A 47 y.o. male comes having been recently released from jail with headache.
What do you see?
Our patient had a colloid cyst in the foramen of Monro obstructing the flow of CSF. The foramen of Monro connects the paired lateral ventricles with the third ventricle at the midline of the brain. Hydrocephalus developed with the increased pressure causing migration of csf into the brain parenchyma. This is called transependymal flow. Our patient exhibited bizarre behavior in the ED and his drug screen was positive for meth. Since the behavior could have been related to the increase in intracranial pressure, he was admitted to neurosurgery, sedated and intubated. Family agreed to surgery.
the third ventricle connects the lateral ventricles.
The normal pressure of CSF is 20 MM of mercury. As the pressure increases, it gradually becomes higher than mean arterial pressure causing a decrease in cerebral perfusion. To compensate for the lack of oxygen the sympathetic nervous system is activated increasing BP and the increased BP signals the carotid and aortic baroreceptors of activate the parasympathetic nervous system causing the heart rate to decrease. Pressure from the swollen ischemic brain compresses the brainstem in a rostral caudal progression leading to hyperventilation, ataxic breathing and finally apnea.
our pt had a colloid cyst obstructing the foramen of monro
The clinical features of hydrocephalus are notoriously variable depending on the rapidity of onset of the condition. The most rapid deteriorations are seen in young adults with colloid cysts of the third ventricle where there is an acute rise in ICP caused by a ball valve effect of the cyst. Young adults with middle cerebral artery strokes can also present with increased ICP resulting in sudden death.
Clinically, suspicion of increased ICP should occur with the following signs and symptoms: headaches, vomiting and alteration of mental status. Hydrocephalus can also cause blindness because the meninges of the brain also surround the optic nerve and as ICP increases, the pressure on the meninges can compress the blood supply to the optic nerve causing ischemia. Herniation and death will result in untreated hydrocephalus.
hydrocephalus that occurs more slowly results in thinning of the cortex of the brain
CUSHING’S TRIAD is a clinical syndrome of hypertension, bradycardia and irregular respiration and is a sign of impeding brain herniation
Our patient underwent emergent ventricular drains followed by a R frontal craniotomy with resection of the colloid cyst. He was discharged with psychiatric follow up.
Horn E, Feiz-Erfan I, Bristol R, et al. Treatment options for third ventricular colloid cysts: comparison of open microsurgical versus endoscopic resection. 2008. Neurosurgery 62:1076-1083.
Hellwig D, Bauer B, Schulte M, et al. Neuroendoscopic treatment for colloid cysts of the third ventricle: the experience fo a decade.2008 Neurosurgery 62:1101-1109.
Benghanem S, Mazeraud A, AzabouE, et al. 2020. Brainstem dysfunction in critically ill patients. Crit Care;24:5
Plum F, Posner J. the diagnosis of stupor and coma. Comtemp Neurol Ser. 1972;10:1-286.
Actually the mass is here, at the arrow, the third and fourth ventricles are not dilated.