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Biomedical subjects

S S Papacostas

Publications and source records attributed to S S Papacostas.

10 recordsLinked to original sources

Epileptic seizures followed by nonepileptic manifestations: a video-EEG diagnosis.

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.

Electroencephalography↗

Ulnar neuropathy at Guyon's canal: electrophysiological and surgical findings.

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.

Adult↗

Vestibular symptoms and signs are correlated with abnormal neurogenic vestibular evoked potentials in patients with multiple sclerosis.

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.

Adolescent↗

Radial nerve F-waves: normative values with surface recording from the extensor indicis muscle.

OBJECTIVES: In the present study we set out to obtain normative values for radial nerve F-waves, with surface recording from the extensor indicis muscle. METHODS: Forty-nine patients with unrelated complaints were tested. Surface recording electrodes were placed on the extensor indicis muscle. This was found by asking the patient to extend the second digit against resistance. The active surface recording electrode was placed over the most distal portion of the muscle, near the radial border of the ulnar bone near the wrist. Stimulation was performed near the lateral epicondyle between the radial and ulnar bones. RESULTS: The mean F-wave minimum latency was found to be 20.55 ms, with an upper limit of 24.35 ms. The absolute interside minimum latency difference was found to have a mean of 0.55 ms, with a maximum of 1.7 ms. The mean amplitude of the F-waves was 145.61 microV and the mean mF/M ratio was 0.022. F-waves were unobtainable in 2/62 (3.2%) of limbs. Normative values for the radial nerve motor response were also obtained. Three cases are described to illustrate the usefulness of the above technique. CONCLUSIONS: It is technically feasible to record radial nerve F-waves from the extensor indicis muscle.

Adult↗

The Kleine-Levin syndrome. Report of a case and review of the literature.

Kleine-Levin syndrome is a rare self-limited disorder which usually affects adolescent males and is characterized by episodic hypersomnia, increased appetite, and behavioral/psychiatric disturbances. Individuals are normal between the attacks. The case of an adolescent boy is presented who suffered from recurrent sleepiness, hyperphagia, and behavioral disturbances such as rocking, punching and pacing, and was originally misdiagnosed as suffering from encephalitis. Before the diagnosis of Kleine-Levin was given, the patient underwent unnecessary investigations and treatment which, in turn, complicated his clinical condition both physically as well as psychologically. In the course of five years he had four such episodes which appeared to have progressively milder manifestations. Between episodes he was normal. It is important that the diagnosis is suspected early, especially in adolescent males who present with recurrent episodes of somnolence, increased appetite, and abnormal behavior, since it most often represents a benign and self-limited entity and does not warrant extensive investigations or treatment. It is also important to distinguish this syndrome from more serious organic and psychiatric diseases with more serious prognoses. The differential diagnosis of this syndrome is discussed and a review of the literature is presented including evidence and hypotheses regarding its pathophysiology.

Child↗

Neurogenic vestibular evoked potentials in three cases of vestibular system dysfunction.

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.

Adult↗

Parallel auditory vestibular evoked neurogenic and myogenic potential results in a case of peripheral vestibular dysfunction, showing that the former originates from the vestibular system.

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.

Evoked Potentials, Auditory↗

Vertigo and imbalance caused by a small lesion in the anterior insula.

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.

Adult↗

Acquired dementia with retinitis pigmentosa.

The coexistence of mental retardation and retinitis pigmentosa has been well described in a number of congenital syndromes such as the Lawrence-Moon and Bardet-Biedl disorders. In contrast to this, little information is available regarding the association of acquired dementia with retinitis pigmentosa. This report summarizes the clinical features of a developmentally normal adult having the unusual symptom complex of retinitis pigmentosa, early-onset dementia, sensorineural hearing loss, and sensorimotor neuropathy. Though the coexistence of retinitis pigmentosa and dementia in this particular patient may be completely coincidental, it could be representative of a previously unrecognized subset of dementing illness. The literature pertaining to related symptom complexes is reviewed and discussed.

Atrophy↗