Refractory Idiopathic Intracranial Hypertension
Refractory Idiopathic Intracranial Hypertension
Object. Ventriculoperitoneal (VP) shunts have not been widely used for idiopathic intracranial hypertension (IIH) because of the difficulty of placing a shunt into normal or small-sized ventricles. The authors report their experience with stereotactic placement of VP shunts for IIH.
Methods. The authors reviewed the clinical records of all patients in whom stereotaxis was used to guide the placement of a VP shunt for IIH at their institution. All shunts were placed using stereotactic guidance to target the frontal horn of the lateral ventricle. Patients were contacted at a mean postoperative interval of 15.1 months. No patients were lost to follow up.
The authors identified 13 patients who underwent placement of a stereotactically guided VP shunt for IIH over a 6- year period. A trial of either acetazolamide or steroid therapy had failed in all patients. Prior surgical treatments included optic nerve sheath fenestrations in seven patients and cerebrospinal fluid diversionary procedures, other than stereotactic VP shunt procedures, in nine patients. Twelve patients reported excellent or good durable symptomatic relief at the time of follow up. No patient suffered progression of visual deficits. Four patients experienced persistent headaches following the procedure. Three patients required a revision of the VP shunt for technical failure.
Conclusions. Stereotactically guided VP shunt placement is an effective and durable treatment option in many cases of IIH that are refractory to more traditional medical and surgical approaches.
Idiopathic intracranial hypertension, also known as pseudotumor cerebri or benign intracranial hypertension, is a disorder of elevated ICP in the absence of any demonstrable disease. This disorder may affect children and adults, and women are more frequently affected than men. Typically, patients complain only of headaches. Except for papilledema and sixth cranial nerve paresis, neurological examination is usually normal. Chronic papilledema may lead to optic atrophy and progressive visual loss. Although subtle visual loss is present in a large majority of patients with IIH, significant loss of central vision is usually a late development. Patients with pseudotumor cerebri must undergo frequent ophthalmological examinations to identify early signs of visual deterioration.
There are several treatment modalities that appear to be effective. Acetazolamide does provide relief to some patients and is often the initial treatment of choice. Steroid therapy has also been used with some success. Idoipathic intracranial hypertension has been associated with obesity, and some patients do improve with weight loss. Additionally, special diets and gastric surgery have been suggested as possible treatment modalities.
Indications for surgical treatment of IIH include significant visual loss, progressive visual loss, or severe headache that persists despite medical intervention. Optic nerve sheath fenestration is a frequently performed surgical procedure for this condition, most often bilaterally in two stages. Optic nerve sheath fenestrations are effective at relieving papilledema and progressive visual loss in most cases. In contrast to CSF diversionary procedures, however, optic nerve sheath fenestrations are ineffective at relieving headaches. Reported complications of optic nerve sheath fenestrations include peripapillary hemorrhage, new visual field deficits, blindness, cranial nerve paresis, and stroke.
The most frequently performed CSF diversion procedure for IIH has been LP shunt placement. Lumboperitoneal shunts result in rapid resolution of symptoms of elevated ICP. Although LP shunts are quite effective at relieving intracranial hypertension, shunt failure and low pressure-induced headaches are frequently seen. The difficulty of introducing a catheter into ventricles of normal or small size has led most surgeons to favor LP over VP shunts in these patients. Stereotaxis, however, may be used to overcome this limitation of traditional VP shunt placement.
Object. Ventriculoperitoneal (VP) shunts have not been widely used for idiopathic intracranial hypertension (IIH) because of the difficulty of placing a shunt into normal or small-sized ventricles. The authors report their experience with stereotactic placement of VP shunts for IIH.
Methods. The authors reviewed the clinical records of all patients in whom stereotaxis was used to guide the placement of a VP shunt for IIH at their institution. All shunts were placed using stereotactic guidance to target the frontal horn of the lateral ventricle. Patients were contacted at a mean postoperative interval of 15.1 months. No patients were lost to follow up.
The authors identified 13 patients who underwent placement of a stereotactically guided VP shunt for IIH over a 6- year period. A trial of either acetazolamide or steroid therapy had failed in all patients. Prior surgical treatments included optic nerve sheath fenestrations in seven patients and cerebrospinal fluid diversionary procedures, other than stereotactic VP shunt procedures, in nine patients. Twelve patients reported excellent or good durable symptomatic relief at the time of follow up. No patient suffered progression of visual deficits. Four patients experienced persistent headaches following the procedure. Three patients required a revision of the VP shunt for technical failure.
Conclusions. Stereotactically guided VP shunt placement is an effective and durable treatment option in many cases of IIH that are refractory to more traditional medical and surgical approaches.
Idiopathic intracranial hypertension, also known as pseudotumor cerebri or benign intracranial hypertension, is a disorder of elevated ICP in the absence of any demonstrable disease. This disorder may affect children and adults, and women are more frequently affected than men. Typically, patients complain only of headaches. Except for papilledema and sixth cranial nerve paresis, neurological examination is usually normal. Chronic papilledema may lead to optic atrophy and progressive visual loss. Although subtle visual loss is present in a large majority of patients with IIH, significant loss of central vision is usually a late development. Patients with pseudotumor cerebri must undergo frequent ophthalmological examinations to identify early signs of visual deterioration.
There are several treatment modalities that appear to be effective. Acetazolamide does provide relief to some patients and is often the initial treatment of choice. Steroid therapy has also been used with some success. Idoipathic intracranial hypertension has been associated with obesity, and some patients do improve with weight loss. Additionally, special diets and gastric surgery have been suggested as possible treatment modalities.
Indications for surgical treatment of IIH include significant visual loss, progressive visual loss, or severe headache that persists despite medical intervention. Optic nerve sheath fenestration is a frequently performed surgical procedure for this condition, most often bilaterally in two stages. Optic nerve sheath fenestrations are effective at relieving papilledema and progressive visual loss in most cases. In contrast to CSF diversionary procedures, however, optic nerve sheath fenestrations are ineffective at relieving headaches. Reported complications of optic nerve sheath fenestrations include peripapillary hemorrhage, new visual field deficits, blindness, cranial nerve paresis, and stroke.
The most frequently performed CSF diversion procedure for IIH has been LP shunt placement. Lumboperitoneal shunts result in rapid resolution of symptoms of elevated ICP. Although LP shunts are quite effective at relieving intracranial hypertension, shunt failure and low pressure-induced headaches are frequently seen. The difficulty of introducing a catheter into ventricles of normal or small size has led most surgeons to favor LP over VP shunts in these patients. Stereotaxis, however, may be used to overcome this limitation of traditional VP shunt placement.
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