The Insidious Symptoms Of Diverticulitis
Magnetic resonance imagings (MRI) showed the nodular lesion of the third ventricle to be hyper intense, without enhancement, in Symptoms of Diverticulitis weighted spin-echo sequences, and mainly hypo intense in-weighted spin-echo sequences.
External ventricular drainage resulted in clinical and radio logic improvement. The cyst was evacuated by endoscopy, and pathologic examination revealed colloid cyst material.
A 58-year-old woman presented with cognitive deterioration, memory loss and apathy of approximately 3 months' duration. Her history was unremarkable. Neurologic examination revealed temporal -- spatial disorientation, mental slowness, memory alteration, right crural paresis and hyperreflexia in the left leg.
A cranial CT examination showed a homogeneous nodular lesion localized in the third ventricle, with minimal peripheral contrast uptake, as well as biventricular hydrocephalus and left atrial diverticula. MRI scanning revealed a nodular lesion in the anterior third of the third ventricle, which was hyper intense on weighted spinecho sequences and had areas of hypo intense signal on weighted spin-echo sequences, as well as active biventricular hydrocephalus and left atrial diverticula. The patient underwent surgery for excision of the lesion. Pathologic examination revealed a colloid cyst. Massive ventricular dilatation causes stretching and dehiscence of the fornix with formation of unilateral or bilateral pial pulsion diverticula of the inferomedial wall of the atrium. Such dilatation may result from a partial defect in the ipsilateral tentorial band, which leads to herniation of the wall. Enlargement of the pial pouch creates a dramatic subarachnoid cyst, which may herniate downward through the incisura into the supracerebellar and quadrigeminal cistern. These atrial diverticula can compress the mesencephalic tectum and can be mistaken for an arachnoid cyst or an ependymal cyst(f.1,3) of the quadrigeminal cistern. It is important to recognize these cysts and distinguish them from atrial diverticula, since these cysts can cause hydrocephalus, which should be treated with a direct intracystic shunt or excised. In contrast, atrial diverticula generally improve or disappear with suitable drainage of the hydrocephalus. This indicates that, although atrial diverticula are favoured by the defect in the tentorial band, they are secondary to severe, chronic hydrocephalus. The CT and MRI images showed clearly the herniation of the atrial wall, tentorial hypoplasia and, on occasion, lateral displacement of the internal cerebral veins. They also demonstrated the possible mass effect on the area of the quadrigeminal platform and vermian cistern. Bilateral diverticula can be seen in cases with shortening of both tentorial bands. The formation of atrial diverticula has been described in severe hydrocephalus secondary to brain stem gliomas, hypothalamic gliomas, third ventricular epidermoidomas and other tumours. Other nontumoral causes include granular ependymitis, aqueductal gliosis, external hydrocephalus and atresia of the foramen of Monro. Colloid cysts of the third ventricle are rare, benign, congenital cystic neoplasms. They account for 0.25% to 0.5% of all intracranial cysts. Although the most widely accepted theory is that they originate in the primitive neuroepithelium of the tela choroidea they present non-neuronal traces of olfactory mucosa, and for this reason the term ''neuroepithelial cyst'' is not exact. Their location in the anterior part of the third ventricle can obstruct the foramina of Monro and create acute or chronic hydrocephalus, which can become severe. Colloid cysts are usually biventricular and symmetrical, but can be unilateral.
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