Management of patients with a neurovascular conflict involving the optic nerve and a non-diseased intracranial artery: Three cases.

Introduction: Determining whether a neurovascular conflict (NVC) involving the anterior visual pathway (AVP) and a non-diseased intracranial artery is amenable for microvascular decompression is challenging. Moreover, it is unclear whether microvascular decompression of the optic nerve is an effective therapy. Research question: What are the outcomes of different treatment strategies for NVCs involving the AVP and a non-diseased intracranial artery? Material and methods: Data on patients with symptomatic NVCs involving the AVP and a non-diseased intracranial artery was collected and included treatment and outcome parameters. The case series was drafted in accordance with the CARE guidelines. Results: Three patients aged 53,53 and 55 visited our out-patient clinic with a suspected symptomatic NVC between the optic nerve and a non-diseased intracranial artery. A conservative treatment was opted for in the first patient aimed at treating her glaucoma, with temporary improvement of symptoms. Microvascular decompression of the optic nerve was performed in two patients. One operated patient developed post-operative complications resulting in posterior circulation perfusion decline, while the other experienced a worse tunnel vision with a decrease in visual acuity. Discussion and conclusion: The diagnosis of a symptomatic NVC between the AVP and a non-diseased intracranial artery should be considered with caution, i.e. after exclusion of all other causes. Microvascular decompression can be performed but does not necessarily improve symptoms. A better understanding of the pathophysiological mechanisms underlying these NVCs is warranted to determine the benefit of microvascular decompression of the optic nerve.

Coexistence of cerebral aneurysm and meningioma--pure accident?

OBJECTIVES: Coexisting intracerebral aneurysms and meningiomas occur relatively rarely, without a clear relationship, although an aneurysm can be located within a meningioma. The aim of this retrospective study was to identify possible explanations for the coexistence of these conditions and to present a rationale for treatment strategies. PATIENTS AND METHODS: Ninety-five patients with coexistent meningioma and aneurysm were found in the National Library of Medicine, and 11 more patients were retrieved from our own database. RESULTS: Co-occurrence of both pathologies, sometimes solitary, sometimes multiple, was mostly found in women (3:1). Clinical symptoms in the majority of patients were caused by tumour growth, whereas aneurysm rupture was seen only in a few cases. Consequently tumour resection was performed first in 58 out of the 95 patients, and aneurysm treatment in 38 patients. From available data, the mortality rate three decades before was approximately 40%, but decreased in the last years, due to microsurgical and endovascular techniques. All of our patients were alive after 1 year of follow-up. In patients with intratumoural aneurysms, only three published and one our own case, were treated for both pathologies. CONCLUSIONS: The coexistence of meningioma and aneurysm seems to be a coincidence. Treatment should primary focus on the cause of presenting symptoms, but in cases with intratumoural aneurysm, the aneurysm should be treated first. Due to the development of microsurgical and endovascular techniques peri-procedural mortality and morbidity has decreased.

Influence of the organophosphorus compound DFP on inhibitory motor systems and esterase activity in the spinal cord of cats.

In high spinal cats, the acute time-dependent changes of both the activity of spinal reflex pathways and the activity of three different esterases (acetylcholinesterase, carboxylesterase and neurotoxicant target enzyme) in the spinal cord were investigated after intravenous application of the organophosphorus compound di-isopropyl phosphofluoridate (DFP). There is no general depression of spinal reflexes by DFP. While the recurrent inhibition is completely abolished for a long time and the reflexes to a flexor (PBSt) are depressed but with a shorter recovery time, the reflexes to an extensor (GS) are distinctly less depressed or even facilitated. Reflex pathways from skin afferents to motoneurones did not react in a uniform way to DFP, e.g. inhibitory nociceptive pathways were less affected than excitatory ones. Esterase activities were heavily depressed and recovered with different time courses. The acute DFP action cannot be explained by a uniform intoxication of all spinal functions but probably emerges from a differential action on different interneuronal systems.