Discussions (D)
Terence R. Anthoney in Neuroanatomy and the Neurologic Exam, 2017
Most authors of recent texts in basic neuroanatomy who describe several nuclei within the superior olivary complex include either lateral and medial superior olivary nuclei (e.g., C&S, p. 368; K&S, p. 406–407) or else principal (or main, or chief) and accessory superior olivary nuclei (e.g., A&B, p. 147–148; MarMar, p. 183; M&F, p. 58). Usually, the principal nucleus is described as lateral to the accessory nucleus (e.g., A&B, p. 147 [Fig. 6–7]), and occasionally the medial nucleus is also listed as being the accessory nucleus (e.g., W&W, p. 909; N&D, p. 352). Thus, the principal nucleus and the lateral nucleus seem to be identical, as do the accessory nucleus and the medial nucleus. Crosby, Humphrey, and Lauer, however, clearly disagree: “It [the “superior olivary nucleus’] is often represented by two cell groups, a more medial chief and a more lateral accessory olive. …… In the cat, where the superior olivary complex is divided into medial and lateral portions (instead of chief and accessory olivary nuclei),. …” (1962, p. 161)
Anatomy
Stanley A. Gelfand in Hearing, 2017
The superior olivary complex constitutes the next way station in the auditory pathway, and is distinguished as the first (lowest) level that receives information originating from both sides of the head (bilateral representation). The SOC is made up of the medial superior olive (MSO), the lateral superior olive (LSO), and the medial nucleus of the trapezoid body (MNTB), as well as rather diffuse accumulations of cell bodies known as the periolivary nuclei (Moore, 1987, 2000; Schwartz, 1992; Helfert and Aschoff, 1997; Kulesza, 2007). Each MSO receives bilateral inputs from the right and left AVCNs, and then projects to the ipsilateral inferior colliculus via the lateral lemniscus on its own side. The LSO also receives inputs directly from the AVCN on the same side as well as from the opposite AVCN via the ipsilateral MNTB. In turn, the LSO projects bilaterally to the inferior colliculi via the lateral lemnisci on both sides. As just implied, the MNTB receives its input from the opposite AVCN and then projects to the LSO on its own side. Although generally similar to the SOCs of lower mammals in many ways, the human SOC has a relatively smaller LSO, which has a nub that gives it an almost Y-like configuration instead of the other (often S) shapes found in many lower animals (Kulesza, 2007). The human SOC also has more prominent periolivary cell groups and the trapezoid body does not appear to be quite as well organized into an identifiable nucleus (Moore, 2000).
Shy-Drager Syndrome and Multiple System Atrophy
David Robertson, Italo Biaggioni in Disorders of the Autonomic Nervous System, 2019
Although the EEG is not particularly valuable in evaluating patients with MSA, brainstem auditory evoked potentials may help to differentiate the disorder from PAF and Parkinson’s disease. There is abnormal latency and amplitude (ratio of wave V/I) in most patients with MSA; this was not present in any PAF patients and occurred in only one patient with Parkinson’s disease (Prasher and Bannister, 1986). The auditory pathway disruption was felt likely to occur in the superior olivary complex. In another study (Uematsu, Hamada and Gotoh, 1987), prolonged interpeak (I—III) latency correlated with the degree of pontine atrophy determined by computerized tomography (CT).
A discussion of children with obvious hearing and balance disorders being mislabelled in the psycho-neuro-developmental and educational world: an historical analysis
Published in Hearing, Balance and Communication, 2019
Margaret R. Glenney
The behavioral symptoms of hyperacusis can sometimes be so pronounced that children cry and cover their ears with many sounds; that parents seek out earmuffs for their children when they take them to the mall, or out in public, or do so infrequently, or not at all. Not only is this a behavioral complaint, but there is research to support it. Wilson et al. [26] report that efferent inhibition strength of the medial olivocochlear potential is a physiological correlate for the symptom of hyperacusis in ASD children. Rudimentary understanding of the central auditory nervous system acknowledges that the superior olivary complex is the first efferent juncture in the auditory nervous system. So, it seems reasonable to conclude that with the autistic child, the problems perhaps start there along the central auditory pathway. This is also the first juncture where synapses from the auditory input for each ear begin to cross to the contralateral side.
Masking level difference among brazilian military personnel: a comparison between pilots and non-pilots
Published in International Journal of Audiology, 2021
Graziela Maria Martins-Moreira, Alessandra Spada Durante
In Brazil, the hearing of military pilots is monitored by means of regular periodic audiometry (Brasil, 2003, 2013), but there is no recommendation to also evaluate how they perform in the SIN recognition task which closely reflects the pilots’ typical operational environment and requires binaural interaction. Among central auditory abilities potentially affected by noise exposure, binaural interaction, assessed by the masking level difference test (MLD), is critical to pilot performance as it can improve speech intelligibility by an amount equivalent to a 4 dB shift in signal-to-noise ratio (S/N) in the cockpit of an aircraft during flight (Tobias 1972). To achieve this improvement, the auditory system uses subtle interaural time differences caused by phase inversion of the acoustic stimulus to better detect sounds presented in noise under a binaural condition. Such subtle stimulus differences aid in sound lateralisation and speech recognition in the presence of competitive auditory information. The seat of this ability is the lower brainstem, more specifically the superior olivary complex and the inferior colliculus (Bartz et al. 2015; Clinard, Hodgson, and Scherer 2017), but also receives contributions from the cortex (Fowler 2017). In order to confirm the neural correlations for MLD, which involve the thalamus, the insula, and a neural process that crosses the corpus callosum, researchers used functional magnetic resonance imaging (Wack et al. 2012) and diffusion tensor imaging (Wack et al. 2014).
Peripheral and central auditory function in adults with epilepsy and treated with carbamazepine
Published in Hearing, Balance and Communication, 2019
Sherifa A. Hamed, Amira M. Oseily
It is well known that anatomical and functional integrity of the peripheral and central auditory pathway are important for normal hearing. In the last three decades, there is an increasing interest in assessment and monitoring of hearing impairment from any cause using BAEPs [27,28,30,33,41]. BAEPs have proven to be more sensitive in detecting subclinical hearing impairment than PTA. BAEPs (short- and middle-latencies) reflect auditory pathway function starting from the auditory nerve and throughout the brainstem [42]. Results of short and middle BAEPs are interpreted as absolute wave latencies (I–V) and interpeak latencies. Waves I originates from afferent activity of the dendrites of the acoustic nerve fibres (first-order neurons) as they leave the cochlea and enter the internal auditory canal. Wave III shows the activity in superior olivary complex which is intimately related to the trapezoid body. Wave V is associated with the lateral lemniscus, the location is the rostral brainstem in or near the inferior colliculus. The I–III, III–V and I–V interpeak latencies (IPLs) reflect brainstem conduction time [42], while long-latency evoked response (also known as event-related potentials [ERPs]) reflects the function within the auditory cortex [43].
Related Knowledge Centers
- Auditory System
- Calyx of Held
- Dorsal Cochlear Nucleus
- Inferior Colliculus
- Lateral Lemniscus
- Pons
- Sound Localization
- Trapezoid Body
- Olivary Body
- Calyx of Held
- Ventral Cochlear Nucleus