- Gamma Knife radiosurgery for the treatment of Nelson's syndrome: a multicenter, international study. [Journal Article]
- JNJ Neurosurg 2019 Jul 12; :1-6
- CONCLUSIONS: GKRS affords a high rate of pituitary adenoma control and improvement in ACTH level for the majority of Nelson's syndrome patients. Hypopituitarism is the most common adverse effect from GKRS in Nelson's syndrome patients and warrants longitudinal follow-up for detection and endocrine replacement.
- Repeat Resection of a Cavernous Malformation of the Optic Nerve/Chiasm via a Frontotemporal Approach: 2-Dimensional Operative Video. [Journal Article]
- ONOper Neurosurg (Hagerstown) 2019 Jul 11
- Cavernous malformations are benign vascular lesions that can arise throughout the central nervous system. The occurrence of a cavernous malformation within the optic nerve or chiasm, however, is extr…
Cavernous malformations are benign vascular lesions that can arise throughout the central nervous system. The occurrence of a cavernous malformation within the optic nerve or chiasm, however, is extremely uncommon. The case described in this video involved a 36-yr-old woman who presented 3 mo after undergoing a left frontotemporal craniotomy for resection of an optic nerve cavernous malformation. She had initially presented to an outside hospital with vision loss, and the left optic nerve lesion was identified and resected. Although her vision had reportedly improved slightly postoperatively, she awoke 3 mo later with bilateral subjective blurriness and new visual field deficits. Magnetic resonance imaging revealed enlargement of the left optic apparatus hemorrhagic lesion, corresponding to residual cavernous malformation. Given the recurrence of hemorrhage and the associated visual symptoms, the patient underwent a redo left frontotemporal craniotomy for resection of the optic nerve and chiasmal lesion. Histopathologic evaluation revealed thick-walled vessels with focal intervening glial tissue, an absence of neoplastic cells, and hemorrhage, consistent with a cavernous malformation. The patient tolerated the procedure well. Postoperatively, she experienced immediate amelioration in her visual symptoms. She was discharged home on postoperative day 3, and her bitemporal visual field deficit continued to progressively improve through her last ophthalmologic appointment 14 mo after surgery. Postoperative and subsequent surveillance neuroimaging demonstrated complete resection of the cavernous malformation without evidence of recurrence. This case demonstrates the techniques utilized to ensure complete resection of the malformation in this very eloquent region. The patient provided consent for publication.
- Biophysically motivated efficient estimation of the spatially isotropic R 2 * component from a single gradient-recalled echo measurement. [Journal Article]
- MRMagn Reson Med 2019 Jul 10
- CONCLUSIONS: Since the proposed second-order model features orientation-dependent and -independent components at distinct temporal orders, it can be used to remove the orientation dependence of R 2 * using only a single GRE measurement.
- [Interdisciplinary Management of Sellar Masses]. [Journal Article]
- PPraxis (Bern 1994) 2019; 108(9):599-608
- Interdisciplinary Management of Sellar Masses Abstract. Sellar masses may present with an impairment of pituitary function (hypopituitarism), hormone hypersecretion (prolactinoma, acromegaly, glucoco…
Interdisciplinary Management of Sellar Masses Abstract. Sellar masses may present with an impairment of pituitary function (hypopituitarism), hormone hypersecretion (prolactinoma, acromegaly, glucocorticoid excess) or neurological symptoms (visual impairment, headache). An increasing number of them is discovered as an incidentaloma. Among the various entities, benign pituitary adenomas and cystic lesions are most frequently encountered. The work-up includes a laboratory evaluation for hormone hyper- or hyposecretion and an MRI of the pituitary gland. If the optic chiasm is compromised, a visual field examination is mandatory. Except for prolactinomas, symptomatic sellar masses are usually resected via an endoscopic transsphenoidal approach. If a total resection is not feasible because of the invasion of surrounding structures, debulking to relieve pressure from the optic chiasm is the primary goal and radiotherapy may be considered. Residual hormone excess can be treated medically. In the early postoperative period special attention to the development and treatment of disordered body water homeostasis and hypopituitarism is crucial. Interdisciplinary work-up and decision making are of utmost importance and will offer the best management.
- Visually evoked potentials. [Journal Article]
- HCHandb Clin Neurol 2019; 160:501-522
- The term visually evoked potential (VEP) refers to electrical potentials recorded from scalp overlying visual cortex that have been extracted from the electroencephalogram by signal averaging. Usuall…
The term visually evoked potential (VEP) refers to electrical potentials recorded from scalp overlying visual cortex that have been extracted from the electroencephalogram by signal averaging. Usually the recording electrode is placed on the midline of the occipital scalp at the back of the head. VEPs are used to quantify the functional integrity of the optic nerves, pathways to the visual cortex of the brain, and occipital cortex. Any abnormality that affects the visual pathways or visual cortex in the brain can affect the VEP. Examples include slowing neuronal transmission, such as produced by myelin plaques common in multiple sclerosis, or gliomas on optic nerves in neurofibromatosis slowing the speed of the VEP wave peaks. Compression of the optic pathways, such as from hydrocephalus or from a pituitary tumor, affects the VEP. There are several methods of recording VEPs. In patients over about 3 years of age VEPs are usually recorded using a video monitor presenting patterned stimuli. In sedated patients and infants, flashes of light from a strobe flash or an array of LEDs are used to stimulate the eye. Multifocal VEPs expand the visual field topographic mapping to beyond 40 degrees of the central visual field.
- Wiring the Binocular Visual Pathways. [Review]
- IJInt J Mol Sci 2019 Jul 04; 20(13)
- Retinal ganglion cells (RGCs) extend axons out of the retina to transmit visual information to the brain. These connections are established during development through the navigation of RGC axons alon…
Retinal ganglion cells (RGCs) extend axons out of the retina to transmit visual information to the brain. These connections are established during development through the navigation of RGC axons along a relatively long, stereotypical pathway. RGC axons exit the eye at the optic disc and extend along the optic nerves to the ventral midline of the brain, where the two nerves meet to form the optic chiasm. In animals with binocular vision, the axons face a choice at the optic chiasm-to cross the midline and project to targets on the contralateral side of the brain, or avoid crossing the midline and project to ipsilateral brain targets. Ipsilaterally and contralaterally projecting RGCs originate in disparate regions of the retina that relate to the extent of binocular overlap in the visual field. In humans virtually all RGC axons originating in temporal retina project ipsilaterally, whereas in mice, ipsilaterally projecting RGCs are confined to the peripheral ventrotemporal retina. This review will discuss recent advances in our understanding of the mechanisms regulating specification of ipsilateral versus contralateral RGCs, and the differential guidance of their axons at the optic chiasm. Recent insights into the establishment of congruent topographic maps in both brain hemispheres also will be discussed.
- Modulating proteoglycan receptor PTPσ using intracellular sigma peptide improves remyelination and functional recovery in mice with demyelinated optic chiasm. [Journal Article]
- MCMol Cell Neurosci 2019 Jul 02; :103391
- Multiple sclerosis (MS) is an autoimmune disease characterized by myelin and axonal damage in the central nervous system (CNS). Glial scar which is a hallmark of MS contains repair inhibitory molecul…
Multiple sclerosis (MS) is an autoimmune disease characterized by myelin and axonal damage in the central nervous system (CNS). Glial scar which is a hallmark of MS contains repair inhibitory molecules including chondroitin sulfate proteoglycans (CSPGs). CSPGs inhibit repair of damaged area through various receptors including protein tyrosine phosphatase sigma (PTPσ). In the current study we use intracellular sigma peptide (ISP), an inhibitor of PTPσ signaling, in LPC-induced focal demyelination of mouse optic chiasm. ISP treatment resulted in decreased demyelination, reduced astrogliosis, and increased newly generated oligodendrocytes which subsequently led to enhanced remyelination. Analyzing of electrophysiological (as performed by visual evoked potential recording) and behavioral (performed by visual cliff test) outcomes showed that ISP-treatment improved the integrity of optic pathway as well as the visual acuity. When ISP was administrated only during the repair phase, histological, electrophysiological and behavioral studies showed its regenerative effect. Our results demonstrated the possibility of using ISP as a new strategy to inhibit PTPσ for myelin protection, myelin repair in demyelinated axons, and functional neural pathway conductivity restoration in patients suffering from MS.
- Multiple myeloma with multiple neurological presentations. [Journal Article]
- PNPract Neurol 2019 Jul 04
- Multiple myeloma is a haematological malignancy with clonal plasma cell proliferation and production of monoclonal immunoglobulins. Its neurological complications are relatively common, caused by bot…
Multiple myeloma is a haematological malignancy with clonal plasma cell proliferation and production of monoclonal immunoglobulins. Its neurological complications are relatively common, caused by both the disease and the treatment. Neurologists should therefore be familiar with its neurological manifestations and complications. We describe a 40-year-old woman who presented with lower cranial neuropathies mimicking variant Guillain-Barré syndrome, with normal brain and spinal cord imaging and cerebrospinal fluid (CSF) albuminocytological dissociation, and subsequently diagnosed with IgD myeloma. She relapsed repeatedly with differing neurological presentations: numb chin syndrome and twice with impaired vision, first from cerebral venous sinus thrombosis and later from leptomeningeal infiltration of the optic chiasm. We discuss the neurological complications of myeloma, emphasising the need to consider it in a wide variety of neurological presentations and repeatedly to reassess its associated neurological diagnoses. We also highlight the complexity of myeloma treatment.
- The Human Visual Pathway Communicates Directly With the Subarachnoid Space. [Journal Article]
- IOInvest Ophthalmol Vis Sci 2019 Jun 03; 60(7):2773-2780
- CONCLUSIONS: The results indicate direct communication between CSF of subarachnoid space and the extravascular space of the human visual pathway. Extravascular entry of the CSF tracer is a prerequisite for a glymphatic system, the present findings may suggest its presence. The existence of a glymphatic system in the human visual pathway could bring novel perspectives on the pathophysiology and treatment of ophthalmic diseases.
New Search Next
- Current treatment of optic nerve gliomas. [Journal Article]
- COCurr Opin Ophthalmol 2019 Jun 24
- CONCLUSIONS: Although standard chemotherapy remains the mainstay of ONG treatment, newer molecularly targeted therapies such as mitogen-activated protein kinase kinase inhibitors and bevacizumab represent a promising new treatment modality, and clinical studies are ongoing.