When does low mean high? Isolated cerebral ventricular increased intracranial pressure in a patient with a Chiari I malformation

Chiari 1 malformation with optic disc drusen

A 32 year old female patient with CM 1 diagnosis was referred for the management of papilledema. Ophthalmologic examination revealed normal visual acuity (20/20 in both eyes), normal optic nerve function tests and normal slit-lamp biomicroscopic findings. Fundoscopy revealed bilateral irregular optic nerve heads with blurred margins. B scan ultrasonography (USG) and Spectral domain optical coherence tomography were performed and bilateral optic nerve heads were diagnosed as ODD. We concluded that the pseudopapilledema must be taken into account before making papilledema diagnosis in patients with CM 1 to protect the patients from redundant interventional procedures.

Chiari Type 1 Malformation-induced Intracranial Hypertension with Diffuse Brain Edema Treated with Foramen Magnum Decompression: A Case Report

Chiari type 1 malformation (CM1) rarely causes papilloedema, which is indicative of high intracranial pressure with or without ventricular dilatation. Furthermore, concomitant brain parenchymal abnormalities have not been reported to date. In this paper, the authors report on a young woman of CM1-induced intracranial hypertension (ICH) with diffuse brain edema with a focus on venous sinus assessment, and discuss the surgical strategy. A 24-year-old woman presented to Nagoya University Hospital complaining of 4-year history of severe occipital headache and blurry vision with slowly progressive worsening. Head and whole spine MRI showed a CM1 with diffuse white matter hyperintensities (WMH) on T2-weighted imaging and narrowed brain sulci without hydrocephalus. Lumbar puncture revealed extremely high opening pressure. Detailed blood examination and other radiographical imaging studies denied the presence of tumor, collagen disease, encephalitis and other entities. Head magnetic resonance venography and angiography demonstrated severe transverse sinus stenosis on both sides. Foramen magnum decompression was performed to alleviate the ICH by restoration of cerebrospinal fluid (CSF) stagnation at the foramen magnum with successful outcome. The patient completely recovered from preoperative symptoms immediately after surgery. The diffuse WMH and narrowing brain sulci have been resolving. The most feasible explanation for this complicated pathophysiology was ICH induced by CM1 led to transverse sinus collapse, resulting in diffuse WMH as a result of venous hypertension. This case report is the first illustration of successful surgical treatment of CM1 with diffuse brain edema with a focus on venous sinus assessment.

Chiari type 1 malformation in a pseudotumour cerebri patient: is it an acquired or congenital Chiari malformation?

Chiari malformation type 1 (CM1) is a developmental abnormality of the cerebellar tonsils. Patients with CM1 commonly present with headache. Papilloedema is rarely seen in CM1. However, a 52-year-old woman presented to the hospital with a headache and her ophthalmological examination revealed bilateral papilloedema. Her cranial MRI was compatible with borderline CM1. Bilateral papilloedema and headache suggested idiopathic intracranial hypertension (IIH) as the preliminary diagnosis. IIH is a rare case in CM1. This article argues about this association and discusses as to whether it is an acquired or congenital Chiari malformation.

Papilloedema due to Chiari I malformation

The Chiari I malformation is a congenital abnormality characterised by downward displacement of the cerebellar tonsils through the foramen magnum into the cervical spine. It presents clinically most often in young adult women. Known ocular manifestations linked to Chiari I consist primarily of oculomotor paresis with cranial nerve VI palsy and convergence/divergence abnormalities. Papilloedema is a rare manifestation of Chiari I with a clinical presentation often similar to that of idiopathic intracranial hypertension. To highlight this unusual complication, the authors report a 64-year-old female who developed papilloedema as the only presenting neurological symptom resulting from a Chiari I malformation.

Monitoring papilledema in a patient with pineal pilocytic astrocytoma by using Heidelberg Retina Tomograph II. Case report

The Heidelberg Retina Tomograph (HRT) II is a confocal scanning laser device used to acquire images of the optic nerve head. In this paper the authors report a novel use of this device in the assessment of papilledema in a patient with pilocytic astrocytoma of the pineal region. They also present a new technique to objectively produce 3D data of the optic nerve head. An 11-year-old girl presented with headache and bilateral papilledema; magnetic resonance imaging revealed a lesion in the pineal region. A suboccipital craniectomy was performed, and HRT images were obtained both before (baseline) and after (follow-up) the operation. The authors analyzed the height variation of the retinal surface along the vertical and horizontal cross-lines passing the center of the optic nerve head. The postoperative images, studied on the 2nd day after operation, demonstrated visible reduction of the papilledema. The height variation of the retinal surface along the contour line created by the software demonstrated that elevation of the optic nerve head became depressed due to resolved swelling. The height variation of the retinal surface along vertical and horizontal cross-lines demonstrated significant differences between the elevated preoperative curve and the postoperative curve (p < 0.001), consistent with improvement of her symptoms. Initial data suggest that changes in the optic nerve head topography after surgical decompression can be quantitatively documented by 3D data from the HRT II.

Acute deterioration in occult Chiari malformation following missile spinal trauma

✓Patients with Chiari malformation (CM) Type I typically experience chronic, slowly progressive symptoms. Rarely, however, do they suffer acute neurological deterioration following an iatrogenic decrease in caudal cerebrospinal fluid pressure due to, for example, a lumbar puncture. To our knowledge, acute neurological deterioration following missile spinal injury in CM has not been previously described.

The authors report on a 16-year-old girl who was shot in the abdomen and lumbar spine. Although neurologically intact on initial workup, she developed precipitous quadriplegia and apnea in a delayed fashion. Tonsillar herniation with medullary compression and cerebellar infarction was diagnosed on magnetic resonance imaging. Suboccipital decompression resulted in significant neurological improvement. Well-formed tonsillar ectopia diagnosed at surgery suggested a preexisting CM.

The authors conclude that missile spinal trauma can precipitate medullary compression and acute neurological decline, especially in patients with preexisting tonsillar ectopia. Immediate operative decompression to relieve impaction at the cervicomedullary junction can result in significant neurological recovery.

Chiari I malformation and intra-cranial hypertension:a case-based review

OBJECTIVE

To present clinical and morphological findings before and after surgery in a child with Chairi I malformation (CMI) and intra-cranial hypertension (IH). The literature is reviewed and pathophysiologic factors are discussed.

CLINICAL PRESENTATION

A 13-year-old obese boy with a 3-week history of headaches, neck pain, torticollis and progressive visual deterioration was admitted. Bi-lateral chronic papilloedema and decrease in visual acuity were found in the presence of a previously diagnosed CMI. INTERVENTION AND FOLLOW-UP: Intra-cranial pressure monitoring demonstrating increased pressure levels was followed by a sub-occipital decompression, C1 laminectomy and duroplasty. Post-operatively, the boy improved markedly, the 6 months follow-up opthalmological examination demonstrated resolution of papilloedema, but consecutive bi-lateral optic nerve atrophy.

CONCLUSION

IH with progressive visual deterioration represents one of the varying clinical presentations of CMI and may be classified as a secondary form of idiopathic IH. Neuro-ophthalmological examination in all patients with CMI is recommended to identify the real incidence of this presentation. Altered CSF dynamics, venous hypertension and obesity as co-factors may be causative pathophysiologic factors.

Prevalence of Chiari I malformation and cerebellar ectopia in patients with pseudotumor cerebri

BACKGROUND

Chiari I malformation (CM) may be present pre-surgically in pseudotumor cerebri (PTC) patients. Whether inferior tonsillar displacement (ITD) is coincidental or linked to increased intracranial pressure is unclear. This study aimed to identify the prevalence of both CM and cerebellar ectopia (CE) (ITD below the foramen magnum > or = 5 mm and 2-4 mm, respectively) in PTC patients.

METHODS

Retrospective review combined with prospective assessment of 68 PTC patients with available brain magnetic resonance imaging (MRI) scans and reports. Data collected included patient demographics, height, weight, co-morbid conditions, and medications. MRIs were analyzed for cerebellar tonsillar position, and results were compared with original reports.

RESULTS

Of 68 PTC patients, 60 (88%) had normal position of the cerebellar tonsils and 8 (12%) had ITD by report. Of the latter group, 4 were identified as CM and 4 as CE. On review of MRIs, however, 16 patients (24%) had ITD, 7 having CM and 9 having CE. All patients with ITD were female, most were overweight or obese, and most had presumed idiopathic intracranial hypertension (IIH).

CONCLUSION

ITD exists pre-surgically in a significant percentage of PTC patients. ITD is most common in obese or overweight women with presumed IIH. In fact, this subset of patients may actually represent a secondary form of PTC and may benefit from correction of ITD to restore normal intracranial pressure.

Revision surgery for chiari malformation decompression

Chiari malformations comprise four different hindbrain anomalies originally described by Hans Chiari, a professor of pathology at the German University in Prague. There are four basic Chiari malformations. The reasons for revision of Chiari malformation decompression may be for conservative or inadequate initial decompression or the development of postoperative complications. Another reason involves cases of both hindbrain herniation and syringomyelia in patients who have undergone adequate posterior fossa decompression without resolution of symptoms, signs, or radiological appearance of their syrinx cavity. Additionally, symptom recurrence has been reported in association with various types of dural grafts. Reoperation or revision surgery for patients with Chiari malformations is common and may not be due to technical error or inadequate decompression. The types of revision surgeries, their indications, and initial presentations will be reviewed.