50 likes | 223 Views
Middle and long-latency evoked potentials. MLEP and LLEP. Responses that reflect the synchronous activity of large groups of neurons located at the level of the auditory mid-brain and cortex. Advantages.
E N D
MLEP and LLEP • Responses that reflect the synchronous activity of large groups of neurons located at the level of the auditory mid-brain and cortex
Advantages • Elicit more frequency-specific responses and are not as dependent on neural synchrony as are the ABR and ECoG. • May be used in evaluating hearing in patients suspected to have auditory dyssynchrony/neuropathy • LLEP has the added advantage that speech can be used instead of tonal stimuli.
Disadvantages • Adversely affected by sedation and anesthesia • Can vary considerably depending on subject state • Are not fully developed until about 10 years of age • Require the patient to be awake and attentive, even if not actively involved in the task.
Indications • MLEP and LLEP are often used in cases where the functioning of the higher-order auditory pathways is questioned. • They have been shown to be abnormal in individuals with multiple developmental delays, central auditory processing disorders, schizophrenia, and/or learning disabilities; however, the sensitivity and the specificity of these techniques is largely unknown. • Finally, it was shown that it is possible to record MLRs and LLRs in subjects diagnosed with no ABR secondary to a diagnosis of auditory neuropathy.