|Year : 2017 | Volume
| Issue : 1 | Page : 46-48
Prelingual auditory verbal agnosia, A rare condition
Violeta Necula, Cristina Mirela Stamate, Krishna Luchoo, Marcel Cosgarea
Department of Otorhinolaryngology, “Iuliu Hatieganu” University of Medicine and Pharmacy, Cluj-Napoca, Romania
|Date of Web Publication||6-Feb-2017|
Dr. Violeta Necula
Department of Otorhinolaryngology, “Iuliu Hatieganu” University of Medicine and Pharmacy, 8th Babes Street, Cluj-Napoca
Source of Support: None, Conflict of Interest: None
Auditory agnosia, agnosia for speech is a rare condition, caused mostly by stroke, in adults, while in children it is often a sequel of herpes simplex encephalitis or is associated with epilepsy, in Landau–Kleffner syndrome. This article presents a rare case of verbal auditory agnosia as a result of meningoencephalitis, caused probably by herpes simplex virus. The patient's developed encephalitis at the age of 1 year and 4 months. After her recovery, the family noticed the absence of language development. She was initially diagnosed with profound hearing loss, and the hearing aids did not help her. The speech therapy developed her lip-reading skills with a hard-to-understand pronunciation. Later, audiometry showed a nearly normal peripheral auditory system and magnetic resonance imaging revealed the characteristic brain lesions in both the temporal lobes, explaining the patient's evolution. Assessment of children with delayed speech development must consider the central hearing disorders as a differential diagnosis.
Keywords: Auditory verbal agnosia, central deafness, herpes encephalitis
|How to cite this article:|
Necula V, Stamate CM, Luchoo K, Cosgarea M. Prelingual auditory verbal agnosia, A rare condition. Indian J Otol 2017;23:46-8
| Introduction|| |
Auditory agnosia is a rare auditory deficit due to bilateral lesions of the primary auditory cortex or acoustic radiations. It is divided into four categories: general auditory agnosia, agnosia for speech, for environmental sounds and music., Auditory verbal agnosia is specific for speech sounds and represent the inability to comprehend speech. Nonverbal sounds are heard and comprehended.
In adults, the most common causes of auditory agnosia are cerebrovascular accident, dementia  or tumor within the third ventricle, meanwhile, in children, possible causes include herpes simplex encephalitis and Landau–Kleffner syndrome.
| Case Report|| |
A 24-year-old female patient presented to our clinic for audiological assessment with complaints of speech perception impairment and difficulties in speech production. In childhood, she was diagnosed with profound hearing loss, as a result of which she started using hearing aids; however, she discontinued them because they bothered her.
After a normal early development, at the age of 1 year and 4 months, she was diagnosed with meningoencephalitis of unknown etiology. Cerebrospinal fluid cultures were negative for bacteria or mycoplasma. After this episode, the family noticed a decline in speech perception and production. She was able to recognize some environmental sounds such as doorbell, telephone, door knock, or the noise of fallen object.
She was trained intermittently by speech therapists developing visual skills like lip-reading and the language in some manner.
Clinical examination did not reveal any pathologiec aspect except the delay in speech development and lack of speech perception. Audiological assessment is presented in [Figure 1].
|Figure 1: Puretone audiogram - medium sensorineural hearing loss; auditory steady state response - thresholds on 30–40 dB HL; auditory brainstem response - normal configurations and thresholds; Type A tympanogram; acoustic reflex present ipsi- and contralateral; distortion products otoacoustic emissions with responses on both ears.|
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Taking into considerations the audiological results with a history of encephalitis and the absence of speech perception the patient was suspected of central hearing loss of auditory agnosia. The patient underwent a magnetic resonance imaging (MRI) examination, and bilateral temporal lobe lesions were detected, predominantly on the right side [Figure 2] and [Figure 3].
|Figure 2: Fluid-attenuated inversion recovery-type acquisitions on coronal plan: Sequelar pathological hypersignal on gyriform and cortico-subcortical junctional areas, in the posterosuperior temporal gyrus, with an atrophic appearance (extremely thin cortex, linear), more visible on the right side, secondary of inflammatory disease.|
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|Figure 3: The fluid-attenuated inversion recovery-type acquisition in sagital plan reveals a peripheral hypersignal, gyriform but also junctional, cortico-subcortical, in posterosuperior temporal gyrus, more obvious on the right side; quite obvious the atrophic, very thin appearance of involved cortex.|
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Neurological examination did not reveal any additional impairment.
For a better communication, the patient continued to work with a speech therapist, attempting to improve her lip-reading and pronunciation.
| Discussion|| |
This is a rare case of prelingual verbal auditory agnosia in a young patient with severe speech production and perception disorders, which occurred after an episode of encephalitis at the age of 1 year and 4 months. The early onset of the disease had severe repercussions in subsequent language evolution because of lack of auditory feedback, necessary for speech production. Unclear pronunciation, similar to a deaf person, and childhood pure tone thresholds, which showed severe to profound hearing impairment, enabled the patient to be considered deaf–mute. The current audiological assessment showed a medium hearing loss in contrast to the lack of speech perception and a normal peripheral auditory system. MRI confirmed brain lesions in both superior temporal gyri, more pronounced on the right side.
In children, auditory agnosia is due to herpes encephalitis or is associated with epilepsy in Landau–Kleffner syndrome. Herpes simplex is the most common cause of acute sporadic encephalitis in children  and its incidence is one case/250,000 population/year in the USA and 2.5/1,000,000 population/year in Sweden. In the absence of therapy, mortality exceeds 70%, and only 2.5% of surviving individuals return to normal neurological function. Herpes simplex encephalitis is characterized by acute focal, necrotizing brain lesions, particularly in the temporal and orbitofrontal region. Our patient had bilateral lesions of temporal region, more pronounced on the right, similar to the cases submitted by Kaga et al.
If the injury occurs before the language development, the lack of auditory feedback prevents the speech development and the communication mainly relies on visual cues. Word-deaf children are mute, and only few of them succeed to acquiring adequate language.
Clinical manifestations, in this case, were similar to deaf-mute and the voice quality was also affected. The initial diagnosis was severe to profound hearing loss, based on the child's lack of response to sounds on puretone audiogram; however, this was arrived without making a complete objective assessment. Hearing aids did not help the patient, which is understandable now when we found that she could hear environmental sounds but could not understand speech.
The patient was able to acquire only a poor language and developed lip-reading with the help of speech therapists. She attended mainstream school, and she learnt to read and write; however, her academic performances were poor.
Similar cases were presented by Kaga et al. In one of the reported cases, the onset was at 1 year and 2 months with bilateral temporal lobe lesions, like in our case. Language acquisition was difficult, communication was performed using sign language, and the patient attended a special school for deaf. Temporal lobe lesions were typical for agnosia.
Currently, children who do not cooperate for behavioral testing are evaluated using objective electroacoustic tests. A history suggestive of encephalitis or epilepsy can lead us to think of a much rare condition which is the auditory agnosia. In this situation, referring the patient to a neuropsychiatric or a neurologic assessment and MRI of the brain could help establish a diagnosis.
In this case, prelingual onset of the illness caused significant communication disorder that limited language development. The orientation of child to a special school would bring greater benefits to developing communication-based on sign language and lip-reading because hearing aids are useless.
Assessment of children with delayed speech development and normal peripheral auditory system must consider auditory agnosia as a differential diagnosis, a rare disease but with devastating consequences.
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Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3]