Evaluation of saccular and inferior vestibular nerve function in children with auditory neuropathy spectrum disorder.

PURPOSE: The aim of the current work was to evaluate the function of the saccule and inferior vestibular nerve in children with auditory neuropathy spectrum disorder (ANSD) by recording the cervical-evoked myogenic potentials (C-VEMP) on those children and to compare C-VEMP results in ANSD children of pre-lingual onset to those in ANSD children of post-lingual onset. METHODS: The study included 38 ANSD children of pre-lingual onset, 16 ANSD children of post-lingual onset, and 20 control children. All participant children were subjected to C-VEMP testing using 500 Hz tone burst stimuli. RESULTS: The vast majority of ANSD children of pre-lingual onset (35 out of 38; 92.1%) had bilateral intact C-VEMP response with C-VEMP parameters (amplitude, asymmetric ratio, latency, and inter-aural latency difference) that were not statistically different than those in the control children. Only three children had bilateral absent C-VEMP response. On the other hand, the majority of ANSD children of post-lingual onset (11 out of 16; 68.75%) had bilateral absent C-VEMP response. The remaining five children had bilateral intact C-VEMP response with C-VEMP parameters that were not statistically different than those in the control children. CONCLUSIONS: The pathology of ANSD spares the saccule and inferior vestibular nerve in the vast majority of ANSD children of pre-lingual onset, while it involves them in the majority of ANSD of post-lingual onset reflecting different site(s) of lesion between the two ANSD categories. Such results have important clinical implications as regards to the management of ANSD in children.

Clinical criteria of positional vertical nystagmus in vestibular migraine.

OBJECTIVES: The goal of this study was to identify key diagnostic criteria for positional vertical nystagmus caused by vestibular migraine (VM). MATERIALS AND METHODS: The study group included a case series of 13 subjects with VM (10 females and three males with age 38.6 ± 8.9 years); they were complaining of positional vertigo. They were subjected to thorough audiovestibular examination and treated with cinnarizine or topiramate Results: The entire study group demonstrated positional vertical nystagmus (eight patients had up-beating nystagmus and five patients had down-beating nystagmus). The vertigo and nystagmus were elicited in one or more of the following positions: the right & left Dix-Hallpike, supine with head center, head right, and head left positions. The nystagmus had no latency period. It was persistent, non-fatigable and markedly reduced by visual fixation. Prophylactic therapy of VM (topiramate or cinnarizine) cured the positional vertigo in 92% of the study group. Neither the positional vertigo nor the nystagmus recurred in a 3-6 months follow-up period. CONCLUSIONS: VM can induce characteristic form of vertical positional nystagmus and vertigo, which would be treated by medications used for controlling the VM.

Epileptiform electroencephalogram abnormality in children with congenital sensorineural hearing loss.

OBJECTIVES: This work was designed to study electroencephalogram findings in children with congenital sensorineural hearing loss and correlate these findings with the SNHL parameters as duration, etiology, severity, and type. METHODS: Ninety children with bilateral congenital sensorineural hearing loss served as the study group. They were free from any neurological disorders or symptoms that are commonly associated with abnormal electroencephalogram as convulsions or loss of consciousness. Twenty children having normal hearing with no history of otological or neurological disorders served as the control group. All children participating in the study were subjected to full medical and audiological history, otological examination, neurological examination, audiological evaluation and electroencephalogram recording. RESULTS: Mean age of the children in the control group was 3.56 ± 2.1 years and mean age of the children in the study group was 3.8 ± 2.2 years. While none of the control children had abnormal electroencephalogram, 38 (42.2%) of children with congenital SNHL had epileptiform electroencephalogram abnormality. The epileptiform abnormality was generalized in 14 children (36.8%), focal temporal in 17 children (44.7%) and focal other than temporal in 7 children (18.4%). According to the hemispheric side affected, the abnormality was right in 14 children (36.8%), left in 10 children (26.3%) and bilateral in 14 children (36.8%). No statistically significant predominance of specific site or side of the epileptiform abnormality was found. Similarly, no statistical significant prevalent of the epileptiform abnormality was found in relation to the age or sex of children, duration of hearing loss or etiology of hearing loss (i.e., genetic vs. neonatal insults). On the other hand, the epileptiform abnormality was statistically prevalent in children with moderate degree of hearing loss, and in children with auditory neuropathy spectrum disorder. CONCLUSIONS: The epileptiform electroencephalogram abnormality is a common finding in children with congenital sensorineural hearing loss especially those with auditory neuropathy spectrum disorder, suggesting the affection of the central nervous system despite the absence of neurological symptoms or signs. These findings raise the question of the requirement of medical treatment for those children and the effect of such treatment in their rehabilitation.