Kanehiro Hasuo

Surgical treatment of moyamoya disease in pediatric patients--comparison between the results of indirect and direct revascularization procedures.

Either encephaloduroarteriosynangiosis (EDAS) or superficial temporal artery to middle cerebral artery (STA-MCA) anastomosis combined with encephalomyosynangiosis (EMS) has been performed on most of the children with moyamoya disease in our department. EDAS alone was done in the parietal region of 13 sides in 10 patients, and STA-MCA anastomosis with EMS in the parietal region was done on 7 sides in 6 patients. The surgical results of these two different procedures were then compared. Postoperative collateral formation was observed on external carotid angiograms, and the improvement of clinical symptoms was monitored for 1 year after the bypass procedure. STA-MCA anastomosis with EMS was found to be superior to EDAS in both the development of collateral circulation (P less than 0.05) and postoperative clinical improvement (P less than 0.01). EDAS can be done easily and safely on small children with moyamoya disease, but STA-MCA anastomosis with EMS is considered to be more appropriate, whenever possible.

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.

Surgical treatment for paediatric patients with moyamoya disease by indirect revascularization procedures (EDAS, EMS, EMAS).

SummarySurgical results of paediatric patients with Moyamoya disease who were treated by indirect revascularization procedures are reported. Encephalo-duro-arterio-synangiosis (EDAS), encephalomyo-arterio-synangiosis (EMAS), and/or encephalo-myo-synangiosis (EMS) were performed on 47 sides of 29 children with Moyamoya disease. The results of those non-anastomotic EC-IC bypass procedures were evaluated clinically, angiographically, and by computed tomography (CT). Postoperative external carotid angiograms showed a good collateral formation through EDAS, EMAS, or EMS in about 70–80 percent of all surgically treated sides. The symptoms such as TIA, RIND, and/or involuntary movements disappeared in the cases with a good collateral formation but not in those with insufficient development of the collateral circulation. The indirect EC-IC bypass surgery seems effective for most of the children with Moyamoya disease who present with ischaemic signs.

Comparison of magnetoencephalography, functional MRI, and motor evoked potentials in the localization of the sensory-motor cortex.

To clarify the topographical relationship between peri-Rolandic lesions and the central sulcus, we carried out presurgical functional mapping by using magnetoencephalography (MEG), functional magnetic resonance imaging (f-MRI), and motor evoked potentials (MEPs) on 5 patients. The sensory cortex was identified by somatosensory evoked magnetic fields using MEG (magnetic source imaging (MSI)). The motor area of the hand region was identified using f-MRI, during a hand squeezing task. In addition, transcranial magnetic stimulation localized the hand motor area on the scalp, which was mapped onto the MRI. In all cases, the sensory cortex was easily identified by MSI and the results of MSI correlated well with the findings obtained by the intraoperative recording of somatosensory evoked potentials. In contrast, the motor cortex could not be localized by f-MRI due to either the activated signal of the large cortical vein or the lack of any functional activation in the area of peri-lesional edema. MEPs were also unable to localize the entire motor strip. Therefore, at present, MSI is considered to be the most reliable method to localize peri-Rolandic lesions [corrected].

Leukoencephalopathy in HTLV-I-associated myelopathy/tropical spastic paraparesis: MRI analysis and a two year follow-up study after corticosteroid therapy

Magnetic resonance imaging (MRI) of the brain was studied in 35 patients with HTLV-I-associated myelopathy (HAM)/tropical spastic paraparesis (TSP), 19 HTLV-I seropositive carriers without HAM/TSP (non-HAM/TSP carriers), 18 patients with HTLV-I seronegative spastic spinal paraparesis (SSP), and 82 HTLV-I seronegative controls with other neurological disorders. The incidence of white matter lesions was significantly higher in HAM/TSP (66%) than in the controls (23%) and SSP (11%). HAM/TSP exceeded non-HAM/TSP carriers significantly in the incidence of multiple white matter lesions (37% vs 10%). HAM/TSP affected the deep and subcortical cerebral white matter multifocally, sparing the periventricular regions. None of the lesions were enhanced by gadolinium-DTPA. HAM/TSP patients with the white matter lesions had both a longer duration of disease and a greater disability than did those without lesions. The white matter lesions gradually increased in number, as the disability status became worse, in spite of the high dose corticosteroid treatment. All these observations suggest that the MRI abnormalities of the HAM/TSP brain may reflect the chronic perivascular inflammation with progressive gliosis (chronic disseminated encephalomyelitis). We propose that brain MRI can be successfully utilized as a reliable and non-invasive measure for following the disease progression in HAM/TSP.

Intracranial venous angiomas.

Publications in the scientific literature are controversial in regard to the clinical significance of intracerebral venous angiomas. The present study of 11 patients with venous angiomas underscores the clinical importance of these lesions as potential causes of cerebral hemorrhage and obstructive hydrocephalus. The clinical and radiographic manifestations in 9 of these 11 patients correlated well. In cases of venous angiomas, the venous phase of angiography must be carefully scrutinized, particularly in patients with subarachnoid or intracerebral hemorrhage. Some diagnostic problems related to the angiography of venous angiomas are discussed.

Cerebral hemodynamic change in the child and the adult with moyamoya disease.

To clarify the differences in cerebral hemodynamics and metabolism between children and adults with bilateral moyamoya disease, we measured regional cerebral blood flow, regional oxygen extraction fraction, regional metabolic rate for oxygen, regional cerebral blood volume, and regional transit time using positron emission tomography in nine patients (five children and four adults) and compared the values with those in controls (four children with unilateral moyamoya disease and six normal adults). The major differences between pediatric and adult patients were in regional cerebral blood volume and regional oxygen extraction fraction. Regional cerebral blood volume was more markedly increased relative to the control value in the children than in the adults. Also, regional oxygen extraction fraction was greater than control in areas with low blood flow in the children but was never increased in the adults. However, in the adults, only regional transit time was significantly prolonged relative to the control values. The increased regional oxygen extraction fraction relative to the control value observed in children with moyamoya disease may explain why transient ischemic attacks are a common symptom in this group.

Encephalo-duro-arterio-synangiosis in children with Moyamoya disease

SummaryEncephalo-duro-arterio-synangiosis (EDAS) was done in 16 Japanese children with Moyamoya disease on 22 sides. The results were evaluated clinically, angiographically, and by positron emission computed tomography (PET). Postoperative external carotid angiograms showed a good collateral circulation through EDAS in 72 percent of the treated sides. Two-thirds of the sides examined by PET showed improvement in cerebral blood circulation, particularly at the surgically-treated cortex. Postoperatively the symptoms disappeared in those with good new collateral formation. TIA, RIND, and/or involuntary movement disappaered in 31 percent and partially so in 44 percent 6 months after EDAS. The TIA in the lower limb and/ or involuntary movement persisted in some children. This surgical approach seems applicable particularly for children with the ischaemic type of Moyamoya disease, however, the procedure also has drawbacks. Development of collateral circulation was insufficient in some cases, and the territories of the anterior cerebral artery (ACA) or posterior cerebral artery (PCA) were often not covered, even in those with a good new collateral formation in the middle cerebral arterial (MCA) area.

Hypertrophie cranial pachymeningitis due to aspergillus flavus

A 59-year-old woman suffered from occipital headache and bilateral cranial nerve VII, VIII, IX, X, XI and right XII deficit after developing otitis media. Magnetic resonance imaging (MRI) showed a thickening of the dura mater which was enhanced by gadolinium-DTPA (Gd). Aspergillus flavus was identified from the culture of otorrhea. She was treated with miconazole, flucytosin and fluconazole, which resulted in an improvement of the clinical symptoms and a thinning of the Gd-enhanced lesions on MRI. This is the first case of hypertrophic cranial pachymeningitis caused by Asp. flavus infection.

Spontaneous disappearance of a middle fossa arachnoid cyst associated with subdural hematoma

The case of a 7-year-old boy with a middle fossa arachnoid cyst that spontaneously disappeared is presented. Computed tomography (CT) scan revealed an arachnoid cyst in the right middle fossa with a thin subdural hematoma on the same side. As the subdural hematoma spontaneously resolved, the cyst became smaller and finally disappeared without surgical intervention after 18 months on the follow-up CT scans. Possible mechanisms of the spontaneous disappearance of an arachnoid cyst are discussed.