Neuro-Ophthalmological Features of Primary Diffuse Leptomeningeal Gliomatosis

Papilledema: A Review of the Pathophysiology, Imaging Findings, and Mimics

Increased intracranial pressure is the most common cause of papilledema. Multiple etiologies such as cerebral edema, hydrocephalus, space occupying lesions, infection, and idiopathic intracranial hypertension among others should be considered. Imaging plays a critical role in the detection of pathologies that can cause papilledema. MRI with contrast and CE-MRV, in particular, are key for the diagnosis of idiopathic intracranial hypertension. This review will focus in common and infrequent causes of papilledema, the role of imaging in patients with papilledema as well as its potential mimickers.

[Primary leptomeningeal gliomatosis treated with temozolomide: a case report]

A 35-year-old man was admitted to our department for loss of consciousness. CT and MRI revealed diffuse enhancement of the subarachnoid space surrounding the brainstem and the cerebellar sulci, without any parenchymal lesions in the brain or the spinal cord. Furthermore, gadolinium-enhanced MRI revealed a nodular lesion with heterogeneous enhancement in the right prepontine cistern, at the site from which a biopsy was obtained via right lateral suboccipital craniotomy on the day following admission. Histopathological examination of the resected specimen revealed glioblastoma multiforme. Based on the radiological and histopathological findings, the patient was diagnosed with primary leptomeningeal gliomatosis (PLG). The patient received temozolomide chemotherapy with concurrent radiotherapy and showed radiological remission, 12 months after diagnosis. However, he developed local recurrence 6 months later and died 23 months after diagnosis. Autopsy findings showed tumor cell infiltration of the leptomeninges, as well as the brain and spinal parenchyma. PLG should be considered in the differential diagnosis in patients with diffuse leptomeningeal enhancement even without parenchymal lesions on radiological imaging. A surgical biopsy is recommended for prompt and accurate diagnosis in such cases.

Primary diffuse leptomeningeal gliomatosis mimicking tuberculous meningitis

Primary diffuse leptomeningeal gliomatosis is a disease with an aggressive course that can result in death. To date, 82 cases have been reported. Here, the case of a 3-year-old male patient presenting with strabismus, headache, and restlessness is reported. Physical examination revealed paralysis of the left abducens nerve, neck stiffness, and bilateral papilledema. Tuberculous meningitis was tentatively diagnosed, and antituberculosis treatment was initiated when cranial imaging revealed contrast enhancement around the basal cistern. Craniocervical magnetic resonance imaging (MRI) was performed when there was no response to treatment, and it revealed diffuse leptomeningeal contrast enhancement around the basilar cistern, in the supratentorial and infratentorial compartments, and in the spinal region. Primary diffuse leptomeningeal gliomatosis was diagnosed by a meningeal biopsy.

Primary diffuse leptomeningeal gliomatosis in children: a clinical pathologic correlation

PURPOSE

To describe a rare case of primary diffuse leptomeningeal gliomatosis (PDLG) presenting with progressive proptosis and direct involvement of the optic nerve sheath in a child and review of the relevant literature.

METHODS

Retrospective review of a single case and systematic literature review of 26 biopsy-proven cases reported in the MEDLINE-indexed English literature. A 10-year-old girl developed proptosis and progressive visual loss associated with thickening of the optic nerve sheaths and dilation of the subarachnoid spaces with multilobulated appearance of the brain meninges and thickened peripheral nerve root sheaths. Biopsy of the optic nerve sheath was diagnostic. The patient underwent chemotherapy combined with oral temozolomide and conformational radiotherapy to the brain and spine. She died 3 years after the onset of the disease. An extensive review of the published literature using the key words "primary diffuse leptomeningeal gliomatosis" and "optic nerve" confirmed the case herein reported to be the first case of primary diffuse leptomeningeal gliomatosis in which direct optic nerve infiltration was demonstrated during the course of the disease.

RESULTS

Immunohistochemistry demonstrated expression of CD56 and glial fibrillary acidic protein, and an elevated level of Ki-67; all the other markers were negative.

CONCLUSIONS

According to a comprehensive literature review, we report the first case of PDLG that presented with bilateral proptosis and direct involvement of the optic nerve during the course of the disease. These new findings may explain an alternative mechanism of visual loss and proptosis in PDLG. We emphasize the importance of close collaboration between neurologists and ophthalmologists in all cases of visual symptoms associated with a neurologic condition. In case of optic nerve involvement, ophthalmologists could provide an easier route to achieve tissue specimen early in the course of this rare and fatal disease.

Malignant meningitis presenting as pseudotumor cerebri

Malignant leptomeningitis can present as the clinical syndrome of pseudotumor cerebri due to infiltration of arachnoid villi in the superior sagittal sinus. We show that malignant pachymeningitis can also present with pseudotumor cerebri, likely due to cerebral venous hypertension from transverse sinus compression. We present 3 cases of pseudotumor cerebri due to pachymeningeal or leptomeningeal metastases and discuss the mechanism of intracranial hypertension in such cases, its diagnosis and treatment.