Introduction
Epilepsy is a common neurological disorder; in developed countries, the incidence ranges from 24 to 53 per 100 000 person-years.Reference Burneo, Tellez-Zenteno and Wiebe1 Auditory auras are commonly associated with temporal lobe epilepsy; however, they are also a rare feature of partial seizures. Florindo et al. studied 8000 patients with epilepsy, only 121 of whom reported an auditory sensation at the onset of seizures.Reference Florindo, Bisulli, Pittau, Naldi, Striano and Striano2 The relatively low incidence of auditory aura probably accounts for the limited literature on the subject.
We report the case of a 31-year-old man referred to our department with short episodes of bilateral deafness, which subsequently transpired to be auditory auras.
Case report
A 31-year-old man had originally presented to the out-patient department with occasional symptoms of bilateral fullness in the ears associated with deafness. These episodes lasted 30 seconds to one minute. There was no history of vertigo. The patient had normal otoscopic findings, and pure tone audiometry and tympanometry were within normal limits. His past medical history included allergic rhinitis and seasonal asthma, and anterior rhinoscopy was consistent with this. There was no abnormality of the nasopharynx.
The patient was diagnosed with probable eustachian tube dysfunction, and was given an explanation of his symptoms.
Eights months later, he presented to the neurology department with a history of further episodes of bilateral ear fullness followed by generalised seizures. At this point, his sensation of bilateral ear fullness was diagnosed as an auditory aura. Further enquiry into his family history revealed that his paternal uncle and a cousin also suffered from epilepsy.
Computed tomography and magnetic resonance imaging brain scans were undertaken but were unremarkable. An electroencephalogram showed intermittent slow waves in the left temporal region but no paroxysmal activity.
The patient was commenced on lamotrigine and his seizures ceased. His auditory auras continued for a further year but resolved with an increase in his medication dose.
Discussion
In 1876, Hughlings-Jackson reported two cases of epileptic auditory aura.Reference Hogan and Kaiboriboon3 The term aura has been defined as a ‘qualitative disturbance undergone by the consciousness, a consequence of the onset of a partial epileptic seizure’.Reference Alvarez-Silva, Alvarez-Silva, Alvarez-Rodriguez, Perez-Echeverria, Campayo-Martinez and Rodriguez-Fernandez4 Epileptic auditory auras may be elementary or complex. Elementary auditory auras are simple noises such as ringing, buzzing, or hissing, and more commonly arise from the temporal lobe, presumably in or around Heschl's gyrus (the primary auditory cortex).Reference Florindo, Bisulli, Pittau, Naldi, Striano and Striano2, Reference Clarke, Otsubo, Weiss, Chitoku, Chuang and Logan5 Auditory distortions (hyper- or hypoacusis) and (rarely) deafness can also occur.Reference Florindo, Bisulli, Pittau, Naldi, Striano and Striano2, Reference Penfield and Perot6 Complex auditory hallucinations are characterised by the presence of hallucinations or illusions of more complex sounds, such as music or voices.Reference Florindo, Bisulli, Pittau, Naldi, Striano and Striano2, Reference Mohamed, Otsubo, Pang, Chuang, Rutka and Dirks7
An increasing body of evidence suggests that genetic factors play an important role in temporal lobe epilepsy. Auditory aura may be a manifestation of autosomal dominant partial epilepsy with auditory features, which in some families is linked to mutations in the leucine-rich glioma inactivated 1 gene.Reference Bisulli, Tinuper, Avoni, Striano, Striano and d'Orsi8, Reference Vadlamudi, Scheffer and Berkovic9
Our patient had initially been diagnosed with eustachian tube dysfunction due to his symptoms of ear fullness and deafness. This case highlights a rare presentation of temporal lobe epilepsy with short-lived, episodic auditory symptoms.
We recommend that enquiries regarding previous epilepsy, and any family history of epilepsy, should be a routine part of history-taking for patients presenting with tinnitus or fluctuating hearing loss.
• Auditory aura is a rare presentation of temporal lobe epilepsy
• Auditory aura may be a manifestation of autosomal dominant partial epilepsy with auditory features
• The reported patient presented with auditory symptoms due to temporal lobe epilepsy
• All patients presenting with fluctuating hearing loss should be questioned about previous epilepsy and any family history of epilepsy
