Moyamoya syndrome after proton beam therapy in a pediatric patient with a pineal germ cell tumor and a germline polymorphism in RNF213

The effects of RNF213, which leads to moyamoya disease susceptibility, on radiation-induced moyamoya syndrome (MMS) remain unknown. We report a case of MMS after proton beam therapy (PBT) was deployed to treat a brain tumor in a patient with an RNF213 polymorphism. An 8-year-old boy underwent whole ventricular and local PBT for a pineal germ cell tumor and was diagnosed with radiation-induced MMS 9 months later. He underwent right and left revascularization surgeries for cerebral hemodynamic compromise at 17- and 18-years of age, respectively. Genetic analysis revealed a heterozygous germline polymorphism RNF213 p.R4810K. This is the first report to suggest an association between RNF213 polymorphism and radiation-induced MMS.

Effective Smartphone Application Use for Postoperative Management of Moyamoya Disease

Continuous and careful management is necessary after revascularization surgery for moyamoya disease (MMD). The postoperative information has been shared in person or by telephone and emails among doctors; however, this is not always efficient. We aimed to describe the feasibility of remote diagnosis and text chats using a smartphone application on postoperative MMD management. Twenty consecutive patients who underwent combined direct and indirect revascularization for MMD were prospectively investigated in this study. In ten patients, the operator viewed postoperative images uploaded on a smartphone screen using the Join application (Allm Inc., Tokyo, Japan). The doctors shared the radiological findings and treatment plans using the group text chat function and performed postoperative management. We evaluated the intermodality agreements of radiological findings between the smartphone screen and conventional viewer. Postoperative courses were compared between the two patient groups that used or did not use the application. All postoperative images were uploaded to the cloud server and the operator viewed them remotely on the smartphone screen without restriction of location. Detected abnormal findings were cerebral hyperperfusion (CHP), CHP-related watershed shift phenomenon, fluid-attenuated inversion recovery cortical hyperintensity, high signal intensity on diffusion-weighted imaging, CHP-related crossed cerebellar diaschisis, and hypoperfusion. Radiological agreement between the modalities was good in all cases, and additional findings were not obtained on the conventional viewer. The postoperative courses of the Join group were as good as those of the control group. Remote radiological diagnosis and text chat using a smartphone application were feasible and useful for efficient and safe postoperative MMD management.

Visual dysfunction and neurodegeneration caused by severe inflammatory optic neuropathy after coil embolization of a paraclinoid aneurysm: illustrative case

BACKGROUND

Visual impairment due to delayed optic neuropathy is a rare complication of the endovascular treatment of paraclinoid aneurysms. An inflammatory response induced in the treated aneurysm wall is a known mechanism underlying this pathophysiology. The authors describe a case with severe and progressive optic neuropathy leading to neuronal degeneration and severe visual dysfunction.

OBSERVATIONS

A 42-year-old female with a history of surgical clipping for a paraclinoid aneurysm presented with a recurrence. Although the patient was unaware of any visual dysfunction, a preoperative ophthalmological examination revealed mild inferior quadrantanopia in the left eye. The coil embolization procedure was uneventful; however, the following day, the patient experienced progressive visual impairment, which worsened despite the initiation of steroid therapy. Ophthalmological examination revealed a severe decrease in visual acuity and further deterioration of the visual field. Magnetic resonance imaging showed remarkable swelling and edema of the left optic nerve adjacent to the treated aneurysm. Despite continued steroid therapy, the patient's visual function did not recover well due to subsequent optic nerve degeneration.

LESSONS

Optic neuropathy after endovascular procedures can lead to severe visual dysfunction. Careful management is essential, particularly when treating a symptomatic paraclinoid aneurysm, even if symptoms are only apparent on detailed examination.

Predictive value of the hemispheric magnetic resonance angiography score on the development of indirect pial synangiosis after combined revascularization surgery for adult moyamoya disease

PURPOSE

It is difficult to precisely predict indirect bypass development in the context of combined bypass procedures in moyamoya disease (MMD). We aimed to investigate the predictive value of magnetic resonance angiography (MRA) signal intensity in the peripheral portion of the major cerebral arteries for indirect bypass development in adult patients with MMD.

METHODS

We studied 93 hemispheres from 62 adult patients who underwent combined direct and indirect revascularization between 2005 and 2019 and genetic analysis for RNF213 p.R4810K. The signal intensity of the peripheral portion of the major intracranial arteries during preoperative MRA was graded as a hemispheric MRA score (0-3 in the middle cerebral artery and 0-2 in the anterior cerebral and posterior cerebral arteries, with a high score representing low visibility) according to each vessel's visibility. Postoperative bypass development was qualitatively evaluated using MRA, and we evaluated the correlation between preoperative factors, including the hemispheric MRA score and bypass development, using univariate and multivariate analyses.

RESULTS

A good indirect bypass was observed in 70% of the hemispheres. Hemispheric MRA scores were significantly higher in hemispheres with good indirect bypass development than in those with poor indirect bypass development (median: 3 vs. 1; p < 0.0001). Multiple logistic regression analysis revealed hemispheric MRA score as an independent predictor of good indirect bypass development (odds ratio, 2.1; 95% confidence interval, 1.3-3.6; p < 0.01). The low hemispheric MRA score (< 2) and wild-type RNF213 predicted poor indirect bypass development with a specificity of 0.92.

CONCLUSION

Hemispheric MRA score was a predictive factor for indirect bypass development in adult patients who underwent a combined bypass procedure for MMD. Predicting poor indirect bypass development may lead to future tailored bypass surgeries for MMD.

Systemic immune-inflammation index in dural arteriovenous fistula: a feasible biomarker reflecting its clinical characteristics

PURPOSE

The systemic immune-inflammation index (SII), a marker of systemic inflammation, can be calculated using peripheral blood tests. Although the SII has been reported as a feasible biomarker in various cerebrovascular diseases, no studies have explored in dural arteriovenous fistula (DAVF). A retrospective cohort study was performed to test whether the SII reflects the clinical characteristics of DAVF and whether this index could serve as a feasible biomarker.

METHODS

This study included 28 patients who underwent endovascular treatment (39 sessions) for DAVF between 2014 and 2023. The SII was calculated using the following formula: platelet count multiplied by neutrophil count divided by lymphocyte count. We investigated the correlation between the SII and various clinical characteristics of DAVF, including symptom manifestation, and digital subtraction angiography findings. Additionally, we compared pre- and post-endovascular treatment changes in the SII.

RESULTS

A significantly higher SII was observed in patients with multiple lesions, clinical symptoms (particularly aggressive symptoms), pseudophelebitic pattern (PPP), and sinus occlusion. Multivariate regression analysis revealed that the presence of symptoms (coefficient 270.9, P = 0.021) and PPP (coefficient 272.4, P = 0.017) were independent factors contributing to SII elevation. Notably, following endovascular treatment, there was a significant decrease in the elevated SII in patients whose symptoms resolved (P = 0.039) and where the DAVF was angiographically cured (P = 0.012).

CONCLUSION

Elevation of the SII in patients with advanced DAVF and its decrease following endovascular treatment suggests that the SII reflects the disease condition and indicates its potential as a promising biomarker.

Impact of intraoperative cortical indocyanine green extravasation on local vasogenic edema immediately after direct revascularization in an adult with moyamoya disease: illustrative case

BACKGROUND

Local vasogenic edema induced after direct revascularization in moyamoya disease (MMD) is associated with blood-brain barrier dysfunction, potentially leading to postoperative cerebral hyperperfusion (CHP) or delayed intracerebral hemorrhage. This phenomenon allows the leakage of fluids, proteins, and other substances from the blood vessels into the extracellular compartment. Typically, such edema is observed postoperatively rather than intraoperatively.

OBSERVATIONS

A 48-year-old female with ischemic-onset MMD underwent revascularization on her left hemisphere with Suzuki's angiographic stage III. Direct bypass was successfully performed, as confirmed by intravenous indocyanine green (ICG) video angiography. Subsequently, ICG extravasation was observed near the anastomosis site, despite the absence of cortical injury or bleeding under white light microscopy. Postoperative radiological imaging showed reversible pure vasogenic edema in the corresponding area, with no evidence of CHP. The patient did not exhibit neurological deterioration and was discharged home on postoperative day 16.

LESSONS

ICG, characterized by low molecular weight, water solubility, and high affinity with plasma proteins, can extravasate, serving as a direct indication of local vasogenic edema induced by direct revascularization in MMD. To enhance comprehension of the vulnerability of the blood-brain barrier in MMD, it is advisable to gather cases with prolonged observations of ICG video angiography after direct revascularization.

Long-term Outcomes of Combined Revascularization Surgery for Moyamoya Disease in the Elderly: A Single Institute Experience

The opportunity to treat older patients with Moyamoya disease (MMD) is increasing. However, the surgical outcomes after combined direct and indirect revascularization for elderly patients with MMD are not fully understood, especially for those ≥60 years old. This retrospective study examined 232 consecutive hemispheres of 165 adults with MMD who underwent combined revascularization. Clinical features and surgical outcomes were compared between the elderly (≥60 years) and nonelderly group (<60 years). Thirteen (5.6%, 64.4 ± 4.0 years old) and 219 hemispheres (94.4%, 40.2 ± 10.8 years old) were included in the elderly and nonelderly group, respectively. The proportion of clinical presentations before surgery did not differ. However, the prevalence of hypertension and hyperlipidemia was significantly higher in the elderly group than in the nonelderly group. Meanwhile, hyperthyroidism was observed only in the nonelderly group. No significant intergroup differences were observed in the incidence of perioperative complications occurring within four weeks postsurgery. Notably, the elderly group was more prone to develop perioperative intracerebral hemorrhage (odds ratio (OR) 3.14, 95% confidence interval (CI) 0.45-13.5) than the nonelderly group. During a median follow-up period of 7.8 years, the incidence of stroke recurrence occurring later than four weeks postsurgery was not significantly different between the groups (hazard ratio, 1.19; 95% CI 0.133-10.6). The prevalence of independent outcomes (76.9% vs. 90.4%, P = 0.14) and mortality (7.7% vs. 1.4%, P = 0.21) did not differ significantly between the elderly and nonelderly groups, respectively. Perioperative intracerebral hemorrhage may be common in the elderly and should be considered to achieve a favorable surgical outcome.

Post-traumatic stress disorder in international surgeons undertaking trauma electives in a South African trauma centre

BACKGROUND

Post-traumatic stress disorder (PTSD) is a well-documented psychiatric outcome in patients who experience physical trauma. The phenomenon is less studied in the staff involved in caring for such patients. The aim was to investigate the prevalence of PTSD in visiting international surgeons undergoing elective trauma training and to compare to local and international rates.

METHODS

A trauma screening questionnaire (TSQ) survey was conducted among surgeons completing their elective trauma service placements in the Pietermaritzburg Metropolitan Trauma Service.

RESULTS

Nineteen surveys were completed (32% response rate). Mean age was 38.9 (SD 6.5). Median postgraduate working experience was 5 (2-10) years. Median time of stay in South Africa was 6 (1-72) months. Compared to preelective experience, there was a five-fold increase in the level of trauma resuscitation experience reported during elective placement. 10.5% of surgeons scored > 5 in the TSQ suggesting probable PTSD. No statistical differences in age, years of prior experience, prior trauma rotation, number of major resuscitations, or length of stay in South Africa were observed in those scoring positive versus negative screening in the TSQ questionnaire.

CONCLUSION

Despite being exposed to increased levels of trauma related injury, we observed low rates of positive screening for PTSD in our cohort of visiting international surgeons involved in elective trauma service placements. Investigation of potential protective factors against PTSD in this South African tertiary trauma centre is warranted.

Moyamoya Syndrome Associated with Late-onset Idiopathic Aqueduct Stenosis Successfully Treated with Endoscopic Third Ventriculostomy

Moyamoya disease (MMD) is a rare idiopathic cerebrovascular disorder that causes transient ischemic attack (TIA) and ischemic stroke in the pediatric population. Herein, we report an extremely rare case of Moyamoya syndrome (MMS) and late-onset idiopathic aqueduct stenosis, a unique form of non-communicating hydrocephalus. A 17-year-old female presented with an intractable headache and occasional faintness. Pertinent medical history included a fourth ventricle epidermoid cyst without any evidence of aqueduct stenosis, which was surgically removed when she was two years of age. The patient subsequently experienced a TIA and was diagnosed with MMD at 14 years of age. Under the definitive diagnosis of MMS associated with a brain tumor, the patient underwent surgical revascularization of the symptomatic right hemisphere without complications. Although the ischemic symptoms resolved postoperatively, a medically intractable headache with occasional faintness persisted. Serial magnetic resonance imaging ultimately revealed newly developed non-communicating hydrocephalus due to acquired aqueduct stenosis at the age of 17. After careful exclusion of the development of either or both a periventricular anastomosis and vault moyamoya vessels along the surgical route using cerebral angiography, we performed an endoscopic third ventriculostomy (ETV) via the right anterior horn without complications. A complete resolution of her chronic headache with the shrinkage of the third ventriculomegaly was observed postoperatively. In cases of MMS associated with symptomatic aqueduct stenosis, transdural collaterals on the cranial vault and periventricular collaterals should be meticulously evaluated preoperatively using cerebral angiography to safely perform an ETV.

Deep learning-based video-analysis of instrument motion in microvascular anastomosis training

PURPOSE

Attaining sufficient microsurgical skills is paramount for neurosurgical trainees. Kinematic analysis of surgical instruments using video offers the potential for an objective assessment of microsurgical proficiency, thereby enhancing surgical training and patient safety. The purposes of this study were to develop a deep-learning-based automated instrument tip-detection algorithm, and to validate its performance in microvascular anastomosis training.

METHODS

An automated instrument tip-tracking algorithm was developed and trained using YOLOv2, based on clinical microsurgical videos and microvascular anastomosis practice videos. With this model, we measured motion economy (procedural time and path distance) and motion smoothness (normalized jerk index) during the task of suturing artificial blood vessels for end-to-side anastomosis. These parameters were validated using traditional criteria-based rating scales and were compared across surgeons with varying microsurgical experience (novice, intermediate, and expert). The suturing task was deconstructed into four distinct phases, and parameters within each phase were compared between novice and expert surgeons.

RESULTS

The high accuracy of the developed model was indicated by a mean Dice similarity coefficient of 0.87. Deep learning-based parameters (procedural time, path distance, and normalized jerk index) exhibited correlations with traditional criteria-based rating scales and surgeons' years of experience. Experts completed the suturing task faster than novices. The total path distance for the right (dominant) side instrument movement was shorter for experts compared to novices. However, for the left (non-dominant) side, differences between the two groups were observed only in specific phases. The normalized jerk index for both the right and left sides was significantly lower in the expert than in the novice groups, and receiver operating characteristic analysis showed strong discriminative ability.

CONCLUSION

The deep learning-based kinematic analytic approach for surgical instruments proves beneficial in assessing performance in microvascular anastomosis. Moreover, this methodology can be adapted for use in clinical settings.

Chronological Volume Changes of the Temporal Muscle Pedicle Used for Encephalo-myo-synangiosis in Combined Revascularization for Moyamoya Disease: A Prospective Observational Study

Although postoperative neurological events due to brain compression by the swollen temporal muscle are a rare complication, the chronological volume changes of the temporal muscle pedicle and their clinical impact have not yet been documented. This prospective observational study aimed to investigate the chronological volume changes in the temporal muscle pedicle in Moyamoya disease (MMD). Eighteen consecutive combined revascularization procedures using the temporal muscle were performed for symptomatic MMD in 2021. The postoperative pedicle volume was quantified using repeated computed tomography images on postoperative days (PODs) 0, 1, 7, 14, and 30. Postoperative neurological events with radiological evaluations and collateral development evaluated using magnetic resonance angiography obtained 6 months after surgery were studied. On average, the postoperative temporal muscle pedicle volume was most significantly increased by as much as 112% ± 9.6% on POD 7 (P < 0.001) and decreased by as little as 52% ± 21% on POD 30 (P < 0.0001) relative to POD 0. One exceptional patient (overall incidence, 5.6%) demonstrated postoperative transient neurological events due to brain compression by the swollen temporal muscle with decreased focal cerebral blood flow in the adjacent cortical area. The postoperative collateral development via direct and indirect revascularizations was confirmed in 16 (89%) and 12 (67%) hemispheres, respectively. All patients, except for one rebleeding case, showed independent outcomes at the mean latest follow-up period on 290 ± 96 days after surgery. Our observations confirmed the temporal profile of muscle pedicle volume changes after combined revascularization. Through routine attempts to avoid the unfavorable effects of temporal muscle swelling, combined revascularization can provide favorable outcomes in symptomatic MMD.

Association of RNF213 polymorphism and cortical hyperintensity sign on fluid-attenuated inversion recovery images after revascularization surgery for moyamoya disease: possible involvement of intrinsic vascular vulnerability

A cortical hyperintensity on fluid-attenuated inversion recovery images (FLAIR cortical hyperintensity (FCH)) is an abnormal finding after revascularization surgery for moyamoya disease. This study aimed to investigate the pathophysiology of FCH through genetic analyses of RNF213 p.R4810K polymorphism and perioperative hemodynamic studies using single-photon emission computed tomography. We studied 96 hemispheres in 65 adults and 47 hemispheres in 27 children, who underwent combined direct and indirect revascularization. Early or late FCH was defined when it was observed on postoperative days 0-2 and 6-9, respectively. FCH scores (range: 0-6) were evaluated according to the extent of FCH in the operated hemisphere. FCHs were significantly more prevalent in adult patients than pediatric patients (early: 94% vs. 78%; late: 97% vs. 59%). In pediatric patients, FCH scores were significantly improved from the early to late phase regardless of the RNF213 genotype (mutant median [IQR]: 2 [1-5] vs. 1 [0-2]; wild-type median: 4 [0.5-6] vs. 0.5 [0-1.75]). In adults, FCH scores were significantly improved in patients with the wild-type RNF213 allele (median: 4 [2-5.25] vs. 2 [2, 3]); however, they showed no significant improvement in patients with the RNF213 mutation. FCH scores were significantly higher in patients with symptomatic cerebral hyperperfusion than those without it (early median: 5 [4, 5] vs. 4 [2-5]; late median: 4 [3-5] vs. 3 [2-4]). In conclusion, the RNF213 p.R4810K polymorphism was associated with prolonged FCH, and extensive FCH was associated with symptomatic cerebral hyperperfusion in adult patients with moyamoya disease.

Negative Remodeling of Carotid Canal during Spontaneous Disease Progression in Moyamoya Disease

OBJECTIVE

This study was aimed to observe the changes in the carotid canal over time by measuring the carotid canal diameter longitudinally in adult patients with moyamoya disease in whom disease stage progressed spontaneously.

MATERIALS AND METHODS

Of 70 adult patients with moyamoya disease, 10 adult patients on 15 sides with spontaneous progression of the disease stage during conservative follow-up were included in this study. Other 10 moyamoya cases on 15 sides were selected as the controls without disease progression. All patients were followed up for at least 60 months after the progression of disease stage was confirmed. In addition, 5 patients who underwent microvascular decompression were included as healthy controls. The carotid canal diameter was measured with bone window CT and source images of TOF MR angiography at initial presentation, and then were serially monitored with the latter.

RESULTS

There was a significant correlation between the values obtained from CT and MRI (R²=0.992, P<0.001). The carotid canal diameter in moyamoya disease at initial presentation was 4.29±0.61 mm, being smaller than 5.20±0.51 mm in healthy controls (P<0.01). In response to disease progression, the carotid canal diameter started to decrease at 6 months after disease progression was confirmed, and reduced to about 85% of the original level during 60 months (P<0.01). However, the phenomenon was not observed in patients without disease progression.

CONCLUSIONS

The carotid canal diameter can decrease in response to disease progression even in adult moyamoya disease. "Negative" bone remodeling may play a key role in this unique phenomenon.

Abstract TMP117: Optogenetic Stimulation Effects On Cortico-thalamic Circuit Plasticity After Stroke

Introduction: Post-stroke optogenetic stimulation in the ipsilesional primary motor cortex (iM1) can promote functional recovery. Recent brain imaging data indicate that iM1-stimulated stroke mice restore activation of the ipsilesional cortico-thalamic tract. To determine whether iM1 stimulation enhanced post-stroke plasticity in the cortico-thalamic tract, we investigate the expression of plasticity markers in the ipsilesional thalamus (iTH). We selectively stimulate the cortico-thalamic circuit to investigate its influences on plasticity changes and functional outcome.

Methods: C57BL6 male mice (6-7 weeks old) were injected and implanted in iM1 with AAV1-CaMKIIa-hChR2 virus and optical fiber for iM1 stimulation. Another set of mice were injected with AAV1-CaMKIIa-hChR2 virus in iM1 with an optical fiber implanted in ipsilesional thalamus (iTH) to selectively stimulate the cortico-thalamic circuit. Six weeks after virus injection, mice underwent transient middle cerebral artery occlusion (tMCAo, 30min), followed by optogenetic stimulations from PD5-14. Functional recovery was evaluated by rotating beam tests at pre-stroke and post-stroke days (PD) 4, 7 and 14. Brain sections were immunostained with plasticity marker synaptophysin and imaged for co-localization with ChR2. Thalamic tissues were processed with western blot for plasticity markers.

Results: iM1-stimulated mice (Stim group) exhibited significant functional recovery at post-stroke day14 on the rotating beam test, when compared to non-stimulated mice (NoStim group) (p<0.05). GAP43, an axonal growth marker, was significantly higher in iTH of iM1-stimulated mice (p<0.05). Moreover, we detected higher co-localization of ChR2 + /Synaptophysin + terminals in iTH of iM1-stimulated mice (p<0.05). Robust ChR2 is detected in the iM1-iTH motor cortico-thalamic circuit and selective stimulation of this cortico-thalamic circuit is sufficient to improve recovery (p<0.05).

Conclusion: Our results show that cortico-thalamic circuit plays a key role in functional recovery after stroke. Ongoing studies investigates the transcriptome and plasticity changes in the cortico-thalamic circuit circuit.

Brain-wide neural dynamics of poststroke recovery induced by optogenetic stimulation

Poststroke optogenetic stimulations can promote functional recovery. However, the circuit mechanisms underlying recovery remain unclear. Elucidating key neural circuits involved in recovery will be invaluable for translating neuromodulation strategies after stroke. Here, we used optogenetic functional magnetic resonance imaging to map brain-wide neural circuit dynamics after stroke in mice treated with and without optogenetic excitatory neuronal stimulations in the ipsilesional primary motor cortex (iM1). We identified key sensorimotor circuits affected by stroke. iM1 stimulation treatment restored activation of the ipsilesional corticothalamic and corticocortical circuits, and the extent of activation was correlated with functional recovery. Furthermore, stimulated mice exhibited higher expression of axonal growth-associated protein 43 in the ipsilesional thalamus and showed increased Synaptophysin+/channelrhodopsin+ presynaptic axonal terminals in the corticothalamic circuit. Selective stimulation of the corticothalamic circuit was sufficient to improve functional recovery. Together, these findings suggest early involvement of corticothalamic circuit as an important mediator of poststroke recovery.

Optogenetic Stimulation Reduces Neuronal Nitric Oxide Synthase Expression After Stroke

Post-stroke optogenetic stimulation has been shown to enhance neurovascular coupling and functional recovery. Neuronal nitric oxide synthase (nNOS) has been implicated as a key regulator of the neurovascular response in acute stroke; however, its role in subacute recovery remains unclear. We investigated the expression of nNOS in stroke mice undergoing optogenetic stimulation of the contralesional lateral cerebellar nucleus (cLCN). We also examined the effects of nNOS inhibition on functional recovery using a pharmacological inhibitor targeting nNOS. Optogenetically stimulated stroke mice demonstrated significant improvement on the horizontal rotating beam task at post-stroke days 10 and 14. nNOS mRNA and protein expression was significantly and selectively decreased in the contralesional primary motor cortex (cM1) of cLCN-stimulated mice. The nNOS expression in cM1 was negatively correlated with improved recovery. nNOS inhibitor (ARL 17477)-treated stroke mice exhibited a significant functional improvement in speed at post-stroke day 10, when compared to stroke mice receiving vehicle (saline) only. Our results show that optogenetic stimulation of cLCN and systemic nNOS inhibition both produce functional benefits after stroke, and suggest that nNOS may play a maladaptive role in post-stroke recovery.

Late (5-20 years) outcomes after STA-MCA anastomosis and encephalo-duro-myo-arterio-pericranial synangiosis in patients with moyamoya disease

OBJECTIVE

Surgical revascularization is known to reduce the incidence of further ischemic and hemorrhagic events in patients with moyamoya disease, but the majority of previous studies report only short-term (< 5 years) outcomes. Therefore, in this study the authors aimed to evaluate late (5-20 years) outcomes of moyamoya patients after superficial temporal artery to middle cerebral artery (STA-MCA) anastomosis and indirect bypass (encephalo-duro-myo-arterio-pericranial synangiosis [EDMAPS]).

METHODS

Cumulative incidences of late morbidity/mortality and disease progression were evaluated among 93 patients who underwent STA-MCA anastomosis and EDMAPS. All of the patients were prospectively followed up for longer than 5 years postsurgery (10.5 ± 4.4 years). There were 35 pediatric and 58 adult patients. Initial presentation included transient ischemic attack/ischemic stroke in 80 patients and hemorrhagic stroke in 10 patients, and 3 patients were asymptomatic. Surgery was performed in a total of 141 hemispheres. Follow-up MRI/MRA was performed within a 6- or 12-month interval during the follow-up periods.

RESULTS

During the follow-up periods, 92/93 patients were free from any stroke or death, but 1 patient had a recurrence of hemorrhagic stroke (0.10% per patient-year). Disease progression occurred in the territory of the contralateral carotid or posterior cerebral artery (PCA) in 19 hemispheres of 15 patients (1.5% per patient-year). The interval between initial surgery and disease progression varied widely, from 0.5 to 15 years. Repeat bypass surgery for the anterior and posterior circulation resolved ischemic attacks in all 10 patients.

CONCLUSIONS

The study results indicate that STA-MCA anastomosis and EDMAPS would be the best choice to prevent further ischemic and hemorrhagic stroke for longer than 10 years on the basis of the demonstrated widespread improvement in cerebral hemodynamics in both the MCA and ACA territories in the study patients. However, after 10 years postsurgery regular follow-up is essential to detect disease progression in the territory of the contralateral carotid artery and PCA and prevent late cerebrovascular events.

Combined structural and diffusion tensor imaging detection of ischemic injury in moyamoya disease: relation to disease advancement and cerebral hypoperfusion

OBJECTIVE

The microstructural integrity of gray and white matter is decreased in adult moyamoya disease, suggesting covert ischemic injury as a mechanism of cognitive dysfunction. Establishing a microstructural brain imaging marker is critical for monitoring cognitive outcomes following surgical interventions. The authors of the present study determined the pathophysiological basis of altered microstructural brain injury in relation to advanced arterial occlusion, cerebral hypoperfusion, and cognitive function.

METHODS

The authors examined 58 patients without apparent brain lesions and 30 healthy controls by using structural MRI, as well as diffusion tensor imaging (DTI). Arterial occlusion in each hemisphere was classified as early or advanced stage based on MRA and posterior cerebral artery (PCA) involvement. Regional cerebral blood flow (rCBF) was measured with N-isopropyl-p-[123I]-iodoamphetamine SPECT. Furthermore, cognitive performance was examined using the Wechsler Adult Intelligence Scale, Third Edition and the Trail Making Test (TMT). Both voxel- and region of interest-based analyses were performed for groupwise comparisons, as well as correlation analysis, using parameters such as cognitive test scores; gray matter volume; fractional anisotropy (FA) of association fiber tracts, including the inferior frontooccipital fasciculus (IFOF) and superior longitudinal fasciculus (SLF); PCA involvement; and rCBF.

RESULTS

Compared to the early stages, advanced stages of arterial occlusion in the left hemisphere were associated with a lower Performance IQ (p = 0.031), decreased anterior cingulate volumes (p = 0.0001, uncorrected), and lower FA in the IFOF, cingulum, and forceps major (all p < 0.01, all uncorrected). There was no significant difference in rCBF between the early and the advanced stage. In patients with an advanced stage, PCA involvement was correlated with a significantly lower Full Scale IQ (p = 0.036), cingulate volume (p < 0.01, uncorrected), and FA of the left SLF (p = 0.0002, uncorrected) compared to those with an intact PCA. The rCBF was positively correlated with FA of the SLF, IFOF, and forceps major (r > 0.34, p < 0.05). Global gray matter volumes were moderately correlated with TMT part A (r = 0.40, p = 0.003). FA values in the left SLF were moderately associated with processing speed (r = 0.40, p = 0.002).

CONCLUSIONS

Although hemodynamic compensation may mask cerebral ischemia in advanced stages of adult moyamoya disease, the disease progression is detrimental to gray and white matter microstructure as well as cognition. In particular, additional PCA involvement in advanced disease stages may impair key neural substrates such as the cingulum and SLF. Thus, combined structural MRI and DTI are potentially useful for tracking the neural integrity of key neural substrates associated with cognitive function and detecting subtle anatomical changes associated with persistent ischemia, as well as disease progression.

Abstract MP58: Motor Cortex and Spinal Cord Transcriptome After Post-Stroke Optogenetic Neuronal Stimulation

Background: Post-stroke brain stimulation is a promising neurorestorative technique to promote recovery. However, the underlying molecular mechanisms driving recovery are still unclear. Here we investigate the molecular changes in both the primary motor cortex and the cervical spinal cord after large cortical stroke in mice receiving repeated optogenetic stimulations in the ipsilateral primary motor cortex (iM1).

Methods: C57Bl6 male mice (8 weeks) underwent stereotaxic surgery to express Channelrhodopsin2 in excitatory neurons in iM1, with optical fiber implanted in the same location. After five weeks the mice underwent a transient middle cerebral artery occlusion to induce stroke. Optogenetic stimulations were given daily from post-stroke days (PD) 5-14. Non-stimulated mice were used as controls. Rotating beam test was used to evaluate functional recovery after stroke. At PD 7 and 15, ipsi- and contralesional primary motor cortex (iM1 and cM1) and cervical spinal cords (iSp and cSp) were dissected and processed for RNA sequencing.

Results: Repeated iM1 stimulations resulted in a robust recovery on the rotating beam test at PD14, with significant improvement in distance traveled (p<0.05). RNA sequencing analysis (stimulated vs non-stimulated mice) revealed differential transcriptome in both motor cortex and spinal cord. Higher number of differentially expressed genes (DEGs) were observed in the ipsilesional regions (iM1 and iSp). At PD 7, stimulated mice exhibited upregulation of activity-dependent and neuroplasticity-related genes in iM1. Interestingly, at PD15, cholesterol metabolism and neuroinflammatory related genes in iM1 were downregulated. The expressions of the genes were negatively correlated with behavioral recovery. Higher number of DEGs were altered in the spinal cord than motor cortex, suggesting more dynamic molecular changes occur in this area during the post-stroke reinnervation processes. Expressions of synaptogenesis related genes were altered in both iSp and cSp at both timepoints.

Conclusions: These transcriptome data reveal important insights into the molecular signaling involved in post-stroke stimulation-induced recovery and provide potential drug targets for enhancing recovery in stroke patients.

Abstract P749: Functional and Molecular Characterization of Endothelial and Vascular Smooth Muscle Cells Derived From Moyamoya Disease-Induced Pluripotent Stem Cells

Background: Moyamoya disease (MMD) is a rare, progressive steno-occlusive cerebrovascular disorder of the internal carotid artery, leading to stroke. Affected arteries exhibited thickened intima with depleted elastic lamina and media, indicating a dysfunction of the vascular smooth muscle cells (VSMCs) and endothelial cells (ECs). However, the pathogenesis of the disease is still unclear. We aim to address this gap in knowledge by using patient derived induced pluripotent stem cells (iPSCs), to generate VSMCs and ECs.

Methods: Peripheral blood mononuclear cells (PBMCs) from controls and MMD patients (n=3 per group) were used for generating iPSCs. Functional properties of differentiated ECs and VSMCs in normoxia/hypoxia model (1%O 2 ) were assessed for cell proliferation by BrDU incorporation, migration by scratch assays and apoptosis by exposure to hydrogen peroxide (H2O2). In vitro angiogenic tube formation was assessed with ECs alone, as well as ECs and VSMCs as a co-culture. Hypoxia inducible factor 1α (HIF1α) and Intercellular adhesion molecule-1 (ICAM-1) activation was determined using qPCR and western blot in VSMCs.

Results: Functional proliferative assays showed that MMD ECs proliferated faster than control ECs. Migration assays showed that MMD ECs migrate slower in response to VEGF after hypoxia. MMD ECs were found to be more sensitive to insults such as H2O2 treatment and exhibited more apoptosis. In contrast, MMD VSMCs proliferate and migrate similar to controls, but exhibited elevated levels of HIF1α, ICAM-1 mRNA and protein expression. MMD and control ECs showed similar levels of tube formation in single cultures, however, when co-culturing with VSMCs, MMD VSMCs failed to support EC tubes beyond 24 h, resulting in tube destabilization.

Conclusions: Our preliminary results indicate that both MMD VSMCs and ECs are dysfunctional and may be related to the elevated expression of HIF1α and ICAM-1, possibly contributing to MMD pathology. Current ongoing studies include investigating the interactions between MMD VSMCs and ECs using co-cultures, as well as transcriptome analysis of these differentiated cells, which will provide important insights into the cellular and molecular mechanisms underlying MMD.

Specific clinical features and one-stage revascularization surgery for moyamoya disease with severe cerebral ischemia in the territory of posterior cerebral artery

BACKGROUND

There are no reports describing the surgical procedure for moyamoya disease (MMD) patients with severe cerebral ischemia in the territory of the posterior cerebral artery (PCA) at initial presentation. In this study, therefore, we describe their clinical and radiological features and clinical results of one-stage revascularization surgery for both anterior and posterior circulation.

METHODS

This study included 6 MMD patients who had severe cerebral ischemia in the PCA territory and underwent one-stage revascularization surgery for both anterior and posterior circulation. Of these, one patient underwent it on both sides. Their clinical and radiological data were precisely analyzed. Compared with usual procedure, craniotomy was extended towards the temporo-parietal area more widely. The parietal branch of superficial temporal artery (STA) was anastomosed to the angular or posterior temporal artery, while the frontal branch was anastomosed to the frontal branch of MCA. Ultimate indirect bypass was added. Their clinical and radiological outcomes were evaluated.

RESULTS

Their neurological symptoms included visual and speech disturbance as well as numbness of the extremities. Cerebral infarct was distributed in the posterior temporal, parietal, and/or occipital lobe. Cerebral hemodynamics and metabolism were also impaired in the same regions. These findings were completely different from those in MMD patients without PCA lesion. Postoperative course was uneventful, and none of them recurred stroke during a mean follow-up period of 10.5 years. Surgical collaterals widely provided blood flow to the entire hemispheres, including the occipital lobe. Cerebral hemodynamics and metabolism markedly improved after surgery.

CONCLUSION

One-stage revascularization surgery for both anterior and posterior circulation is feasible and effective to prevent future stroke in MMD patients with severe cerebral ischemia in the PCA territory at initial presentation.

Ameliorative Effects of Combined Revascularization Surgery on Abnormal Collateral Channels in Moyamoya Disease

OBJECT

Abnormal collateral channels, so-called moyamoya vessels, play a critical role to compensate cerebral ischemia, but carry the risk for hemorrhagic stroke in moyamoya disease (MMD). The present study was aimed to clarify if superficial temporal artery to middle cerebral artery (STA-MCA) anastomosis and encephalo-myo-duro-arterio-pericranial synangiosis (EDMAPS) can efficiently regress the abnormal collateral channels in MMD patients.

METHODS

This study included 92 hemispheres of 61 MMD patients who underwent STA-MCA anastomosis combined with EDMAPS between 2013 and 2019. There were 17 children and 44 adults. We retrospectively analyzed the findings on cerebral angiography before and 3 to 6 months after surgery, including Suzuki's angiographical stage, the development of surgical collaterals, and the extent of abnormal collateral channels such as lenticulostriate, thalamic, and choroidal channels.

RESULTS

Following surgery, no pediatric and adult patients experienced any stroke during follow-up periods (40.2±25.5 and 54.9±19.7 months, respectively). Suzuki's stage significantly advanced in both adult and pediatric patients after surgery (P=0.042 and P<0.001). In adult patients, all of the lenticulostriate, thalamic, and choroidal channels significantly regressed after surgery (P<0.001, P=0.012, and P=0.004, respectively). In pediatric patients, however, lenticulostriate and choroidal channels significantly regressed (P=0.005 and P=0.034, respectively). Correlation analysis revealed that the development of surgical collaterals determined the postoperative regression of choroidal channels (P<0.001).

CONCLUSION

STA-MCA anastomosis and EDMAPS may be one of the most effective procedures to widely provide surgical collaterals to the operated hemispheres and prevent not only ischemic but also hemorrhagic stroke by regressing the hemorrhage-prone abnormal collateral channels in MMD.

Using postoperative remodeling of donor arteries on MR angiography to predict the development of surgical collaterals in moyamoya disease

OBJECTIVE

The calibers of donor arteries can change dynamically after bypass surgery in patients with moyamoya disease (MMD). The present study aimed to evaluate the cutoffs of caliber changes in donor arteries associated with good surgical revascularization and to assess the impact of clinical factors potentially related to bypass development.

METHODS

The authors studied 71 hemispheres of 30 adults and 16 children with MMD who underwent combined direct and indirect revascularization. They quantitatively measured the calibers of the superficial temporal artery (STA), deep temporal artery (DTA), and middle meningeal artery (MMA) with MR angiography (MRA) source images and calculated the postoperative caliber change ratios (CCRs) to assess direct and indirect bypass development. These values were compared with the findings of digital subtraction angiography, in which revascularization areas were categorized into 3 groups (poor, good, and excellent).

RESULTS

In both adult and pediatric hemispheres, the median STA and DTA CCRs were higher in better-revascularization groups (p < 0.05), while MMA CCRs were not significantly different among the groups. Receiver operating characteristic analysis revealed that the cutoff STA CCRs of > 1.1 and > 1.3 were associated with good direct revascularization in adult and pediatric hemispheres, respectively. Cutoff DTA CCRs of > 1.6 and > 1.2 were associated with good indirect revascularization in adult and pediatric hemispheres, respectively. Considering these cutoff values, STA and DTA CCRs showed high median values, irrespective of age, severity of cerebrovascular reserve, disease stage, and disease-onset type.

CONCLUSIONS

Caliber changes in STAs and DTAs can be easily measured using MRA, and they could be indicators of direct and indirect bypass development. The dual development of a direct and indirect bypass was most frequently observed in the context of a combined bypass procedure in both adults and children with MMD.

The scourge of knife crime: trends in knife-related assault managed at a major centre in South Africa

BACKGROUND

Knife wounds are common and represent a major burden to the South African healthcare system. This study reviews trends in spectrum, management and outcome of these injuries at a single trauma centre in KwaZulu-Natal(KZN).

METHOD

The regional hybrid electronic registry (HEMR) was reviewed for the period January 2013 - December 2018, and all patients who suffered a knife-related assault were identified and reviewed.

RESULTS

During the period under review, a total of 2117 patients suffered a knife-related assault. Regions injured were as follows: head 445, neck 572, face 258, chest 939, abdomen 649, pelvic/urogenital 49, upper limb 418, and lower limb 105. The median ISS was 9 (4-10). Imaging comprised 1242 chest X-rays, 315 abdominal X-rays, 162 abdominal ultrasounds/ FAST, and 929 CT scans of which 634 were CT angiograms. A total of 783 (37%) patients required an operation. The rate of laparotomy was 447/649 (69%) and of thoracotomy/sternotomy/thoracoscopy 95/939 (10%). The rate of vascular exploration for upper and lower limb vascular injury was 101/523 (19%). Mortality was 49/2117 (2.3%)..

CONCLUSION

Although our clinical outcomes over this period appear to be consistent, suggesting a familiarity with managing knife-related trauma, the persistently high rate of knife-related injury suggests that we have failed to develop a preventative strategy to try and reduce this scourge.

Clinical and Radiological Features of Childhood Onset Adult Moyamoya Disease: Implication for Hemorrhagic Stroke

Some of the pediatric moyamoya patients spend their childhood without diagnosed as moyamoya disease (MMD) because of their mild ischemic attacks and emerge again with ischemic or hemorrhagic stroke in their adulthood. This study was aimed to clarify the clinical characteristics of adult moyamoya patients with childhood onset and elucidate the impact of long disease period on their clinical features. Present study included 116 untreated hemispheres of 69 adult patients with MMD. They were divided into two groups: childhood onset group (26 hemispheres of 14 patients) and adult onset group (90 hemispheres of 55 patients). Clinical features were compared between the two groups. The incidence of hemorrhagic stroke was significantly higher in childhood onset group (P = 0.0091). Lenticulostriate and choroidal channels were more developed in childhood onset group (P = 0.044 and P <0.001, respectively). Vault moyamoya was more frequently observed in childhood onset group (P <0.001). The development of surgical collaterals through indirect bypass was more marked in childhood onset group (P = 0.0019). Multivariate analysis revealed that childhood onset and developed choroidal channels were significantly associated with the occurrence of hemorrhagic stroke (OR 4.31 [95% CI 1.21-15.4], P = 0.025 and OR 6.78 [95% CI 1.78-25.8], P = 0.0050, respectively). This study clearly shows that adult moyamoya patients with childhood onset have more developed spontaneous collaterals, which may, in turn, highly causes hemorrhagic stroke. Adult moyamoya patients with "childhood onset" should be recognized as a novel and important concept when elucidating the underlying mechanisms of hemorrhagic stroke in MMD.