Artificial Neural Network Computer Tomography Perfusion Prediction of Ischemic Core.

Background and Purpose- Computed tomography perfusion (CTP) is a useful tool in the evaluation of acute ischemic stroke, where it can provide an estimate of the ischemic core and the ischemic penumbra. The optimal CTP parameters to identify the ischemic core remain undetermined. Methods- We used artificial neural networks (ANNs) to optimally predict the ischemic core in acute stroke patients, using diffusion-weighted imaging as the gold standard. We first designed an ANN based on CTP data alone and next designed an ANN based on clinical and CTP data. Results- The ANN based on CTP data predicted the ischemic core with a mean absolute error of 13.8 mL (SD, 13.6 mL) compared with diffusion-weighted imaging. The area under the receiver operator characteristic curve was 0.85. At the optimal threshold, the sensitivity for predicting the ischemic core was 0.90 and the specificity was 0.62. Combining CTP data with clinical data available at time of presentation resulted in the same mean absolute error (13.8 mL) but lower SD (12.4 mL). The area under the curve, sensitivity, and specificity were 0.87, 0.91, and 0.65, respectively. The maximal Dice coefficient was 0.48 in the ANN based on CTP data exclusively. Conclusions- An ANN that integrates clinical and CTP data predicts the ischemic core with accuracy.

Optimal Computed Tomographic Perfusion Scan Duration for Assessment of Acute Stroke Lesion Volumes.

BACKGROUND AND PURPOSE: The minimal scan duration needed to obtain reliable lesion volumes with computed tomographic perfusion (CTP) has not been well established in the literature. METHODS: We retrospectively assessed the impact of gradual truncation of the scan duration on acute ischemic lesion volume measurements. For each scan, we identified its optimal scan time, defined as the shortest scan duration that yields measurements of the ischemic lesion volumes similar to those obtained with longer scanning, and the relative height of the fitted venous output function at its optimal scan time. RESULTS: We analyzed 70 computed tomographic perfusion scans of acute stroke patients. An optimal scan time could not be determined in 11 scans (16%). For the other 59 scans, the median optimal scan time was 32.7 seconds (90th percentile 52.6 seconds; 100th percentile 68.9 seconds), and the median relative height of the fitted venous output function at the optimal scan times was 0.39 (90th percentile 0.02; 100th percentile 0.00). On the basis of a linear model, the optimal scan time was T0 plus 1.6 times the width of the venous output function (P<0.001; R2=0.49). CONCLUSIONS: This study shows how the optimal duration of a computed tomographic perfusion scan relates to the arrival time and width of the contrast bolus. This knowledge can be used to optimize computed tomographic perfusion scan protocols and to determine whether a scan is of sufficient duration. Provided a baseline (T0) of 10 seconds, a total scan duration of 60 to 70 seconds, which includes the entire downslope of the venous output function in most patients, is recommended.

Stimulation-Induced Transient Nonmotor Psychiatric Symptoms following Subthalamic Deep Brain Stimulation in Patients with Parkinson's Disease: Association with Clinical Outcomes and Neuroanatomical Correlates.

BACKGROUND: The clinical and neurobiological underpinnings of transient nonmotor (TNM) psychiatric symptoms during the optimization of stimulation parameters in the course of subthalamic nucleus deep brain stimulation (STN-DBS) remain under intense investigation. METHODS: Forty-nine patients with refractory Parkinson's disease underwent bilateral STN-DBS implants and were enrolled in a 24-week prospective, naturalistic follow-up study. Patients who exhibited TNM psychiatric manifestations during DBS parameter optimization were evaluated for potential associations with clinical outcome measures. RESULTS: Twenty-nine TNM+ episodes were reported by 15 patients. No differences between TNM+ and TNM- groups were found in motor outcome. However, unlike the TNM- group, TNM+ patients did not report improvement in subsyndromal depression or quality of life. TNM+ episodes were more likely to emerge during bilateral monopolar stimulation of the medial STN. CONCLUSIONS: The occurrence of TNM psychiatric symptoms during optimization of stimulation parameters was associated with the persistence of subsyndromal depression and with lower quality of life ratings at 6 months. The neurobiological underpinnings of TNM symptoms are investigated yet remain difficult to explain.

Palliative epilepsy surgery in Aicardi syndrome: a case series and review of literature.

PURPOSE: Aicardi syndrome (AS) is a severe neurodevelopmental disorder characterized by the triad of seizures, agenesis of corpus callosum, and chorioretinal lacunae. Seizures in AS are typically frequent, of various types, and refractory to medical therapy. Optimal treatment of seizures in AS remains undetermined. METHODS: We report a series of four patients with Aicardi syndrome who underwent surgical management of their epilepsy including two with corpus callosotomy (CC) of a partial corpus callosum and three with vagus nerve stimulator implantation. RESULTS: Seizure outcome was variable and ranged from near complete resolution of seizures to worsening of seizure profile. The most favorable seizure outcome was seen in a patient with partial agenesis of the corpus callosum treated with CC. CONCLUSIONS: Seizure outcome following CC or vagus nerve stimulation in patients with Aicardi syndrome is variable. Although palliative epilepsy surgery may result in improvement in the seizure profile in some patients, studies on larger patient cohorts are needed to identify the precise role that surgery may play in the multidisciplinary approach to controlling seizures in Aicardi syndrome.

Health-related quality of life before and after pediatric epilepsy surgery: the influence of seizure outcome on changes in physical functioning and social functioning.

Health-related quality of life (HRQOL) is an important outcome in pediatric epilepsy surgery, but there are few studies that utilize presurgical ratings to assess the effect of surgery on HRQOL. We collected parental ratings on the Quality of Life in Childhood Epilepsy (QOLCE) questionnaire for 28 children who participated in neuropsychological assessment before and after epilepsy surgery. Our results revealed significant improvements in overall HRQOL after surgery, especially in physical and social activities. These changes were apparent despite generally unchanged intellectual and psychological functioning. Children with better seizure outcome had more improvement in HRQOL; however, improvements were not statistically different among children with Engel class I, II, and III outcomes. Our results suggest that children can experience significant improvements in HRQOL following epilepsy surgery even when neuropsychological functioning remains unchanged. Moreover, improvements in HRQOL appear evident in children who experience any worthwhile improvement in seizure control (Engel class III or better).

Wireless neurochemical monitoring in humans.

Electrochemical techniques have long been utilized to investigate chemical changes in the neuronal microenvironment. Preclinical models have demonstrated the successful monitoring of changes in various neurotransmitter systems in vivo with high temporal and spatial resolution. The expansion of electrochemical recording to humans is a critical yet challenging goal to elucidate various aspects of human neurophysiology and to create future therapies. We have designed a novel device named the WINCS (Wireless Instantaneous Neurotransmitter Concentration Sensing) system that combines rapid scan voltammetry with wireless telemetry for highly resolved electrochemical recording and analysis. WINCS utilizes fast-scan cyclic voltammetry and fixed potential amperometry for in vivo recording and has demonstrated high temporal and spatial resolution in detecting changes in extracellular levels of a wide range of analytes including dopamine, adenosine, glutamate, serotonin, and histamine. Neurochemical monitoring in humans represents a new approach to understanding the neurophysiology of the central nervous system, the neurobiology of numerous diseases, and the underlying mechanism of various neurosurgical therapies. This article addresses the current understanding of electrochemistry, its application in humans, and future directions.

Evaluation of cutaneous allodynia following induction of cortical spreading depression in freely moving rats.

BACKGROUND: Cortical spreading depression (CSD) is a wave of depolarization followed by depression of bioelectrical activity that slowly propagates through the cortex. CSD is believed to be the underlying mechanism of aura in migraine; however, whether CSD can elicit pain associated with migraine headache is unclear. METHODS: Awake, freely moving rats were monitored for both CSD events and behavioral responses resulting from dural-cortical pinprick and/or KCl injection to the occipital cortex. RESULTS: We observed tactile allodynia of the face and hindpaws, as well as enhanced Fos expression within the trigeminal nucleus caudalis (TNC) following CSD induced by KCl injection into the cortex, but not by pinprick. Application of KCl onto the dura elicited cutaneous allodynia and increased Fos staining in the TNC but did not elicit CSD events. CONCLUSIONS: These data suggest that sustained activation of trigeminal afferents that may be required to establish cutaneous allodynia may not occur following CSD events in normal animals.

Atypical Intracerebral Developmental Venous Anomalies in Sturge-Weber Syndrome: A Case Series and Review of Literature.

BACKGROUND: Intracranial vascular abnormalities in Sturge-Weber syndrome, including leptomeningeal angiomatosis, anomalous cortical venous structures, and transmedullary developmental venous anomalies, are well recognized. Prominent vascular flow voids on T2-weighted magnetic resonance imaging (MRI) are occasionally identified in patients with Sturge-Weber syndrome, raising concern of arteriovenous malformations, a congenital high-flow vascular malformation with a risk of bleeding. METHODS: We report four patients with prominent flow voids on conventional MRI that suggested high-flow lesions. RESULTS: Diagnostic evaluation was performed with cerebral angiography in one patient and with a combination of magnetic resonance angiography and magnetic resonance venography in three patients. In all four patients, the conventional MRI-identified lesions represented prominent developmental venous anomalies and not arteriovenous malformations. CONCLUSIONS: This series highlights that developmental venous anomalies may appear in individuals with Sturge-Weber syndrome as unusually large and seemingly high-flow lesions on MRI. Noninvasive imaging with magnetic resonance angiography and magnetic resonance venography can be used in the management of such patients for further characterization of these vascular structures.

Thermal properties of contemporary bipolar systems using infrared imaging.

BACKGROUND: Bipolar coagulation has enhanced the capabilities and safety profile of contemporary neurosurgery and has become indispensable in the neurosurgical armamentarium. Nevertheless, significant heat transfer issues remain to be resolved before it can achieve the status of minimal risk. METHODS: The Codman irrigating forceps, Codman ISOCOOL forceps, and Ellman bipolar forceps, powered by either Synergy or Ellman generators set at various power levels, were compared to investigate the combinations that would allow for the lowest rate of heat transfer. Using an infrared camera and ThermaGRAM imaging software, the temperature was calculated and used to estimate the degree of heat transfer. RESULTS: Codman ISOCOOL forceps powered the Ellman Surgitron generator showed the greatest dissipation (at mid-power, the luminance decreased from 250 units to 80 units within 60 seconds) and the least production of heat after activation. Codman ISOCOOL forceps powered by the Codman SYNERGY MALIS generator showed less heat dissipation (at mid-power, the luminance decreased from 250 units to 195 units within 60 seconds) than the Ellman forceps and Ellman Surgitron generator combination (at mid-power, the luminance decreased from 250 units to 125 units within 60 seconds). CONCLUSIONS: These data suggest that the incorporation of the Ellman Surgitron Generator can result in the reduction of thermal transfer with conventional bipolar forceps compared with other generators. The combination with Codman ISOCOOL forceps can maximize the potential safety associated with bipolar coagulation. With regard to the use of comarketed pairs of forceps and generators, the combination of Ellman Surgitron Generator and Ellman bipolar forceps provided the best thermal profile.

Wireless control of intraspinal microstimulation in a rodent model of paralysis.

OBJECT: Despite a promising outlook, existing intraspinal microstimulation (ISMS) techniques for restoring functional motor control after spinal cord injury are not yet suitable for use outside a controlled laboratory environment. Thus, successful application of ISMS therapy in humans will require the use of versatile chronic neurostimulation systems. The objective of this study was to establish proof of principle for wireless control of ISMS to evoke controlled motor function in a rodent model of complete spinal cord injury. METHODS: The lumbar spinal cord in each of 17 fully anesthetized Sprague-Dawley rats was stimulated via ISMS electrodes to evoke hindlimb function. Nine subjects underwent complete surgical transection of the spinal cord at the T-4 level 7 days before stimulation. Targeting for both groups (spinalized and control) was performed under visual inspection via dorsal spinal cord landmarks such as the dorsal root entry zone and the dorsal median fissure. Teflon-insulated stimulating platinum-iridium microwire electrodes (50 µm in diameter, with a 30- to 60-µm exposed tip) were implanted within the ventral gray matter to an approximate depth of 1.8 mm. Electrode implantation was performed using a free-hand delivery technique (n = 12) or a Kopf spinal frame system (n = 5) to compare the efficacy of these 2 commonly used targeting techniques. Stimulation was controlled remotely using a wireless neurostimulation control system. Hindlimb movements evoked by stimulation were tracked via kinematic markers placed on the hips, knees, ankles, and paws. Postmortem fixation and staining of the spinal cord tissue were conducted to determine the final positions of the stimulating electrodes within the spinal cord tissue. RESULTS: The results show that wireless ISMS was capable of evoking controlled and sustained activation of ankle, knee, and hip muscles in 90% of the spinalized rats (n = 9) and 100% of the healthy control rats (n = 8). No functional differences between movements evoked by either of the 2 targeting techniques were revealed. However, frame-based targeting required fewer electrode penetrations to evoke target movements. CONCLUSIONS: Clinical restoration of functional movement via ISMS remains a distant goal. However, the technology presented herein represents the first step toward restoring functional independence for individuals with chronic spinal cord injury.

Outcomes after anterior or complete corpus callosotomy in children.

BACKGROUND: Corpus callosotomy (CC) is a valuable palliative surgical option for children with medically refractory epilepsy due to generalized or multifocal cortical seizure onset. OBJECTIVE: To investigate the extent of CC resulting in optimal seizure control in a pediatric patient population and to evaluate the modification of seizure profile after various CC approaches. METHODS: The records of 58 children (3-22 years of age at the time of surgery) with medically refractory epilepsy who underwent CC between 1995 and 2011 were retrospectively reviewed. RESULTS: Anterior two thirds callosotomy resulted in resolution of absence (P = .03) and astatic (P = .03) seizures, whereas anterior two thirds callosotomy followed by second-stage completion resulted in resolution of generalized tonic-clonic (GTC) (P = .03), astatic (P = .005), and myoclonic (P = .03) seizures in addition to a trend toward resolution of absence seizures (P = .08). Single-stage upfront complete callosotomy resulted in resolution of absence (P = .002), astatic (P < .0001), myoclonic (P = .007), and complex partial (P = .008) seizures in addition to a trend toward resolution of GTC (P = .06). In comparing a composite of subjects who underwent anterior two thirds callosotomy alone or 2-stage complete callosotomy before the second stage to complete the callosotomy with subjects who underwent upfront complete CC, a more favorable outcome was found in those with the upfront complete CC (P = .02). CONCLUSION: Single-stage upfront complete callosotomy is effective in relieving a broader spectrum of seizure types than anterior two thirds callosotomy or 2-stage complete callosotomy in children. The advantages of single-stage complete callosotomy must be weighed against the potentially higher risk of neurological and operative complications.

Attenuation of ethanol withdrawal by ceftriaxone-induced upregulation of glutamate transporter EAAT2.

Alcohol withdrawal syndrome (AWS) is a potentially fatal outcome of severe alcohol dependence that presents a significant challenge to treatment. Although AWS is thought to be driven by a hyperglutamatergic brain state, benzodiazepines, which target the GABAergic system, comprise the first line of treatment for AWS. Using a rat model of ethanol withdrawal, we tested whether ceftriaxone, a ß-lactam antibiotic known to increase the expression and activity of glutamate uptake transporter EAAT2, reduces the occurrence or severity of ethanol withdrawal manifestations. After a 2-week period of habituation to ethanol in two-bottle choice, alcohol-preferring (P) and Wistar rats received ethanol (4.0 g/kg) every 6 h for 3-5 consecutive days via gavage. Rats were then deprived of ethanol for 48 h during which time they received ceftriaxone (50 or 100 mg/kg, IP) or saline twice a day starting 12 h after the last ethanol administration. Withdrawal manifestations were captured by continuous video recording and coded. The evolution of ethanol withdrawal was markedly different for P rats vs Wistar rats, with withdrawal manifestations occurring >12 h later in P rats than in Wistar rats. Ceftriaxone 100 mg/kg per injection twice per day (200 mg/kg/day) reduced or abolished all manifestations of ethanol withdrawal in both rat variants and prevented withdrawal-induced escalation of alcohol intake. Finally, ceftriaxone treatment was associated with lasting upregulation of ethanol withdrawal-induced downregulation of EAAT2 in the striatum. Our data support the role of ceftriaxone in alleviating alcohol withdrawal and open a novel pharmacologic avenue that requires clinical evaluation in patients with AWS.

Lateral hypothalamic kindling induces manic-like behavior in rats: a novel animal model.

The lateral hypothalamus integrates critical physiological functions such as the sleep-wake cycle, energy expenditure, and sexual behaviors. These functions are severely dysregulated during mania. In this study, we successfully induced manic-like behavioral phenotypes in adult, male Wistar rats through bilateral lateral hypothalamic area kindling (LHK). To test the validity of the model, we studied the effect of standard antimanic medications lithium (47.5 mg/kg) or valproic acid (200 mg/kg) twice/day for 15 days in attenuating manic-like behaviors in the LHK rat. Compared with pre-kindling behaviors, LHK rats displayed significantly increased sexual self-stimulation (P = 0.034), excessive rearing (P = 0.0005), feeding (P = 0.013), and grooming (P = 0.007) during the kindling interval. LHK rats also drank more alcohol during the mania-induction days compared with baseline ethanol consumption levels (P = 0.01). Moreover, LHK rat exhibited increased total locomotor activity (P = 0.02) with reduced rest interval (P < 0.001) during the mania induction and post-mania days compared with baseline activity levels and rest intervals. Chronic administration of lithium or valproic acid significantly attenuated manic-like behaviors in the LHK rat model. Given the behavioral phenotype and the response to standard antimanic medications, the LHK rats may provide a model for studying manic psychopathology in humans.

Clinical experience with the surgicel family of absorbable hemostats (oxidized regenerated cellulose) in neurosurgical applications: a review.

INTRODUCTION: Oxidized regenerated cellulose has a long history of safe and effective use in the surgical setting. Surgicel Original, Fibrillar and Nu-Knit absorbable hemostats are composed of oxidized regenerated cellulose and are sterile, absorbable knitted fabrics that are flexible and adhere readily to bleeding surfaces. The purpose of this paper is to discuss neurosurgical applications for these absorbable hemostatic agents. METHODS: The authors reviewed the literature and described their clinical experience with Surgicel hemostatic products. RESULTS: Neurosurgical applications of the hemostatic products include the management of diffuse capillary oozing following bipolar cautery in brain tumor resection beds and the control of epidural oozing during spinal surgery. As an adjunct to standard hemostatic procedures, these products facilitate rapid hemostasis and have bactericidal activity that extend to antibiotic-resistant organisms such as methicillin-resistant Staphylococcus aureus, Staphylococcus epidermidis, and Streptococcus pneumonia, as well as Pseudomonas aeruginosa. Although generally safe and well-tolerated, these hemostatic agents should be removed when used around, in, or in proximity to, foramina in bone, areas of bony confine, the spinal cord, and/or the optic nerve or chiasm because it may otherwise swell and cause unwanted pressure. CONCLUSION: The physical, hemostatic, and bactericidal characteristics of this material makes it a useful adjunct for conventional hemostatic and controlling capillary, venous, and small arterial hemorrhage during neurosurgery. .

Lack of differential motor outcome with subthalamic nucleus region stimulation in Parkinson's disease.

Deep brain stimulation (DBS) has emerged as a viable therapy for Parkinson's disease (PD). The impact of subthalamic nucleus (STN) lead placement (lateral versus medial) on motor outcome, however, has not been systematically evaluated. Forty-eight patients with PD underwent STN-DBS surgery and were evaluated postoperatively for 48 weeks for motor improvement as measured by the Unified Parkinson's Disease Rating Scale (UPDRS) part III (standardized motor examination) and levodopa equivalent daily dose (LEDD). Postoperative MRI was used to identify the location of the active stimulating contact and motor outcome was analyzed. STN-DBS was associated with significant improvement in motor outcome as determined by a reduction in the UPDRS part III subscore from 34.44 ± 1.29 at baseline to 18.76 ± 1.06 at end visit (p<0.0001) and a reduction in LEDD from 1721 ± 152 mg/day at baseline to 1134 ± 119 mg/day at end visit (p=0.0024). Patients with stimulating contacts in the medial STN compared to the lateral STN did not demonstrate any significant differences in motor outcome (UPDRS, p=0.5811; LEDD, p=0.7341). No significant differences were found in motor outcome between patients with STN stimulation compared to stimulation of surrounding fiber tracts (p=0.80). No significant difference in stimulation voltage was noted with respect to lead location. Our study did not find a significant effect for the location of active contact and motor outcome neither within the subregions of the STN nor between the STN and surrounding fibers. Further research is needed to better understand the neurophysiological basis for these results.

Development of the Mayo Investigational Neuromodulation Control System: toward a closed-loop electrochemical feedback system for deep brain stimulation.

OBJECT: Conventional deep brain stimulation (DBS) devices continue to rely on an open-loop system in which stimulation is independent of functional neural feedback. The authors previously proposed that as the foundation of a DBS "smart" device, a closed-loop system based on neurochemical feedback, may have the potential to improve therapeutic outcomes. Alterations in neurochemical release are thought to be linked to the clinical benefit of DBS, and fast-scan cyclic voltammetry (FSCV) has been shown to be effective for recording these evoked neurochemical changes. However, the combination of FSCV with conventional DBS devices interferes with the recording and identification of the evoked analytes. To integrate neurochemical recording with neurostimulation, the authors developed the Mayo Investigational Neuromodulation Control System (MINCS), a novel, wirelessly controlled stimulation device designed to interface with FSCV performed by their previously described Wireless Instantaneous Neurochemical Concentration Sensing System (WINCS). METHODS: To test the functionality of these integrated devices, various frequencies of electrical stimulation were applied by MINCS to the medial forebrain bundle of the anesthetized rat, and striatal dopamine release was recorded by WINCS. The parameters for FSCV in the present study consisted of a pyramidal voltage waveform applied to the carbon-fiber microelectrode every 100 msec, ramping between -0.4 V and +1.5 V with respect to an Ag/AgCl reference electrode at a scan rate of either 400 V/sec or 1000 V/sec. The carbon-fiber microelectrode was held at the baseline potential of -0.4 V between scans. RESULTS: By using MINCS in conjunction with WINCS coordinated through an optic fiber, the authors interleaved intervals of electrical stimulation with FSCV scans and thus obtained artifact-free wireless FSCV recordings. Electrical stimulation of the medial forebrain bundle in the anesthetized rat by MINCS elicited striatal dopamine release that was time-locked to stimulation and increased progressively with stimulation frequency. CONCLUSIONS: Here, the authors report a series of proof-of-principle tests in the rat brain demonstrating MINCS to be a reliable and flexible stimulation device that, when used in conjunction with WINCS, performs wirelessly controlled stimulation concurrent with artifact-free neurochemical recording. These findings suggest that the integration of neurochemical recording with neurostimulation may be a useful first step toward the development of a closed-loop DBS system for human application.

Concussions in soccer: a current understanding.

OBJECTIVE: Traumatic brain injury (TBI) is a significant public health problem in the United States, with approximately 1.5-2 million TBIs occurring each year. However, it is believed that these figures underestimate the true toll of TBI. Soccer is the most popular sport in the world and has a following of millions in the United States. Soccer is a sport not traditionally identified as high-risk for concussions, yet several studies have shown that concussion rates in soccer are comparable to, and often exceed those of, other contact sports. As many as 22% of all soccer injuries are concussions. METHODS: Soccer is a sport not traditionally identified as high risk for concussions, yet several studies have shown that concussion rates in soccer are comparable to, and often exceed those of, other contact sports. As many as 22% of all soccer injuries are concussions. Head injury during soccer is usually the result of either "direct contact" or contact with the ball while "heading" the ball. Relationships between the number of headers sustained in a single season and the degree of cognitive impairment (attention and visual/verbal memory) have been demonstrated. It is also likely that multiple concussions may cause cumulative neuropsychologic impairment in soccer players. RESULTS: Although our understanding of risk factors for sports-related concussions is far from complete, there is great potential for prevention in sports-related concussions. Several measures must be taken to avert the development of concussions in soccer and, when they take place, reduce their effects. These include the development and testing of effective equipment during play, the maintenance of regulatory standards for all such equipment, educating young athletes on the safe and appropriate techniques used during play, and strict adherence to the rules of competition. CONCLUSIONS: In spite of such preventive measures, concussions in soccer will continue to occur. Considering the frequency of concussions in soccer, the serious sequelae of these concussions, and because almost half of concussed soccer players were noncompliant with recommended American Academy of Neurology return-to-play guidelines, further measures must be taken to protect players, in addition to understanding those criteria that result in removing an injured player from competition and the steps by which to safely return an athlete to competition after injury.

Characterization of the supplementary motor area syndrome and seizure outcome after medial frontal lobe resections in pediatric epilepsy surgery.

BACKGROUND: In adults, resection of the medial frontal lobe has been shown to result in supplementary motor area (SMA) syndrome, a disorder characterized by transient motor impairment. Studies examining the development of SMA syndrome in children, however, are wanting. OBJECTIVE: To characterize the development of SMA syndrome and to analyze seizure outcomes after surgery in the medial frontal lobe for medically intractable epilepsy. METHODS: Thirty-nine patients with medically intractable epilepsy who underwent surgery in the medial frontal lobe were reviewed retrospectively. The progression of neurological impairment and seizure outcome after surgery was recorded, and the extent of cortex resected was analyzed. RESULTS: After resection in the region of the SMA, 23 patients (59%) developed postoperative neurological impairment; 17 (74%) were identified as SMA syndrome. No neurological impairment was found after surgery in 16 patients (41%). Six patients (15%) experienced permanent neurological impairment. The majority of patients (82%) who developed SMA syndrome had resolution of their symptoms by 1 month postoperatively. Preoperative magnetic resonance imaging finding of lesional cases was associated with a significantly decreased likelihood of developing SMA syndrome (P = .02). Seizure outcome was favorable after surgery in most patients. CONCLUSION: Surgery for medically intractable epilepsy in the region of the medial frontal cortex is effective and associated with reversible neurological impairment in children. All patients had resolution of their SMA syndrome by 6 months postoperatively.

Association of magnetic resonance imaging identification of mesial temporal sclerosis with pathological diagnosis and surgical outcomes in children following epilepsy surgery.

OBJECT: Mesial temporal sclerosis (MTS) is widely recognized as a significant underlying cause of temporal lobe epilepsy. Magnetic resonance imaging is routinely used in the preoperative evaluation of children with epilepsy. The purpose of this study was to evaluate the prevalence, reliability, and prognostic value of MRI identification of MTS and MRI findings indicative of MTS in a series of patients who underwent resection of the medial temporal lobe for medically refractory epilepsy. METHODS: The authors reviewed the medical records and preoperative MRI reports of 25 patients who had undergone medial temporal resections (anterior temporal lobectomy or functional hemispherotomy) for medically intractable epilepsy. The preoperative MRI studies were presented for blinded review by 2 neuroradiologists who independently evaluated the radiographs for selected MTS features and provided a final interpretation. To quantify interrater agreement and accuracy, the findings of the 2 blinded neuroradiologists, the nonblinded clinical preoperative radiology report, and the final pathology interpretation were compared. RESULTS: The preoperative MRI studies revealed MTS in 6 patients (24%), and histopathological analysis verified MTS in 8 (32%) of 25 specimens. Six MRI features of MTS were specifically evaluated: 1) increased hippocampal signal intensity, 2) reduced hippocampal size, 3) atrophy of the ipsilateral hippocampal collateral white matter, 4) enlarged ipsilateral temporal horn, 5) reduced gray-white matter demarcation in the temporal lobe, and 6) decreased temporal lobe size. The most prevalent feature of MTS identified on MRI was a reduced hippocampal size, found in 11 of the MRI studies (44%). Analysis revealed moderate interrater agreement for MRI identification of MTS between the 2 blinded neuroradiologists and the nonblinded preoperative report (Cohen κ 0.40-0.59). Interrater agreement was highly variable for different MTS features indicative of MTS, ranging from poor to near perfect. Agreement was highest for increased hippocampal signal and decreased temporal lobe size and was consistently poor for reduced gray-white matter demarcation. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and proportion perfect agreement were highest for increased hippocampal signal and reduced hippocampal size. An MRI finding of MTS was not predictive of seizure outcome in this small series. CONCLUSIONS: Mesial temporal sclerosis identification on brain MRI in children evaluated for medial temporal resections has a PPV of 55%-67% and an NPV of 79%-87%. Increased hippocampal signal and reduced hippocampal size were associated with high predictive values, while gray-white differentiation and an enlarged temporal horn were not predictive of MTS. Seizure outcome following medial temporal resections was not associated with MRI findings of MTS or MRI abnormalities indicative of MTS in this small sample size.