Moyamoya disease case reports

A rare case of MMD in a 34-year-old pregnant woman with transient ischemic attacks (TIAs) for 1 month, manifesting as frequent weakness in right limbs for several minutes without obvious cause. The diagnostic digital subtraction angiography (DSA) examination revealed Suzuki Grade I on the left side and Grade IV on the right side under modified Suzuki scoring. No-hyperventilation test single-photon emission computed tomography (no-HVT SPECT) showed more decreased CBF in the right side of the brain, but HVT SPECT demonstrated a more impaired CVR on the left side. Comprehensively, which side should be operated on is confusing when the changes of CVR and CBF are inconsistent.

The main diagnosis, therapeutics interventions, and outcomes: The patient was diagnosed with bilateral MMD and underwent combined bypass surgery on the left side of the brain. The symptoms of admission were completely relieved after surgery and there were no further cerebrovascular events during the follow-up period of 4 months.

Conclusion: CVR is a primary surgical indication of MMD, especially when the impairment of CVR and CBF are not consistent in the ipsilateral hemisphere. Meanwhile, HVT is the vital vasoactive challenges test for measuring CVR in MMD ¹⁾

A 5-year-and-9-month-old boy developed repetitive episodic involuntary winking of the right eye along with ipsilateral shoulder shrugging movements in an absolutely conscious state, associated with paroxysmal shouts and loud laughs and punctuated with abusive verbal expressions (coprolalia). These episodic features, over the course of the next 1.5 years, got progressively accentuated by situations which evoked stress. In addition, there was progressive regression of verbal and cognitive milestones, emotional lability and aspects of attention deficit hyperactive disorder. The child was evaluated by a neurologist with magnetic resonance imaging of the brain, which showed characteristic ischaemic areas involving the basal ganglia and fronto-parietal cortical areas along the middle cerebral artery territory, predominantly on the left side. Subsequent cerebral angiography revealed extensive stenosis of bilateral (predominantly left-sided) internal cerebral arteries and middle cerebral arteries with evidence of diffuse leptomeningeal collaterals. The electroencephalography was reported to be normal. He was eventually diagnosed to be suffering from Moyamoya disease with associated Tourette's syndrome. Subsequently, the child underwent left-sided superficial temporal artery to middle cerebral artery bypass along with encephaloduroarteriomyosynangiosis. Significant clinico-radiological improvement was noted after 3 months. The clinical deficiencies had dramatically resolved. There was evidence of excellent development of both direct and indirect surgical collaterals along the left middle cerebral artery territory. He could go back to school.

Probably this is the first case reporting an association of paediatric Moyamoya disease with Tourette's syndrome, which significantly resolved after cerebral revascularisation surgery ²⁾.

A 21-year-old male patient presented with signs and symptoms of intracranial hemorrhage. Upon investigation, a diagnosis of bilateral MMD was made, and one sided direct bypass surgery was subsequently performed. At 3-year follow-up, there is no evidence of recurrent cerebral vascular event.

This case provided further evidence that direct bypass surgery is beneficial for patient in terms of blood flow improvement and symptom relieve. Although there is no consensus on whether bilateral surgical intervention is mandatory for patient with bilateral MMD, unilateral bypass might be sufficient enough. Further study is required to evaluate the best approach for such group of patient ³⁾.

An autopsy analysis was conducted on a 39-year-old woman with MMD who had died of a brainstem infarction. The patient had undergone bilateral indirect bypass surgeries 22 years earlier. Sufficient revascularization via bilateral external carotid arterial systems was confirmed by cerebral angiography before her death. Macroscopic observation of the operative areas revealed countless meandering vessels on the internal surface of the dura mater connected with small vessels on the brain surface and in the subpial brain tissue. Notably, microscopic analysis of these vessels revealed the characteristic 3-layer structure of an arterial wall. This autopsy analysis was the first to confirm that indirect bypass surgery had induced the formation of a new arterial network (arteriogenesis) and that this network had been maintained for more than 20 years to compensate for the chronic cerebral ischemia caused by the MMD ⁴⁾.

A 39-year-old man had been diagnosed with moyamoya disease and underwent a bilateral encephaloduroarteriosynangiosis (EDAS) intervention at the age of 9 years. During the 30 years after his bilateral EDAS, he experienced no cerebrovascular events. However, at age 39, he suddenly presented with mild consciousness disturbance and vomiting and was transferred to a local hospital. Brain CT showed an intracerebral hemorrhage associated with ventricular hematoma. He was referred for further investigation and treatment. Cerebral angiography showed faint collaterals through the site of the bilateral EDAS and development of basal moyamoya vessels. SPECT showed decreased cerebral blood flow(CBF)and cerebrovascular reactivity(CVR)in the right frontal lobe. We diagnosed him with delayed cerebral hemorrhage due to delayed rupturing of fragile moyamoya vessels after indirect bypass. The patient underwent a repeat bypass surgery (STA-MCA anastomosis and encephalo-duro-myo-arterio-pericranial synangiosis;EDMAPS) on the right side. He showed improvement in cerebral hemodynamics after surgery, and has since remained free from cerebrovascular events. Hemorrhagic events occurring a very long time after indirect bypass surgery in pediatric-onset moyamoya disease are rare. In such cases, a lifelong follow-up strategy may be necessary. Repeat bypass surgery may be a powerful tool to prevent such hemorrhagic events ⁵⁾.