Cerebrovascular occlusive disease with and without the moyamoya vascular network in children

Screening of Moyamoya Disease From Retinal Photographs: Development and Validation of Deep Learning Algorithms

BACKGROUND

Moyamoya disease (MMD) is a rare and complex pathological condition characterized by an abnormal collateral circulation network in the basal brain. The diagnosis of MMD and its progression is unpredictable and influenced by many factors. MMD can affect the blood vessels supplying the eyes, resulting in a range of ocular symptoms. In this study, we developed a deep learning model using real-world data to assist a diagnosis and determine the stage of the disease using retinal photographs.

METHODS

This retrospective observational study conducted from August 2006 to March 2022 included 498 retinal photographs from 78 patients with MMD and 3835 photographs from 1649 healthy participants. Photographs were preprocessed, and an ResNeXt50 model was developed. Model performance was measured using receiver operating curves and their area under the receiver operating characteristic curve, accuracy, sensitivity, and F1-score. Heatmaps and progressive erasing plus progressive restoration were performed to validate the faithfulness.

RESULTS

Overall, 322 retinal photographs from 67 patients with MMD and 3752 retinal photographs from 1616 healthy participants were used to develop a screening and stage prediction model for MMD. The average age of the patients with MMD was 44.1 years, and the average follow-up time was 115 months. Stage 3 photographs were the most prevalent, followed by stages 4, 5, 2, 1, and 6 and healthy. The MMD screening model had an average area under the receiver operating characteristic curve of 94.6%, with 89.8% sensitivity and 90.4% specificity at the best cutoff point. MMD stage prediction models had an area under the receiver operating characteristic curve of 78% or higher, with stage 3 performing the best at 93.6%. Heatmap identified the vascular region of the fundus as important for prediction, and progressive erasing plus progressive restoration result shows an area under the receiver operating characteristic curve of 70% only with 50% of the important regions.

CONCLUSIONS

This study demonstrated that retinal photographs could be used as potential biomarkers for screening and staging of MMD and the disease stage could be classified by a deep learning algorithm.

Childhood Moyamoya: Looking Back to the Future

Moyamoya is a chronic, progressive steno-occlusive arteriopathy that typically affects the anterior circulation arteries of the circle of Willis. A network of deep thalamoperforating and lenticulostriate collaterals develop to by-pass the occlusion giving rise to the characteristic angiographic "puff of smoke" appearance. Moyamoya confers a lifelong risk of stroke and neurological demise, with peak age of presentation in childhood ranging between five and 10 years. Moyamoya disease refers to patients who do not have a comorbid condition, whereas moyamoya syndrome refers to patients in whom moyamoya occurs in association with an acquired or inherited disorder such as sickle cell disease, neurofibromatosis type-1 or trisomy 21. The incidence of moyamoya disease and moyamoya syndrome demonstrates geographic and ethnic variation, with a predominance of moyamoya disease in East-Asian populations. Antiplatelet therapy and surgical revascularization procedures are the mainstay of management, as there are no available treatments to slow the progression of the arteriopathy. Future research is required to address the major gaps that remain in our understanding of the pathologic basis, optimal timing for surgery, and determinants of outcome in this high-stroke risk condition of childhood.

Contralateral acute vascular occlusion following revascularization surgery for moyamoya disease

OBJECTIVE

Revascularization surgery is a safe and effective surgical treatment for symptomatic moyamoya disease (MMD) and has been shown to reduce the frequency of future ischemic events and improve quality of life in affected patients. The authors sought to investigate the occurrence of acute perioperative occlusion of the contralateral internal carotid artery (ICA) with contralateral stroke following revascularization surgery, a rare complication that has not been previously reported.

METHODS

This study is a retrospective review of a prospective database of a single surgeon's series of revascularization operations in patients with MMD. From 1991 to 2016, 1446 bypasses were performed in 905 patients, 89.6% of which involved direct anastomosis of the superficial temporal artery (STA) to a distal branch of the middle cerebral artery (MCA). Demographic, surgical, and radiographic data were collected prospectively in all treated patients.

RESULTS

Symptomatic contralateral hemispheric infarcts occurred during the postoperative period in 34 cases (2.4%). Digital subtraction angiography (DSA) was performed in each of these patients. In 8 cases (0.6%), DSA during the immediate postoperative period revealed associated new occlusion of the contralateral ICA. In each of these cases, revascularization surgery involved direct anastomosis of the STA to an M4 branch of the MCA. Preoperative DSA revealed moderate (n = 1) or severe (n = 3) stenosis or occlusion (n = 4) of the ipsilateral ICA and mild (n = 2), moderate (n = 4), or severe (n = 2) stenosis of the contralateral ICA. The baseline Suzuki stage was 4 (n = 7) or 5 (n = 1). The collateral supply originated exclusively from the intracranial circulation in 4/8 patients (50%), and from both the intracranial and extracranial circulation in the remaining 50% of patients. Seven (88%) of 8 patients improved symptomatically during the acute postoperative period with induced hypertension. The modified Rankin Scale (mRS) score at discharge was worse than baseline in 7/8 patients (88%), whereas 1 patient had only minor deficits that did not affect the mRS score. At the 3-year follow-up, 3/8 patients (38%) were at their baseline mRS score or better, 1 patient had significant disability compared with preoperatively, 2 patients had died, and 1 patient was lost to follow-up. Three-year follow-up is not yet available in 1 patient.

CONCLUSIONS

Acute occlusion of the ICA on the contralateral side from an STA-MCA bypass is a rare, but potentially serious, complication of revascularization surgery for MMD. It highlights the importance of the hemodynamic interrelationships that exist between the two hemispheres, a concept that has been previously underappreciated. Induced hypertension during the acute period may provide adequate cerebral blood flow via developing collateral vessels, and good outcomes may be achieved with aggressive supportive management and expedited contralateral revascularization.

Outcome of revascularization in moyamoya disease: Evaluation of a new angiographic scoring system

Background:

Moyamoya disease (MMD) is a chronic progressive cerebrovascular occlusive disease affecting commonly the anterior circle of Willis. Matushima grade inadequately reflects the angiographic changes postrevascularization procedure.

Aims:

To analyze the clinical and angiographic outcome of revascularization procedures (direct [ST-middle cerebral artery (MCA) anastomosis] and indirect [encephalo-duro-arterio-myo-synangiosis (EDAMS)]) in MMD and validate a new angiographic scoring system.

Materials and Methods:

Retrospective study included symptomatic patients of MMD who underwent revascularization; both indirect and combined methods between January 2002 and April 2012. Follow-up angiography was done after at least 3 months. We devised a novel scoring system the “angiographic outcome score” (AOS) including reformation of distal MCA and anterior cerebral artery, regression of basal moyamoya vessels, leptomeningeal collaterals and overall perfusion. AOS was applied to the angiograms independently by a neuroradiologist and a neurosurgeon that were blinded toward its preoperative or postoperative status.

Results:

Totally 33 patients underwent 36 EDAMS and 4 combined procedures (EDAMS + ST-MCA bypass). The mean follow-up was 20 months. None had recurrent transient ischemic attack or fresh infarct. Postoperative AOS was significantly higher than preoperative AOS. The Spearman rho showed positive correlation between Matushima grade and postoperative AOS. Significant regression of basal moyamoya vessels and increase in number of loci of transdural collaterals was seen.

Conclusions:

EDAMS is a simple yet effective method of revascularization in both pediatric as well as adult age groups. AOS is a simple, precise and easily reproducible scoring system, which reflects the favorable angiographic changes after revascularization.

A case with unusual stroke and fulminant outcome in a Hispanic male

Patient: Male, 42

Final Diagnosis: Moyamoya disease (MMD)

Symptoms: Aphasia • concentration difficulty • dysarthria • personality change

Medication: —

Clinical Procedure: —

Specialty: Radiology

Spontaneous occlusion of the circle of Willis in children: pediatric moyamoya summary with proposed evidence-based practice guidelines. A review

Moyamoya is a progressive arteriopathy of unknown origin affecting the branches of the internal carotid artery (ICA). The arteriopathy can present as an isolated medical condition, affecting both sides of the brain ("moyamoya disease") or can be unilateral or found in association with systemic disorders ("moyamoya syndrome"). The ischemia resulting from luminal narrowing predisposes children to transient ischemic attacks and stroke-the primary presentations of affected patients. Although it is rare-affecting 1 in 1 million children in the US-moyamoya is implicated in 6% of all childhood strokes. Diagnosis is defined by characteristic findings on arteriograms, including stenosis of the branches of the ICA and a pathognomonic spray of small collateral vessels in this region, descriptively likened to a "puff of smoke" ("moyamoya" in Japanese). Treatment is predicated on restoration of cerebral blood flow by surgical revascularization. The rarity of this disorder has limited research and the development of evidence-based clinical management. While acknowledging these limitations, in this article the authors aim to summarize current studies of pediatric moyamoya, with the objective of providing a framework for construction of evidence-based guidelines for treatment. The compilation of current data in these guidelines should serve as a resource to aid pediatric neurosurgeons in their role as advocates for providing appropriate care to affected children.

Surgical management of paediatric stroke

Childhood cerebrovascular disease is characterised by a wide range of relatively rare conditions. The management of a selection of some of the more frequently encountered, complex conditions is reviewed. The key to achieving the optimal therapeutic strategy for the individual child is multidisciplinary team management within a specialist neurovascular team. Access to rehabilitation is crucial.

Intracerebral hemorrhage and Moyamoya disease in pregnancy

PURPOSE

To present a case of Moyamoya disease with intracranial hemorrhage complicating pregnancy.

CLINICAL FEATURES

A 36-yr-old parturient at 34 wk gestation presented with left hemiparesis, headache, nausea and vomiting. Subsequent deterioration in level of consciousness and the development of a dilated right pupil necessitated immediate intubation. Urgent non-contrast CT scan revealed a large right intracerebral hematoma with transtentorial herniation. The patient underwent simultaneous emergency Cesarean section and craniotomy. A postoperative angiogram revealed findings consistent with Moyamoya disease. The neonate survived but the patient developed severe cerebral edema and died eleven days postoperatively.

CONCLUSION

Adult patients with Moyamoya disease often present with intracranial hemorrhage which poses unique anesthetic challenges. We report a case of intracerebral hemorrhage during pregnancy, which is known to be associated with high morbidity and mortality. The anesthetic techniques are reviewed and discussed.

Risk factors for neurologic deterioration after revascularization surgery in patients with moyamoya disease

To investigate the risk factors for postoperative neurological deterioration in patients with moyamoya disease, we retrospectively reviewed the perioperative course of 368 cases of revascularization surgery in 216 patients with this disease. Risk factors anecdotally associated with postoperative ischemic events were analyzed by comparing groups with or without a history of such events on the operative day. Ischemic events were noted in 14 cases (3.8%), 4 of which were defined as strokes and the others as transient ischemic attack (TIA). Postoperative neurological deterioration more often developed in patients who suffered from frequent TIAs, had precipitating factors for TIA, and underwent indirect nonanastomotic revascularization. The authors conclude that the incidence of postoperative ischemic events were related more to the severity of moyamoya disease and the type of surgical procedure than to other factors, including anesthetic management.

IMPLICATIONS

Although preventing stroke is the major concern for patients with moyamoya disease, risk factors for perioperative cerebral ischemia have not been clarified. We retrospectively analyzed the perioperative course in 368 cases with this disease and found that the severity of the disease and type of surgical procedure were major determinants of postoperative cerebral ischemia.

Renovascular hypertension in children with moyamoya disease

OBJECTIVES

To examine the incidence, clinical and radiologic findings, and response to treatment of renovascular hypertension (RVHT) in moyamoya disease (MMD).

METHODS

A retrospective analysis of medical records in six RVHT cases (8.3%) among 72 MMD patients observed from November 1987 to December 1995.

RESULTS

The age at onset of MMD ranged from 9 months to 7 years 1 month (mean, 3.3 years). The most common initial manifestation of MMD was transient ischemic attack. Hypertension was detected between 4 years 4 months and 12 years 3 months (mean, 7.87 years). Unstimulated plasma renin activity was elevated in all six cases. Renal ultrasonography and captopril technetium 99m-labeled dimercaptosuccinic acid scan showed abnormal findings in four of five and in three of four available studies, respectively. However, both imaging studies showed abnormal findings only in the most severely affected kidneys even with bilateral renal artery stenosis. Renal arteriography revealed bilateral lesions in three of the patients and unilateral lesions in the others. Renal angioplasty was performed in four cases but was successful in only one and partially successful in another. A renal artery specimen obtained during renal autotransplantation showed intimal fibroplasia. At the last follow-up, one patient had normal blood pressure without the use of antihypertensive agents, but the other five patients needed this medication to control blood pressure.

CONCLUSION

Because RVHT may be more commonly associated with MMD than has hitherto been appreciated, it is recommended that blood pressure be carefully followed and that diagnostic procedures for RVHT be carried out in hypertensive patients with MMD.

The relevance of hemodynamic factors to perioperative ischemic complications in childhood moyamoya disease

Of 124 children younger than 15 years who underwent surgery for moyamoya disease, 21 (16.9%) experienced perioperative ischemic complications that could not be unequivocally attributed to the surgery. Eleven of the 21 patients experienced infarctions, and 10 experienced reversible ischemic neurological deficits without new lesions, as revealed by computed tomographic scans. An examination of the patients' perioperative clinical and laboratory data revealed that the mean values of intra- and postoperative minimum arterial carbon dioxide pressure, maximum arterial carbon dioxide pressure, and mean arterial pressure were similar in patients with and without ischemic complications. However, in patients with perioperative complications, the incidence of preoperative transient ischemic attacks (TIAs) and intra- and postoperative hypercapnia (maximum arterial carbon dioxide pressure > 45 mm Hg) was significantly higher. In addition, 7 of the 11 perioperative infarctions occurred in patients with frequent preoperative TIAs and intra- and postoperative hypercapnia. Cerebral blood flow studies with preoperative acetazolamide loading showed that the new infarctions were located in areas in which the cerebral blood flow had been compromised. Our results suggest that the occurrence of frequent preoperative TIA is an important indicator of the instability of the cerebral hemodynamics and of the risk of perioperative ischemic complications. To prevent these complications, preoperative management aimed at stabilizing the hemodynamic status is very important. Children who have moyamoya disease and who experience frequent preoperative TIAs are at risk for ischemic brain damage caused by hypercapnia as well as hypocapnia and hypotension. The establishment and maintenance of normocapnia with normotension are highly desirable for the perioperative management of moyamoya disease in children.

Predictors of outcome of stroke in infants and children based on clinical data and radiologic correlates

Outcome predictors were analyzed in 45 infants and children with cerebrovascular disorders (CVD), based on clinical features and radiological correlates. The clinical features at presentation could be categorized into three major groups: (1) generalized: alteration of consciousness with or without seizures--24 patients (54%); (2) focal: acute hemiplegia or monoplegia with or without focal seizures--18 patients (40%); (3) cerebellar disturbances--3 patients (6%). The underlying etiology was detected in 80% of children. Thirty-seven patients (82%) survived the initial debilitating event, of whom 11 (29.7%) recovered completely and the rest had either motor or cognitive handicaps during an average follow-up period of 4.2 years (range 1.5-11 years). A head CT performed in all children revealed ischemic infarction in 29 patients (64.4%), while the others had hemorrhagic infarction. Of those with an initial generalized neurological presentation, as many as 50% had multi-focal lesions on CT. All children with focal neurological findings had a solitary localized lesion on CT, mainly in the distribution of the middle cerebral artery. Statistical analysis for outcome prediction showed that the following variables were associated with increased risk of immediate death: (1) hemorrhagic infarction demonstrated by brain CT (p = 0.031); (2) patients who presented with a generalized neurological disorder, namely alteration of consciousness, with or without seizures (p = 0.036). No other clinical or laboratory variables were predictive of imminent death, motor or cognitive handicaps. These may therefore serve as outcome predictors of stroke in the pediatric age group.

Perioperative complications of encephalo-duro-arterio-synangiosis: prevention and treatment

We performed encephalo-duro-arterio-synangiosis on 169 sides of 81 Moyamoya and 8 non-Moyamoya patients in the past 10 years. The advantage of this operation is its minimal operative invasion, giving rise to few operative complications. During 10 years of practice, however, we encountered some perioperative problems. Perioperative cerebral infarction of varying severity was seen in six Moyamoya patients. Severe hyperventilation with crying was the main trigger of infarction. Two patients developed wound infection with Gram-negative rods. Removal of an infected bone flap was necessary. One Moyamoya patient developed malignant hyperthermia during the operation. One acute epidural hematoma necessitated an emergency hematoma removal. Five patients showed a temporary aggravation of involuntary movements. Prolonged mild fever and temporary and limited hair loss around the wound were often observed. Cases and their treatment are presented with discussion of preventive measures.

Electroclinical study of video-game epilepsy

Seven patients (five boys, two girls) with video-game epilepsy (VGE) are reported, which reflects the fact that these games have increased in popularity recently among Japanese children. Their ages at onset ranged from four to 13 years. The seizure phenomena were of three types: generalised tonic-clonic, partial seizure and headache. Interictal physical and neurological examinations were within normal limits. EEGs taken while they played video-games confirmed the diagnosis of VGE and revealed three triggers of seizures: flashing lights, special figure patterns and scene-changing. They were recommended to avoid playing video-games, but sodium valproate was effective if seizures persisted even after such avoidance.

Symptoms and their pattern of progression in childhood moyamoya disease

In the series of 81 childhood moyamoya patients, the common pattern of clinical progression seen in 77 patients was revealed to be no more than four. The characteristics of each type of clinical progression were presented for a better understanding of the disease and for an initiation of early treatment of this rather rare and insidiously progressive disease. Type I (21 cases) and type II (15 cases) are cases without infarction, even in those types there are cases with poor IQ. Type III (17 cases) and type IV (24 cases) are cases with infarction and an early operation is mandatory. Types I and II are also good candidates for early operation, for IQ deterioration insidiously progress in these types and there is no way of knowing them from type III before infarctions occur. We now have effective surgical measures to improve the ischemic conditions of this disease.

Ischaemic stroke in the basal ganglia and internal capsule in childhood

Ischaemic stroke in childhood is rare. In particular, there have only been a few reports of lacunar infarcts in children. In this study, four children with true lacunar infarcts and four with larger subcortical infarcts are described. We compare the clinical features and the possible pathogenesis of ischaemic strokes in the basal ganglia and internal capsule in childhood with those in adults, and discuss diagnostic and therapeutic management.

Mendelian etiologies of stroke

There are many genetic disorders associated with an increased risk for stroke that may easily be overlooked in the evaluation of both adult and pediatric acute stroke victims. The recognition of a genetic disorder as the cause of a stroke has important implications not only for the immediate care of the stroke victim, but often also for others in the patient's family who may be at risk for the same disease and for whom preventive measures sometimes can be taken. We present here a comprehensive review of genetic disorders associated with stroke in the nongeriatric age groups for which a causative role in the evolution of stroke has been recognized or is likely. For each disorder, the major clinical and biochemical characteristics as well as the probable pathogenetic mechanisms of stroke are discussed, together with the appropriate testing required to screen for and confirm the diagnosis. The great variety of genetic disorders and mechanisms causing stroke underscores the increasing importance of understanding genetic disease for appropriate diagnosis and treatment of a common clinical problem affecting both children and adults.

Moyamoya disease--a review of clinical experience and anaesthetic management

Moyamoya disease is a rare neurovascular condition that affects both children and adults. Increasingly these patients present for surgical management to improve the cerebral circulation since medical therapy is essentially ineffective. Because of the precarious cerebral circulation, these patients represent an anaesthetic challenge. In this report we review the pathophysiology of moyamoya disease, summarize our experience with seven patients and discuss the anaesthetic management.

Prognosis of occlusive disease of the circle of Willis (moyamoya disease) in children

The prognosis of 27 patients with moyamoya disease was studied. The ages at onset ranged from 11 months to 4-11/12 years. Follow-up study was performed within 4 years from the onset in 13, 5 to 9 years in 5, and 10 to 15 years in 9. Transient ischemic attacks (TIA) occurred most often during the first four years and decreased thereafter. Intellectual deterioration and neurologic deficits increased with time. Outcome included no sequelae in five (19%), occasional TIA or headache alone in nine (33%), mild intellectual and/or motor impairment in seven (26%), requirement for special school or care by parents or institutions after reaching the teen years in three (11%), continuous 24-hour care in two (7%), and death in one (3%). Poor prognosis was correlated with an early age at onset and hypertension.