib (400 mg, twice daily per 21-day cycle) and either placebo (placebo-sorafenib arm) or mapatumumab (30 mg/kg on day 1 per 21-day cycle; mapatumumab-sorafenib arm). The primary end point was time to (radiologic) progression (TTP), assessed by blinded independent central review. Key secondary end points included progression-free survival, overall survival, and objective response.

RESULTS

In total, 101 patients were randomized (placebo-sorafenib arm: N = 51; mapatumumab-sorafenib arm: N = 50). There was no significant difference in median TTP between both arms [5.6 versus 4.1 months, respectively; adjusted hazard ratio (one-sided 90% confidence interval) 1.192 (0-1.737)]. No mapatumumab-related benefit was identified when TTP was evaluated in the stratified subgroups. The addition of mapatumumab to sorafenib did not demonstrate improvement in the secondary efficacy end points. The reported frequency of adverse events (AEs) and serious AEs was comparable in both treatment arms.

CONCLUSIONS

The addition of mapatumumab to sorafenib did not improve TTP or other efficacy end points, nor did it substantially change the toxicity profile of sorafenib in patients with advanced HCC. Based on these results, further development of the combination of mapatumumab and sorafenib in HCC is not planned.

Multiaxial mechanical behavior of human fetal membranes and its relationship to microstructure

This study was directed to the measurement of the mechanical response of fetal membranes to physiologically relevant loading conditions. Characteristic mechanical parameters were determined and their relation to the microstructural constituents collagen and elastin as well as to the pyridinium cross-link concentrations analyzed. 51 samples from twelve fetal membranes were tested on a custom-built inflation device, which allows mechanical characterization within a multiaxial state of stress. Methods of nonlinear continuum mechanics were used to extract representative mechanical parameters. Established biochemical assays were applied for the determination of the collagen and elastin content. Collagen cross-link concentrations were determined by high-performance liquid chromatography measurements. The results indicate a distinct correlation between the mechanical parameters of high stretch stiffness and membrane tension at rupture and the biochemical data of collagen content and pyridinoline as well as deoxypyridinoline concentrations. No correlation was observed between the mechanical parameters and the elastin content. Moreover, the low stretch stiffness is, with a value of 105 ± 31 × 10(-3) N/ mm much higher for a biaxial state of stress compared to a uniaxial stress configuration. Determination of constitutive model equations leads to better predictive capabilities for a reduced polynomial hyperelastic model with only terms related to the second invariant, I 2, of the right Cauchy-Green deformation tensor. Relevant insights were obtained on the mechanical behavior of fetal membranes. Collagen and its cross-linking were shown to determine membrane's stiffness and strength for multiaxial stress states. Their nonlinear deformation behavior characterizes the fetal membranes as I 2 material.

New constraint on the existence of the μ+ → e+ γ decay

The analysis of a combined data set, totaling 3.6 × 10(14) stopped muons on target, in the search for the lepton flavor violating decay μ(+) → e(+)γ is presented. The data collected by the MEG experiment at the Paul Scherrer Institut show no excess of events compared to background expectations and yield a new upper limit on the branching ratio of this decay of 5.7 × 10(-13) (90% confidence level). This represents a four times more stringent limit than the previous world best limit set by MEG.

Measurement of muon capture on the proton to 1% precision and determination of the pseudoscalar coupling gP

The MuCap experiment at the Paul Scherrer Institute has measured the rate Λ(S) of muon capture from the singlet state of the muonic hydrogen atom to a precision of 1%. A muon beam was stopped in a time projection chamber filled with 10-bar, ultrapure hydrogen gas. Cylindrical wire chambers and a segmented scintillator barrel detected electrons from muon decay. Λ(S) is determined from the difference between the μ(-) disappearance rate in hydrogen and the free muon decay rate. The result is based on the analysis of 1.2 × 10(10) μ(-) decays, from which we extract the capture rate Λ(S) = (714.9 ± 5.4(stat) ± 5.1(syst)) s(-1) and derive the proton's pseudoscalar coupling g(P)(q(0)(2) = -0.88 m(μ)(2)) = 8.06 ± 0.55.

New limit on the lepton-flavor-violating decay μ+→e+γ

We present a new result based on an analysis of the data collected by the MEG detector at the Paul Scherrer Institut in 2009 and 2010, in search of the lepton-flavor-violating decay μ(+)e(+)γ. The likelihood analysis of the combined data sample, which corresponds to a total of 1.8×10(14) muon decays, gives a 90% C.L. upper limit of 2.4×10(-12) on the branching ratio of the μ(+)→e(+)γ decay, constituting the most stringent limit on the existence of this decay to date.

A novel duplication of chromosome (13)(q14.1q21.3) in a patient with mental retardation and microcephaly

We report on a mentally retarded female with behavioural problems, microcephaly, mild facial dysmorphisms, short stature and small hands with thin fingers due to a de novo partial duplication within the long arm of chromosome 13(q14.1q21.3). She was primarily referred to the outpatient department of neuropsychiatry because of short lasting psychotic episodes. No formal psychiatric diagnosis was made and the behavioural problems appeared the result of anxieties provoked by novel situations, enhanced by the intellectual disability. To the author's knowledge, this duplication has not been published previously and it is considered causative of the phenotype.

Fast self-collision detection and simulation of bifurcated stents to treat abdominal aortic aneurysms (AAA)

In this paper, we present a fast and robust collision detection algorithm for bifurcated stent graft simulation. The algorithm is designed for simulating bifurcations of Y-stents in blood vessels in CT-data. For stent simulation, we use the active contours method (ACM) which realizes internal and external forces acting on the stent. The internal forces are for the elastic and smoothing behavior of the stent surface. The external forces (balloon force and resistance of the vessel wall) pull and push the stent towards the artery wall. In addition to these two forces, another force interacts in the bifurcated part of the stent. For this purpose, the algorithm uses axis aligned bounding boxes (AABB) that are placed along these bifurcated parts. Our simulation and collision detection algorithm is evaluated on computed tomography angiography (CTA) data with variations in anatomy and location of pathology.

Measurement of the muon capture rate in hydrogen gas and determination of the proton's pseudoscalar coupling gP

The rate of nuclear muon capture by the proton has been measured using a new technique based on a time projection chamber operating in ultraclean, deuterium-depleted hydrogen gas, which is key to avoiding uncertainties from muonic molecule formation. The capture rate from the hyperfine singlet ground state of the microp atom was obtained from the difference between the micro(-) disappearance rate in hydrogen and the world average for the micro(+) decay rate, yielding Lambda(S)=725.0+/-17.4 s(-1), from which the induced pseudoscalar coupling of the nucleon, g(P)(q(2)=-0.88m(2)(micro))=7.3+/-1.1, is extracted.

High statistics measurement of the K+-->pi0e+nu (K+e3) branching ratio

E865 at the Brookhaven National Laboratory AGS collected about 70 000 K(+)(e3) events to measure the K(+)(e3) branching ratio relative to the observed K+-->pi(+)pi(0), K+-->pi(0)micro(+)nu, and K+-->pi(+)pi(0)pi(0) decays. The pi(0) in all the decays was detected using the e(+)e(-) pair from pi(0)-->e(+)e(-)gamma decay and no photons were required. Using the 2002 Particle Data Group branching ratios for the normalization decays, we obtain BR(K(+)(e3(gamma)))=(5.13+/-0.02(stat)+/-0.09(syst)+/-0.04(norm))%, where K(+)(e3(gamma)) includes the effect of virtual and real photons. This result is approximately 2.3sigma higher than the current Particle Data Group value. Implications for the V(us) element of the CKM matrix, and the matrix's unitarity are discussed.

Experimental study of the radiative decays K+-->mu(+)nue(+)e(-) and K+-->e(+)nue(+)e(-)

Experiment 865 at the Brookhaven Alternating Gradient Synchrotron obtained 410 K+-->e(+)nue(+)e(-) and 2679 K+-->mu(+)nue(+)e(-) events including 10% and 19% background. The branching ratios were measured to be [2.48+/-0.14(stat)+/-0.14(syst)]x10(-8) (m(ee)>150 MeV) and (7.06+/-0.16+/-0.26)x10(-8) (m(ee)>145 MeV), respectively. Results for the decay form factors are presented.

New measurement of K(+)(e4) decay and the s-pave pi pi-scattering length a(0)(0)

A sample of 4 x 10(5) events from the decay K(+)-->pi(+)pi(-)e(+)nu(e) (K(e4)) has been collected in experiment E865 at the Brookhaven Alternating Gradient Synchrotron. The analysis of these data yields new measurements of the K(e4) branching ratio [(4.11+/-0.01+/-0.11) x 10(-5)], the s-wave pi pi scattering length [a(0)(0) = 0.216+/-0.013(stat)+/-0.004(syst)+/-0.005(theor)], and the form factors F, G, and H of the hadronic current and their dependence on the invariant pi pi mass.

Search for lepton flavor violation in K+ decays into a charged pion and two leptons

A search for lepton flavor violating decays, K+ --> mu+ mu+ pi-, K+ --> e+ e+ pi-, K+ --> pi+ e+ mu-, K+ --> mu+ e+ pi-, and pi0 --> e+ mu-, was performed using the data collected in Experiment E865 at the Brookhaven Alternating Gradient Synchrotron. No signal was found in any of the decay modes. At the 90% confidence level, the branching ratios are less than 3.0x10(-9), 6.4x10(-10), 5. 2x10(-10), 5.0x10(-10), and 3.4x10(-9), respectively.

Improved limit on the rate of the decay K+ --> pi(+)&mgr;(+)e(-)

We report results of a search for the lepton-family number violating decay K+-->pi(+)&mgr;(+)e(-) from data collected by experiment E865 in 1996 at the Alternating Gradient Synchroton of Brookhaven National Laboratory. We place an upper limit on the branching ratio at 3.9x10(-11) ( 90% C.L.). Together with results based on data collected in 1995 and an earlier experiment, E777, this result establishes a combined 90% confidence level upper limit on the branching ratio at 2.8x10(-11). We also report a new upper limit on the branching ratio for pi(0)-->&mgr;(+)e(-) of 3.8x10(-10) ( 90% C. L.).

First direct observation of coulomb explosion during the formation of exotic atoms

A Doppler broadening of x-ray transitions from pionic nitrogen and muonic oxygen, which is attributed to Coulomb explosion of the molecules, has been observed by using a crystal spectrometer. Large linewidths indicate fast ionization of the molecules and a charge of (3-4)e for the accelerated fragments.

New measurement of the rare decay K+ --> pi(+)&mgr;(+)&mgr;(-)

More than 400 K+-->pi(+)&mgr;(+)&mgr;(-) events were observed in a rare K+ decay experiment at the Brookhaven Alternating Gradient Synchrotron. Normalized to the K+-->pi(+)pi(+)pi(-) decay, the branching ratio is determined to be [9.22+/-0.60(stat)+/-0. 49(syst)]x10(-8). This branching ratio and the &mgr;&mgr; mass spectrum is in very good agreement with the measurement of the K+-->pi(+)e(+)e(-) decay, but deviates significantly from the previous measurement.

[Psychic coping with spontaneous abortion]

Spontaneous abortion is the early and involuntary loss of pregnancy and occurs in about 15 to 20% of all pregnancies. In this study, Filipp's heuristic model for critical life events was used to evaluate general and specific causal attributions and depressive symptoms after spontaneous abortion. A sample of 100 women was investigated at four measuring points between diagnosis and five weeks after the spontaneous abortion. The results regarding depressive symptom levels showed that two days after the miscarriage, 50% of the women were severely depressed, and five weeks later 30% were still depressed. Depressive symptoms were increased in cases of prior reproductive loss and when pregnancy was planned or desired. With regard to general causal attributions, women who tended to more internal, stable, and global attributions showed a significantly higher level of depressive symptoms than women with external, unstable, and specific attributions. In the area of specific attributions regarding pregnancy loss, the same patterns of results were found.

Normative volumetric data of the developing hippocampus in children based on magnetic resonance imaging

PURPOSE

To acquire normative data of the hippocampus and its postnatal growth in 50 children (age, 1 month to 15 years) without epilepsy.

METHODS

Morphometry of the hippocampus was carried out by using a spoiled FLASH 3D sequence (sagittal orientation), whereas the volume of the brain was assessed with a T2-weighted spin-echo sequence (transverse orientation). The volume of the hippocampus and the brain was determined by following Cavalieri's principle. Growth curves of the brain and hippocampus were fitted to a nonlinear Boltzmann sigmoidal equation.

RESULTS

Intra-/interobserver coefficient of variation was 2.0/4.9% for hippocampal volume measurements and 2.0/2.1% for brain volumetry. A significant difference in volume was noted between the right and left hippocampus (p < 0.001), with the right side being larger on average by 0.10 cc. Correlation coefficients of growth curves ranged between 0.71 and 0.94. Growth curves demonstrated a faster development of the hippocampus in girls. A steeper slope of hippocampal growth as compared with brain growth was found in girls, whereas in boys, the slope of brain growth was steeper.

CONCLUSIONS

Our findings will be of help in evaluating vulnerable phases of the hippocampal formation with accelerated growth, thereby leading to a better understanding of the development of hippocampal sclerosis in early childhood.

Topographic mapping of brain electrical activity in children with food-induced attention deficit hyperkinetic disorder

In 15 children suffering from food induced attention deficit hyperkinetic syndrome, topographic EEG mapping of brain electrical activity was carried out following avoidance and ingestion of previously identified provoking foods. A crossover design was used and recordings were interpreted independently by two investigators, one of whom was blind to the order of testing. During consumption of provoking foods there was a significant increase in betal activity in the frontotemporal areas of the brain. This investigation is the first one to show an association between brain electrical activity and intake of provoking foods in children with food-induced attention deficit hyperactivity disorder.

CONCLUSIONS

These data support the hypothesis that in a subgroup of children with attention deficit hyperactivity disorder certain foods may not only influence clinical symptoms but may also alter brain electrical activity.

MRI of primary meningeal sarcomas in two children: differential diagnostic considerations

Meningeal sarcomas are very rare, highly aggressive tumours affecting children more frequently than adults. The clinical course and MRI of meningeal sarcomas in two cases are discussed with special regard to possible misinterpretation. In one case MRI demonstrated a circumscribed mass in contact with the meninges, with central areas of haemorrhage. In the other, a case of primary leptomeningeal sarcomatosis, several MRI examinations over the course of almost a year were unhelpful, despite severe neurological complaints. Then MRI revealed meningeal contrast enhancement all over the brain and spinal canal, together with cerebral infarcts. MRI of meningeal sarcomas has not been discussed in the literature. MRI did not permit specific diagnosis, but enabled visualisation of the extent of the tumour and/or meningeal involvement. Early histological diagnosis is indispensable for adequate treatment.

Endocrine disorders in septo-optic dysplasia (De Morsier syndrome)--evaluation and follow up of 18 patients

Septo-optic dysplasia (SOD) is characterized by hypoplasia of the optic nerve, various types of forebrain defects and hormonal deficiencies. We have studied the clinical and endocrinological characteristics of 18 such patients retrospectively to: (1) better define the endocrine abnormalities in children with SOD; and (2) to find approaches for the interdisciplinary long-term care of children with SOD. The children were seen at the Children's Hospital of the University of Munich from 1976 to 1992 (8 boys, 10 girls; age at initial presentation: 1 day-13 years of age, mean 1.9 years). Unilateral hypoplasia of the optic nerve was found in 7 cases, bilateral hypoplasia in 11. Sonographic, CCT or MRI yielded the following results: 4 of the patients had a cavum septum pellucidum, 3 patients had hypoplasia of the cerebellum, 1 aplasia of the corpus callosum and 1 aplasia of the fornix. An empty sella with or without an ectopic pituitary was seen in 4 cases. Height standard deviation score (SDS) at time of diagnosis was -4.0 to +0.4, mean -2.92. Endocrine deficiencies were present in all 11 patients who had undergone endocrinological investigations. Seven patients suffered from isolated growth hormone (GH) deficiency or multiple hypopituitarism. One had diabetes insipidus centralis, 2 had hypogonadotropic hypogonadism, 1 had hypothyroidism and 2 adrenal insufficiency. Hypothalamic testing was performed only in a subset of patients: in 5 of 11 children tested a thyrotropin releasing hormone (TRH test), in two out of nine a gonadotropin releasing hormone (GnRH) test, and in three out of six GH releasing hormone (GHRH) test yielded abnormal results. High prolactin levels were measured in two out of five patients.

CONCLUSION

SOD is characterized by optic nerve hypoplasia and a variety of endocrine deficiencies. In addition, forebrain malformations are present in most SOD patients. Hormonal disorders are present in some SOD patients which may be of hypothalamic origin and need to be investigated systematically.

Glutamate in pyridoxine-dependent epilepsy: neurotoxic glutamate concentration in the cerebrospinal fluid and its normalization by pyridoxine

BACKGROUND

Pyridoxine-dependent epilepsy is a rare autosomal recessive disorder. Untreated patients suffer from a progressive encephalopathy with mental retardation, intractable epilepsy, and progressive neurological signs and symptoms. Lifelong supplementation with vitamin B6 is the treatment of choice. However, despite early treatment, many patients develop mental retardation.

OBJECTIVES

To assess the role of glutamate as an excitatory neurotransmitter and neurotoxin in pyridoxine-dependent epilepsy.

METHODS

We examined cerebrospinal fluid (CSF) levels of glutamate, gamma-aminobutyric acid, and pyridoxal-5'-phosphate in a patient with pyridoxine dependency while on and off vitamin B6 treatment.

RESULTS

Off vitamin B6 the glutamate level was two hundred times normal. An intermediate dose of vitamin B6 (5 mg/kg BW/day) caused normalization of the EEG and remission of the seizures, but the CSF glutamate concentration was still ten times normal. With a higher dose of pyridoxine (10 mg/kg BW/day) the CSF glutamic acid normalized.

CONCLUSIONS

The results indicate that control of epilepsy might not suffice as the therapeutic aim in treating of pyridoxine dependency. In view of the evidence for the role of excitatory amino acids in destruction of CNS nerve cells, the optimal treatment must counteract the raised levels of CSF glutamate and the dosage of vitamin B6 must be adjusted accordingly. The development of mental retardation might theoretically be prevented by adjusting the dose of vitamin B6 to achieve not only remission of epilepsy but also normalization of CSF glutamate.