A Case of Transient, Isolated Cranial Nerve VI Palsy due to Skull Base Osteomyelitis

Isolated Abducens Nerve Palsy in the Setting of Isolated Sphenoid Sinusitis: A Case Report

The cranial nerves (CNs) are responsible for multiple functions, including extraocular mobility, facial sensation and movement, hearing, mastication, tongue movement and sensation, and swallowing. Beyond these vital roles, they can also demonstrate importance in their diagnostic value. Isolated or combined palsies provide insights into potential localizations and various underlying etiologies, including stroke, tumor, and infections that may guide further neurological evaluation. CN VI, the abducens nerve, singularly innervates the lateral rectus muscle, which is responsible for the abduction of the eyes. Despite its long anatomic trajectory, making it susceptible to intracranial injury, an isolated abducens nerve palsy is extremely rare. The most common clinical presentation includes headache, diplopia, and the inability to abduct the afflicted eye. This case report introduces a 71-year-old female with a medical history of malignancy and pancytopenia who presented to the emergency room with complaints of ear pain and swelling and subsequently developed diplopia secondary to unilateral CN VI palsy. Magnetic resonance imaging (MRI) revealed isolated sphenoid sinusitis for which she was clinically asymptomatic. She was treated with a regimen of ampicillin-sulbactam, an oral anti-inflammatory agent, and a tapered course of methylprednisolone with a rapid and complete resolution of the abducens nerve palsy and sinusitis. Acute isolated diplopia is an unusual neurologic condition prompting the need for rapid and thorough investigation. Although exceedingly rare and infrequently cited in the literature, isolated abducens nerve palsies secondary to sphenoid sinusitis should be entertained in the differential diagnosis of this presentation.

Cranial nerve palsy prevalence and associated factors in patients with malignant otitis externa

Objective

To identify the prevalence of cranial nerve (CN) palsy and its associated factors in malignant otitis externa (MOE).

Methods

In a retrospective study, records of MOE patients from 2011 to 2014 were reviewed. MOE and CN involvement were evaluated based on patient demographics, clinical, and paraclinical data.

Results

Overall, 119 MOE patients with a mean age of 65.9 ± 11.3 were included. 69.7% were male, and 63.0% had a history of diabetes. The most common symptoms and signs were otalgia (97.5%), otorrhea (44.5%), and ear canal erythema/edema (24.4%). Thirty-three patients (27.7%) had CN involvement. The facial nerve was mostly involved (26.1%). Skull base osteomyelitis (SBO) was present in 59 patients. When excluding patients younger than 30 and older than 80, age decade was correlated with CN palsy. 66.9% of patients with CN palsy and 65.6% without CN palsy were male, which was significantly different. The following factors were not significantly different between patients with and without CN palsy: Comorbidities, signs and symptoms, diagnostic delay, erythrocyte sedimentation rate level, fasting blood sugar, hemoglobin A1c level, antifungal therapy, hospitalization duration, and SBO on imaging. Tinnitus was correlated with SBO evidence on imaging (specificity: 96.7%).

Conclusion

CN involvement occurs in about three out of 10 MOE patients. Male gender and advanced age may be related to a higher incidence rate of CN palsy. Tinnitus can be a specific indicator of SBO. These findings could help in better decision-making for early interventions.

Level of Evidence

4.

Rare case of a 3-year-old with Candida skull base osteomyelitis: lessons to be learnt

Skull base osteomyelitis (SBO) is a serious and rare condition most commonly seen in elderly diabetic or immunocompromised patients as a complication of otitis externa. We present the case of a previously healthy 3-year-old girl who presented to the paediatric emergency department with vomiting, fever, lethargy, headache and left-sided facial nerve palsy. The initial CT head revealed left-sided otitis media with otomastoiditis and she was managed with intravenous antibiotics and myringotomy with grommet insertion with initial improvement. Two weeks later she re-presented having deteriorated and a dedicated mastoid CT and temporal bone MRI showed SBO. She underwent urgent cortical mastoidectomy where microbiological analysis of the cultures and specimen grew Candida albicans She was subsequently treated with long-term antifungals and antibiotics, and eventually recovered with good effect. The diagnostic dilemma and the empirical treatment of such a rare case are discussed.