Treatment of hydrocephalus

Treatment of hydrocephalus

Acute obstructive hydrocephalus is an emergency because of the risk of rapid progression to coma and death, sometimes with very sudden deterioration, a ‘hydrocephalic attack’. It may be relieved by addressing the underlying pathology , for instance by excision of a tumour responsible for an obstructive hydrocephalus. Most often, however, temporary ventricular drainage is required as a precaution in the preoperative and perioperative period or as an emergency in an obtunded or deteriorating patient. External ventricular drain External ventricular drains (EVDs) are an e ff ective temporary measure to relieve hydrocephalus. Most commonly they are inserted through a burr hole at Kocher’s point (right of midline, anterior to the coronal suture), perpendicular to the brain surface, so that the catheter tip rests adjacent to the fora men of Monro in the lateral ventricle. Intrathecal antibiotics may also be delivered through the EVD. Lumbar drains are an alternative means of temporary CSF diversion. Emil Theodor Kocher , 1841–1917, Professor of Surgery , Berne, Switzerland. In 1909, he was awarded the Nobel Prize in Physiology or Medicine for his work on the thyroid. V entriculoperitoneal shunting comprises the insertion of a proximal or ventricular catheter into the lateral ventricle, while a distal catheter is tunnelled subcutaneously to the abdomen. V entriculoatrial, ventriculopleural and lumboperi - toneal shunting are also occasionally employed. A shunt valve inserted between the proximal and distal catheters regulates flow through the system by opening at a predetermined pressure ( Figure 48.8 ); the shunt valve typically incorporates a CSF reservoir, which allows for percutaneous sampling. An anti-siphon system may also be incorporated to prevent exces - sive drainage in the standing position. Programmable valves o ff er variable opening pressures, adjusted magnetically using a device applied externally over the valve. Shunt complications Shunts are vulnerable to disconnection, infection, blockage and overdrainage, so that 15–20% require replacement within 3 years. Features of shunt infection typically include fever, head - ache and meningism; 75% of infections present within 1 /uni00A0 month, reflecting introduction at the time of insertion. The diagnosis can be confirmed by CSF tap from the shunt reser - voir or lumbar puncture if safe to do so. The shunt is remov ed and external ventricular drainage or serial lumbar punctures instituted to cover a course of antibiotic therapy . Once CSF sampling confirms resolution of the infection and a normal protein concentration, a shunt can be inserted at a new site . Patients with blocked shunts present clinical features of hydrocephalus, which can be confirmed on CT , and the shunt reservoir may be di ffi cult to compress or refill only slowly . The - majority of blockages are attributable to cellular and protein - aceous debris, especially due to infection, but choroid plexus adhesion, blood clot or failure of the valve mechanism may also be responsible. In the context of obstructive and congenital

Figure 48.8 Examples of ventriculoperitoneal shunt valves.

because of the potential for rapid deterioration owing to uncontrolled rises in ICP . Overdrainage can result in low-pressure headaches, which are typically worse on standing. Collapse of the ventricles can cause accumulation of fluid or blood in the subdural space, resulting in subdural hyg roma or subdural haematoma. The slit ventricle syndrome describes the situation in children treated with shunts, whose ventricles and subarachnoid spaces are underdeveloped, resulting in poor brain compliance. In these patients normal fluctuations in ICP are exaggerated so that coughing and straining may cause symptoms of raised ICP . Any shunt blockage may not be evident on scan as the ventricles fail to enlarge. Endoscopic third ventriculostomy This procedure is especially useful in obstructive hydroceph alus due to aqueduct stenosis. A neuroendoscope is inserted into the frontal horn of the lateral ventricle and then into the third ventricle via the foramen of Monro. The floor of the ventricle is then opened between the mamillary bodies and the pituitary recess. Free drainage between the third ventricle and the adjacent subarachnoid cisterns is then possible, without the infection risk posed by implanted tubing. Reblockage of this route is common, however, and many patients will subse quently require a shunt. Rare but serious complications include damage to the basilar artery or forniceal damage, resulting in permanent memory impairment. Summary box 48.3 Treating hydrocephalus /uni25CF /uni25CF /uni25CF /uni25CF

Temporary CSF diversion can be achieved with an EVD In the long term a shunt, usually connecting the lateral ventricles with the peritoneal cavity in the abdomen (ventriculoperitoneal shunt), is the mainstay of management Shunt blockage and infection are common complications In certain cases, obstructive hydrocephalus can be managed by endoscopic third ventriculostomy

Treatment of hydrocephalus

Acute obstructive hydrocephalus is an emergency because of the risk of rapid progression to coma and death, sometimes with very sudden deterioration, a ‘hydrocephalic attack’. It may be relieved by addressing the underlying pathology , for instance by excision of a tumour responsible for an obstructive hydrocephalus. Most often, however, temporary ventricular drainage is required as a precaution in the preoperative and perioperative period or as an emergency in an obtunded or deteriorating patient. External ventricular drain External ventricular drains (EVDs) are an e ff ective temporary measure to relieve hydrocephalus. Most commonly they are inserted through a burr hole at Kocher’s point (right of midline, anterior to the coronal suture), perpendicular to the brain surface, so that the catheter tip rests adjacent to the fora men of Monro in the lateral ventricle. Intrathecal antibiotics may also be delivered through the EVD. Lumbar drains are an alternative means of temporary CSF diversion. Emil Theodor Kocher , 1841–1917, Professor of Surgery , Berne, Switzerland. In 1909, he was awarded the Nobel Prize in Physiology or Medicine for his work on the thyroid. V entriculoperitoneal shunting comprises the insertion of a proximal or ventricular catheter into the lateral ventricle, while a distal catheter is tunnelled subcutaneously to the abdomen. V entriculoatrial, ventriculopleural and lumboperi - toneal shunting are also occasionally employed. A shunt valve inserted between the proximal and distal catheters regulates flow through the system by opening at a predetermined pressure ( Figure 48.8 ); the shunt valve typically incorporates a CSF reservoir, which allows for percutaneous sampling. An anti-siphon system may also be incorporated to prevent exces - sive drainage in the standing position. Programmable valves o ff er variable opening pressures, adjusted magnetically using a device applied externally over the valve. Shunt complications Shunts are vulnerable to disconnection, infection, blockage and overdrainage, so that 15–20% require replacement within 3 years. Features of shunt infection typically include fever, head - ache and meningism; 75% of infections present within 1 /uni00A0 month, reflecting introduction at the time of insertion. The diagnosis can be confirmed by CSF tap from the shunt reser - voir or lumbar puncture if safe to do so. The shunt is remov ed and external ventricular drainage or serial lumbar punctures instituted to cover a course of antibiotic therapy . Once CSF sampling confirms resolution of the infection and a normal protein concentration, a shunt can be inserted at a new site . Patients with blocked shunts present clinical features of hydrocephalus, which can be confirmed on CT , and the shunt reservoir may be di ffi cult to compress or refill only slowly . The - majority of blockages are attributable to cellular and protein - aceous debris, especially due to infection, but choroid plexus adhesion, blood clot or failure of the valve mechanism may also be responsible. In the context of obstructive and congenital

Figure 48.8 Examples of ventriculoperitoneal shunt valves.

because of the potential for rapid deterioration owing to uncontrolled rises in ICP . Overdrainage can result in low-pressure headaches, which are typically worse on standing. Collapse of the ventricles can cause accumulation of fluid or blood in the subdural space, resulting in subdural hyg roma or subdural haematoma. The slit ventricle syndrome describes the situation in children treated with shunts, whose ventricles and subarachnoid spaces are underdeveloped, resulting in poor brain compliance. In these patients normal fluctuations in ICP are exaggerated so that coughing and straining may cause symptoms of raised ICP . Any shunt blockage may not be evident on scan as the ventricles fail to enlarge. Endoscopic third ventriculostomy This procedure is especially useful in obstructive hydroceph alus due to aqueduct stenosis. A neuroendoscope is inserted into the frontal horn of the lateral ventricle and then into the third ventricle via the foramen of Monro. The floor of the ventricle is then opened between the mamillary bodies and the pituitary recess. Free drainage between the third ventricle and the adjacent subarachnoid cisterns is then possible, without the infection risk posed by implanted tubing. Reblockage of this route is common, however, and many patients will subse quently require a shunt. Rare but serious complications include damage to the basilar artery or forniceal damage, resulting in permanent memory impairment. Summary box 48.3 Treating hydrocephalus /uni25CF /uni25CF /uni25CF /uni25CF

Temporary CSF diversion can be achieved with an EVD In the long term a shunt, usually connecting the lateral ventricles with the peritoneal cavity in the abdomen (ventriculoperitoneal shunt), is the mainstay of management Shunt blockage and infection are common complications In certain cases, obstructive hydrocephalus can be managed by endoscopic third ventriculostomy

Treatment of hydrocephalus

Acute obstructive hydrocephalus is an emergency because of the risk of rapid progression to coma and death, sometimes with very sudden deterioration, a ‘hydrocephalic attack’. It may be relieved by addressing the underlying pathology , for instance by excision of a tumour responsible for an obstructive hydrocephalus. Most often, however, temporary ventricular drainage is required as a precaution in the preoperative and perioperative period or as an emergency in an obtunded or deteriorating patient. External ventricular drain External ventricular drains (EVDs) are an e ff ective temporary measure to relieve hydrocephalus. Most commonly they are inserted through a burr hole at Kocher’s point (right of midline, anterior to the coronal suture), perpendicular to the brain surface, so that the catheter tip rests adjacent to the fora men of Monro in the lateral ventricle. Intrathecal antibiotics may also be delivered through the EVD. Lumbar drains are an alternative means of temporary CSF diversion. Emil Theodor Kocher , 1841–1917, Professor of Surgery , Berne, Switzerland. In 1909, he was awarded the Nobel Prize in Physiology or Medicine for his work on the thyroid. V entriculoperitoneal shunting comprises the insertion of a proximal or ventricular catheter into the lateral ventricle, while a distal catheter is tunnelled subcutaneously to the abdomen. V entriculoatrial, ventriculopleural and lumboperi - toneal shunting are also occasionally employed. A shunt valve inserted between the proximal and distal catheters regulates flow through the system by opening at a predetermined pressure ( Figure 48.8 ); the shunt valve typically incorporates a CSF reservoir, which allows for percutaneous sampling. An anti-siphon system may also be incorporated to prevent exces - sive drainage in the standing position. Programmable valves o ff er variable opening pressures, adjusted magnetically using a device applied externally over the valve. Shunt complications Shunts are vulnerable to disconnection, infection, blockage and overdrainage, so that 15–20% require replacement within 3 years. Features of shunt infection typically include fever, head - ache and meningism; 75% of infections present within 1 /uni00A0 month, reflecting introduction at the time of insertion. The diagnosis can be confirmed by CSF tap from the shunt reser - voir or lumbar puncture if safe to do so. The shunt is remov ed and external ventricular drainage or serial lumbar punctures instituted to cover a course of antibiotic therapy . Once CSF sampling confirms resolution of the infection and a normal protein concentration, a shunt can be inserted at a new site . Patients with blocked shunts present clinical features of hydrocephalus, which can be confirmed on CT , and the shunt reservoir may be di ffi cult to compress or refill only slowly . The - majority of blockages are attributable to cellular and protein - aceous debris, especially due to infection, but choroid plexus adhesion, blood clot or failure of the valve mechanism may also be responsible. In the context of obstructive and congenital

Figure 48.8 Examples of ventriculoperitoneal shunt valves.

because of the potential for rapid deterioration owing to uncontrolled rises in ICP . Overdrainage can result in low-pressure headaches, which are typically worse on standing. Collapse of the ventricles can cause accumulation of fluid or blood in the subdural space, resulting in subdural hyg roma or subdural haematoma. The slit ventricle syndrome describes the situation in children treated with shunts, whose ventricles and subarachnoid spaces are underdeveloped, resulting in poor brain compliance. In these patients normal fluctuations in ICP are exaggerated so that coughing and straining may cause symptoms of raised ICP . Any shunt blockage may not be evident on scan as the ventricles fail to enlarge. Endoscopic third ventriculostomy This procedure is especially useful in obstructive hydroceph alus due to aqueduct stenosis. A neuroendoscope is inserted into the frontal horn of the lateral ventricle and then into the third ventricle via the foramen of Monro. The floor of the ventricle is then opened between the mamillary bodies and the pituitary recess. Free drainage between the third ventricle and the adjacent subarachnoid cisterns is then possible, without the infection risk posed by implanted tubing. Reblockage of this route is common, however, and many patients will subse quently require a shunt. Rare but serious complications include damage to the basilar artery or forniceal damage, resulting in permanent memory impairment. Summary box 48.3 Treating hydrocephalus /uni25CF /uni25CF /uni25CF /uni25CF

Temporary CSF diversion can be achieved with an EVD In the long term a shunt, usually connecting the lateral ventricles with the peritoneal cavity in the abdomen (ventriculoperitoneal shunt), is the mainstay of management Shunt blockage and infection are common complications In certain cases, obstructive hydrocephalus can be managed by endoscopic third ventriculostomy