Acute Hydrocephalus Resulting from Neuromyelitis Optica: A Case Report and Review of the Literature

Neuromyelitis Optica Presenting as Non-Communicating Hydrocephalus: A Case Report

Neuromyelitis Optica (NMO) is a demyelinating disease predominantly involving optic nerves, spinal cord and peri-ventricular regions which are rich in Aquaporin-4 receptors. Aquaporin-4 (AQP4) antibodies are implicated in the pathogenesis of NMO. Association of hydrocephalus ( communicating and non communicating) with NMO is very rare. We report a case of 32 years old female patient who presented with 2 months history of progressive headache, visual obscurations and gait imbalance . Clinical examination revealed bilateral papilloedema with preserved visual acuity. She had truncal and gait ataxia. Rest of the examination of nervous system was normal. MRI brain showed non- communicating hydrocephalus and T2 and FLAIR hyperintensities in periventricular and periaqueductal regions. AQP4 antibodies were positive in serum and negative in cerebrospinal fluid(CSF). Ventriculo - peritoneal shunt was placed and she was treated with steroids and azathioprine. Her headache and visual symptoms improved. However, after 8 months she presented with acute optic neuritis of right eye which was treated with intravenous methylprednisolone and plasmapharaesis.

AQP4 autoantibodies in patients with idiopathic normal pressure hydrocephalus

Idiopathic normal pressure hydrocephalus (iNPH) is a common neurological disorder with unknown etiology. A selective depletion of aquaporin 4 (AQP4) has been shown in iNPH patients. We collected serum and cerebrospinal fluid (CSF) from 43 iNPH patients and 35 with other neurodegenerative conditions, and serum from 43 healthy subjects. All samples were tested for AQP4-IgG/IgA/IgM antibodies using a live cell-based assay. No patients or controls had serum/CSF AQP4-IgG/IgA. One/43 iNPH patient and 0/43 controls tested positive for serum AQP4-IgM. The AQP4-IgM-positive iNPH patient had no clinico-radiological distinctive features. AQP4 antibodies are unlikely to play a role in iNPH pathogenesis.

Acute communicating hydrocephalus caused by extravasation of digital subtraction angiography contrast medium: a case report and literature review

With the increasing use of endovascular technology in the treatment of various conditions, there has been an inevitable rise in cases with extravasation of contrast medium. We present a case in which extravasation of a large quantity of contrast medium resulted in acute communicating hydrocephalus. A 78-year-old woman came to the hospital because of abnormal right-sided limb movement, and was diagnosed with occlusion of the left internal carotid artery. The patient underwent timely intra-arterial mechanical thrombectomy. Postoperative computed tomography (CT) examination revealed a high-density shadow of the left basal ganglia and left frontal lobe. Twelve hours later, the patient fell into a coma. Repeat head CT indicated acute hydrocephalus with no evidence of obstruction. The patient underwent emergency external ventricular drainage, and the drainage fluid was observed to be clear. The patient regained consciousness after the procedure and the drainage tube was removed 4 days later. The patient had no recurrence of hydrocephalus. The mechanisms and treatment of this condition are discussed.

Role of aquaporins in hydrocephalus: what do we know and where do we stand? A systematic review

INTRODUCTION

Glymphatic fluid circulation may be considered the lymphatic system of the brain and the main role of such system seems to be played by aquaporins (AQPs), a family of proteins which regulates water exchange, in particular AQP4 and 1. Alterations of glymphatic fluid circulation through AQPs variations are now emerging as central elements in the pathophysiology of different brain conditions, like hydrocephalus. This systematic review provides an insight about the role of AQPs in hydrocephalus establishment and compensation, investigating their possible role as diagnostic tools or therapeutic targets.

METHODS

PubMed database was screened searching for the relevant existing literature in English language published until February 29th 2020, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Statement.

RESULTS

A total of 40 articles met the inclusion criteria for our systematic analysis. AQP4 resulted the most studied water channel, followed by AQP1. The changes in cerebrospinal fluid (CSF), brain parenchyma and choroid plexus (CP) in different hydrocephalus type were analyzed. Moreover, important pharmacological interactions regarding AQP and molecules or conditions were discussed. A very interesting result is the general consensus on increase of AQP4 in hydrocephalic patients, unless in patients suffering from idiopathic normal pressure hydrocephalus, where AQP4 shows a tendency in reduction.

CONCLUSION

AQP seem to play a central role in the pathophysiology of hydrocephalus and in its compensation mechanisms. Further studies are required to definitively establish their precise roles and their quantitative changes to allow their utilization as diagnostic tools or therapeutic targets.