Bilateral abducens palsy in closed head injury: A comprehensive review of literature based on a case report

Isolated bilateral sixth nerve palsies are rare, particularly in the setting of trauma. Most post-head injury cases with bilateral abducens palsy involve either basal skull fractures, particularly clival fractures. We present a case of bilateral abducens palsy after closed head injury in a young male who presented to the emergency department and a comprehensive literature review based on our clinical case. A Medline search for bilateral abducens palsy in closed head injury showed 89 results. Articles were excluded if crush head injury, non-traumatic bilateral abducens nerve palsy, associated vascular malformations were reported. After thorough search and filtering of those articles, fifty-one publications were found which reported and discussed about traumatic bilateral abducens palsy with closed head injury. In these 51 articles, a total of 139 cases were recorded. Several theories have been postulated to explain mechanisms of abducens nerve injury in trauma both in immediate and delayed settings. In our case, patient presented with immediate onset of bilateral abducens palsy. On imaging, clival fracture was seen in CT brain, which can be attributed for the nerve injury. Cases with retroclival extradural haematoma had higher chances of multiple cranial nerve injuries. Cases with multiple basal skull fracture involving petrous temporal bone fracture had higher chances of facial nerve injury. Along with bilateral involvement, the poorer outcome for recovery can be related with the severity of the adduction deficit. Our case showed no improvement in bilateral abduction during follow-up at 6 months. Clinical presentation of traumatic bilateral abducens nerve palsy is rare following closed head trauma and is usually associated with other injuries which are incompatible with life. It can be associated with other nerve injuries depending on basal skull fractures.

Bilateral Abducens Nerve Palsy and the possible Association with COVID-19: A Case Report

Cranial nerve neuropathy could be a part of neurological spectrum of COVID-19 disease. Research suggests SARS-CoV-2 infection can trigger an aberrant immune response in some individuals, causing inflammatory nerve damage leading to anosmia and neuropathy. We report here a 50-year-old female patient who presented to the outpatient clinic in Saint John Eye Hospital with a two months history of binocular, horizontal diplopia five days after recovery from SARS-CoV-2 infection, PCR positive test obtained by a nasopharyngeal swab on April 1st, 2021 with upper respiratory tract symptoms. The patient was diagnosed with bilateral abducens nerve palsy. The main cause was presumed to be post-viral as the patient had controlled diabetes “HBA1C: 7%” and had no pre-existing microvascular risk factors. Diplopia still exists after two months of bilateral abducens nerve palsy. Measurements confirmed bilateral limited abductions in both eyes with right or alternating convergent squint. This case report supports the hypothesis that direct or indirect virally mediated injuries along the routes of the cranial nerves can cause neuropathy and olfactory dysfunction. The longer latency effects of COVID-19 infection are not well understood. This case report aims to raise awareness amongst clinicians of coronavirus-induced neurological symptoms

Four-dimensional digital subtraction angiography for exploration of intraosseous arteriovenous fistula in the sphenoid bone

Background: Intraosseous arteriovenous fistula (AVF) is a rare clinical entity that typically presents with symptoms from their effect on surrounding structures. Here, we report a case of intraosseous AVF in the sphenoid bone that presented with bilateral abducens palsy. Case Description: A previously healthy man presented with tinnitus for 1 month, and initial imaging suspected dural AVF of the cavernous sinus. Four-dimensional digital subtraction angiography (4D-DSA) imaging and a three-dimensional (3D) fused image from the bilateral external carotid arteries revealed that the shunt was in a large venous pouch within the sphenoid bone that was treated through transvenous coil embolization. His symptoms improved the day after surgery. Conclusion: This is a case presentation of intraosseous AVF in the sphenoid bone and highlights the importance of 4D-DSA and 3D fused images for planning the treatment strategy.

Rare neurological presentations of Dengue Fever

In presence of abnormal neurological features infective, immunological and metabolic etiologies are also needed to be kept as possibility. Dengue fever may present with variety of neurological manifestations. This case series includes rare neurological presentation of dengue fever including first ever reported case of dengue fever induced bilateral abducens nerve palsy with another case of dengue cerebellitis. This case series along with previous studies suggest that imaging may be normal in these cases. This case series also highlighted the possible immunological etio-pathogenesis and role of steroids as treatment modality.