Development of a ceiling-suspended angiographic unit for interventional neuroradiology

La risonanza magnetica nelle encefalomiopatie mitocondriali

Le encefalopatie mitocondriali sono un gruppo eterogeneo di malattie, in parte ancora in corso di definizione, per cui è sempre necessaria una conferma biochimica.

Alcune malattie mitocondriali, come i difetti della β- ossidazione degli acidi grassi, possono causare gravi squilibri metabolici con ipoglicemia e coma che si ripercuotono in modo aspecifico sul sistema nervoso centrale determinando quadri di sofferenza cerebrale diffusa. Altre malattie mitocondriali determinano danni più specifici sul SNC. Nella prima infanzia la malattia più caratteristica è la malattia di Leigh, che determina alterazioni principalmente nel tegmento pontino e mesencefalico e nei nuclei della base. Alcuni casi presentano lesioni caratteristiche nei nuclei subtalamici, altri presentano reperti più aspecifici e diffusi simili a quadri di leucodistrofia.

In età più tardiva (seconda infanzia o età adulta) la malattia più interessante dal punto di vista neuroradiologico è il MELAS, che presenta lesioni cortico-sottocorticali nelle regioni posteriori con distribuzione non tipicamente vascolare, sopra e sottotentoriali, che tuttavia possono essere ricondotte ai territori più distali dei vasi. Calcificazioni nei nuclei della base sono presenti in circa la metà dei casi.

Un'altra encefalopatia mitocondriale dell'età giovanile o adulta è la sindrome di Kearns-Sayre, in cui la RM può dimostrare alterazioni nel tronco, nei talami, nei nuclei della base e nella sostanza bianca sottocorticale.

Alterazioni nel neostriato possono essere osservate nelle sindromi distoniche associate ad atrofia ottica di Leber. Non sono descritte invece lesioni specifiche nel MERRF, in cui atrofia ed alterazioni della sostanza bianca sono state occasionalmente osservate. Esistono infine casi che presentano quadri clinici e neuroradiologici intermedi tra le varie sindromi mitocondriali.

L'obiettivo di questa revisione è dimostrare alcuni aspetti tipici delle sindromi più comuni e indicare quali aspetti neuroradiologici, a volte inattesi, devono suggerire l'ipotesi di encefalopatia mitocondriale, permettendo cosi di indirizzare in modo corretto ulteriori indagini diagnostiche.

Bilateral hypertrophic olivary nucleus degeneration on magnetic resonance imaging in children with Leigh and Leigh-like syndrome

OBJECTIVE

Bilateral hypertrophic olivary degeneration on brain MRI has been reported in a few metabolic, genetic and neurodegenerative disorders, including mitochondrial disorders. In this report, we sought to analyse whether bilateral symmetrical inferior olivary nucleus hypertrophy is specifically associated with mitochondrial disorders in children.

METHODS

This retrospective study included 125 children (mean age, 7.6 ± 5 years; male:female, 2.6:1) diagnosed with various metabolic and genetic disorders during 2005-2012. The routine MRI sequences (T1 weighted, T2 weighted and fluid-attenuated inversion-recovery sequences) were analysed for the presence of bilateral symmetrical olivary hypertrophy and central tegmental tract or dentate nuclei signal changes. The other imaging findings and the final diagnoses were noted.

RESULTS

The cohort included patients with Leigh and Leigh-like syndrome (n = 25), other mitochondrial diseases (n = 25), Wilson disease (n = 40), Type 1 glutaric aciduria (n = 14), maple syrup urine disease (n = 13), giant axonal neuropathy (n = 5) and L-2 hydroxy glutaric aciduria (n = 3). Bilateral inferior olivary nucleus hypertrophy was noted in 10 patients, all of whom belonged to the Leigh and Leigh-like syndrome group.

CONCLUSION

Bilateral hypertrophic olivary degeneration on MRI is relatively often, but not routinely, seen in children with Leigh and Leigh-like syndrome. Early detection of this finding by radiologists and physicians may facilitate targeted metabolic testing in these children.

ADVANCES IN KNOWLEDGE

This article highlights the occurrence of bilateral hypertrophic olivary nucleus degeneration on MRI in children with Leigh and Leigh-like syndrome, compared with other metabolic disorders.

Magnetic resonance imaging in lactic acidosis

Mitochondrial defects, defects in gluconeogenesis, and biotin-responsive multiple carboxylase deficiency are disorders characterized by primary lactic acidosis. In this review, characteristic findings in magnetic resonance imaging (MRI) of the brain, as related to histopathological abnormalities, are described for the different disorders and the diagnostic value of the MRI findings is discussed. Inborn errors of metabolism with primary lactic acidosis should be considered in particular when MRI shows lesions similar to or reminiscent of effects of focal or generalized hypoxia-ischaemia, or when MRI shows signs of chronic neurodegeneration, but rarely in cases with predominantly white-matter changes.

Improvement of cerebral blood flow and clinical symptoms associated with embolization of a large arteriovenous malformation: case report

We report a patient with an unruptured, large arteriovenous malformation that was treated by staged, superselective embolization with liquid agents and by an investigation of the hemodynamic changes accompanying embolization. A 29-year-old man presented with headache and left upper quadrantanopsia. A neuroradiological study revealed a large right temporo-occipital arteriovenous malformation, and angiography disclosed poor filling of the adjacent vessels. In the venous phase, marked cortical reflux, suggesting venous hypertension, was also observed. Single photon emission computed tomography scanning with N-isopropyl-p-iodine-123- iodoamphetamine disclosed a low-perfusion area in the ipsilateral occipital and temporal lobes. After embolization, cerebral blood flow and the clinical symptoms attributed to ischemia improved. A follow-up study 1 year later demonstrated that the patient's improvement was stable. Single photon emission computed tomography confirmed that embolization achieves an improved cerebral blood flow.

Successful treatment of an arteriovenous malformation by chemical embolization with estrogen followed by conventional radiotherapy

A case of the successful treatment of a thalamic arteriovenous malformation (AVM) by chemical embolization with conjugated estrogen followed by conventional radiotherapy is described. A 22-year-old woman suddenly developed headache, nausea, and consciousness disturbance. Computed tomographic scans revealed left thalamic and ventricular bleeding. Angiograms disclosed a left thalamic AVM with a maximum diameter of 2 cm. The AVM was fed mainly by the left medial posterior choroidal artery and drained into the basal vein. Chemical embolization with 300 mg of conjugated estrogen via a leak balloon catheter was carried out. Although the size of the nidus of the AVM was unchanged immediately after embolization, it became smaller 9 days later. In spite of the further reduction in size, the AVM still existed 2 years later. Conventional radiotherapy with a total dose of 30 Gy was performed. Follow-up angiograms 40 months after radiotherapy demonstrated disappearance of the AVM. This case report suggests progressive and stable embolizing capabilities of chemical embolization with conjugated estrogen and its suitableness for following radiotherapy, including stereotactic radiosurgery.

Surgical excision of giant cerebellar hemispheric arteriovenous malformations following preoperative embolization. Report of two cases

The authors present two cases of giant cerebellar hemispheric arteriovenous malformation (AVM) managed with staged preoperative embolization and surgical resection. A new embolization technique is described, combining injection of estrogen alcohol and polyvinyl acetate into AVM's by superselective catheterization of feeding arteries. Polyvinyl acetate proved to be an ideal liquid embolic material; because it polymerizes quickly and remains in a gelatinous state after injection, there was no difficulty in cutting and retracting the obliterated AVM during surgery. Intraoperative digital subtraction angiography was useful for confirming complete excision of the large and complex AVM.