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Vagus nerve stimulation (VNS) is an acceptable and effective adjunctive therapy for pharmacoresistant epilepsy. It is generally well tolerated and the most frequent side effects reported include respiratory dysfunction. We report the case of a female patient with intractable epilepsy who was implanted with the device and achieved a significant reduction in the number of her seizures. However, she developed central-type sleep apnea documented polysomnographically. Upon reduction of her VNS parameters, the apnea resolved and her sleep study reverted to normal. To our knowledge, this is the first case reported with polysomnographic evidence of VNS induction of central-type sleep apnea.

Objective: To present and discuss a case of a woman who for many years was presumed to have nonepileptic seizures (NES), but proved to actually have both electrical and non-electrical seizures, the latter occurring in a close temporal association with the former. To also discuss the seimiology her true as well as NES and compare to other cases identified from a literature review on this subject., Materials and Methods: Closed-circuit video-EEG monitoring was performed in order to capture and subsequently analyse the patient's events., Results: During video-EEG monitoring, she proved to have short electrical seizures followed by psychogenic elaborations. Her NES had obscured her true seizures for a number of years., Conclusions: Psychogenic elaboration of an epileptic seizure (ES) may occur in the same patient and the latter may obscure the former. The use of video-EEG monitoring may delineate the correct diagnosis and help clarify the relationship of the two types of events.

The exact location of the vestibular cortex in humans has not yet been established. Isolated lesions in the insula are exceptional. We describe a patient with recurrent episodes of vertigo and imbalance following a small lesion in the anterior insula. Myogenic and neurogenic vestibular evoked potentials were both performed using auditory stimuli. The former was recorded from the sternocleidomastoid muscle and the latter from the parietal areas on the scalp. Brainstem auditory evoked potentials, threshold latency series, pure tone audiometry and video nystagmography were also performed, as was brain MRI. All evoked potential studies and pure tone audiometry were within normal limits, ruling out peripheral and brainstem causes for the patient's symptoms. Video nystagmography revealed high slow phase velocities bilaterally with caloric stimulation, and saccadic tracking on the smooth pursuit examination. The MRI revealed a small lesion in the right anterior insula. To our knowledge this is the first reported case of vestibular symptoms and signs from a lesion in the anterior insula on MRI. In addition, its effects on the nystagmogram suggest that this area may be part of the pathway that controls smooth pursuit.

Purpose: Vestibular evoked myogenic potentials (VEMPs) uses high intensity clicks with recording from the tonically active sternocleidomastoid muscle, taking advantage of the close proximity of the saccule to the oval window. Our group has used the same stimulus to record Vestibular Evoked Neurogenic Potentials (VENPs) directly from the brain. VEMPs are now regarded the electrophysiological gold standard in peripheral vestibular system examination. We present a case of peripheral vestibular dysfunction to show that both VEMPs and VENPs provide similar results during recovery., Methods: A case of Meniere's Disease in recovery is examined. VEMPs were recorded using a 105 dB nHL click stimulus from the ipsilateral sternocleidomastoid muscle. VENPs were recorded using an ipsilateral parietal to Fpz montage and a 1 kHz tone-pip stimulus. Standard BAEPs and threshold latency series (TLS) were performed., Results: VEMP and VENP were unobtainable from the left side at initial presentation in a patient with Meniere's Disease, with normal BAEP and TLS bilaterally. After one month of therapy both the VEMP and VENP normalized., Conclusions: As VEMPs are known to originate from the vestibular system, the parallel VENP result suggests the same for the latter VENP may prove to be useful and complement VEMP in determining vestibular dysfunction.

Objectives: Symptoms of disequilibrium in multiple sclerosis (MS) are common. Neurogenic vestibular evoked potentials (NVsEPs) are saccular responses to tone-pip acoustic stimuli and are recordable from the parietal areas ipsilaterally to the stimulated ear. We wished to determine possible correlations of abnormal findings in NVsEP with clinical neurological findings related to the vestibular system, and demyelination seen on MRI., Patients and Methods: NVsEPs were performed by delivering a 1 kHz tone-pip stimulus monoaurally with contralateral masking noise via headphones. Brainstem auditory evoked potentials were performed in the standard manner., Results: Thirty-three patients had either been diagnosed with MS or had possible MS. There is statistical evidence that the presence of symptoms is likely to give an abnormal NVsEP, but no correlation exists between the presence or absence of vestibular symptoms and signs and an abnormal BAEP. No correlation was found between the presence of brainstem lesions on MRI and an abnormal NVsEP. Correlation exists between abnormal NVsEP and the level of disability using Expanded Disability Status Scale scores., Conclusion: We have found that with increasing involvement of abnormal NVsEPs, there is a significant correlation with symptoms and signs that can be referred to the vestibular system.

Published correlations between electrophysiological and surgical findings are relatively rare in cases of ulnar nerve compression at the wrist, compared to the more common compression of the ulnar nerve at the elbow. We describe a patient who presented with clinical and electrodiagnostic findings of a pure motor ulnar neuropathy involving the territory of the deep branch. Surgical exploration revealed that a ganglion cyst caused compression of the deep ulnar motor branch at Guyon's canal. This case illustrates the usefulness of electrodiagnostic studies in the localization of nerve entrapment prior to surgery.

Objectives: To demonstrate that neurogenic vestibular evoked potentials (NVsEP) may be specific to the vestibular system using three cases of vestibular system dysfunction and normal auditory function,, Methods: Neurogenic vestibular evoked potentials were performed by recording from the parietal areas of the scalp using a tone-pip auditory stimulus via headphones. Brainstem auditory evoked potentials (BAEPs) and NVsEP were performed in all three cases., Results: Brainstem auditory evoked potentials were within normal limits in all three cases. All three patients showed abnormalities in their NVsEP In the third case, the responses normalized after treatment., Conclusions: The findings support further the hypothesis that NVsEP are specific to the vestibular system and are a separate response from the BAEP SIGNIFICANCE: Neurogenic vestibular evoked potentials is an easy examination to carry out and can be performed in any clinical neurophysiological laboratory that is familiar with BAEPs. Examinations used to diagnose vestibular system disorders at present include the glycerol dehydration test, electrocochleography, myogenic vestibular evoked potentials and electronystagmography. Neurogenic vestibular evoked potentials may also prove to be useful.