Roberto Bovo* Anna Berto* Silvia Palma* Stefano Ceruti $ Alessandro Martini* Departments of *Audiology and $Neuroradiology, Ferrara University, Ferrara, Italy Key Words Hypertrophic pachymeningitis Hearing loss Vestibular areflexia Magnetic resonance imaging Rheumatoid factor Original Article International Journal of Audiology 2007; 46:107  110 Symmetric sensorineural progressive hearing loss from chronic idiopathic pachymeningitis Hipoacusia sensorineural sime ´ trica progresiva a partir de una paquimeningitis idiopa ´ tica Abstract We present the case of a 68 year-old man with a diffused hypertrophic pachymeningitis (HP) involving both inter- nal auditory canals. The clinical symptoms were head- ache, decreased vision in one eye, progressive bilateral and symmetrical sensory-neural hearing loss (PSNHL) responsive to steroid treatment. Although hearing loss is a frequent manifestation of HP, only few studies reported an adequate audiological assessment and follow-up. Mechanisms related to the auditory involvement are discussed on the basis of audiological data. Gadolinium enhanced MRI is the most adequate technique for HP detection and for the differential diagnosis. A delay in the diagnosis of HP seems to be quite common and the consequences may be severe, especially in cases of optic nerve involvement. For these reasons, a cerebral MRI should probably be included in the assessment of PSNHL, especially when neurological signs coexist or are reported in the medical history. Sumario Presentamos el caso de un hombre de 68 an ˜os de edad con una paquimeningitis hipertro ´fica difusa (HP) que involucra ambos conductos auditivos internos. Los sı ´ntomas clı ´nicos fueron cefalea, disminucio ´n de la visio ´n en un ojo, hipoacusia sensorineural sime ´trica, bilateral y progresiva (PSNHL) que respondı ´an al trata- miento con esteroides. Aunque la hipoacusia es una manifestacio ´n frecuente de la HP, pocos estudios han reportado una evaluacio ´ n audiolo ´gica y un seguimiento adecuados. Los mecanismos relacionados con el compro- miso auditivo se discuten con base en datos audiolo ´gicos. Estudios de MRI con contraste de gadolinio constituyen la te ´cnica ma ´ s adecuada para la deteccio ´ n de la HP y para el diagno ´stico diferencial. Parece ser frecuente el retraso en el diagno ´stico de la HP y las consecuencias pueden ser severas, especialmente en casos de compromiso del nervio o ´ptico. Por estas razones, un MRI cerebral deberı ´a ser incluido en la evaluacio ´n de la PSNHL, especialmente cuando los signos neurolo ´gicos coexisten o se reportan en la historia me ´dica. Hypertrophic cranial pachymeningitis (HP) is a rare form of fibrosing chronic inflammatory process, characterized by a marked thickening of intracranial dura mother. The clinical features are headaches and progressive cranial nerve palsies due to a fibrous entrapment or to ischemic damage of neurovascular structures. In most cases (80%) aetiology is unknown, although secondary forms can be caused by infective, autoimmune or neoplastic diseases. Diagnosis is made by contrast-enhanced magnetic resonance imaging (MRI) and open biopsy of the dura in selected cases. The idiopathic variety (IHP) is a diagnosis of exclusion and could represent a focal autoimmune disease. It is often responsive to steroid treatment and either hearing loss, or other cranial nerve damage, may be reversible if treated promptly. We review a case of IHCP involving both internal auditory canals. Mechanisms related to the auditory involve- ment are discussed on the basis of audiological data. Clinical case In June 2004a 68 year-old man came to our observation due to recurrent episodes of vertigo, gait unbalance, bilateral tinnitus, and a progressive hearing loss over the previous three months. He also complained of a worsening of the headaches that were chronic, lasting for several hours every day, refractory to analgesic treatment. Clinical history was characterized by: a mild blood hypertension, a previous work-related noise expo- sure, an episode of transient diplopia, and blurred vision in the right eye in 1989; and a diffused, nonpulsatile headache associated to retro-orbital pain with a progressive left-sided monocular blindness in 1996, when a optic neuropathy was diagnosed. Pure-tone audiometry showed a bilateral, down-sloping sensory-neural hearing loss (Figure 1). Speech audiometry showed a PB word lists performance-intensity function worse than expected, especially in the left ear. The maximum identi- fication scores for both ears were no more than 60%. ABR with 80 dB nHL clicks was normal. The acoustic reflex was normally evoked bilaterally, indicating loudness recruitment. Vestibular examination showed a complete bilateral canal paresis (100% with ice water). A cerebral MR showed a diffused thickening of intracranial dura mother, slightly asymmetrical, with a max- imum thickness of 1 cm, around the left parietal hemisphere (Figure 2); facial and auditory nerves were not visible in both canals, which were occupied by an extension of enhancing dura mater (Figure 3). Neurological examination revealed atassic gait with enlarged basis and slight paresis of right abducens nerve. Erythrocyte sedimentation rate (ESR), C reactive protein (CRP), and ISSN 1499-2027 print/ISSN 1708-8186 online DOI: 10.1080/14992020600969744 # 2007 British Society of Audiology, International Society of Audiology, and Nordic Audiological Society Roberto Bovo Audiology Department, Ferrara University, C 50. Giovecca 203, I-44100 Ferrara, Italy. E-mail: roberto.bovo@unife.it Received: April 27, 2006 Accepted: August 21, 2006