Posterior Head Region Research Articles

Differentiating rhythmic high-amplitude delta with superimposed (poly) spikes from extreme delta brushes: limitations of standardized nomenclature and implications for patient management.

Following the standardized nomenclature proposed by the American Clinical Neurophysiology Society (ACNS), rhythmic high-amplitude delta activity with superimposed spikes (RHADS) can be reported as an extreme delta brush (EDB). The clinical implications of similar electrographic patterns being reported as RHADS versus EDB are important to highlight. We aim to review the electrographic characteristics of RHADS, evaluate whether RHADS is seen in other neurological disorders, and identify the similar and unique characteristics between RHADS and EDB to ultimately determine the most accurate way to differentiate and report these patterns. We believe that the differentiation of RHADS and EDB is important as there is a vast difference in the diagnostic approach and the medical management of associated underlying etiologies. We conducted an extensive search on MEDLINE and Pubmed utilizing various combinations of keywords. Searching for "gamma polymerase and EEG", or "RHADS" or "Alpers syndrome and EEG" or "EEG" AND "Alpers-Huttenlocher syndrome". Three articles were found to be focused on the description of "RHADS" pattern in Alpers Syndrome. No publication to date were found when searching for the terms "EDB" AND "children", AND "infant" AND "adolescent" excluding "encephalitis" and "neonate". Although RHADS and EDB appear as similar EEG patterns, meticulous analysis can differentiate them. RHADS is not exclusive to patients with Alpers-Huttenlocher syndrome and may manifest in regions beyond the posterior head region. Reactivity to eye-opening and response to anesthesia can be two other elements that help in the differentiation of these patterns. RHADS is not exclusive to patients with AHS and may manifest in regions beyond the posterior head region. Reactivity to eye-opening and response to anesthesia are features that help in the differentiation of these patterns.

CLINICAL FEATURES, ELECTROENCEPHALOGRAM FINDINGS AND TREATMENT OF SELF-LIMITED FOCAL EPILEPSIES OF CHILDHOOD

Objectives: The objective is to study the clinical features of self-limited focal epilepsies of childhood and to describe their electroencephalogram (EEG) findings and treatment. Methods: Twenty cases of self-limited focal epilepsies of childhood attending the Department of Neurology Government Medical College, Kozhikode, between August 2019 and July 2020 were included in the study. Details of history, examination, EEG, and treatment were collected. Results: The age at first seizure was 1.5–12 years. Most children were diagnosed with self-limited focal epilepsy of childhood with centrotemporal spikes. One child had Panayiotopoulos syndrome. Most of the seizures occurred during sleep. The majority were generalized tonic–clonic seizures. The majority had bilateral centrotemporal spikes in EEG. The child with Panayiotopoulos had bilateral spikes from the posterior head region. All were treated with antiepileptics. Conclusion: Self-limited focal epilepsy of childhood with centrotemporal spikes was the most common self-limited focal epilepsy of childhood. They had typical centrotemporal epileptiform discharges, seen bilaterally in most. The most commonly used drug was valproate. None had any major adverse effects on therapy.

Characterization of eyes, photoreceptors, and opsins in developmental stages of the arrow worm Spadella cephaloptera (Chaetognatha).

The phylogenetic position of chaetognaths, or arrow worms, has been debated for decades, however recently they have been grouped into the Gnathifera, a sister clade to all other Spiralia. Chaetognath photoreceptor cells are anatomically unique by exhibiting a highly modified cilium and are arranged differently in the eyes of the various species. Studies investigating eye development and underlying gene regulatory networks are so far missing. To gain insights into the development and the molecular toolkit of chaetognath photoreceptors and eyes a new transcriptome of the epibenthic species Spadella cephaloptera was searched for opsins. Our screen revealed two copies of xenopsin and a single copy of peropsin. Gene expression analyses demonstrated that only xenopsin1 is expressed in photoreceptor cells of the developing lateral eyes. Adults likewise exhibit two xenopsin1 + photoreceptor cells in each of their lateral eyes. Beyond that, a single cryptochrome gene was uncovered and found to be expressed in photoreceptor cells of the lateral developing eye. In addition, cryptochrome is also expressed in the cerebral ganglia in a region in which also peropsin expression was observed. This condition is reminiscent of a nonvisual photoreceptive zone in the apical nervous system of the annelid Platynereis dumerilii that performs circadian entrainment and melatonin release. Cryptochrome is also expressed in cells of the corona ciliata, an organ in the posterior dorsal head region, indicating a role in circadian entrainment. Our study highlights the importance of the Gnathifera for unraveling the evolution of photoreceptors and eyes in Spiralia and Bilateria.

Comparison of [99mTc]Tc-tilmanocept with [99mTc]Tc-sulphur colloids and [99mTc]Tc-albumin colloids for sentinel lymph node detection in patients with cutaneous malignancies of the head

PurposeSentinel lymph node (SLN) biopsy is a staging procedure in the management of cutaneous malignancies of the head. The ideal radiopharmaceutical is controversial. This study aimed to compare [99mTc]Tc-tilmanocept (TcTM) with [99mTc]Tc-sulphur colloid (TcSC) and [99mTc]Tc-albumin colloid (TcAC) for SLN detection in the head and neck region.MethodsData from 62 patients with cutaneous malignancies of the head who were injected with TcTM, TcSC, or TcAC before SLN imaging (SLN-I) and SLN excision (SLN-E) between 2012 and 2021 were retrospectively analysed. SLN-I was performed using planar lymphoscintigraphy and SPECT/CT, and a gamma probe was used for SLN-E. The SLN-I localisation rate (patients with SLNs) and degree (SLN number) and SLN-E relocalisation rate (patients with SLNs) and ratio (SLN number in SLN-E/SLN number in SLN-I) were compared between TcTM, TcSC, and TcAC.ResultsTcTM showed similar SLN-I localisation rates for primaries in the anterior and posterior head region compared with TcSC (84.6% vs. 72.4%, p=0.680; both 100.0%) and TcAC (84.6% vs. 75.0%, p=1.000; both 100.0%). The SLN-I localisation degree for TcTM was higher for primaries in the anterior head region and similar for primaries in the posterior head region compared with TcSC (3.2 vs. 2.3, p=0.034; and 1.8 vs. 2.2, p=0.506) and TcAC (3.2 vs. 2.0, p=0.038; and 1.8 vs. 2.7, p=0.329). The SLN-E relocalisation rates and ratios were similar for all.ConclusionOn the basis of a limited study design that compared three different tracers in three different patient groups, TcTM showed comparable overall performance to TcSC and TcAC.

Phosphatidylethanol in whole blood: A complementary biomarker to ethyl glucuronide in hair

Establish the importance of interpreting the analyses of two alcohol use biomarkers, with a different detection window, when monitoring long-term alcohol consumption of an individual. In many medico-legal cases, such as liver transplantation and traffic incidents, there is a need to provide a proof of alcohol abstinence. Long-term alcohol consumption, particularly proving abstinence, remains a challenge. Therefore, various alcohol consumption biomarkers are used to gain information about the drinking behaviour of an individual. Ethyl glucuronide in hair (hEtG) is a reliable long-term alcohol use biomarker due to its long detection window, depending on the length of hair, allowing for a retrospective evaluation of alcohol use (Crunelle. Drug and Alcohol Dependence 2014:1–11). Phosphatidylethanol 16:0/18:1 (PEth) in whole blood is a direct alcohol biomarker that has gained increasing interest, due to its detection window of two to four weeks. (Ulwelling. Journal of Forensic Science 2018;63(6):1634–1640) This study explores the usefulness of analysis of PEth as a complementary biomarker to hEtG to evaluate alcohol use more accurately over the last weeks to months. Hair and whole blood samples were obtained over a three-year period in a medico-legal context, from the University Hospital Antwerp and analysed by Toxicological Centre University of Antwerp and the National Institute investigation of Criminalistics and Criminology (NICC), Belgium. Individuals ( n = 952) were assessed for a 3- or 6- month period of alcohol abstinence. Hair samples were taken from the posterior head region (0–3 or 0–6 cm). The sample preparation for hair analysis consisted in solid-phase extraction. At NICC, analysis was performed on an LC-MS/MS (Kummer. Journal of Analytical Toxicology 2015;39(1):17–23). At the Toxicological Centre, the extract was analysed on a GC-MS/MS (Cappelle. Forensic Science International 2015;249:20–24). Whole blood was collected on the same day as the hair sample and analysed for PEth using liquid-liquid extraction. In both laboratories, the analyses were performed on a LC-MS/MS. (Dumitrascu, Drug Testing 2021;13:1219; Van Uytfanghe, Talanta 2021;223:121694). PEth and hEtG results were classified into three groups, according to thresholds for abstinent/low, moderate, or excessive alcohol consumption (Society of Hair Testing, 2016; Van Uytfanghe. Talanta 2021;223:121694). Spearman correlation test (rs = 0.692, P = 0.001) showed a significant and moderate correlation between the two biomarkers. It was found that 341 individuals were classified abstinent according to the hair analysis (hEtG < 5 pg/mg) out of which 82% were also classified abstinent according to the whole blood analysis (Peth < 20 ng/mL). Furthermore, 329 individuals were classified as heavy drinkers through hair analysis (hEtG > 30 pg/mg), of which 57% presented a PEth concentration > 200 ng/mL, confirming the classification. Fifty-two individuals (15%) were categorised as abstinent/low alcohol consumption through hEtG analysis, but as moderate drinkers through PEth analysis (20–200 ng/mL). This might be explained by recent, moderate alcohol consumption. While PEth can be detected if alcohol was consumed in the past two to four weeks, EtG had insufficient time to be incorporated into the cut hair sample. Out of 329 individuals classified as heavy drinkers based on hEtG analysis, 45 were categorised abstinent through PEth analysis, suggesting these subjects stopped drinking two to four weeks prior to sample collection. A moderate agreement of Kappa reliability analysis (k = 0.444) between PEth and hEtG confirms that, for a more accurate overview of the drinking behaviour of an individual, both biomarkers are needed. This study demonstrates the necessity of analysing two alcohol use biomarkers with different detection windows, when investigating alcohol use retrospectively. PEth in whole blood is a complementary biomarker to hEtG, as it captures the last two to four weeks of alcohol consumption, which would be missed when only analysing for hEtG.

Electroclinical Features in Epilepsy Surgery Candidates With Epileptic Spasms.

Electroclinical features in surgical candidates with epileptic spasms differ significantly from the other focal epilepsy phenotypes. EEG findings tend to be more diffuse and less localizing in children with epileptic spasms. These are illustrated with five case studies to highlight three different categories of findings on interictal and ictal EEG: lateralizing , nonlateralizing , and false lateralizing . Hemihypsarrhythmia on interictal EEG is the most striking lateralizing abnormality that occurs in a minority of surgical candidates. Persistent focal epileptiform discharges in one region or asymmetric physiologic rhythms decreased over the abnormal hemisphere may provide localization clues. Ictal EEG patterns are diffuse and nonlocalizing in over half of the patients. Ictal patterns are best expressed in the posterior head regions even in patients with epileptogenic zone in anterior regions. Semiologically, epileptic spasms tend to be symmetrical in majority of surgical candidates. Asymmetric spasms and coexisting focal seizures (concurrent or remote), when present, may provide localization findings. False lateralizing interictal or ictal EEG abnormalities, paradoxically higher over the healthier hemisphere, occur in the setting of large encephaloclastic/volume loss lesions. In these patients, the diffuse discharges are less expressed over the abnormal hemisphere with less cerebral tissue. Recognition of such false lateralizing findings is important to avoid excluding appropriate surgical candidates based on the EEG findings alone. Epileptogenic lesions are visible on brain MRI in majority of surgical candidates with epileptic spasms. Electroclinical findings are often concordant with the lesion, but discordant findings are not uncommon in children with epileptic spasms.

Posterior Quadrant Disconnection for Childhood Onset Sub-Hemispheric Posterior Head Region Epilepsy: Indications in an Indian Cohort and Outcome

Background: Posterior quadrant disconnection (PQD) is an under-utilized surgical technique in the management of refractory epilepsy. There is a dearth of data pertinent to post-PQD seizure outcomes. Methods: This retrospective study analyzed patients with drug-resistant childhood-onset epilepsy who underwent PQD at our center from 2009 to 2018. The clinical, imaging, and electrophysiological data were reviewed. The seizure outcome was noted from the latest follow-up in all patients. Results: Fifteen patients underwent PQD, with a mean age at onset of epilepsy of 3.3 ± 4.6 years. All patients had seizure onset in childhood with focal onset of seizures, and in addition, 5 had multiple seizure types. All cases underwent presurgical workup with MRI, video-EEG, psychometry, while PET/MEG was done if required. Engel Ia and ILAE I outcomes were considered to be favorable. The histology of the specimen showed 9 patients (60%) had gliosis, 4 (26.7%) had focal cortical dysplasia (FCD), while 1 patient had nodular heterotopia and another had polymicrogyria-pachygyria complex. Postoperative follow-up was available in 14 cases. One patient was lost to follow-up. Mean follow-up duration for the cohort was 45 + 24 months. At last, follow-up (n = 14), 66.7% (10 cases) had favorable outcome (Engel Ia). At the end of 1-year follow-up, up to 73% (n = 11) of the patients were seizure-free. Four patients developed transient hemiparesis after surgery which improved completely by 3–6 months. Conclusions: Gliosis was more common etiology requiring PQD in our series than Western series, where FCD was more common. PQD is a safe and effective surgical modality in childhood-onset epilepsy with posterior head region epileptogenic focus.

Status Triphasicus Versus Status Epilepticus?

Generalized periodic patterns with triphasic wave morphology, long referred to as triphasic waves [TWs], had been associated with metabolic encephalopathies, although other neurologic and systemic causes have since been identified. In a recent classification of periodic patterns, TWs were formally grouped with the generalized periodic discharges, which are often associated with ictal activity. The interpretation of generalized periodic patterns with TWs as nonictal can have significant implications in the management of comatose patients in nonconvulsive status epilepticus. Electrographic characteristics that help distinguish nonictal periodic patterns with TWs from generalized periodic discharge ictal patterns include (1) TWs in long runs of periodic bilaterally synchronous and symmetric discharges, maximal in frontocentral or posterior head regions with and without a frontal-to-occipital lag or posterior-to-anterior lag, respectively; (2) recurrent spontaneous and/or low-dose benzodiazepine-induced attenuation and/or suppression of the periodic pattern and replacement with a diffuse slow wave activity throughout a prolonged EEG recording; and (3) stimulation-induced activation and/or increase in frequency and/or organization of TWs. We coined the term of status triphasicus to describe the electrographic periodic pattern of TWs with these three distinct characteristics. In this article, we discuss the advantages and limitations of keeping the status triphasicus pattern as a distinct electrographic entity different from periodic ictal generalized periodic discharge patterns. We discuss the circumstances in which a status triphasicus pattern can be associated with ictal activity and propose a simple pragmatic classification of status triphasicus that encompasses the different clinical scenarios it can be associated with.

How cerebral cortex protects itself from interictal spikes: The alpha/beta inhibition mechanism.

Interactions between interictal epileptiform discharges (IEDs) and distant cortical regions subserve potential effects on cognition of patients with focal epilepsy. We hypothesize that “healthy” brain areas at a distance from the epileptic focus may respond to the interference of IEDs by generating inhibitory alpha and beta oscillations. We predict that more prominent alpha‐beta oscillations can be found in patients with less impaired neurocognitive profile. We performed a source imaging magnetoencephalography study, including 41 focal epilepsy patients: 21 with frontal lobe epilepsy (FLE) and 20 with mesial temporal lobe epilepsy. We investigated the effect of anterior (i.e., frontal and temporal) IEDs on the oscillatory pattern over posterior head regions. We compared cortical oscillations (5–80 Hz) temporally linked to 3,749 IEDs (1,945 frontal and 1,803 temporal) versus an equal number of IED‐free segments. We correlated results from IED triggered oscillations to global neurocognitive performance. Only frontal IEDs triggered alpha‐beta oscillations over posterior head regions. IEDs with higher amplitude triggered alpha‐beta oscillations of higher magnitude. The intensity of posterior head region alpha‐beta oscillations significantly correlated with a better neuropsychological profile. Our study demonstrated that cerebral cortex protects itself from IEDs with generation of inhibitory alpha‐beta oscillations at distant cortical regions. The association of more prominent oscillations with a better cognitive status suggests that this mechanism might play a role in determining the cognitive resilience in patients with FLE.

Effect of Near-Infrared Pulsed Light on the Human Brain Using Electroencephalography.

In our previous study, the low-level laser (LLL) stimulation at the palm with a stimulation frequency of 10 Hz was able to induce significant brain activation in normal subjects. The electroencephalography (EEG) changes caused by the stimulation of light-emitting diode (LED) in normal subjects have not been investigated. This study aimed at identifying the effects of LED stimulation on the human brain using EEG analysis. Moreover, the dosage has been raised 4 times than that in the previous LLL study. The LED array stimulator (6 pcs LEDs, central wavelength 850 nm, output power 30 mW, and operating frequency 10 Hz) was used as the stimulation source. The LED stimulation was found to induce significant variation in alpha activity in the occipital, parietal, and temporal regions of the brain. Compared to the previous low-level laser study, LED has similar effects on EEG in alpha (8–12 Hz) activity. Theta (4–7 Hz) power significantly increased in the posterior head region of the brain. The effect lasted for at least 15 minutes after stimulation ceased. Conversely, beta (13–35 Hz) intensity in the right parietal area increased significantly, and a biphasic dose response has been observed in this study.

Cement augmentation of calcar screws may provide the greatest reduction in predicted screw cut-out risk for proximal humerus plating based on validated parametric computational modelling: Augmenting proximal humerus fracture plating.

AimsFixation of osteoporotic proximal humerus fractures remains challenging even with state-of-the-art locking plates. Despite the demonstrated biomechanical benefit of screw tip augmentation with bone cement, the clinical findings have remained unclear, potentially as the optimal augmentation combinations are unknown. The aim of this study was to systematically evaluate the biomechanical benefits of the augmentation options in a humeral locking plate using finite element analysis (FEA).MethodsA total of 64 cement augmentation configurations were analyzed using six screws of a locking plate to virtually fix unstable three-part fractures in 24 low-density proximal humerus models under three physiological loading cases (4,608 simulations). The biomechanical benefit of augmentation was evaluated through an established FEA methodology using the average peri-screw bone strain as a validated predictor of cyclic cut-out failure.ResultsThe biomechanical benefit was already significant with a single cemented screw and increased with the number of augmented screws, but the configuration was highly influential. The best two-screw (mean 23%, SD 3% reduction) and the worst four-screw (mean 22%, SD 5%) combinations performed similarly. The largest benefits were achieved with augmenting screws purchasing into the calcar and having posteriorly located tips. Local bone mineral density was not directly related to the improvement.ConclusionThe number and configuration of cemented screws strongly determined how augmentation can alleviate the predicted risk of cut-out failure. Screws purchasing in the calcar and posterior humeral head regions may be prioritized. Although requiring clinical corroborations, these findings may explain the controversial results of previous clinical studies not controlling the choices of screw augmentation.

An unusual presentation of neuropathic pain following cervical spinal cord injury: a case report

BackgroundWe report a patient with unusual occipital neuropathic pain (at-level neuropathic pain) due to a small central cervical spinal cord injury (SCI).Case presentationA 50-year-old man presented with severe bilateral occipital pain after falling from a height of 2 m, 2 weeks ago. The degree of pain was evaluated to be 9 out of 10 using the numeric rating scale (NRS). The nature of the pain was tingling, burning, and piercing, and hyperalgesia was present over the bilateral posterior head regions. Greater occipital nerve block with bupivacaine and dexamethasone was not effective. On axial T2-cervical magnetic resonance imaging (MRI), a focal high signal change was observed in the central portion of the spinal cord at the C2 level. We deliberated that the patient’s pain was due to the SCI observed on MRI, and after administration of oral medications, the NRS pain score reduced from 9 to 2.ConclusionsNeuropathic pain caused by SCI varies according to the location and degree of injury of the pain-related neural tracts; therefore, clinicians should closely observe the pain patterns and findings on imaging in patients with SCI to determine the cause of pain accurately.

Differences in Cell Proliferation and Craniofacial Phenotype of Closely Related Species in the Pupfish Genus Cyprinodon.

Understanding the genetic basis for phenotypic differences is fundamental to the study of macroevolutionary patterns of biological diversity. While technological advances in DNA sequencing have made researching genetic variation in wild taxa routine, fully understanding how these variants affect phenotype requires taking the next step to investigate how genetic changes alter cell and tissue interactions that ultimately produce phenotypes. In this article, we investigate a role for cell proliferation as a developmental source of craniofacial diversity in a radiation of 3 species of Cyprinodon from San Salvador Island, Bahamas. Patterns of cell proliferation in the heads of hatching-age fish differ among species of Cyprinodon, and correlate with differences in allometric growth rate among the jaws of 3 distinct species. Regional patterns of cell proliferation in the head are complex, resulting in an unintuitive result in which lower levels of cell proliferation in the posterior head region are associated with the development of relatively larger jaws in one species. We combine these data with previously published morphological and genomic data to show how studying the mechanisms generating phenotype at the cellular and tissue levels of biological organization can help mechanistically link genomic studies with classic morphological studies.

Lobar disconnective versus resective surgery in epilepsy: Surgical outcome and safety

Epilepsy surgery is an alternative & potentially more beneficial treatment intervention for some patients with drug-resistant epilepsy. While earlier studies have demonstrated the benefit of respective surgeries, in terms of seizure control, there is a recent interest in disconnective surgeries, especially lobar disconnection, with an attempt to avoid or minimize the morbidity that was associated with respective surgeries. The aim of our study is to analyze the surgical outcome and safety of disconnective surgery in drug-resistant focal epilepsy arising from either the anterior or posterior head region over a period of ten years, & compare the results to patients undergoing respective surgery alone without disconnective surgery. Our objectives are to collect information on the two groups & compare them for postoperative seizure control & perioperative risks. Our study follows a quasi-experimental study design in a single-center, King Faisal Specialist Hospital & Research Center, in Riyadh. Following the approval of our institute’s Institutional Review Board, the medical records from the last ten years were reviewed to identify eligible patients for the study. We identified a total of 117 patients who underwent disconnective surgery &/or resective surgery for focal drug resistant epilepsy. Final results of the study will be shared following abstract approval. There are no available published studies that compare lobar disconnective surgery to resective surgery as a treatment for focal drug-resistant epilepsy. We hope that our study would provide insight on the benefits of lobar disconnective surgery among all age groups.

Valproic Acid Induced Pancreatitis in an Arab Male

Valproate, a commonly used antiepileptic, is known to cause pancreatitis, which may present days to years after initiation of therapy. A 20-year-old Arab male patient with electroencephalogram (EEG) confirmed epileptiform activity over the left posterior head region was initiated with tablet carbamazepine 400 mg twice daily in the year 2015 and based on subsequent EEG findings (suggestive of more of generalized myoclonic seizure) carbamazepine was withdrawn gradually and started with sodium valproate 500 mg twice daily and levetiracetam 1 g twice daily. During treatment, the patient had status epileptics, treated with diazepam and lamotrigine 50 mg was added. Laboratory data indicated low valproate level, 47 μg/mL (normal range: 50–125 μg/mL) resulting in two episodes of myoclonic jerks necessitating lamotrigine dose escalation (100 mg twice daily). A month later, the patient developed nystagmus and tremors, and lamotrigine dose was deescalated to 75 mg twice daily. Patient was brought to the emergency with severe abdominal pain and vomiting since the day before and valproate level was 179 μg/mL (>150 μg/mL μg/mL is considered toxic), a diagnosis of acute pancreatitis due to valproate was made and the patient was treated in the intensive care unit. The causality assessment of the adverse drug reaction was “probable” (Naranjo score 8), and severity was “Severe” (Level 5; Modified Hartwig and Siegel scale), and the adverse reaction was “Not preventable” (Modified Schumock and Thornton scale). This report suggests the need for constant clinical monitoring and the need for therapeutic drug monitoring for patients undergoing valproate therapy.

T17. Seizures with focal evolution in the left temporal region in a teenager with Jaevons syndrome

Focal epileptiform discharges in the posterior head regions [Viravan S et al. Epilepsia 2011; 52(7):1273–9] and focal occipital seizures [Giraldez BC and Serratosa JM Seizure 2015, 32: 72–4] has been previously reported in a patients with epilepsy with eyelid myoclonia (EM) with or without absence seizures or Jeavons syndrome. We describe the semiology and ictal EEG with temporal-perisylvian features in a 13-year -old female with Jeavons syndrome. We describe the clinical and electroencephalographic findings of a 13-year -old female who presented with seizures from the age of 10 years. At the time of the evaluation the patient was treated with a therapeutic dose of lamotrigine. Seizure frequency was daily with presentation out of sleep and early morning. Video EEG recorded the typical seizures. Interictal EEG showed a normal awake and sleep patterns. Interictal EEG showed independent and bisynchronous right and left parieto-occipital sharp waves and polyspikes. There were sharp waves in the left posterior lateral and posterior temporal region (T7 and P7) seen in runs during sleep. Generalized photoparoxysmal response was noted at 10–20 Hz. There was eyelid myoclonia with increased bilateral posterior polyspikes elicited by eye closure (1 every 15–20 s.) that worsened at night when the room was dark (1 every 3–10 s). We recorded a 9 min habitual seizure out of sleep that began with a cluster of EM, 1 per second as the only ictal symptoms for 4.5 min. During this phase, the patient was responsive, able to speak and follow commands. Ictal EEG showed bursts of posterior dominant polyspikes concurrent with EM. Then the patient became unresponsive and had oral automatisms. Ictal EEG in this phase showed a rhythmic theta activity in the left posterior temporal region (maximum T7-P7 electrodes) that evolved into repetitive sharp waves in the same region. As the seizure progressed, the patient developed clonic activity in the right side of the neck that marched to the right arm and right leg. Postictally, there was a suppression of spikes in the left hemisphere while spikes persisted in the right posterior temporal region (P8 electrode). After load with intravenous Levetiracetam, photoparoxysmal response and eye closure activated interictal discharges dramatically resolved. Left temporal interictal epileptiform discharged persisted. Brain MRI was normal. FDG PET scan showed diffuse cortical hypometabolism maximum in the left hemisphere. We report seizures with focal evolution in temporal region in a teenager with Jaevons syndrome. It is possible that she has two independent epileptic syndromes but the possibility of focal seizure being triggered by hyper excitable parieto-occipital cortex is also possible given the anatomic proximity and neuronal network connecting these regions.

High Amplitude Background Slow Waves in Normal Children Aged 3 to 18 Months: Implications for the Consideration of Hypsarhythmia.

To assess for the presence of high amplitude EEG background slow waves in normal young children. One hundred children with normal development ages 3 to 18 months had normal EEGs for spells and did not have seizures or epilepsy. Three electroencephalographers retrospectively reviewed 5 minutes of stable stage II sleep to measure background slow waves for peak-to-peak amplitudes. A standard 10-20 longitudinal bipolar montage was used. Interrater agreement was assessed by intraclass correlation coefficient. Interrater agreement between reviewers in the assessment of recurrent slow wave amplitudes was excellent (intraclass correlation coefficient = 0.97). Slow wave amplitudes were the highest in the posterior head regions for all patients. We found recurring slow waves of <200 µV, 200 to 299 µV, 300 to 399 µV, 400 to 499 µV, and >500 µV in 17%, 49%, 30%, 3% and 1%, respectively. Although hypsarhythmia typically includes high amplitude background slow waves of >200 or >300 µV, we found that 83% and 34% of normal children had recurring posterior background slow waves of >200 or >300 µV, respectively. These data may be useful in the EEG background assessment of young children, for determining the presence or absence of hypsarhythmia, and determining treatment response in children with epileptic spasms.

Interictal regional paroxysmal fast activity on scalp EEG is common in patients with underlying gliosis

ObjectiveInterictal regional paroxysmal fast activity (RPFA) on scalp EEG is common in patients with focal cortical dysplasia (FCD). Little data exists regarding the presence of RPFA in other etiologies. MethodsWe studied the association between RPFA and etiology on MRI in patients with drug resistant focal epilepsy undergoing presurgical evaluation in 2011. RPFA was defined as ≥3 consecutive spikes with a frequency of ≥10 Hz lasting ≥300 ms but <4 s. Results626 patients fulfilled the inclusion criteria. Of these, 138 (22%) patients had RPFA while rest had other interictal epileptiform discharges (IEDs). RPFA was located at posterior head region in 52.2% patients, frontal regions in 24.6% patients and over temporal regions in 17.4% patients. Focal gliosis (61, 44%) and FCD (27, 19%) were common etiologies in patients with RPFA. Compared to patients with other IEDs, patients with RPFA were more likely to have focal gliosis (61/138 vs. 39/488; p < 0.0001) or FCD (27/138 vs 37/488; p < 0.001) as the etiology of epilepsy. ConclusionIn developing countries, focal gliosis is more common than FCD as the underlying etiology in patients with RPFA on scalp EEG. SignificanceFocal gliosis should be considered as one of the common substrate for RPFA on scalp EEG.

The functional head of the Cambrian radiodontan (stem-group Euarthropoda) Amplectobelua symbrachiata

BackgroundSegmental composition and homologies of the head of stem-group Euarthropoda have been the foci of recent studies on arthropod origins. An emerging hypothesis suggests that upper-stem group euarthropods possessed a three-segmented head/brain, including an ocular segment (protocerebrum) followed by the deutocerebrum with associated antennae/raptorial limbs and the tritocerebrum, while in the lower stem, head structures of Radiodonta are wholly associated with the protocerebrum and its preceding part. However, this hypothesis is incompletely tested because detailed knowledge on the head components of radiodontans is patchy, and informative articulated specimens are lacking for many taxa. Amplectobelua symbrachiata is the most common radiodontan species in the Chengjiang biota (ca. 520 Ma), normally known as isolated frontal appendages. Here we present detailed descriptions of new articulated specimens that elucidate the morphology and function of its head structures, and discuss their implications for hypotheses about euarthropod cephalic organisation.ResultsIn addition to a central oval head shield, A. symbrachiata also bears a pair of P-elements connected by an elongated rod. The mouth consists of sets of smooth and tuberculate plates, in contrast to the typical radial oral cones of other radiodontans. Previously identified ‘palm-like teeth’ are located external to the mouth in the posterior head region, and are interpreted as segmental gnathobase-like structures (GLSs) associated with at least three reduced transitional flaps in a one (pair)-to-one (pair) pattern, consistent with an appendicular nature. Comparisons with other panarthropods show that GLSs are morphologically similar to the mandibles and other gnathobasic mouthparts of euarthropods, as well as to the jaws of onychophorans, indicating their functional integration into the feeding activities of A. symbrachiata.ConclusionsThe functional head of A. symbrachiata must include the reduced transitional segments (and their associated structures), which have been identified in several other radiodontans. This functional view supports the idea that the integration of segments (and associated appendages) into the head region, probably driven by feeding, occurred along the euarthropod stem-lineage. However, the number of reduced transitional segments varies between different groups and it remains uncertain whether GLSs represent proximal or distal parts of appendages. Our study is the first description of appendicular structures other than the frontal appendages in the functional head region of radiodontans, revealing novel feeding structures in the morphological transition from the lower- to the upper- stem-group of Euarthropoda.

MRI brain aids in diagnosing an overlooked cause of acute encephalopathy

A 38-year-old male with no significant past medical or substance abuse history presented with a five-day history of vomiting and bloody stools following ingestion of undercooked beef. He was admitted to critical care unit with a diagnosis of hemolytic-uremic-syndrome. Despite aggressive antibiotics and dialysis treatment his mental status deteriorated, requiring intubation on seventh day of admission following 3 episodes of generalized-tonic-clonic seizures. Electroencephalogram (EEG) revealed generalized seizures arising focally from posterior head regions. Magnetic-resonance-imaging (MRI) brain showed symmetric posterior rhombencephalitis with bilateral thalamic involvement (figure A-D). Cerebrospinal-fluid (CSF) analysis showed mild pleocytosis (WBCs: 31, PMNs: 98%), elevated protein (133 mg/dL) and glucose (92 mg/dL). The serum albumin dropped from 4.7 g/dL on admission to 2.3 g/dL on day 7 of admission. Neurology was consulted. On initial examination, patient was stuporous without obvious cranial nerve or focal neurologic deficits (Fig. 1A–D ). (A)Hypoxic ischemic encephalopathy(B)Wernicke’s encephalopathy(C)Creutzfeld-Jakob disease(D)Listerial rhombencephalitis Answer on page 361 The author(s) received no financial support for authorship or publication of this manuscript. The authors have no conflict of interest. (1)S. Farooq: reports no disclosures.(2)A. Willcox: reports no disclosures.(3)J. Figueroa: reports no disclosures. (1)S. Farooq: Manuscript write up and literature search.(2)A. Willcox: revision of manuscript and literature search.(3)J. Figueroa: Critical revision of the manuscript for important intellectual content. MRI brain aids in diagnosing an overlooked cause of acute encephalopathyJournal of Clinical NeuroscienceVol. 44PreviewB: Wernicke’s encephalopathy Full-Text PDF