Rare Complications of CSF Diversion: Paradoxical Neuroimaging Findings in a Double, Chiasmic Case Report.

Two patients with CSF shunting systems exhibited symptoms of altered intracranial pressure. Initial neuroimaging led to misinterpretation, but integrating clinical history and follow-up imaging revealed the true diagnosis. In the first case, reduced ventricular size was mistaken for CSF overdrainage, while the actual problem was increased intracranial pressure, as seen in slit ventricle syndrome. In the second case, symptoms attributed to intracranial hypertension were due to CSF overdrainage causing tonsillar displacement and hydrocephalus. Adjusting the spinoperitoneal shunt pressure resolved symptoms and imaging abnormalities. These cases highlight the necessity of correlating clinical presentation with a deep understanding of CSF dynamics in shunt assessments.

Relationships of the vidian nerve and internal carotid artery: MRI and intraoperative surgical evaluation.

Objective: Skull base anatomy around the internal carotid artery (ICA) is extremely complex. Among anatomical landmarks studied, the vidian canal has been thoroughly evaluated, unlike the vidian nerve (VN). Our aim is to evaluate the VN-ICA relationships, and understand their role in terms of surgical planning. Methods: Fifty MRI examinations of 100 healthy petro-spheno-clival regions were reviewed in order to evaluate the relationship between the vidian nerve axis (VNA) and the petrous ICA. Twenty-seven cases of expanded endonasal approaches to petrous apex region were evaluated to check the VN-ICA relationship intraoperatively. Results: MRI evaluations showed that, in 23% of cases, the VNA was below the edge of the ICA, in 45% it was at the edge of the ICA and in 32% it ended up above the edge of the ICA. Surgically speaking, in 9 of 28 petrous apex approaches, the VN ended above the inferior edge of the petrous carotid. Conclusions: MRI evaluation adds useful information in planning the surgical approach to petro-spheno-clival regions, even if the identification of VNA, in these cases, may not be radiologically possible. Surgical experience confirms the importance of VN identification in guiding the surgeon in complex cases, and also outline the possible risks of relying only on this landmark.

3-T magnetic resonance angiography in primary angiitis of the central nervous system.

OBJECTIVE: Primary angiitis of the central nervous system (PACNS) is a rare disease characterized by an inflammatory process of intracranial vessels. Magnetic resonance angiography (MRA) (3 T) offers increased signal-to-noise ratio and background suppression, leading to better depiction of the intracranial vessels. The aim of our work was to compare the sensitivity of 3-T MRA to that of 1.5-T MRA in the diagnosis of PACNS. METHODS: Eight patients with PACNS and signs of angiitis at digital subtraction angiography (DSA) underwent MRA at 1.5 and 3 T. Magnetic resonance angiograms obtained with time-of-flight (TOF) technique were evaluated for the presence of stenosis with respect to DSA. RESULTS: In PACNS patients, DSA identified 827 intracranial stenoses. Sensitivity for vessel stenosis of 3-T TOF MRA was 47% and 14% for 1.5-T TOF. CONCLUSIONS: Time-of-flight MRA at 3 T improved the sensitivity of MRA in the noninvasive preliminary evaluation of patients with PACNS.

Abducens nerve palsy in a congenital anomalous neurovascular development of the sixth cranial nerve and anterior inferior cerebellar artery: A case report.

Abducens nerve palsy is a common ocular motor paralysis with a broad set of etiopathogenetic causes. Magnetic resonance imaging is a key diagnostic technique to investigate organic causes of sixth nerve palsy, as it allows a detailed representation of the course of the nerve, particularly in its intracisternal tract. Anatomical variants of the sixth cranial nerve comprise duplications and fenestrations in various traits. Anatomical variants of cerebellar arteries have also been described. We report the case of a patient with abducens nerve palsy presumably related to a neurovascular conflict due to a peculiar anatomical variant, which consists in a cerebellar artery passing through the intracisternal duplication of the abducens nerve.

Autoimmune limbic encephalitis related to SARS-CoV-2 infection: Case-report and review of the literature.

BACKGROUND: SARS-CoV-2 infection is associated with a wide spectrum of neurological complications, including encephalitis. Most cases showed features consistent with a central nervous system (CNS) cytokine-mediated damage. However, few cases arguing for an autoimmune mechanism have been described, mainly as single reports or sparse in large case series involving other CNS manifestations. In this paper, we described a case of definite autoimmune limbic encephalitis (LE) COVID-19 related and reviewed the existing literature on other reported cases. CASE REPORT: Two weeks after the onset of COVID-19 infection, a 74-year-old woman presented with subacute confusion and focal motor seizures with impaired awareness, starting from left temporal region. Cerebrospinal fluid analysis revealed hyperproteinorrachia. Brain MRI showed bilateral T2/FLAIR hyperintensities in both hippocampi and total body PET/TC scan revealed hypermetabolism in basal ganglia bilaterally. A diagnosis of autoimmune LE was made. Thus, high dose corticosteroids and antiseizure medications were started, with a marked improvement of neurological conditions. LITERATURE REVIEW: We systematically reviewed the literature to identify all well-documented cases of definite autoimmune LE (according to Graus criteria) in patients with COVID-19 infection, identifying other five cases exhibiting a good response to immunomodulating therapy. CONCLUSION: A very limited number of autoimmune LE have been described until now. It is important to monitor neurological symptoms in COVID-19 patients and to consider the possibility of an autoimmune LE, in particular when altered mental status and seizures appear late in the disease course. This allows to promptly start the appropriate treatments and avoid unnecessary delays.

Cerebellar mass as a location of acute lymphoblastic leukaemia.

A 22-year-old man with acute lymphoblastic leukaemia was referred to our observation for headache, cervical pain and sopor. A computed tomography study revealed triventricular obstructive hydrocephalus due to a left cerebellar hyperdense mass impinging on the fourth ventricle. A magnetic resonance study demonstrated an area of hyperintensity on T2-weighted images, hypointensity on T1, restricted diffusivity and contrast enhancement involving the left hemispherical cerebellar cortex and the vermis and causing cerebellar herniation. After surgical excision of the lesion, histological examination revealed an infiltrate of lymphoblastic leukaemia with B cells. Leukaemic intracranial masses are rare. Our report describes a case presenting a cerebellar mass of leukaemic tissue characterized by high cellularity and low apparent diffusion coefficient value comparable to acute ischaemia. Therefore leukaemic intracranial mass has to be considered in the differential diagnosis of cerebellar masses.