Brainstem arteriovenous malformation presenting with dyspraxic handwriting in a young girl.

We report the case of a 11-year-old girl who developed an isolated hand-writing disorder with dysgraphia at the beginning of the school year in the sixth grade. A brain magnetic resonance angiography showed a round arteriovenous malformation sited in the left side of the midbrain extending to the ipsilateral medio-basal thalamus. Child neurologists should never neglect a thorough neurological evaluation in case of isolated worsening of handwriting, to rule out possible underlying organic causes.

Management of hemangiomas and pediatric vascular malformations.

Pediatric vascular anomalies can be difficult to diagnose and complex to treat. One must be able to distinguish hemangiomas from various vascular malformations, as well as appreciate their dynamic course with time. Thorough understandings of the clinical and diagnostic techniques used to evaluate these lesions are paramount for the treating surgeon. In addition, knowledge of current treatments from watchful waiting to radical extirpation is mandatory. This must all be done in the setting of a developing child. We present a current review of the literature regarding the comprehensive care of pediatric vascular lesions.

Treating vascular lesions.

The treatment of acquired vascular lesions is one of the most commonly requested and performed cutaneous laser procedures. Furthermore, every year, 40,000 children are born in the United States each with congenital vascular lesions and malformations. Laser treatment of vascular lesion is based on the principle of selective photothermolysis, conceived in the 1980s. A variety of different lasers and light sources have since been used in the treatment of vascular lesions: lasers with wavelengths between green and yellow, near infrared lasers, and broadband light sources. Despite limitations, this remains the treatment of choice today. This publication addresses acquired and congenital vascular lesions as different entities and proposes a separation of vascular lesions into those that can easily be treated from those where clearance is difficult. Different treatment modalities and the various endpoints of individual vascular lesions will be discussed.

Sedation for paediatric stereotactic radiosurgery: the dexmedetomidine experience.

Dexmedetomidine is a potent alpha2 adrenergic agonist, with sedative and analgesic properties which may make it a suitable sedative agent for procedures on paediatric patients. A six-year-old boy required sedation for stereotactic radiosurgical ablation of an arteriovenous malformation on two occasions. Sedation with dexmedetomidine was planned, with increased dosage used on the second occasion. On both occasions dexmedetomidine was inadequate as a sole agent and required supplementation with other agents.

Scalp arteriovenous malformation draining into the superior sagittal sinus associated with an intracranial arteriovenous malformation: just a coincidence? Case report.

OBJECTIVE AND IMPORTANCE: Recent experimental and clinical evidence suggests that hemodynamic changes in the venous system can induce the formation of new arteriovenous malformations (AVMs). In a rat model, increased venous pressure induces the formation of soft tissue and dural AVMs. We report a clinical observation that may support these data. CLINICAL PRESENTATION: A 4-year-old boy with a midline scalp AVM draining into the superior sagittal sinus had an associated intracranial/parenchymal AVM. The cerebral AVM increased venous pressure in the superior sagittal sinus as revealed by angiography. INTERVENTION: The scalp AVM was resected, and the intracranial AVM was treated by use of the gamma knife. CONCLUSION: On the basis of reported experimental data and the morphological and hemodynamic characteristics in this patient's two lesions, we suggest that the scalp AVM might have been induced by hypertension in the superior sagittal sinus. This clinical observation supports the notion suggested by experimental studies that hemodynamic changes can induce the formation of associated AVMs.

Transpupillary laser phototherapy of tumors and vascular anomalies of retina and choroid: theoretical approach and clinical implications.

BACKGROUND: Small retinal and choroidal tumors situated near the optic nerve or macula, such as retinoblastomas and malignant melanomas, as well as various other anomalies, in particular vascular malformations, may successfully be treated by photocoagulation. Model assumptions geared towards maximizing efficiency and minimizing undesirable side effects are forwarded, and the most important parameters subserving photothermal destruction, such as radiation field and thermal energy, analyzed. The influence exerted by physical traits of various tissues involved are also considered. METHODS: The model approximations presented are based on classical radiation and absorption laws, as well as on the scattering properties of the various tissues implicated, these being considered as a function of wavelength and their relevance to the photodestructive task at hand. Particular attention is paid to the rate processes and reaction kinetics of irradiated proteins. CONCLUSIONS: Radiation sources emitting in the near-infrared range of the electromagnetic spectrum, such as the diode (810 nm) and the cw Nd:YAG (1064 nm) lasers, are optimal for the treatment of tumors and large, voluminous entities (such as Hippel-Lindau angiomas), owing to the good tissue penetration properties of their light. Those emitting in the shorter wavelength range, such as the argon ion (488 and 514 nm) and first harmonic--mode Nd:YAG (532 nm) lasers, are not suitable for such tasks, but they are ideal for the destruction of fine sanguinous structures, within which their light is strongly absorbed but through which it penetrates poorly. For the treatment of large anomalous structures, a combined short/long wavelength--strategy should also be considered as a viable alternative. Such a "wavelength mixture" is emitted by the xenon high pressure lamp of the once renowned Meyer-Schwickerath light coagulator. The precision and safety of photothermal destruction methods depend, in the first approximation, upon the details of the pulse energy deposition (wavelength, pulse height and duration, pulse dynamics, mode composition, focussing), the choice of which is determined by the optical and thermal constants of the irradiated tissues. Higher pulse energies will, of course, be more effective in destroying neoplastic cells, but the risk of producing undesired collateral heat damage will also increase concomitantly. Until we can ascertain the physical properties of the pathological tissues treated with certainty, we will hardly be able to achieve more than an approximation of an ideal treatment strategy. But with increasing developments in in vivo-diagnostic techniques, we expect that this goal will be attainable in the not too distant future.

Acute intracranial hemorrhage caused by acupuncture.

A 44-year-old Chinese man developed severe occipital headache, nausea, and vomiting during acupuncture treatment of the posterior neck for chronic neck pain. Computed tomography of the head showed hemorrhage in the fourth, third, and lateral ventricles. A lumbar puncture confirmed the presence of blood. Magnetic resonance angiography with gadolinium did not reveal any saccular aneurysms or arteriovenous malformations. The patient's headache resolved over a period of 28 days without any neurological deficits. Acupuncture of the posterior neck can cause acute intracranial hemorrhage.

Arteriovenous malformation of the rectum: report of a case.

We report herein the case of a 38-year-old man found to have a rectal arteriovenous malformation (AVM). The patient was admitted to our hospital for investigation of fresh anal bleeding and general malaise. Barium-enema examination showed a slightly elevated lesion in the rectum, and a selective superior rectal angiogram subsequently revealed an AVM in the peripheral region of the superior rectal artery, which was presumed to be the cause of the anal bleeding. Colonoscopic examination disclosed a submucosal tumor-like lesion in the left posterior wall of the rectum, 3cm above the anal verge. After marking the boundaries by clipping, transanal resection of the lesion was performed. Histological examination revealed an irregularly expanded arteriovenous aggregation in the submucosal layer. The patient had a favorable postoperative course, and no residual AVM was seen on a postoperative selective inferior mesenteric arteriogram. There have been no signs of recurrence in the 2 years since his operation.

Vascular lesions in children: percutaneous MR imaging-guided interstitial Nd:YAG laser therapy--preliminary experience.

PURPOSE: To investigate the use of magnetic resonance (MR) imaging to guide interstitial laser therapy of deep hemangiomas and vascular malformations in children. MATERIALS AND METHODS: Sixteen children aged 3 months to 16 years with symptomatic vascular lesions underwent percutaneous laser treatment. MR imaging guidance of the laser applicator and online thermomonitoring with MR imaging were performed with a 0.2-T open MR system. Follow-up studies were performed 2 days and 6 weeks after thermotherapy. RESULTS: Interactive positioning of the laser applicator was possible in all patients. Online thermomonitoring was possible in 122 of 137 therapy spots (89%). There was a good correlation between volumes of coagulated tissue on intraprocedural T1-weighted images and volumes of coagulated tissue on follow-up T2-weighted images. At 6-week follow-up, MR imaging demonstrated a reduction in lesion size in 10 patients (mean reduction, 72%) and an increase in lesion size in two patients (mean increase, 134%). Clinical symptoms improved in 14 of 16 patients (88%). CONCLUSION: MR imaging-guided laser therapy appears to be a safe and potentially effective minimally invasive treatment for selected children with vascular lesions.

[A rare cause of rectal hemorrhage in children: rectal angiodysplasia]. / Une cause rare de rectorragie chez l'enfant: l'angiodysplasie rectale.

BACKGROUND: Parietal vascular malformations of the intestinal tract are rare and their diagnosis is often difficult. CASE REPORT: A 2 year-old boy had suffered from intermittent rectal bleeding since the age of one year. Endoscopic examination showed unspecific congestive changes and biopsy showed features of chronic inflammatory changes in the rectum. Barium enema was normal. The patient was operated on, but surgery failed to find any cause for these hemorrhages. Rectal bleedings recurred, some of them resulting in severe anemia. Two further endoscopic examination were grossly negative as was inferior mesenteric arteriography. Spontaneous rectal prolapsus occurred when the boy was 4 years old. This allowed resection of all the submucosal veins of the anal canal; it was followed by complete cessation of rectal bleeding with a follow-up of 36 months. Histological examination showed several ectasias of the capillaries and veins in the submucosa and muscular layers. CONCLUSION: Angiectases can occur in a small part of the intestinal tract, and can escape detection by repeated specialized investigation.

Colonoscopy in the diagnosis of unexplained rectal bleeding.

Three hundred six patients with unexplained rectal bleeding were examined by colonoscopy. Significant lesions were found in 30% including polyps having a diameter of 0.5 cm or larger in 14%, carcinoma in 8%, and a small number of patients with inflammatory bowel disease, vascular formations, and radiation colitis. Colonoscopic findings in a large subgroup of patients with diverticulosis established by barium enema did not differ significantly from those of the group as a whole. Significant lesions were also identified in 22% of small subsets of patients with occult bleeding or unexplained melena.