Transverse sinus stenting for pseudotumor cerebri: a cost comparison with CSF shunting.

BACKGROUND AND PURPOSE: Transverse sinus venous stent placement has been shown to lower intracranial pressure in patients with venogenic pseudotumor cerebri and to reverse, or at least stabilize, its symptoms and signs. There have been no studies comparing the cost of venous stenting with the time-honored treatment for pseudotumor cerebri-CSF shunting. The purpose of this study was to compare the cost of trasverse sinus stenting versus CSF shunting for the treatment of pseudotumor cerebri. MATERIALS AND METHODS: This work was a retrospective cost analysis of individual resource use in 86 adults who were stented for pseudotumor cerebri during a 12-year period compared with resource use in 110 children who were shunted for hydrocephalus during a 3-year period. RESULTS: There was no significant difference between the cost of inserting an initial venous stent ($13,863 ± 4890) versus inserting an initial CSF shunt ($15,797 ± 5442) (P = .6337) or between inserting an additional venous stent ($9421 ± 69) versus revising a CSF shunt ($10,470 ± 1245) (P = .4996). There were far fewer additional venous stent insertions per patient than there were subsequent CSF shunt revisions; 87% of stents placed required just 1 stent procedure, whereas only 45% of shunts required 1 shunt procedure. The main cause of the cost difference was the need for repeated revisions of the shunts, especially when they became infected-24 instances of a total 143 shunt procedures (16.8%) at an average cost of $84,729, approximately 5 times the cost of an initial shunt insertion. CONCLUSIONS: Venous stenting costs significantly less per 100 procedures than does CSF shunting, due largely to the high cost of treating shunt infections and the need for repeated shunt revisions.

Transverse sinus stenting for idiopathic intracranial hypertension: a review of 52 patients and of model predictions.

BACKGROUND AND PURPOSE: Transverse sinus stenosis is common in patients with IIH. While the role of transverse sinus stenosis in IIH pathogenesis remains controversial, modeling studies suggest that stent placement within a transverse sinus stenosis with a significant pressure gradient should decrease cerebral venous pressure, improve CSF resorption in the venous system, and thereby reduce intracranial (CSF) pressure, improving the symptoms of IIH and reducing papilledema. We aimed to determine if IIH could be reliably treated by stent placement in transverse sinus stenosis. MATERIALS AND METHODS: We reviewed the clinical, venographic, and intracranial pressure data before and after stent placement in transverse sinus stenosis in 52 of our own patients with IIH unresponsive to maximum acceptable medical treatment, treated since 2001 and followed between 2 months and 9 years. RESULTS: Before stent placement, the mean superior sagittal sinus pressure was 34 mm Hg (462 mm H(2)0) with a mean transverse sinus stenosis gradient of 20 mm Hg. The mean lumbar CSF pressure before stent placement was 322 mm H(2)O. In all 52 patients, stent placement immediately eliminated the TSS pressure gradient, rapidly improved IIH symptoms, and abolished papilledema. In 6 patients, symptom relapse (headache) was associated with increased venous pressure and recurrent stenosis adjacent to the previous stent. In these cases, placement of another stent again removed the transverse sinus stenosis pressure gradient and improved symptoms. Of the 52 patients, 49 have been cured of all IIH symptoms. CONCLUSIONS: These findings indicate a role for transverse sinus stent placement in the management of selected patients with IIH.

Caudate structural abnormalities in idiopathic normal pressure hydrocephalus.

BACKGROUND - Idiopathic normal pressure hydrocephalus (iNPH) is a reversible dementia in which fronto-striatal cognitive deficits and apathy may be present. OBJECTIVES - The study investigated structural volumetric changes in iNPH, apart from ventriculomegaly. MATERIALS AND METHODS - A full-brain voxel-based morphometric analysis between 11 iNPH patients and 14 healthy controls identified regions of interest (ROIs) for manual volumetric analyses. RESULTS - Caudate and corpus callosum ROI measurements revealed diminished caudate nuclei volume in the iNPH group. CONCLUSIONS - The role of the caudate nucleus in cognitive and affective changes in iNPH should now be explored.

Diffusion tensor imaging of benign intracranial hypertension: absence of cerebral oedema.

Cerebral oedema, it has been suggested, may have a role in the pathophysiology of benign intracranial hypertension (BIH). We applied diffusion tensor MR imaging (DTI), a technique able to detect cerebral oedema, to the study of patients with BIH. A quantitative regional analysis of diffusion parameters (trace and relative anisotropy) was conducted by comparing five BIH patients and six healthy controls. A small but significant increase in anisotropy accompanied by a small but significant decrease in trace was found in the putamen and head of the caudate nucleus. No significant changes were demonstrated in the thalamus, cerebral white matter or cortical regions. Our findings support other recent work that suggests cerebral oedema is not a factor in the pathogenesis of BIH.

Cranial venous outflow obstruction and pseudotumor Cerebri syndrome.

The pathophysiology of PTS including idiopathic intracranial hypertension or 'BIH', remains controversial. The older literature frequently referred to pathology in the cerebral venous drainage but more modern imaging techniques (CT and early MR) failed to reveal gross venous pathology. The role of impaired cranial venous outflow has recently been re-examined in the light of new methods of investigation (advanced MR venography and direct microcatheter venography with manometry) and of treatment (venous sinus stenting). Venous sinus obstruction in PTS is a more common factor in the pathogenesis of the condition than previously recognised. Venous obstruction may be primary, that is, it is the underlying aetiological factor in PTS. Venous sinus obstruction may also be secondary to raised CSF pressure which may exacerbate problems with intracranial compliance and raised CSF pressure. Early experience with venous stenting suggests that it may be a helpful treatment for patients with PTS but more experience and longer follow-up is required to define the subgroups of patients for whom it is most appropriate.

MR venography in idiopathic intracranial hypertension: unappreciated and misunderstood.

BACKGROUND: Venous sinus disease must be excluded before diagnosing idiopathic intracranial hypertension but is found only rarely in typical cases. Magnetic resonance venography (MRV) is the technique of choice for investigating this, and provides images that are diagnostic and easy to interpret. However, recent work using more invasive techniques has documented pressure gradients and stenoses in the lateral venous sinuses in many cases of idiopathic intracranial hypertension. OBJECTIVE: To examine the reason for this discrepancy and to establish whether there are characteristic appearances on MRV in idiopathic intracranial hypertension that are routinely overlooked in clinical practice. METHODS: MRVs from 20 patients with idiopathic intracranial hypertension were reviewed, unblinded, by two neuroradiologists, and their appearances rated for focal narrowings and signal gaps. A control group of 40 asymptomatic volunteers, matched for age and sex with the patient group, was recruited prospectively for MRV, and their scans rated in the same way. RESULTS: The lateral sinuses presented a range of appearances with quite different distributions in the two groups (p<0.001). Bilateral lateral sinus flow gaps were seen in 13 of 20 patients with idiopathic intracranial hypertension and in none of 40 controls. CONCLUSIONS: A historical failure to use normal healthy controls to establish the boundaries between imaging artefact, normal anatomical variant, and disease means that the pathological significance of the different appearances of the lateral sinuses on MRV has not so far been appreciated.

Syringomyelia with Chiari malformation; 3 unusual cases with implications for pathogenesis.

Syringomyelia is an important cause of neurological deficit. Most cases of non-traumatic syringomyelia occur in association with a Chiari malformation. We present three unusual examples of syringomyelia with such an association. The first case is that of syringomyelia in a young woman with Marfan's syndrome, a spontaneous CSF leak and intractable intracranial hypotension. The second is a woman with long-standing lumbo-peritoneal shunt for pseudotumour cerebri who developed an acquired Chiari malformation. A young woman with a Dandy-Walker cyst that herniated into the upper cervical canal is the third case. These cases provide a basis for discussion of the pathogenesis and management of syringomyelia and the Chiari malformation in such cases.

Idiopathic intracranial hypertension: 12 cases treated by venous sinus stenting.

BACKGROUND: The high pressures documented in the intracranial venous sinuses in idiopathic intracranial hypertension (IIH) could be the result of focal stenotic lesions in the lateral sinuses obstructing cranial venous outflow. OBJECTIVE: To explore the relation between venous sinus disease and IIH. METHODS: 12 patients with refractory IIH had dilatation and stenting of the venous sinuses after venography and manometry had shown intracranial venous hypertension proximal to stenoses in the lateral sinuses. Intrasinus pressures were recorded before and after the procedure and correlated with clinical outcome. RESULTS: Intrasinus pressures were variably reduced by stenting. Five patients were rendered asymptomatic, two were improved, and five were unchanged. CONCLUSIONS: The importance of venous sinus disease in the aetiology of IIH is probably underestimated. Lateral sinus stenting shows promise as an alternative treatment to neurosurgical intervention in intractable cases.

Pseudotumour cerebri, CSF rhinorrhoea and the role of venous sinus stenting in treatment.

We present a case of pseudotumour cerebri (PTC), which is important as it illustrates the effects of chronically raised CSF pressure, the relationship between PTC and venous sinus obstruction and the successful treatment of PTC using a venous sinus stent. A 38-year-old woman, previously diagnosed with PTC and unsuccessfully treated 10 years previously re-presented with spontaneous CSF rhinorrhoea. Imaging revealed dramatic changes of chronically raised CSF pressure and a defect in the anterior cranial fossa. The CSF leak was corrected surgically and a lumbo-peritoneal shunt inserted to correct a large postoperative subgaleal CSF collection. Direct retrograde cerebral venography (DRCV) demonstrated venous sinus obstruction due to a filling defect. This was associated with a pressure gradient and a high superior sagittal sinus pressure. The venous sinus obstruction was successfully treated with a venous sinus stent and the lumbo-peritoneal shunt was removed. Chronically raised CSF pressure in untreated cases of PTC may cause widespread changes in the skull, which in this case, culminated in a spontaneous CSF leak despite relatively mild headache and visual symptoms. Furthermore, cases of PTC secondary to venous sinus obstruction may be successfully treated using venous sinus stenting. The index of suspicion for venous sinus stenosis or obstruction should be raised in the investigation of patients with PTC.

Low pressure hydrocephalus: issues of diagnosis and treatment in five cases.

Five patients with hydrocephalus who failed to respond to apparently adequate CSF drainage via a functioning shunt (four cases) or external ventricular drain (one case) are described. In three of the four shunted cases, the shunt was ventriculoperitoneal with a medium pressure valve, and in one a combination of peritoneal and atrial shunts both with low pressure valves. All five patients were tested for possible low pressure hydrocephalus by a period of external ventricular drainage at heights of 0 to -5 cm H2O below the reference point (external auditory meatus--EAM). Four of the five patients showed rapid and significant clinical improvement and went on to shunt revision (three) or insertion (one). The shunts were then all peritoneal, of which three were valveless, whilst one had a Sophy programmable valve at the lowest setting. In all four patients the improvement was sustained and was associated with a radiological (CT or MRI) improvement which varied from marked to slight. In the fifth patient there was no improvement with low pressure external drainage and no shunt revision was undertaken. On the basis of these cases the possible entity of low pressure hydrocephalus is discussed with particular reference to mechanism, recognition and management.

Lateral recess cysts in two cases of isolated fourth ventricle.

We report two cases of isolated fourth ventricle with lateral recess cysts. The background, clinical features, treatment and outcomes are presented and discussed. We speculate on the association of these two conditions and propose possible explanations for the clinical features.

Normal pressure hydrocephalus and cerebral blood flow: a review.

Normal pressure hydrocephalus is a neurological disease which poses both diagnostic and therapeutic problems for the clinician. The measurement and characterisation of cerebral blood flow has been proposed as a tool for resolving such problems as well as elucidating its pathophysiology. We review the results of studies in which this tool has been applied to normal pressure hydrocephalus patients and consider the merits of the techniques that have been utilised. Finally, consideration is given to feasible future studies and the methods that could be employed in the study of cerebral blood flow and metabolism in patients with normal pressure hydrocephalus.

Common patterns of increased and decreased fos expression in midbrain and pons evoked by noxious deep somatic and noxious visceral manipulations in the rat.

Immunohistochemical detection of the protein product (Fos) of the c-fos immediate early gene was used to study neuronal activation in the rostral pons and midbrain of halothane-anesthetised rats following noxious deep somatic or noxious visceral stimulation. In animals exposed only to halothane anesthesia, Fos-like immunoreactive (IR) neurons were located in the midbrain periaqueductal gray matter, tectum, and parabrachial nucleus. Following noxious stimulation of hindlimb muscle, knee joint, vagal cardiopulmonary, or peritoneal nociceptors, there was, compared to halothane-only animals, a significant increase in the numbers of Fos-like (IR) cells in the caudal ventrolateral periaqueductal gray and the intermediate gray lamina of the superior colliculus. Given the general agreement that increased Fos expression is a consequence of increased neuronal activity, the finding that a range of noxious deep somatic and noxious visceral stimuli evoked increased neuronal activity in a discrete, caudal ventrolateral periaqueductal gray region is consistent with previous suggestions that this region is an integrator of deep noxious evoked reactions. The noxious deep somatic and noxious visceral manipulations also evoked, compared to halothane-only animals, reductions in the numbers of Fos-like IR cells in the stratum opticum of the superior colliculus and the unlaminated portion of the external subnucleus of the inferior colliculus. To our knowledge this is the first report of reductions in Fos-expression in the tectum evoked by noxious stimulation. In separate experiments, the effects of noxious deep somatic and noxious visceral manipulations on arterial pressure and heart rate were measured. The noxious visceral manipulations evoked substantial and sustained falls in arterial pressure (15-45 mmHg), and heart rate (75-100 bpm), whereas the depressor and bradycardiac effects of the noxious deep somatic manipulations were weaker, not as sustained, or entirely absent. As similar distributions and numbers of both increased and decreased Fos-like IR cells were observed after each of the deep noxious manipulations, it follows that the deep noxious evoked increases and decreases in Fos expression were not secondary to the evoked depressor or bradycardiac effects.