R. N. Sener

The pineal gland: A comparative MR imaging study in children and adults with respect to normal anatomical variations and pineal cysts

This study was undertaken to evaluate the variations in appearance of the normal pineal gland. The findings of 1000 consecutive MR imaging examinations obtained at 0.5 T were studied. The age of the patients ranged from 1 day to 83 years, and findings in children and adults were compared. In all age groups the pineal gland appeared mainly in three forms: (1) nodule-like, (2) crescent-like and (3) ring-like. Overall prevalences of these forms were 52%, 26% and 22%, respectively. Apparent differences in frequencies were evident in children and adults with respect to the crescent-and ring-like types. Cystiform pineal lesions 5 mm or larger in one diameter (anteroposterior, sagittal or transverse) were taken to be true pineal cysts, when compared with the glands ring-like appearance (less than 5 mm). Pineal cysts had a prevalence of 0.6% in children and 2.6% in adults. No symptomatic pineal cyst with mass effect on the lamina tecti was detected in the series. Besides identifying the three anatomical types of the pineal gland as seen on MR imaging and addressing the potential significance of differences in their frequencies in children and adults, the author tries to explain the previous discrepancy between the MR imaging and autopsy series findings with respect to frequencies of the pineal cysts.

The claustrum on MRI: Normal anatomy, and the bright claustrum as a new sign in Wilson's disease

One hundred MRI examinations of normal subjects obtained at 0.5 T were studied in an effort to evaluate the claustrum and to establish a control group for patients with Wilsons disease. The claustrum was detectable unilaterally or bilaterally in 40 out of 100 subjects (40%) on spin-echo long TR (proton density and T2-weighted) MR images as a thin sheet of grey matter enclosed by low signal white matter of the external and extreme capsules. Spin-echo T1-weighted images were negative for the claustrum, however, it was identifiable in 12 out of 25 subjects (48%) studied utilizing the inversion recovery pulse sequence. In addition, eight patients with clinically established diagnoses of Wilsons disease were evaluated. The claustrum was normal (invisible) in four neurologically asymptomatic Wilsons disease patients, however, in 75% (n=3) of the four neurologically symptomatic patients it was bilaterally thickened and bright on long-TR MR images. The bright claustrum appears to be a new sign in Wilsons disease.

Wilson's disease: MRI demonstration of cavitations in basal ganglia and thalami

An MRI study of a patient with Wilsons disease is described, showing bilateral hyperintensity of the basal ganglia and thalami on T2-weighted images. Multiple, small nodular hyperintensities were superimposed on these hyperintense regions which presumably represented cavitations secondary to the spongy degeneration that is one of the histopathological features of cerebral Wilsons disease.

Polycystic brain (cerebrum polycystica vera) associated with ectodermal dysplasia: A new neurocutaneous syndrome

This paper presents a unique case of true polycystic brain in which multiple cysts of curvilinear, round, oval, or layered configuration occurred. These apparently represented extremely dilated Virchow-Robin spaces: the perivascular spaces lined by ependymal/leptomeningeal cells. Irregular retinal pigment epithelium was also evident. In addition, the patient showed ectodermal dysplasia manifesting as thin hair, dystrophic nails, and dental abnormalities. A common ectodermal origin for the brain cysts and the ectodermal changes is proposed, as it is known that the central nervous system (including the ependymal/leptomeningeal cells and the retinal cells), the epidermis (including hair and nails), and the enamel of the teeth have the same origin — the embryonic ectoderm. This association appears to be a new, distinct neurocutaneous syndrome.

Growing skull fracture in a patient with cerebral hemiatrophy

A growing skull fracture or leptomeningeal cyst most commonly occurs in children under the age of 3 years, and is extremely rare in adults. The reason for a growing skull fracture is usually a dural tear in association with the fracture. This paper presents an 18-year-old mentally retarded patient with cerebral hemiatrophy (Dyke-Davidoff-Masson syndrome) associated with a growing skull fracture in the ipsilateral hemicarnium, in whom not only a dural tear but also the ipsilaterally displaced and dilated lateral ventricle due to the original disease apparently contributed to the development of growing skull fracture.

An extensive type of polyostotic fibrous dysplasia

Abstract The case describes an 11-year-old girl affected by an unusually extensive type of polyostotic fibrous dysplasia. The cranium and face and both femurs, tibias, and fibulas were extensively and almost symmetrically involved. Tubulation deformities were noted in the metacarpals and middle phalanges of both hands. These findings appear to represent a very severe manifestation of the disease, as polyostotic fibrous dysplasia is known to be predominantly unilateral. The patient had endocrine dysfunction consistent with McCune-Albright syndrome. Radiological work-up included plain radiography of the skeleton and CT, MR imaging, and MR angiography of the cranium.

CT of gyriform calcification in tuberous sclerosis

This paper presents a patient with typical clinical and CT features of tuberous sclerosis associated with gyriform calcification of the most part of the left frontal lobe. This patient represents the third case of tuberous sclerosis in the literature presenting with gyriform calcification.

Anterior callosal agenesis in mild, lobar holoprosencephaly

The corpus callosum normally grows in a ventral to dorsal direction with the genu appearing first followed by posterior growth to form the body and splenium. In holoprosencephaly there usually is a malformation of the lamina terminalis which results in lack of formation of the corpus callosum. This paper presents a patient with mild, lobar holoprosencephaly in whom a different type of callosal dysgenesis was detected: the callosal body and splenium were apparently formed but the anterior parts were absent. The existence of this type of callosal dysgenesis appears to be in contrast to current theories on callosal development.

Unilateral cortical dysplasia associated with contralateral hyperplasia of the brainstem

Magnetic resonance imaging of a patient with unilateral frontotemporal cortical dysplasia is described. The brainstem showed ipsilateral hypoplasia, a usual but subjective radiological finding reportedly associated with unilateral cortical dysplasias, which inherently may cause underestimation of contralateral brainstem changes. In this patient contralateral hyperplasia of the brainstem was also present, evidenced especially by apparent hyperplasia of the pyramid of the medulla oblongata, where the corticospinal tract runs. Such hyperplasia of the brain stem may reflect a compensation reaction in order to increase the number of fibers in the corticospinal tract within the normal hemisphere, which are actually deficient (hypoplastic) in the contralateral, diseased hemisphere.

Hemimegalencephaly associated with contralateral hemispheral volume loss.

Hemimegalencephaly is a rare malformation characterized by overdevelopment of one cerebral hemisphere. The opposite hemisphere is usually normal. This paper presents a 2-day-old patient with hemimegalencephaly associated with diffuse volume loss in the contralateral hemisphere. To the best of the authors knowledge such an association has not been reported previously. This finding suggested that these patients may suffer from a congenital hemispheral insult of varying degree of severity and variable time of onset.