Prognostic factors for surgical outcomes among patients with multilevel cervical spondylotic myelopathy.

OBJECTIVE: Many clinical and imaging characteristics can influence the prognosis of multilevel cervical spondylotic myelopathy (M-CSM). This study investigated the factors that influence surgical outcomes among patients with M-CSM. PATIENTS AND METHODS: This prospective study included 30 patients who underwent surgical treatment for M-CSM from June 2019 to June 2021. RESULTS: The average age was 62.29 years, and the average follow-up time was 13.13 months. Preoperative, postoperative, and follow-up Modified Japanese Orthopaedic Association (mJOA) scores were 10.17, 13.53, and 16.17, respectively. The average postoperative and follow-up recovery rates were 45.46% and 76.69%, respectively. Patients older than 60 years (p = 0.04), male patients (p = 0.023), and smokers (p = 0.027) had lower preoperative mJOA scores than other groups. Patients with symptoms duration longer than 6 months had lower recovery rates (p = 0.021) than those with shorter symptom duration. Patients with intramedullary hyperintensity in ≤ 2 vertebra (p = 0.041) or anterior surgery (p = 0.022) had better postoperative recovery rates than their counterparts. A shorter period of hyperintensity in the intramedullary region on sagittal T2-weighted magnetic resonance imaging (T2W MRI) was significantly associated with faster discharge (p = 0.044). Patients with type 3 (discrete focal) hyperintensity in the intramedullary region on axial T2W MRI had a 6.75-fold increase in experiencing less than 50% postoperative recovery compared with other groups (odds ratio: 6.75, 95% confidence interval: 2.73-16.67). CONCLUSIONS: Good prognostic factors for a shorter recovery included hyperintensity in the intramedullary region for ≤ 2 levels, shorter period of hyperintensity in the intramedullary region on sagittal T2W MRI, and an anterior surgical approach. A duration of symptoms longer than 6 months and discrete hyperintensity in the intramedullary region on axial T2W MRI were poor prognostic indicators associated with a longer recovery period.

Outcomes of alveolar segmental 'sandwich' osteotomy with interpositional particulate allograft for severe vertical defects in the anterior maxilla and mandible.

The purpose of this study was to report the outcomes of interpositional osteotomy with mineralized allograft in the treatment of alveolar vertical defects in preparation for implant placement. Thirteen defects (11 maxillary and two mandibular) were treated with osteotomy segments ranging in length from two to five missing teeth. The segments were positioned 5-7 mm coronally, with the gap space filled with allograft and then fixated with titanium hardware. Vertical bone augmentation was analyzed by superimposing pre- and post-surgical cone beam computed tomography images and stratified based on the length and number of missing teeth in each edentulous segment. The mean vertical bone gain was 3.7 ± 1.6 mm in the area of greatest vertical defect and the mean length of the transport segment was 20.5 ± 8.1 mm. These segments represented two-, three-, four-, or five-tooth edentulous sites; the mean vertical bone gain for these segments was 1.7 ± 0.5 mm, 3.8 ± 1.0 mm, 4.6 ± 0.9 mm, and 6.7 ± 0.0 mm, respectively. Stability of vertical height gain was found to be directly proportional to the span length of the osteotomy segment, with the largest five-tooth segment achieving the greatest gain. Vertical bone gain in two-tooth segments was minimal, indicating a moderate amount of resorption.

Specifying the neural basis of the spacing effect with multivariate ERP.

The spacing effect refers to the finding that, given a fixed amount of study time, a longer interval between study repetitions improves long-term retention (e.g., Cepeda et al., 2006; Ebbinghaus, 1885/1967; Melton, 1970). Although the spacing effect is a robust and reliable finding in the memory literature, its cognitive and neural mechanisms remain unclear. We used event-related potentials (ERPs) to investigate the neural correlates of the spacing effect in the context of the study-phase retrieval hypothesis, which posits that repeated exposure of an item serves as a reminder of one's previous experience with the item, thereby promoting long-term retention. ERPs were recorded from 30 healthy young adults as they studied pairs of words under three levels of lag, corresponding to 0, 4, or 12 intervening pairs between the first and second occurrences of a target pair. We used two study-phase tasks that differed in the degree of retrieval that was required. During the test phase, participants were tested on paired-associate recall. The results demonstrated a significant effect of spacing on memory performance. However, the effect of encoding task and the interaction between encoding task and spacing were not significant. The results of the partial least squares analyses, which are not constrained by time window or electrode selection, revealed a spacing effect on the ERP data for both study-phase tasks; this effect occurred late in the epoch and was most salient over the centro-parietal scalp region. The results add to the literature on the neural correlates of the spacing effect by providing a more comprehensive account compared to past ERP findings that were focused on testing specific ERP components. They also call for further investigation on the various theoretical accounts of the spacing effect.

Activity of a selective inhibitor of nuclear export, selinexor (KPT-330), against AML-initiating cells engrafted into immunosuppressed NSG mice.

Currently available combination chemotherapy for acute myeloid leukemia (AML) often fails to result in long-term remissions, emphasizing the need for novel therapeutic strategies. We reasoned that targeted inhibition of a prominent nuclear exporter, XPO1/CRM1, could eradicate self-renewing leukemia-initiating cells (LICs) whose survival depends on timely XPO1-mediated transport of specific protein and RNA cargoes. Using an immunosuppressed mouse model bearing primary patient-derived AML cells, we demonstrate that selinexor (KPT-330), an oral antagonist of XPO1 that is currently in clinical trials, has strong activity against primary AML cells while sparing normal stem and progenitor cells. Importantly, limiting dilution transplantation assays showed that this cytotoxic activity is not limited to the rapidly proliferating bulk population of leukemic cells but extends to the LICs, whose inherent drug resistance and unrestricted self-renewal capacity has been implicated in the difficulty of curing AML patients with conventional chemotherapy alone.

Is buccolingual angulation of maxillary anterior implants associated with the crestal labial soft tissue thickness?

We aimed to examine the relationship between crestal labial soft tissue thickness (CLSTT, measured with a digital calliper at the crestal level of casts) and implant buccolingual angulation (IBLA). The records of 22 females and 10 males treated with two bone-level implants (3.3-4.6mm) between the maxillary canines were evaluated. IBLA was recorded as cingulum, incisal, or labial based on the screw access hole position on provisional restorations. Postoperative implant labial bone thickness (ILBT) at the crestal (2mm from crest) and mid-implant levels were measured on sectional cone beam computed tomography scans. The mean (SD) ridge width at the crestal level was 6.81 (0.98) mm. Mean (SD) CLSTT for implants with cingulum, incisal, and labial angulations were 2.98 (0.84), 2.24 (0.51), and 1.71 (0.72) mm, respectively. Significant differences were detected between CLSTT of implants with cingulum and incisal, as well as cingulum and labial angulations (P<0.01). Of implants with cingulum, incisal, and labial angulations, 3.4%, 20%, and 53.3%, respectively, had a CLSTT<2mm. Overall, 74.2% of CLSTT variance could be predicted by IBLA and ILBT at the crestal and mid-implant levels. A significant association between CLSTT and IBLA was noted when ILBT (crestal level) was <2mm (P<0.01). Implants with labial angulations carry a higher risk of soft tissue complications when the crestal implant labial bone thickness is <2mm.

Carcinoid tumor and intravenous octreotide infusion during labor and delivery.

There are limited numbers of reports concerning the management of pregnancy complicated by carcinoid tumors. Octreotide, the synthetic analogue of somatostatin, has been found to be beneficial in preventing the perioperative exacerbation of carcinoid syndrome. We present a case of the successful use of neuraxial analgesia/anesthesia for labor and vaginal delivery in a symptomatic parturient afflicted with carcinoid syndrome, who received an intravenous infusion of octreotide throughout labor and vaginal delivery.

Modifications of local cerebral glucose utilization in thalamic structures following injection of a dopaminergic agonist in the nucleus accumbens--involvement in antiepileptic effects?

Dopaminergic transmission in the nucleus accumbens (NAcc) is implicated in different aspects of reward and motivational mechanisms. More recently, it has been suggested that this nucleus could also be involved in the modulation of generalized epileptic seizures. In particular, microinjection of dopaminergic agonists in the NAcc suppresses the occurrence of epileptic seizures in a model of absence seizures, the GAERS (generalized absence epileptic rats from Strasbourg). The aim of this study was to identify the structures involved in this effect. Local cerebral metabolic rates for glucose utilization (LCMRglc) were measured in different parts of the basal ganglia and output structures after apomorphine injection in the NAcc in GAERS and in the inbred non-epileptic rats (NE), concomitantly with seizure suppression. Apomorphine injection in the NAcc induced a significant increase of glucose intake in the anteromedial, mediodorsal and ventrolateral nuclei of the thalamus in NE rats, while no significant changes were observed in the basal ganglia structures (globus pallidus, subthalamic nucleus, substantia nigra). Furthermore, microinjections of muscimol (100 and 200 pmol/side) in the mediodorsal nucleus of the thalamus in GAERS rats suppressed seizures. These results suggest that the mediodorsal nucleus of the thalamus could be involved in absence seizures modulation. Along with data from the literature, our data suggest that this nucleus could participate in the control of the basal ganglia over generalized epileptic seizures.

Maxillary sinus floor elevation: review of anatomy and two techniques.

A review of maxillary sinus floor elevation as an integral part of restoring the posterior maxilla is discussed. The related anatomy of the area and the current techniques available are reviewed. The classic lateral antrostomy pioneered by Tatum appears to be the most common sinus lift procedure. The more conservative crestal approach, advocated by Summers, provides another effective way of allowing implant fixture placement in the atrophic maxilla.

Evolution of hippocampal epileptic activity during the development of hippocampal sclerosis in a mouse model of temporal lobe epilepsy.

Unilateral intrahippocampal injection of kainic acid in adult mice reproduces most of the morphological characteristics of hippocampal sclerosis (neuronal loss, gliosis, reorganization of neurotransmitter receptors, mossy fiber sprouting, granule cell dispersion) observed in patients with temporal lobe epilepsy. Whereas some neuronal loss is observed immediately after the initial status epilepticus induced by kainate treatment, most reorganization processes develop progressively over a period of several weeks. The aim of this study was to characterize the evolution of seizure activity in this model and to assess its pharmacological reactivity to classical antiepileptic drugs. Intrahippocampal electroencephalographic recordings showed three distinct phases of paroxystic activity following unilateral injection of kainic acid (1 nmol in 50 nl) into the dorsal hippocampus of adult mice: (i) a non-convulsive status epilepticus, (ii) a latent phase lasting approximately 2 weeks, during which no organized activity was recorded, and (iii) a phase of chronic seizure activity with recurrent hippocampal paroxysmal discharges characterized by high amplitude sharp wave onset. These recurrent seizures were first seen about 2 weeks post-injection. They were limited to the injected area and were not observed in the cerebral cortex, contralateral hippocampus or ipsilateral amygdala. Secondary propagation to the contralateral hippocampus and to the cerebral cortex was rare. In addition hippocampal paroxysmal discharges were not responsive to acute carbamazepine, phenytoin, or valproate treatment, but could be suppressed by diazepam. Our data further validate intrahippocampal injection of kainate in mice as a model of temporal lobe epilepsy and suggest that synaptic reorganization in the lesioned hippocampus is necessary for the development of organized recurrent seizures.

Maxillofacial injuries associated with domestic violence.

PURPOSE: The purpose of this study was to report the incidence, causes, and patterns of maxillofacial injury associated with domestic violence. PATIENTS AND METHODS: A retrospective review of patients treated for domestic violence injuries at an inner-city hospital over a 5-year period was done, and data were collected on type and location of injury, mechanism of injury, alcohol involvement, and treatment. RESULTS: The sample consisted of 236 emergency room admissions. The majority (81%) of victims presented with maxillofacial injuries. The fist was a favorite means for assaults (67%). The middle third of the face was most commonly involved (69%). Soft tissue injuries were the most common type of injury (61%). Facial fractures were present in 30% of victims. The average number of mandible fractures per patient was 1.32. The majority of facial fractures (40%) were nasal fractures. Left-sided facial injuries were more common than right sided. CONCLUSIONS: These data confirm that most victims of domestic violence sustain maxillofacial injuries. Midface injuries predominate. The preponderance of facial injuries makes it very likely that oral and maxillofacial surgeons will be involved in the care of these patients.

Intracranial migration of halo fixation pins: a complication of using an extraoral distraction device.

OBJECTIVE: Distraction osteogenesis is a well-accepted technique in the treatment of patients with hypoplastic craniofacial components. Complications of distraction osteogenesis are well described in the literature. We describe a complication of using an external distraction device in a 9-year-old girl with Pfeiffer. INTERVENTION AND RESULTS: A modified Lefort III osteotomy was performed for maxillary hypoplasia with application of an external distraction halo device by a pediatric neurosurgeon. A postoperative computed tomography (CT) scan showed 0.5-cm skull penetration of the cranial pins. The pins were repositioned and the patient was followed up on a regular basis until discharge from the hospital. At 3-week follow-up, a CT scan of the head showed migration of the pins 1.5 cm intracranially. The halo was removed and repositioned at a different site. No detectable neurological sequelae from the pin penetration were noted. The patient developed cellulitis at the site of the penetration and was admitted to the hospital for a course of intravenous antibiotics. There were no other complications, and the rest of her treatment course proceeded as planned. A review of the literature on complications of halo usage as well as suggestions for their management in association with distraction osteogenesis is described.

Brain-derived neurotrophic factor delays hippocampal kindling in the rat.

Epileptic seizures increase the expression of brain-derived neurotrophic factor in the hippocampus. Since this neurotrophin exerts modulatory effects on neuronal excitability in this structure, it may play an important role in hippocampal epileptogenesis. This question was addressed by studying the effects of chronic infusions of recombinant brain-derived neurotrophic factor and brain-derived neurotrophic factor antisense in the hippocampus during the first seven days of hippocampal kindling. Infusion with brain-derived neurotrophic factor (6-24 microg/day) significantly delayed the progression of standard hippocampal kindling and strongly suppressed seizures induced by rapid hippocampal kindling. These suppressive effects were dose dependent, long lasting, not secondary to neuronal toxicity and specific to this neurotrophin, as nerve growth factor accelerated hippocampal kindling progression. They also appeared to be specific to the hippocampus, as infusion of brain-derived neurotrophic factor (48 microg/day) in the amygdala only resulted in a slight and transient delay of amygdala kindling. Conversely to the protective effects of exogenous brain-derived neurotrophic factor, chronic hippocampal infusion of antisense oligodeoxynucleotides (12 nmol/day), resulting in reduced expression of endogenous brain-derived neurotrophic factor in the hippocampus, aggravated seizures during hippocampal kindling. Taken together, our results lead us to suggest that the seizure-induced increase in brain-derived neurotrophic factor expression in the hippocampus may constitute an endogenous regulatory mechanism able to restrain hippocampal epileptogenesis.

Overexpression of neuropeptide Y induced by brain-derived neurotrophic factor in the rat hippocampus is long lasting.

Brain-derived neurotrophic factor (BDNF) plays an important role in hippocampal neuroplasticity. In particular, BDNF upregulation in the hippocampus by epileptic seizures suggests its involvement in the neuronal rearrangements accompanying epileptogenesis. We have shown previously that chronic infusion of BDNF in the hippocampus induces a long-term delay in hippocampal kindling progression. Although BDNF has been shown to enhance the excitability of this structure upon acute application, long-term transcriptional regulations leading to increased inhibition within the hippocampus may account for its suppressive effects on epileptogenesis. Therefore, the long-term consequences of a 7-day chronic intrahippocampal infusion of BDNF (12 microg/day) were investigated up to 2 weeks after the end of the infusion, on the expression of neurotransmitters contained in inhibitory hippocampal interneurons and which display anti-epileptic properties. Our results show that BDNF does not modify levels of immunostaining for glutamic acid decarboxylase, the rate-limiting enzyme for gamma-aminobutyric acid (GABA) synthesis, and somatostatin. Conversely, BDNF induces a long-lasting increase of neuropeptide Y (NPY) in the hippocampus, measured by immunohistochemistry and radioimmunoassay, outlasting the end of the infusion by at least 7 days. The distribution of BDNF-induced neuropeptide Y immunoreactivity is similar to the pattern observed in animals submitted to hippocampal kindling, with the exception of mossy fibres which only become immunoreactive following seizure activity. The enduring increase of neuropeptide Y expression induced by BDNF in the hippocampus suggests that this neurotrophin can trigger long-term genomic effects, which may contribute to the neuroplasticity of this structure, in particular during epileptogenesis.

Evidence for the involvement of the pallidum in the modulation of seizures in a genetic model of absence epilepsy in the rat.

Inhibition of the subthalamic nucleus (STN) has been shown to suppress seizures in different animal models of epilepsy. The aim of this study was to examine the role of the pallidal inputs to the STN in the control of absence seizures in a genetic model in the rat. Disinhibition of the globus pallidus or the ventral pallidum, by local injections of a GABA(A) antagonist, suppressed absence seizures. Conversely, inhibition of the ventral pallidum by a GABA(A) agonist aggravated absence seizures. Furthermore, the antiepileptic effects of intrapallidal injections of a GABA(A) antagonist were correlated with a decrease of extracellular levels of glutamate in the substantia nigra. Our results show that both the globus pallidus and the ventral pallidum exert a modulatory influence on absence seizures and suggest that these effects are mediated through the STN.

Role of the subthalamo-nigral input in the control of amygdala-kindled seizures in the rat.

The substantia nigra pars reticulata (SNpr) is a critical site for the control of epileptic seizures. Potentiation of the inhibitory GABAergic input from the striatum to the SNpr suppresses primary or secondary generalized seizures in the rat. The purpose of this study was to examine the possible involvement of the excitatory glutamatergic input from the subthalamic nucleus to the SNpr in the control of both the electroencephalographic and the motor components of amygdala-kindled seizures in the rat. Microinjections of either an N-methyl-D-aspartate (NMDA) antagonist in the substantia nigra or a GABAA agonist in the subthalamic nucleus, significantly reduced motor seizures but did not modified the afterdischarges. These results provide evidence for the involvement of the subthalamo-nigral projection in the modulation and the propagation of the motor components of amygdala-kindled seizures.