Different MRI-defined tuber types in tuberous sclerosis complex: Quantitative evaluation and association with disease manifestations.

BACKGROUND: Tuberous sclerosis complex (TSC) is a rare genetic disorder with multisystem involvement. A magnetic-resonance (MRI) based classification of tubers into types A, B and C has been proposed. However, the relationship between different tuber types and their quantitative characteristics, also the non-neurological manifestations of TSC remains unknown. AIMS: To quantitatively evaluate different MRI-defined tuber types and to explore their relationships with major disease manifestations in patients with tuberous sclerosis complex. METHODS: We performed quantitative manual assessment of tubers visible on T1W, T2W/FLAIR images and DW/ADC maps of 20 patients with TSC. Tubers were classified into types A, B and C based on their signal intensity on MRI. General clinical information and quantitative tuber characteristics were evaluated. Between-group comparisons were made using the nonparametric Mann-Whitney U test with Bonferroni correction. RESULTS: In total, 20 patients with 770 tubers were evaluated. Type A tubers were most numerous followed closely by Type B tubers, whereas Type C tubers were relatively rare. Tuber size was markedly different among the three tuber types: it increased from Type A to Type B to Type C. Infantile spasms, generalized-tonic clonic seizures, poor seizure control, cardiac rhabdomyomas, SEGA and developmental delay were not associated with quantitative tuber characteristics. Increased total Type B tuber load was associated with early onset epilepsy, while individually larger Type A and Type B tubers were associated with the presence angiomyolipoma (AML) and renal cysts. CONCLUSIONS: MRI-defined tuber types differ significantly in their size and number. Larger total Type B tuber load and larger individual Type A and Type B tubers were found to be most associated with early seizure onset and renal angiomyolipomas, respectively. One possible explanation for the observed differences in the clinical phenotype based on MRI-defined tuber types is not the intrinsic qualitative distinctions between different tuber types, but rather their individual size and total tuber load.

The tuber cinereum as a circumventricular organ: an anatomical study using magnetic resonance imaging.

PURPOSE: The tuber cinereum (TC) comprises the hypothalamic gray matter that forms the anterior portion of the third ventricle floor. However, since it has been rarely documented in previous neuroimaging investigations, the aim of the current study was to explore the morphology of the TC using magnetic resonance imaging (MRI). METHODS: Ninety-two patients were enrolled in this study. Following initial examination with conventional MRI sequences, a contrast study using intravenous gadolinium injection was performed in thin-sliced sections. RESULTS: The TC, which was commonly defined as a linear, enhancing structure on the midsagittal section, was identified in all 92 cases. In 83% of cases, the third ventricle floor had a gentle inflection at the junctional site between the median eminence and TC. The angle formed between the line parallel to the TC and the horizontal line showed considerable variability, which ranged from 0.5° to 56°. Furthermore, a non-enhancing segment of variable length was identified in the posterior-most TC. In 11% of cases, the midline TC was enhanced over the whole length. CONCLUSIONS: Since the most part of the midline TC was enhanced with intravenous gadolinium injection, it may function as a circumventricular organ. The TC should be evaluated with contrast sagittal MRI prior to performing surgery with management of the anterior third ventricle floor.

Central precocious puberty: evaluation by neuroimaging.

To evaluate the incidence of abnormal intracranial findings in children with central precocious puberty, 62 children (51 girls, 11 boys) were examined by computerized tomography and/or magnetic resonance imaging (MRI) of the brain. Forty-four had normal examinations; 18 (11 girls, 7 boys) showed intracranial pathologies, including hamartoma of the tuber cinereum (8 cases), parenchymal loss (3 cases), hypothalamic-chiasmatic lesions (2 cases), lesions of the corpus callosum (2 cases), suprasellar cyst (1 case), and pineal cyst and mesiotemporal sclerosis (1 case each). Based on the correlation between the clinical and the imaging results of this series, the authors recommend MRI as the imaging method of choice in the investigation of precocious puberty.

Application of reconstruction computed tomography in a case of tuber cinereum hamartoma.

A case of a 2-year-old girl with tuber cinereum hamartoma is evaluated by computed tomography (CT). Special reference is made to the application of CT image reconstruction, which has not yet been reported in the literature. The location, extent, shape and size of the mass lesion and also the anatomical relationship to adjacent structures are clearly demonstrated in sagittal and coronal CT images reconstructed from serial thin-section CT images in conjunction with target imaging and a review program.

Hamartomas of the tuber cinereum.

The hamartoma of the tuber cinereum, a midline dysraphic syndrome, corresponds to a mass of normal neuronal tissue implanted in the area of the mamillary bodies. It has no evolutionary potential, but association to other cerebral malformations has been observed. On the basis of 18 personal cases and a review of the literature, the authors evaluate the actual diagnostic criteria and the incidence of different clinical signs such as precocious isosexual puberty, seizures, and mental impairment.

Evaluation of the suprasellar cistern by computed tomography.

The normal suprasellar cistern is a five- or six-pointed, starshaped, fluid-filled structure as demonstrated by computerized axial tomography (CAT). At various levels the normal suprasellar cistern contains the major intracranial vessels and their anastomotic channels, the optic nerves, chiasm, and infundibular stalk. The existence of lesions, either intrinsic structures of or extrinsic structures contiguous to the suprasellar cistern can be detected by their effect on the normal anatomy of the suprasellar cistern or by filling defects produced when studied with metrizamide cisternography.

Radiologic findings of hamartomas of the tuber cinereum and hypothalamus.

Five cases, four histologically proved, or hamartoma of the tuber cinereum and hypothalamus in children (age range: 2--12 years) are reported. Three cases had pubertas praecox, and in all of these the hamartoma was located in the basal cistern between the chiasm and pons, and had a collar button shape and size typical of hamartoma of the tuber cinereum. In the third case, which presented with headache, a huge calcified mass in the suprasellar region was initially thought to be craniopharyngioma. The fourth case had a hamartoma within the substance of the hypothalamus and presented with hyponatremia and temporal lobe seizures.

Neuroradiologic study of hamartomas of the tuber cinereum and hypothalamus.

Five cases, four histologically proven, of hamartoma of the tuber cinereum and hypothalamus in children are reported. The ages of the patients range from 2 to 12 years. Three cases had pubertas praecox, and in all of these the hamartoma was located in the basal cistern between the chiasm and pons and had a collar button shape and size typical of hamartoma of the tuber cinereum. In the third case, a huge calcified mass in the suprasellar region was initially thought to be craniopharyngioma. The fourth case had a hamartoma within the substance of the hypothalamus and presented with hyponatremia and temporal lobe seizures.