Expanding the clinical and genetic spectrum of FDXR deficiency by functional validation of variants of uncertain significance.

Ferrodoxin reductase (FDXR) deficiency is a mitochondrial disease described in recent years primarily in association with optic atrophy, acoustic neuropathy, and developmental delays. Here, we identified seven unpublished patients with FDXR deficiency belonging to six independent families. These patients show a broad clinical spectrum ranging from Leigh syndrome with early demise and severe infantile-onset encephalopathy, to milder movement disorders. In total nine individual pathogenic variants, of which seven were novel, were identified in FDXR using whole exome sequencing in suspected mitochondrial disease patients. Over 80% of these variants are missense, a challenging variant class in which to determine pathogenic consequence, especially in the setting of nonspecific phenotypes and in the absence of a reliable biomarker, necessitating functional validation. Here we implement an Arh1-null yeast model to confirm the pathogenicity of variants of uncertain significance in FDXR, bypassing the requirement for patient-derived material.

Evolution and novel radiological changes of neurodegeneration associated with mutations in C19orf12.

INTRODUCTION: Neurodegeneration with brain iron accumulation (NBIA) comprises a heterogeneous group of disorders with accumulation of iron in the brain, mostly basal ganglia. NBIA subtype mitochondrial membrane protein-associated neurodegeneration (MPAN) is caused by recently discovered mutations in C19orf12, which encodes a protein localized in the mitochondrial membrane. METHODS: The present and past radiological features of 14 MPAN patients were analyzed. RESULTS: Clinical evaluation did not reveal novel findings: spastic para- and tetraparesis with muscle atrophy are typical for MPAN. Dysarthria, parkinsonism, and dystonia are very common but not present in all cases. Present brain imaging demonstrated increased iron levels in the globus pallidus (GP) and substantia nigra (SN) in all patients. In two cases first imaging didn't show typical hypointensity in GP and SN. A novel finding were white matter hyperintensities localized mainly in the periventricular region. CONCLUSIONS: WMH are observed in some MPAN patients, they are age dependent and localized periventricular. If they are due to altered brain and peripheral lipid metabolism remains unknown.

Severe central and peripheral paraneoplastic demyelination associated with tumours of the ovaries.

PURPOSE: The aim of the study is to present MRI examinations of the brain and spinal cord, performed in girls with acute severe neurological presentation of paraneoplastic syndrome associated with ovarian teratomas. Paraneoplastic neurological syndrome (PNS) is a rare disorder caused by remote effects of malignancy in different organs. The pathogenesis of PNS concerns the autoimmune system and specific antibodies. PNS can be seen as encephalomyelitis, limbic encephalitis, progressive multifocal leukoencephalopathy, cerebellar ataxia, brainstem encephalitis, and paraneoplastic cerebellar degeneration. These symptoms are potentially reversible, if the underlying neoplasm is removed. METHODS: We presented three girls, aged 13, 17, and 18 years. They were all referred to the hospital because of an acute onset of severe disseminated encephalomyelitis. All MRI exams were performed on a 1.5 T scanner with a routine brain and spinal cord protocol, including TSE T2-WI and FLAIR sequences. In all cases, a contrast agent was injected in the standard dose. RESULTS: Neurological examination performed at the onset of the disease revealed hemiparesis, seizures, and consciousness disturbances. In one girl, visual field loss was also disclosed. They were all healthy before the onset of the disease. Brain and spinal cord MR imaging revealed multiple hyperintense lesions located supratentorially in the white matter of both hemispheres, in the pons, cerebellum, and spinal cord. Patients were treated with methyloprednisolone IV and IVIG. They all improved but significant sequelae were present. Two of them developed symptoms of acute demyelinating polyradiculoneuropathy within 2 months after the onset of encephalomyelitis. At the same time, brain MRI showed progression of the lesions. In two patients, anti-Yo antibodies were present in blood. Extensive examinations revealed bilateral ovarian teratomas in two patients, and left-sided ovarian teratoma in one case. Surgical resection of teratomas resulted in rapid clinical improvement. CONCLUSIONS: These cases show that in children and adolescents, acute demyelinating disease can be a manifestation of paraneoplastic neurological syndrome. Thus, PNS should always be considered in the differential diagnosis of encephalomyelitis. In female children and adolescents with suspected PNS, it is important to search for ovarian tumours.

Contrast enhancement pattern predicts poor survival for patients with non-WNT/SHH medulloblastoma tumours.

Recent studies revealed the biological heterogeneity of medulloblastoma, with the existence of at least four groups which are associated with several clinical and morphological features. We investigated for further correlations between molecular types, location of tumours, their contrast enhancement pattern and survival of patients. Altogether 76 tumours were analyzed and molecular subtypes were identified by immunohistochemistry using representative antibodies, detection of chromosome 6 monosomy and CTNNB1 mutation. The site of the tumour was assessed on diagnosis using Magnetic Resonance images and intra-operative surgical reports. In addition, the gadolinium enhancement pattern was also investigated in pre-treatment tumours. Cerebellar hemispheric location was associated with SHH tumours (p < 0.001), as opposed to midline location being typical for WNT and non-WNT/SHH tumours. Remarkably, for patients with non-WNT/SHH tumours, the extensive gadolinium enhancement pattern (present in >75% of tumour volume) predicted worse OS and EFS than for those with none/weak or heterogeneous enhancement (>10-75% of tumour volume), (both p < 0.001). Our analysis indicates that distribution of the medulloblastoma tumours location is related to the biological characteristics of tumour. Importantly, the enhancement pattern of the tumour may be a clinically useful prognostic marker for patients with non-WNT/SHH medulloblastomas.

Giant cerebellar cavernous malformation in 4-month-old boy. Case report and review of the literature.

Cavernous malformations (CMs) are rare vascular lesions that affect 0.4-0.9% of the population. The diagnosis of CMs is simple in most typical cases although some lesions may present unusual imaging features: localization, signal intensity, or size. Extremely rare giant CMs can mimic neoplastic lesion because of their size. We report a case of giant cerebellar CM that is more than 6 cm in size, diagnosed in 4-month-old boy. We discuss magnetic resonance findings and histopatholo-gical features of this lesion.

Rhombencephalosynapsis - isolated anomaly or complex malformation?

BACKGROUND: Rhombencephalosynapsis (RES) is a rare malformation of the posterior cranial fossa, characterized by fusion of the cerebellar hemispheres, medial cerebellar peduncles and dentate nuclei. Over the period of 7 years 8 cases of this anomaly have been diagnosed in two pediatric centers in Warsaw including one on the prenatal magnetic resonance imaging (MRI). MATERIAL/METHODS: Material consists of involves one fetus examined at the gestational age of 27 and 33 weeks and 7 children (5 girls and 2 boys) aged 8 months - 16 years. All of them underwent brain MRI with the use of 1.5T scanners. RESULTS: In 1 case RES was an isolated anomaly, in 1 case it was accompanied by hydrocephalus only, in the remaining 6 cases RES was an element of a complex malformation. The additional anomalies were as follows: callosal hypoplasia in 3 children, abnormalities of gyration in 2, brainstem hypoplasia in 2, isolated fourth ventricle in 1, abnormal white matter signal intensity in 4 (in 2 cases in supratentorial compartment, in 1 in the cerebellum and in 1 in the pons), abnormally dilated extraaxial fluid collections in 2, syringohydromyelia in 2. In 5 cases RES was total, in 3 - partial. CONCLUSIONS: Rhombencephalosynapsis has a very characteristic appearance on magnetic resonance imaging which allows diagnosis of this malformation at any age, including prenatal period.

Congenital brain tumors in a series of 56 patients.

INTRODUCTION: Central nervous system tumors diagnosed before the end of the first year of life differ from those found in older children and in adults. The differences include mode of clinical presentation, anatomical distribution, histopathological diagnoses, response to therapy, and outcome. MATERIALS AND METHODS: The material consists of 56 children (23 girls and 33 boys), aged at recognition 32 Hbd-12 months. We reviewed charts and MR exams according to age of the onset of symptoms, location of tumors, treatment, histopathology, and outcomes. Data of the outcome were analyzed using Kaplan-Meier plots and chi-square test. RESULTS: Eleven cases were recognized before 6 weeks of life, 24 before the age of 6 months, and 21 were diagnosed up to the end of 1 year of age. Thirty-eight tumors were located in the supratentorial compartment; 18 were infratentorial. Median age of tumors' recognition was 5.2 months; 4.3 months for supratentorial and 7.2 months for infratentorial tumors. We found 18 glial cell tumors (high and low grade), 15 embryonal tumors, and 12 choroid plexus tumors. CONCLUSIONS: The outcome of congenital CNS tumors depends on the size, location, time of diagnosis, histological type of the tumor, and therapeutic option. Neurosurgical procedures are necessary in most cases. Despite the notable advances in therapy, the outcome remains poor.

Congenital intramedullary spinal cord tumours: a report of two cases.

We present two different cases of congenital intramedullary tumours, one of a patient in whom treatment was started without pathological confirmation of a malignant tumour and the other of a primitive neuroectodermal tumour. Magnetic resonance imaging is the most useful tool in the diagnosis of malignant intramedullary tumours and differentiation from other types of spinal cord lesions.

Arterial hypertension with brachydactyly in a 15-year-old boy.

Autosomal dominant brachydactyly with hypertension is the only form of monogenic hypertension which is not sodium dependent. The disease is characterized by brachydactyly type E, short stature, arterial hypertension and aberrant loop of posterior inferior cerebellar artery (PICA) causing neurovascular conflict. So far the syndrome was described in one family in Turkey and two in Canada. We report a case of a 15-year-old boy who was admitted because of arterial hypertension 160/100 mmHg. He complained also of attacks of bilateral numbness of hands with deterioration of visual field. Examination revealed short stature (156 cm) and bone deformities of hands and feet consistent with brachydactyly type E. Ophthalmoscopy showed mild narrowing of retinal arteries. Serum electrolytes, blood gases, and renal function were normal. Renin activity and aldosterone concentrations were raised, and 24-h urinary excretion of catecholamines and urinary steroid profile were in normal range. Renal Doppler ultrasound was normal, but renal scintigraphy suggested vascular changes in the left kidney. Echocardiographic examination, besides mild left ventricular hypertrophy, was normal. Magnetic resonance angiography (angio-MR) revealed bilateral abnormal PICA loops and neurovascular conflict. Spiral angiotomography of renal arteries revealed narrow additional left renal artery. Both nonconsanguineous parents and younger brother were healthy, with normal height, without bone deformities, and had normal intracranial vessels. Amlodipine and metoprolol were given, and blood pressure lowered to 143/87. Adding rilmenidine gave no effect and enalapril was then added. It led to further improvement in blood pressure control. To our knowledge, this is the first pediatric description of a sporadic form of autosomal dominant brachydactyly with hypertension with abnormalities of brain and renal arteries.