Chiari malformation and spinal interdural cyst: A proposed association and review of the literature

Background: Interdural cysts are rare meningeal cysts with an unclear etiology. They are often mistaken for other mass lesions, including arachnoid cysts and tumors. Correctly identifying and classifying these cysts, as well as how they have formed in individual patients, are crucial to providing effective treatment options for patients. Case Description: We report a case of a patient with shunted idiopathic intracranial hypertension who developed a symptomatic Chiari malformation and was subsequently discovered to have a spinal interdural cyst. The Chiari malformation was likely due to intracranial hypotension secondary to lumbar cerebrospinal fluid (CSF) diversion. Once the shunt was removed, a spinal interdural cyst became clinically and radiographically evident, and the Chiari resolved, suggesting that both entities were effects of shared CSF flow dynamics. Conclusion: This cyst likely originated due to the trauma from remote repeated lumbar punctures and lumboperitoneal shunt placement, allowing CSF to enter the interdural space after the catheter was removed.

Abnormal Intracranial Pulse Pressure Amplitude Despite Normalized Static Intracranial Pressure in Idiopathic Intracranial Hypertension Refractory to Conservative Medical Therapy

Idiopathic intracranial hypertension (IIH) incorporates symptoms and signs of increased intracranial pressure (ICP) and is diagnosed by increased lumbar cerebrospinal fluid pressure. However, our knowledge about the characteristics of ICP abnormality, e.g., changes in pulsatile versus static ICP, remains scarce. This study questioned how overnight pulsatile ICP (mean ICP wave amplitude, MWA) associates with static ICP (mean ICP) in IIH patients who were refractory to conservative medical treatment. The material included 80 consecutive IIH patients undergoing ICP monitoring prior to shunt, as part of work-up for failed conservative medical therapy. In this group, the overnight mean ICP was normalized in 52/80 patients, but with abnormal overnight MWA in 45 of the 52 patients. Even though there was a positive correlation between MWA and mean ICP at group level and within individual ICP recordings, the levels of MWA were abnormal in a high proportion of patients despite normalized mean ICP. Taken together, the present results disclosed lasting abnormal pulsatile ICP despite normalized static ICP in IIH patients refractory to conservative medical therapy, which may reflect the underlying pathophysiology. It is tentatively suggested that abnormal pulsatile ICP in IIH may reflect alterations at the glia–neurovascular interface, resulting in impaired astrocytic pulsation absorber mechanisms.

Combined Endovascular and Microsurgical Management of a Tentorial Arteriovenous Malformation in a Hybrid Neurovascular Operating Room: 2-Dimensional Operative Video

Tentorial margin arteriovenous malformations (AVMs) at the cerebello-mesencephalic fissure are deep lesions, which can be safely resected via a lateral supracerebellar infratentorial approach. This video illustrates the case of a patient who presented with hemorrhage from a tentorial AVM. He was managed in the hybrid neurovascular operating room with Onyx (Medtronic) embolization of a superior cerebellar artery feeder followed by resection of the AVM, which included cerebellar relaxation from lumbar cerebrospinal fluid (CSF) drainage and lateral positioning. Wide cisternal arachnoid dissection at the quadrigeminal cistern allowed for a straight trajectory to the AVM without fixed retraction. Intraoperative transradial angiography confirmed complete AVM exclusion. This video was deemed Institutional Review Board (IRB) exempt by the University of Pennsylvania IRB as it is considered a case report, which does not require IRB approval or patient consent. The patient consented to the procedure.

Reference values for intracranial pressure and lumbar cerebrospinal fluid pressure: a systematic review

Background Although widely used in the evaluation of the diseased, normal intracranial pressure and lumbar cerebrospinal fluid pressure remain sparsely documented. Intracranial pressure is different from lumbar cerebrospinal fluid pressure. In addition, intracranial pressure differs considerably according to the body position of the patient. Despite this, the current reference values do not distinguish between intracranial and lumbar cerebrospinal fluid pressures, and body position-dependent reference values do not exist. In this study, we aim to establish these reference values. Method A systematic search was conducted in MEDLINE, EMBASE, CENTRAL, and Web of Sciences. Methodological quality was assessed using an amended version of the Joanna Briggs Quality Appraisal Checklist. Intracranial pressure and lumbar cerebrospinal fluid pressure were independently evaluated and subdivided into body positions. Quantitative data were presented with mean ± SD, and 90% reference intervals. Results Thirty-six studies were included. Nine studies reported values for intracranial pressure, while 27 reported values for the lumbar cerebrospinal fluid pressure. Reference values for intracranial pressure were − 5.9 to 8.3 mmHg in the upright position and 0.9 to 16.3 mmHg in the supine position. Reference values for lumbar cerebrospinal fluid pressure were 7.2 to 16.8 mmHg and 5.7 to 15.5 mmHg in the lateral recumbent position and supine position, respectively. Conclusions This systematic review is the first to provide position-dependent reference values for intracranial pressure and lumbar cerebrospinal fluid pressure. Clinically applicable reference values for normal lumbar cerebrospinal fluid pressure were established, and are in accordance with previously used reference values. For intracranial pressure, this study strongly emphasizes the scarcity of normal pressure measures, and highlights the need for further research on the matter.

Reference Values For Intracranial Pressure And Lumbar Cerebrospinal Fluid Pressure: A Systematic Review

BackgroundAlthough widely used in the evaluation of the diseased, normal intracranial pressure and lumbar cerebrospinal fluid pressure remains sparsely documented. Intracranial pressure is different from lumbar cerebrospinal fluid pressure. In addition, intracranial pressure differs considerably according to body position of the patient. Despite this, the current reference interval are used indistinguishable for intracranial and lumbar cerebrospinal fluid pressure, and body position dependent reference intervals does not exist. In this study, we aim to establish these reference intervals.MethodA systematic search was conducted in MEDLINE, EMBASE, CENTRAL, and Web of Sciences. Methodological quality was assessed using an amended version of the Joanna Briggs Quality Appraisal Checklist. Intracranial pressure and lumbar cerebrospinal fluid pressure were independently evaluated and subdivided into body positions. Quantitative data were presented with mean ± SD, and 90% reference intervals.ResultsThirty-six studies were included. Nine studies reported values for intracranial pressure, while 27 reported values for the lumbar cerebrospinal fluid pressure. Reference values for intracranial pressure were -5.9 to 8.3 mmHg in the upright position and 0.9 to 16.3 mmHg in supine position. Reference values for lumbar cerebrospinal fluid pressure were 7.2 to 16.8 mmHg and 5.7 to 15.5 mmHg in the lateral recumbent position and supine position, respectively. ConclusionsThis systematic review is the first to provide position-dependent reference values for intracranial pressure and lumbar cerebrospinal fluid pressure. Clinically applicable reference values for normal lumbar cerebrospinal fluid pressure was established, and were in accordance with previously used reference values. For intracranial pressure, this study strongly emphasizes the scarse normal material, and highlights the need for further research on the matter.

Paraneoplastic ganglioradiculoneuritis in a cat with a plasma cell tumour

Case summary An 8-year-old neutered female domestic longhair cat was presented for investigation of a 48 h history of lethargy and pelvic limb ataxia. MRI of the spinal cord and vertebral column (C1 to sacrum) and brain was unremarkable. Lumbar cerebrospinal fluid analysis revealed pleocytosis and increased protein concentration. Thoracic radiographs and abdominal ultrasound were unremarkable. Anti-inflammatory doses of prednisolone were administered. Clinical deterioration occurred over the following 2 days, with the development of lower motor neuron deficits in both thoracic limbs. On repetition of the MRI, bilateral enlargement, T2-weighted hyperintensity, and marked contrast enhancement of the C7, C8 and T1 nerve roots, spinal nerves and brachial plexuses were observed. Infectious disease testing was negative. An immune-mediated inflammatory process was suspected and immunosuppressive doses of prednisolone were commenced. The clinical signs improved transiently, but marked deterioration occurred after 2 weeks. The patient was euthanased and a post-mortem examination was performed. A lymphocytic inflammatory infiltrate was detected in the C7, C8 and T1 nerve roots and dorsal root ganglia, and neoplastic plasma cells were identified in multiple organs. A diagnosis of non-cutaneous extramedullary plasmacytoma with multiorgan involvement and paraneoplastic ganglioradiculoneuritis was reached. Relevance and novel information Paraneoplastic ganglioradiculoneuritis in association with a plasma cell neoplasia has not been previously reported in the cat and should be considered as a differential diagnosis for cats with clinical or imaging evidence of an inflammatory process affecting the nerve roots, spinal nerves or brachial plexuses.