Surgically reversible hypothalamic hypopituitarism due to aqueductal stenosis. Case report

Pathophysiology of long-standing overt ventriculomegaly in adults

OBJECT

Long-standing overt ventriculomegaly in adults (LOVA) is a unique form of hydrocephalus that develops during childhood and manifests symptoms during adulthood. The aim of the present study was to analyze the specific pathophysiological characteristics of LOVA.

METHODS

The specific diagnostic criteria for LOVA include severe ventriculomegaly in adults that is associated with macrocephalus measuring more than two standard deviations in head circumference and/or neuroradiological evidence of a significantly expanded or destroyed sella turcica. Twenty patients who fulfilled these criteria, 14 males and six females, were retrospectively studied. These patients' ages at diagnosis ranged from 15 to 61 years (mean 39.4 years). All had symptoms and/or signs indicating that hydrocephalus first occurred at birth or during infancy in the absence of any known underlying disease. The authors performed a pathophysiological study that included specific variations of magnetic resonance (MR) imaging, such as fluid-attenuated inversion recovery and cardiac-gated cine-mode imaging; intracranial pressure (ICP) monitoring; three-dimensional computerized tomography (CT) scanning; and other techniques. Hydrocephalus was caused by aqueductal stenosis in all patients. Severe ventriculomegaly involving the lateral and third ventricles was associated with a marked expansion or destruction of the sella turcica in 17 cases. Cardiac-gated cine-MR imaging did not reveal any significant movements of cerebrospinal fluid in the aqueduct. Three-dimensional CT ventriculography confirmed that the expanded third ventricle protruded into the sella and, sometimes, extended a diverticulum. Fourteen patients revealed symptoms and signs that indicated increased ICP with prominent pressure waves. Dementia or mental retardation was seen in 11 patients, gait disturbance in 12, and urinary incontinence in eight; all three of these symptoms were observed in seven patients. Thirteen patients experienced visual disturbance. Nine patients underwent ventriculoperitoneal shunt implantation as the initial treatment, leading to postoperative subdural hematoma in all seven cases in which a differential pressure valve was used. Nine patients, three of whom were initially treated by shunt placement, underwent a neuroendoscopic procedure, mainly for third ventriculostomy. Postoperatively, ICP returned to normal, and marked to-and-fro pulsatile movements at the site of ventriculostomy were recognized on cine-MR imaging in patients treated endoscopically. However, the ventriculomegaly was little improved. Consequently, all patients eventually demonstrated improvement in response to either a shunt equipped with a pressure-programmable valve or an endoscopic procedure; however, depression appeared in six patients, who required psychiatric consultation or medication.

CONCLUSIONS

Such remarkably decreased intracranial compliance but relatively high ICP dynamics are the pathophysiological characteristics of LOVA. The therapeutic regimen should be determined based on the individual's specific pathophysiological makeup.

High serum levels of somatomedin-C and diabetes mellitus caused by obstructive hydrocephalus: case report

OBJECTIVE AND IMPORTANCE

This case demonstrates a relationship between hydrocephalus with a huge diverticulum of the third ventricle and high serum levels of somatomedin-C. Somatomedin-C levels become high when the secretion of growth hormone from the adenohypophysis increases, and previous reports state that hydrocephalus decreases the secretion of growth hormone.

CLINICAL PRESENTATION

The patient suffered from diabetes mellitus and obesity, and serum somatomedin-C levels were high. A pituitary adenoma or ectopic growth hormone-producing tumor was suspected. Magnetic resonance imaging did not reveal either of these abnormalities but indicated hydrocephalus with a diverticulum of the third ventricle.

INTERVENTION

After ventriculoperitoneal shunt placement, the blood glucose and serum somatomedin-C levels of the patient decreased toward normal. Six months later, the shunt tube became obstructed and serum somatomedin levels increased. The levels decreased again after shunt revision.

CONCLUSION

To our knowledge, this is the first published report of obstructive hydrocephalus with a diverticulum of the third ventricle compressing the hypothalamus and increasing the serum levels of somatomedin-C.

"Occult" hydrocephalus in children

The authors describe 32 children between 2 and 15 years of age who had hydrocephalus that was only clinically manifest late in life. The clinical picture of these children did not suggest an obvious increase in intracranial pressure; instead, the presenting signs were rather nonspecific and included macrocrania, mild psychomotor retardation, unsteady gait, increased muscle tone and deep tendon reflexes in the lower limbs, impaired ocular movement, epilepsy, and endocrine dysfunction. Their histories suggest the possible causes of the ventricular dilation in about one third of the cases were: perinatal hemorrhage, leptomeningitis, neurofibromatosis, and untreated aneurysm of the great vein of Galen. In 20 patients, however, no positive anamnestic findings were reported. CT scan revealed triventricular dilation in more than half of the cases; tetraventricular dilation was present in 6 patients, and biventricular dilation in the remaining subjects. All children underwent CSF shunting, which resulted in complete recovery in all but 2 cases. The most frequently recorded surgical complication was post-operative subdural effusion (7 subjects), which required surgical treatment in only 2 cases.

Hypothalamic disease presenting as amenorrhoea: value of computed tomography

Five women presenting with amenorrhoea (three with secondary amenorrhoea and galactorrhoea, and two with primary amenorrhoea) were shown to have suprasellar abnormalities by computed tomography. Organic hypothalamic disease was confirmed at surgery (craniopharyngioma in three, intra- and suprasellar Rathke's cleft cyst in one, aqueductal stenosis and suprasellar arachnoid cyst in one). Moderate hyperprolactinaemia was present in the first four, while the last had isolated gonadotrophin deficiency of hypothalamic origin. One of the hyperprolactinaemic women had entirely normal residual pituitary function, visual fields and tomography of the sella. Two of the patients with secondary amenorrhoea and galactorrhoea had resumption of menses during bromocriptine therapy before operation. Spontaneous menarche and subsequent pregnancy occurred after ventriculoatrial shunt in the girl with aqueductal stenosis. Organic hypothalamic diseases may present with amenorrhoea (sometimes as the only symptom) more commonly than previously appreciated. Computed tomography should replace conventional tomography of the sella and should be an essential part of the clinical investigation in all patients with amenorrhoea of hypothalamo-pituitary origin.