Pediatric Moyamoya Disease and Syndrome in Italy: A Multicenter Cohort.

Background: Moyamoya is a rare progressive cerebral arteriopathy, occurring as an isolated phenomenon (moyamoya disease, MMD) or associated with other conditions (moyamoya syndrome, MMS), responsible for 6-10% of all childhood strokes and transient ischemic attacks (TIAs). Methods: We conducted a retrospective multicenter study on pediatric-onset MMD/MMS in Italy in order to characterize disease presentation, course, management, neuroradiology, and outcome in a European country. Results: A total of 65 patients (34/65 women) with MMD (27/65) or MMS (38/65) were included. About 18% (12/65) of patients were asymptomatic and diagnosed incidentally during investigations performed for an underlying condition (incMMS), whereas 82% (53/65) of patients with MMD or MMS were diagnosed due to the presence of neurological symptoms (symptMMD/MMS). Of these latter, before diagnosis, 66% (43/65) of patients suffered from cerebrovascular events with or without other manifestations (ischemic stroke 42%, 27/65; TIA 32%, 21/65; and no hemorrhagic strokes), 18% (12/65) of them reported headache (in 4/12 headache was not associated with any other manifestation), and 26% (17/65) of them experienced multiple phenotypes (≥2 among: stroke/TIA/seizures/headache/others). Neuroradiology disclosed ≥1 ischemic lesion in 67% (39/58) of patients and posterior circulation involvement in 51% (30/58) of them. About 73% (47/64) of patients underwent surgery, and 69% (45/65) of them received aspirin, but after diagnosis, further stroke events occurred in 20% (12/61) of them, including operated patients (11%, 5/47). Between symptom onset and last follow-up, the overall patient/year incidence of stroke was 10.26% (IC 95% 7.58-13.88%). At last follow-up (median 4 years after diagnosis, range 0.5-15), 43% (26/61) of patients had motor deficits, 31% (19/61) of them had intellectual disability, 13% (8/61) of them had epilepsy, 11% (7/61) of them had behavioral problems, and 25% (13/52) of them had mRS > 2. The proportion of final mRS > 2 was significantly higher in patients with symptMMD/MMS than in patients with incMMS (p = 0.021). Onset age <4 years and stroke before diagnosis were significantly associated with increased risk of intellectual disability (p = 0.0010 and p = 0.0071, respectively) and mRS > 2 at follow-up (p = 0.0106 and p = 0.0009, respectively). Conclusions: Moyamoya is a severe condition that may affect young children and frequently cause cerebrovascular events throughout the disease course, but may also manifest with multiple and non-cerebrovascular clinical phenotypes including headache (isolated or associated with other manifestations), seizures, and movement disorder. Younger onset age and stroke before diagnosis may associate with increased risk of worse outcome (final mRS > 2).

Endovascular embolization of pial arteriovenous fistula fed from P1 segment of posterior cerebral artery in 12 years old girl: case report and review of literature.

OBJECTIVE: Intracranial pial arteriovenous fistulas (PAVFs) are rare vascular lesions with peculiar epidemiological, morphological, and pathophysiological characteristics. Since there is no nidus, PAVF treatment has been performed by direct disconnection of the arteriovenous communication via a surgical, endovascular, or a combined approach. We aim to outline the relevant variables to consider in planning an endovascular treatment strategy. METHODS: We present a case of a 12 year old girl with a single feeder PAVF originating from the first segment (P1) of the left posterior cerebral artery with a varicose venous drainage into the right cavernous sinus. RESULTS: We report the successful endovascular exclusion of the fistula with the release of a total of 27 detachable platinum coils with no complications at follow-up. Treatment strategy and nuances are discussed along with a review of the literature. CONCLUSIONS: Morphology, age, embolization strategies, and materials are the different variables to be analyzed in the endovascular treatment of such lesions.

Neuroembolization may expose patients to radiation doses previously linked to tumor induction.

OBJECTIVE: Epidemiological studies indicate a link between low-dose irradiation (<10,000 mGy) to the head and the local occurrence of tumors after decades of delay. Comparable radiation doses can be reached during neuro-endovascular procedures (NEP), but the incidence of similar exposures has not been completely delineated. We compared the levels of radiation to the head measured during NEP to those reported for patients developing radiation-induced cancers. METHODS: In our prospective study we determined the cumulative maximum entrance skin doses (MESD) and the incidence of epilation in 107 consecutive patients submitted to NEP between 2003 and 2007. We also extensively searched the literature and compared our results with the data we found. RESULTS: The cumulative MESD due to NEP was above 3,000 mGy (range 3,101-5,421 mGy) in 18 patients. In 22 we observed partial epilation within 10 weeks from the initial NEP. Sixty cases of epilation after NEP have been previously reported in the literature. The average of the reported MESD was 4,241 mGy (range 2,000-6,640 mGy). CONCLUSION: Physical dosimetry and the incidence of partial epilation indicate that about one fifth of the patients submitted to NEP received radiation doses comparable to those linked to the occurrence of tumors. The potential risks of developing tumors after a long delay, when compared to the immediate benefits of endovascular treatment of aneurysm and arteriovenous malformations (AVM) of the brain, do not counterindicate NEP, but increased awareness of the risk should help physicians and patients to make a fully informed decision when other treatments are available.

Proposed local diagnostic reference levels in angiography and interventional neuroradiology and a preliminary analysis according to the complexity of the procedures.

The aim of this study was to propose local diagnostic reference levels (DRL) for exposure to radiation during diagnostic procedures and neuroradiological interventions such as cerebral angiography and embolisation of cerebral aneurysms (intra-cranial aneurysms and arteriovenous malformations). Hospitals should adopt the national DRLs for use locally or establish their own DRLs based on local practice, if sufficient local data are available. For this purpose we studied a sample of 113 cerebral angiography procedures and 82 embolisations of cerebral aneurysms. The data recorded included the kerma-area product (KAP), the fluoroscopy time and the number of frames for each procedure: third quartiles from the total dosimetric databank were calculated and proposed as provisional local DRL. Since the complexity of a procedure must be taken into account when evaluating the radiation dose, in the case of embolisation of aneurysms (intra-cranial), in this initial phase we assessed whether the complexity of the embolisation procedure is related to the size of the aneurysm and/or its site. We, therefore, re-calculated the DRL for only intra-cranial aneurysms, leaving aside the arteriovenous malformations. Considering that the DRL calculated for all the therapeutic procedures are similar to those calculated considering only intra-cranial aneurysms, at the moment we propose, besides the DRL for cerebral angiography, a single DRL for all interventional procedures, even when the clinical pictures are very different. Local preliminary DRLs were proposed as follows: 180 Gy cm(2), 12 min and 317 frames for cerebral angiography and 487 Gy cm(2), 46 min and 717 frames for interventional procedures (intra-cranial aneurysms and arteriovenous malformations).

Measurement of patient skin dose in vertebroplasty using radiochromic dosimetry film.

STUDY DESIGN: We studied the radiation doses to which patients were exposed during 17 vertebroplasty operations. OBJECTIVE: The radiation doses during vertebroplasty were measured to determine maximum skin dose (MSD), a measure of the likelihood of radiation-induced skin effects. SUMMARY OF BACKGROUND DATA: Vertebroplasty is performed with use of fluoroscopic guidance for needle placement and to monitor bone cement injection. This procedure requires relatively long duration of fluoroscopic guidance, and so, it demands dose measurements for patients. METHODS: From May 2006 to April 2008, 16 patients (7 men and 9 women; mean age 70.19 years, range 30-87 years) underwent a total of 17 vertebroplasty procedures. Total dose-area product (DAP), duration of fluoroscopy, and the parameters for anteroposterior (AP) and lateral (LAT) fluoroscopic and fluorography projections were recorded for each procedure. Gafchromic films were placed on the patients' skin to measure entrance surface dose and to evaluate the MSD. RESULTS: The MSD and DAP were higher in the LAT plane than in the AP plane. These results were expected because the fluoroscopy time was longer, and the number of fluorography runs was higher in the LAT plane than in the AP plane.The MSD values for the AP plane ranged between 0.184 Gy and 1.834 Gy, whereas those for the LAT plane ranged between 0.417 Gy and 2.362 Gy. The frequency distribution of values for both planes showed that most MSD values were in the range of 0 to 0.5 Gy and 0.5 to 1 Gy for the AP plane and 0.5 to 1 Gy and 1 to 1.5 Gy for the LAT plane. There was great variability in the MSD at each value for the parameters among individual instances. CONCLUSION: When evaluating the MSD to a patient, a distinction should be made between AP and LAT projections, because an overall mean MSD value underestimates the contribution of x-ray absorption on the LAT plane. The use of radiochromic films to estimate radiation damage to the skin has been shown to have the limitation of relying on DAP values only.

Radiochromic films for improved evaluation of patient dose in liver interventions.

PURPOSE: To investigate a method for evaluation of the maximum skin dose (MSD) of radiation in patients undergoing interventional radiology procedures in the liver. MATERIALS AND METHODS: Transarterial chemoembolization, transarterial embolization, portal vein embolization, and biliary interventions were the procedures considered in this study. Ninety procedures in 70 patients were studied. The complexity of the biliary interventions was taken into account during the analysis. The MSD was measured with use of GAF chromic XR type R films, whereas the dose-area product (DAP) was measured by a transmission chamber. RESULTS: The MSD was measured in a group of 19 patients. The coefficient of the interpolation line between the skin dose and the DAP (0.0051 cm(-2)) was determined. An approximated value of MSD from the DAP for the remaining 71 procedures was estimated by means of an interpolation line. The mean MSD in the endovascular procedures was 4.4 Gy; for the three different levels of complexity of the biliary procedures, the mean MSDs were 0.4, 1.2, and 3 Gy, respectively. CONCLUSIONS: Radiochromic films are an easy-to-use and efficient method for measuring skin entrance radiation dose and have the advantage of providing information on the MSD as well as the distribution of radiation to the skin. In light of these results, the authors suggest recording the dose for biliary and endovascular procedures as indicated by the International Commission on Radiological Protection and the United States Food and Drug Administration.