Auditory Neuropathy Spectrum Disorder
A 10 year old girl presented to Aster Hospital’s Audiology Department with her parents on 31st July 2017. The family visited the hospital to get clearance from the Audiology Department for her to get admitted into School.
The child had Cerebral Palsy and had been undergoing treatment for the same. Upon thorough investigation of her case, correlative study and testing including BERA, DPOAE, TEOAE and TYMPANOMETRY, it was recognized that the child suffered from a rare disorder known as Auditory Dyssynchrony, which generally has an incidence of 3-4 in every 10,000 children. For the past 10 years the child was being treated for other abnormalities and no hearing test was ever conducted. The child had a speech delay which was considered as the result of Cerebral Palsy.
The primary symptoms/causes of Auditory Dyssynchrony the primary are;
- Normal hearing to profound hearing loss.
- OAE present (indicating normal outer hair cell function of cochlea)
- Absence of acoustic reflexes
- Needs lots of repetition to understand a sentence, command or request
- Problem lies with spiral ganglion cells or pre/post synaptic junction (neuronal firing is dyssynchronized) peripheral
- Speech and language delayed
- Birth defects, syndromes, premature babies, genetics
- Majorly known as neural processing disorder of the auditory system
- Responses to pure tones are adequate
In case of this patient, her results showed;
- Normal hearing since DPOAE AND TEOAE are present.
- BERA shows cochlear micro phonics and emergence of first wave, with flat waveform thereon, confusing with profound hearing loss (classical feature of Auditory dyssynchrony), tube clipping method and polarity reversal method was used.
- Acoustic reflexes absent
- Delayed speech and language
- Needs repetitions to make understand a command (inconsistent responses)
- Cerebral palsy
- Relying on visual cueing
- Inability to understand speech in noisy environments
- Cochlear implants (65-70% success rate)
- Communication devices/boards ( ALD-ASSISTIVE LISTENING DEVICES)
- FM systems
- Modified Speech and language therapy
ANSD (Auditory Neuropathy Spectrum Disorder) Normal Hearing
*Image changed to retain patient’s confidentiality