Test-Retest Reliability of Repetitive Ocular Vestibular Evoked Myogenic Potentials in Myasthenia Gravis Patients and Healthy Control Subjects.

PURPOSE: Repetitive ocular vestibular evoked myogenic potentials (ROVEMP) are a novel diagnostic test to quantify neuromuscular transmission deficits in extraocular muscles in myasthenia gravis. We aimed to investigate the test-retest reliability of the ROVEMP and the effect of amplitude and age. METHODS: We performed the ROVEMP test twice in 19 patients with myasthenia gravis (52.7 ± 19.8 years) and in 15 healthy control subjects (46.5 ± 16 years). The Bland-Altman level of agreement was determined. The relationship between test-retest reliability and signal quality, participant age and signal amplitude was studied. RESULTS: Limits of agreement were from -179.9 to 139.3 in myasthenia gravis patients and from -56.9 to 89.5 in healthy control subjects. Difference between measurements correlated with signal amplitude (r = -0.50, P < 0.001). Combining the primary cohort with previously published data from 114 subjects, we found a significant negative correlation between age and reference amplitude (r = -0.163, P = 0.045). CONCLUSIONS: This study shows that in our hands, the test-retest reliability of the ROVEMP is not optimal. Measurements with higher reference amplitude had a better quality, higher reproducibility, and increased diagnostic yield. We caution against the use of ROVEMP measurements of lower amplitude in clinical practice. In addition, given the correlation between age and amplitude, age matching of healthy control subjects and patients is essential in future studies.

Paroxysmal localized Hyperhidrosis, a case-report: When excessive sweating occurs in combination with severe headaches.

BACKGROUND: Paroxysmal localized hyperhidrosis is a rare disorder of the central autonomic nervous system. No association between paroxysmal hyperhidrosis and severe headache has been previously described in literature.Case description: A 65-year-old woman with idiopathic paroxysmal localized hyperhidrosis combined with severe holocranial headache attacks is described in this case report. Extensive diagnostic testing by means of laboratory examinations, 24-hour urinalyses, chest X-ray, abdominal ultrasound and computed tomography scans, and brain and spinal cord magnetic resonance imaging could not identify an underlying disorder. A diagnosis of idiopathic paroxysmal localized hyperhidrosis was made, and the patient was successfully treated with clonidine 0.075 mg three times a day, without any side effects. CONCLUSION: Paroxysmal localized hyperhidrosis is a rare central autonomic nervous system disorder that can occur in combination with severe headache. Both the headache and paroxysmal hyperhidrosis complaints were treated effectively with clonidine in the patient described in this case-report.

Neurovestibular Dysfunction and Falls in Parkinson's Disease and Atypical Parkinsonism: A Prospective 1 Year Follow-Up Study.

Our primary aim was to determine whether neurovestibular laboratory tests can predict future falls in patients with either Parkinson's disease (PD) or atypical parkinsonism (AP). We included 25 healthy subjects, 30 PD patients (median Hoehn and Yahr stage 2.5, range 1-4), and 14 AP patients (6 multiple system atrophy, 3 progressive supranuclear palsy, and 5 vascular parkinsonism) in a case-control study design (all matched for age and gender). At baseline, all subjects underwent clinical neurological and neurotological assessments, cervical and ocular vestibular evoked myogenic potentials (VEMP), brainstem auditory evoked potentials (BAEP), subjective visual vertical measurements (SVV), and video nystagmography with caloric and rotary test stimulation. After 1 year follow-up, all subjects were contacted by telephone for an interview about their fall frequency (based upon fall diaries) and about their balance confidence (according to the ABC-16 questionnaire); only one participant was lost to follow-up (attrition bias of 1.4%). Cervical and ocular VEMPs combined with clinical tests for postural imbalance predicted future fall incidents in both PD and AP groups with a sensitivity of 100%. A positive predictive value of 68% was achieved, if only one VEMP test was abnormal, and of 83% when both VEMP tests were abnormal. The fall frequency at baseline and after 1 year was significantly higher and the balance confidence scale (ABC-16) was significantly lower in both the PD and AP groups compared to healthy controls. Therefore, VEMP testing can predict the risk of future fall incidents in PD and AP patients with postural imbalance.

Syndrome of transient headache and neurological deficits with cerebrospinal fluid lymphocytosis (HaNDL): A case report with serial electroencephalography (EEG) recordings.. Is there an association with human herpes virus type 7 (HHV-7) infection?

Introduction The syndrome of transient headache and neurological deficits with cerebrospinal fluid lymphocytosis (HaNDL) is a diagnosis made by exclusion. In the literature, different etiological explanations are proposed for HaNDL, including an immune-mediated reaction after a viral infection. Case description We present a case of a 23-year-old woman with several episodes of transient headache, neurological deficits and cerebrospinal fluid lymphocytosis. All diagnostic criteria for the HaNDL syndrome were fulfilled; however, additional cerebrospinal fluid analysis showed a positive polymerase chain reaction (PCR) for human herpes virus type 7 (HHV-7). Discussion The possible role of a (prodromal) viral infection in the etiology of HaNDL is discussed. Also the role of electroencephalography (EEG) recordings is discussed. Serial EEG recordings showed generalized slowing, frontal intermittent rhythmic delta activity (FIRDA) and symmetric triphasic frontal waves with a dilation lag.

Ischemic Stroke as a Complication of Varicella Zoster Encephalitis: A Case Report With Detailed EEG Discussion.

A 72-year-old man with varicella zoster virus (VZV) encephalitis complicated by an ischemic stroke in the right internal capsule, possibly due to secondary small-vessel vasculopathy, is described in this case report. The focus of this article is on the electroencephalogram (EEG) description of varicella zoster encephalitis and secondary vasculopathy because EEG descriptions are scarce in the literature and detailed descriptions are lacking. In this patient's EEG, right temporal theta waves were found in combination with a mild slowing of the background rhythm to 7.5 to 8 Hz in the acute stage with an amplitude asymmetry (right temporal lobe amplitudes were significantly higher compared with the left side). The theta waves were thought to originate from the ischemic lacunar stroke, the slowing of the background rhythm from early encephalitis, and the amplitude asymmetry was presumed to be of physiologic origin. A follow-up EEG 6 days after initiation of treatment with acyclovir showed a normal symmetrical background rhythm of 8 to 8.5 Hz, wherein the theta waves were significantly reduced in abundance, and the amplitude asymmetry was unchanged. In conclusion, the EEG may localize focal abnormalities possibly due to cortical or lacunar ischemia, which could be explained by early small and/or large vessel vasculopathy in patients with suspected VZV encephalitis.