Malignant external otitis with extensive cranial neuropathy but no facial paralysis

Abstract

Sirs: Malignant or necrotizing external otitis (MEO) is a lifethreatening Pseudomonas aeruginosa infection of the external auditory canal leading to skull base osteomyelitis and soft tissue inflammation of the infratemporal fossa. Although MEO primarily belongs to the domain of the earsnose-throat specialist, it represents a true neurological emergency if cranial nerves are affected. The disease is characterised by the following triad: (A) An elderly diabetic or otherwise immunocompromised patient presents with (B) persistent headache, otalgia and auditory discharge after water irrigation for cerumen impaction, (C) complicated by multiple cranial nerve palsies. Due to its close proximity to the external acoustic meatus and the stylomastoid foramen, the facial nerve is the first and foremost involved cranial nerve [1]. However, here we report to our knowledge the first case of a patient with MEO suffering from extensive cranial neuropathy without facial paralysis. In November 2005 a 68-year old man with poorly regulated diabetes mellitus and hypertension consulted an otolaryngologist because of left ear deafness. After irrigation for cerumen impaction, hearing returned to normal. A week later he developed constant left-sided headache and painful drainage of a yellowish smelly fluid from the left ear. Otalgia and otorrhoea resolved two weeks later after repeated irrigations and the prescription of topical hydrocortisone cream. However, headache persisted. The pain extended to the left temporo-mandibular joint and mastoid. In December the patient noticed hypestesia on the left side of the face. In January 2006 he was operated for an abscess of the left external auditory canal. In February he developed slurred speech and hoarseness, in March difficulties with swallowing. He lost six kg in three weeks and complained of constant headache. He was now referred by his otolaryngologist to a university neurological department. On admission he was alert and orientated without fever or neck stiffness. Neurological examination revealed a sensory deficit in the maxillary and mandibular nerve distribution, mild conductive hearing impairment, deviation in the Unterberger’s stepping test, a positive curtain sign with elicitation of the gag reflex, dysphagia, hoarseness and tongue deviation. All symptoms were confined to the left side. Of note, there was no facial paresis. A CT and MRI scan of the head revealed bone erosion of the left occipital condyle and mastoid with extensive soft tissue inflammation around the skull base (Figs. 1, 2); however, the facial nerve remained unaffected (Fig. 1). A diagnosis of MEO with involvement of multiple cranial nerves was made and the patient received ciprofloxacin 750 mg twice daily. Two days later the headache had vanished. After three more days dysphagia and hoarseness had resolved. Culture from a mastoid biopsy revealed Pseudomonas aeruginosa. The patient received eight weeks of antibiotic treatment and made an uneventful recovery. Although MEO affects mostly elderly male diabetics, due to increased frequency of immunosuppression MEO is now seen in patients with AIDS or malignancies as well. When left untreated, MEO has a mortality of more than 50% [1], but since the introduction of ciprofloxacin and other oral antipseudomonal agents in the 1990ies, survival rates are much better. Long-term systemic therapy (>6 weeks) is mandatory and excellently tolerated [2]. Local application of aluminium acetate, known as Burow’s solution [3], might be used additionally. Moreover, hyperbaric therapy has been widely advocated [4, 5], but a recent Cochrane Review concluded that there is so far no evidence from randomized controlled trials for such an approach [6]. Due to undifferentiated ciprofloxacin use for simple external otitis, aberrant and recurrent forms of MEO and even quinolone-resistance are increasingly reported. Sinus and jugular vein thrombosis, meningitis, trismus, facial nerve palsy and other cranial neuropathies, ophtalmoplegia and skull base osteomyelitis often necessitate surgical debridement. Even with aggressive surgical and medical treatment mortality of protracted MEO is high [7]. Thus, early diagnosis of MEO is essential. CT, MRI and SPECT bone imaging provide the anatomic D. Kondziella, MD, DMSC (&) I. Skagervik, MD Dept. of Neurology Goteborg University Hospital Sahlgrenska 41345 Goteborg, Sweden Tel.: +46-730791599 Fax: +46-31826227 E-Mail: daniel_kondziella@yahoo.com LETTER TO THE EDITORS J Neurol (2007) DOI 10.1007/s00415-006-0516-1