Leopold Johann Streletz

Thomas Jefferson University | Jefferson · Department of Neurology

[This corrects the article DOI: 10.1371/journal.pone.0213319.].

Objective To determine if corneal confocal microscopy can identify corneal nerve and endothelial cell abnormalities and may be useful in the prognostication of patients with transient ischemic attack [1] or minor ischemic stroke (IS). Methods Thirty-six patients admitted with TIA (n = 14) or minor IS (n = 22) underwent transcranial Doppler evaluat...

Introduction The Arabian Gulf region is rapidly developing, with major changes in lifestyle that can increase the risk of cardiovascular diseases, including TIA and stroke. Stroke constitutes a major cause of morbidity and mortality in Qatar. Cerebral auto-regulation (AR) is an intrinsic protective mechanism guaranteeing hemodynamic integrity of c...

BACKGROUND The Arabian Gulf region is rapidly developing, with major changes in lifestyle that can increase the risk of cardiovascular diseases, including TIA and stroke. Stroke constitutes a major cause of morbidity and mortality in Qatar. Cerebral auto-regulation is an intrinsic protective mechanism guaranteeinghemodynamic integrity of cerebral c...

Background: Most of the evidence -so far- in support of the link between Transient Ischemic Attack (TIA) and the development of future stroke are -in fact- based on epidemiological rather than scientific evidence. Meanwhile, Current prediction models for long-term prognosis in TIA and stroke patients have limited validity as discrimination between...

Objective: This study reports the prevalence of Nonconvulsive Status Epilepticus (NCSE) in patients with altered mental status (AMS), and describes the clinical presentation, etiology, neurophysiological findings, neuroimaging, treatment, and outcome of NCSE in Qatar. Recording duration of continuous EEG monitoring was also discussed. Methods: Thi...

Objective: This study reports the prevalence of Nonconvulsive Status Epilepticus (NCSE) in patients with altered mental status (AMS), and describes the clinical presentation, etiology, neurophysiological findings, neuroimaging, treatment, and outcome of NCSE in Qatar. Recording duration of continuous EEG monitoring was also discussed. Methods: This...

Introduction Stroke is a major burden on the health system due to high fatality and major disability in survivors. Whilst Stroke incidence has declined in the developed world, it continues to increase in developing nations, including the MENA (Middle East and North Africa) region. This may reflect different risk factors and strategies to treat and...

Objective: Qatar is a small country on the Eastern coast of the Arabian Peninsula. Its population is a unique mixture of native citizens and immigrants. We aimed to describe the features of epilepsy in Qatar as such information is virtually lacking from the current literature. Methods: We summarized information retrospectively collected from 468...

Introduction Stroke, a neurological disorder that continues to be considerable burden on health systems due to high fatality rates and a major disability in survivors. Despite a decline in stroke incidence in the developed world, developing nations are still facing the problem at its eminent peak. Over 80% of all stroke deaths in the world occur in...

Background There has been some anecdotal evidence linking certain infectious pathogens (such as Chlamydia pneumoniae) with stroke. C. pneumoniae infection may be one of several contributing factors for the development of inflammation of blood vessels and atherosclerosis. Furthermore, a number of inflammatory markers (such as plasma CRP, fibrinogen,...

Background: Numerous signal processing techniques have been proposed for automated spindle detection on EEG recordings with varying degrees of success. While the latest techniques usually introduce computational complexity and/or vagueness, the conventional techniques attempted in literature have led to poor results. This study presents a spindle...

Development of a Web-based Hybrid Registry for Acute Stroke in Qatar Leopold J. Streletz1,2, Saadat I. Kamran1,2, Mohammad Shahzad1, Reggie Cruze1, Naveed Akhtar1,2, Ahmed Elsotouhy2, Ahmed Khattab3, Damian Jenkinson3, 1Weill Cornell Medical College-Qatar, 2Hamad General Hospital and Hamad Medical Corporation, Doha, Qatar, 3Bournemouth University,...

Characteristic movements of human body parts ranging from eye twitches to limbs jerky movements have been used for decades by physicians as clinical indicators of certain neurological disorders. Through a multidisciplinary research approach, our team, composed of medical experts, signal-processing specialists, wireless sensing experts, and computer...

To report the intraoperative neurophysiologic discovery of clinically unsuspected non-decussation of the somatosensory and motor pathways. We performed somatosensory evoked potential (SEP) and transcranial electric stimulation (TES) muscle motor evoked potential (MEP) monitoring during scoliosis surgery for a 16 year old patient with familial horiz...

A 17-year-old boy was involved in an accident the, details of which are not well known. It was felt that. he might have had some type of questionable arrest from which he was resuscitated and intubated and assessed as being in "deep coma" by the referring hospital. At our hospital, he was found to be completely unresponsive below the eyes. The only...

Abnormalities of body temperature are perhaps the most common features in many systemic pathologic processes. Such pathologic alterations are nearly always the result of extrinsic factors (for example, systemic pyrogens) which affect the hypothalamic thermoregulatory center by way of circulatory system. Much less common is alterations in temperatur...

Definitive neuroimaging of the brain using computerized tomography (CT) or magnetic resonance imaging (MRI) in extracorporeal membrane oxygenation (ECMO)-treated infants must be delayed until after this therapy is completed. Bedside head ultrasound (HUS) and electroencephalography (EEG) studies during ECMO, if highly correlated with later definitiv...

Peroxynitrite has been implicated in the pathogenesis of multiple sclerosis (MS) and its animal model experimental allergic encephalomyelitis (EAE). Previously, we have shown that administration of uric acid (UA), a peroxynitrite scavenger, is therapeutic in EAE We have also shown that MS patients have lower levels of serum uric acid than healthy i...

Extracorporeal membrane oxygenation is an effective rescue treatment for severe cardiorespiratory failure in term or near-term neonates, although a wide range of neurologic sequelae have been noted in a substantial minority of survivors. The objective of the present study was to determine the value of the neonatal electroencephalogram (EEG) for pre...

Ultraviolet radiation can be transmitted through the ocular media, as well as stimulate the retina, in some invertebrate, vertebrate and mammalian species. This study sought to determine if near ultraviolet radiation (UV-A) can elicit visual evoked potentials (VEPs) in young humans. VEP responses to 10 nm half-peak bandwidths of 340, 360 and 500 nm...

We determined the sensitivity and specificity of neonatal brain-stem auditory evoked potentials (BAEP) as markers for subsequent hearing impairment and for developmental problems found later in infancy and childhood. BAEP studies were performed before discharge in infants treated with extracorporeal membrane oxygenation (ECMO), and two specific abn...

We sought to determine the esophageal sensory function in patients with a C6 or C7 spinal cord injury. A balloon was repetitively distended 10 cm above the lower esophageal sphincter in five patients and nine normal control subjects. Sensation was reported on a scale from 0 to 2 with progressive distension to pain threshold (level 2). Cortical resp...

A recent study from this laboratory using visual evoked potentials (VEPs) demonstrated that children's eyes are capable of detecting ultraviolet radiation. The aim of this study was to compare dose-response relationships in two age groups, 6-10 years (n = 10) and 20-25 years (n = 10). Under photopic viewing conditions (550 lux), exposures of monoch...

We sought to determine the esophageal sensory function in patients with a C6 or C7 spinal cord injury. A balloon was repetitively distended 10 cm above the lower esophageal sphincter in five patients and nine normal control subjects. Sensation was reported on a scale from 0 to 2 with progressive distension to pain threshold (level 2). Cortical resp...

This investigation examined the motor pathways of four, C5-6 spinal cord injured (SCI) patients within 6-17 days of injury. Mapping of the motor cortex was achieved by transcranial magnetic stimulation (TMS) applied to the scalp. Motor evoked potentials were recorded from target muscle groups (Biceps brachii and Abductor pollicis brevis m.). Eviden...

We studied the prognostic significance of electroencephalograms recorded serially at 2- to 4-day intervals during the acute neonatal course of 119 near-term infants with severe respiratory failure treated by venoarterial extracorporeal membrane oxygenation (ECMO). A poor prognosis was defined as early death (n = 27), an abnormally low developmental...

Right common carotid artery (RCCA) ligation after extracorporeal membrane oxygenation by venoarterial bypass may contribute to lateralized cerebral injury. Reconstruction of this artery after extracorporeal membrane oxygenation has proved feasible but has not been evaluated for neurologic outcome in any substantial series of infants. We evaluated R...

Color Doppler imaging revealed a subclavian steal--retrograde flow in the right vertebral artery which shunted blood from the brain's posterior circulation to the right arm via the subclavian artery--in 17 of 54 infants (31%) during extracorporeal membrane oxygenation (ECMO); right vertebral artery flow returned to antegrade after ECMO and removal...

Cerebral evoked potentials (EPs) represent a new technique for the evaluation of afferent outflow from the gastrointestinal tract. We compared EPs obtained with distension of the distal and proximal esophagus. Responses were recorded with the balloon 5 cm proximal to the lower esophageal sphincter and 3 cm distal to the upper esophageal sphincter....

Cerebral evoked potentials (EPs) represent a new technique for the evaluation of afferent outflow from the gastrointestinal tract. We compared EPs obtained with distension of the distal and proximal esophagus. Responses were recorded with the balloon 5 cm proximal to the lower esophageal sphincter and 3 cm distal to the upper esophageal sphincter....

The purpose of this study was to non-invasively evaluate the homuncular organization of the motor cortex in man. We used transcranial magnetic stimulation to induce motor evoked potentials (MEP's) in Abductor Pollicis Brevis (APB) and Biceps Brachii (BB) muscles of 10 healthy volunteers. The practicality and accuracy of magnetic stimulation to scal...

Tc-99m HMPAO brain SPECT was performed in a patient who had partial complex seizures for 1 year after successful acyclovir treatment of biopsy-proven herpes simplex encephalitis 2 years earlier. In spite of antiepileptic medications, her seizures were intractable and occurred daily. Tc-99m HMPAO was administered intravenously while she was having s...

We found electroencephalographic (EEG) studies to be useful for monitoring cerebral function, for confirming seizure activity, and for limited prediction of short-term outcome in 145 neonates who required extra-corporeal membrane oxygenation (ECMO) of reversible respiratory failure. The EEG tracings were classified as normal or as mildly, moderatel...

Transcranial magnetic stimulation was performed on 25 patients with definite multiple sclerosis. Motor evoked potentials were recorded from the anterior tibial muscle. Central motor conduction time was calculated using the equation (F + M-1)/2 by stimulation of the common peroneal nerve. Motor evoked potentials were capable of detecting subclinical...

To determine central conduction times in the corticospinal pathways of humans using magnetic stimulation, we have developed a method for consistently recording conduction times between the motor cortex and the L4-5 level of the spinal cord. In 30 subjects, motor evoked potentials (MEPs) were recorded from the tibialis anterior muscle following cont...

Extracorporeal membrane oxygenation (ECMO) is a modified form of heart/lung bypass therapy utilized in the full-term infant with life-threatening respiratory failure. The risks of ECMO, including intracranial hemorrhages and their subsequent effects, make it important to check the condition of brain function before, during, and after ECMO therapy....

Computer analysis of the EEG was obtained in the course of evaluation of 35 patients with Dementia of the Alzheimer's Type (DAT) and Huntington's disease (HD), and compared to 20 age-matched normal controls. On-line computer analysis of the EEG consisted of: 1) compressed spectral array (CSA) displays (2-6 channels); 2) relative frequency power (4...

Forty-six neonatal infants treated with extracorporeal membrane oxygenation (ECMO) because of respiratory failure had cranial ultrasound (US) and EEG studies during and within one week following ECMO. All had US studies and 12 had EEGs prior to ECMO therapy. An EEG was also obtained in three infants during cannulation of the right common carotid ar...

Somatosensory evoked potentials (SEP) were recorded in a 15 year old patient with multiple thoracic cord meningiomas. Lack of improvement of the quantitative SEP parameters added objective measurement to postoperative assessment of the patient and confirmed the need for further surgery. Clinical follow-up and correlation with SEP parameters of the...

Since controversy continues concerning the value of routine electroencephalographic (EEG) monitoring and selective carotid bypass shunting, we reviewed the neurological morbidity and mortality following elective carotid endarterectomy in 172 patients with symptomatic carotid occlusive disease. The use of EEG monitoring and selective shunting was as...

Brainstem auditory evoked potentials (BAEP) were studied in 93 newborns (49 preterm and 44 fullterm) admitted to the neonatal intensive care unit. One group of 42 infants (28-42 wk CA) were considered at low risk for perinatal complications and served to establish the normal ranges of the BAEP parameters (wave I peak latency and wave I-V interwave...

A general-purpose minicomputer has been adapted and interfaced for the averaging and analysis of clinical evoked potentials and for compressed spectral arrays (CSA) of the routine EEG. In the first 2 years of operation, over 1,000 routine clinical studies of visual evoked potentials (VEP) and brainstem auditory evoked potentials (BAEP) have been pe...

Progressive multifocal leukoencephalopathy occurred in two homosexual men affected with acquired immune deficiency syndrome (AIDS). Both patients received HLA-matched platelet transfusions in an attempt to increase their immune status, but we were unsuccessful in altering their fatal clinical course.

We report on a family with an apparently X-linked neuromuscular disease. Electrophysiologic tests and electron microscopic studies are consistent with the diagnosis of hereditary motor sensory neuropathy type II (HMSN-II), one form of Charcot-Marie-Tooth disease. The manner of inheritance, the observation that males are severely affected from infan...

Brainstem Auditory Evoked Potentials (BAEP) were recorded in 24 high risk neonates in the intensive care unit. The following risk factors were present alone or in combination in all subjects: birth-weight below 1500 gm, gestational age below 33 weeks, intracranial hemorrhage, birth asphyxia, respiratory distress syndrome, sepsis and seizures. The i...

The visual evoked potential to pattern reversal was recorded in 50 patients with sarcoidosis. Abnormalities of latency and amplitude were found in 15 patients (30%), including all 4 patients with clinically evident brain disease and 4 of 17 patients with overt ocular disease. Twenty-nine patients had no clinical evidence of ocular or neurologic dis...

Forty low risk newborn infants were studied with conceptual ages between 28 and 42 weeks. They were distinguished from high risk infants on the basis of neonatal medical complications. Brainstem auditory evoked potentials (BAEP) were recorded from vertex-ipsilateral and contralateral ear reference sites. Monaural 70 dBHL rarefaction clicks were pre...

Recording of visual evoked potentials (VEPs) to pattern reversal is considered to be a reliable diagnostic procedure for examining patients with anterior visual pathway lesions (optic nerves and chiasm). Less consistent results have been reported in studies of more posterior lesions. The VEPs were recorded in 20 patients with occipital lobe lesions...

40 rats were subjected daily for 6 months to an atmosphere containing 50ppm MnBK. 32 of the rats presented with demyelination of the sciatic nerve and 2 of these with axonal hypertrophy.

40 rats were subjected daily for 6 months to an atmosphere containing 50 ppm MnBK. 32 of the rats presented with demyelination of the sciatic nerve and 2 of these with axonal hypertrophy.

Tellurium-induced neuropathy: correlative physiological, morphological and electron microprobe studies Elemental tellurium (Te) was included in the normal diet of 15–day-old rats and every day thereafter for 35 days. Within 24 hours a segmental demyelination was seen in the sciatic nerve. On the 2nd day, Te was localized in the cytoplasm of the Sch...

We have studied two cases of the syndrome of myokymia and impaired muscular relaxation with continuous motor unit activity. Both patients complained of muscle twitching, weakness, stiffness, and hyperhydrosis during their illness. Myokymia was present over the entire body in both. On repetitive testing of muscle strength each patient showed initial...

Early (0-8 msec), middle (8-50 msec) and long (50-500 msec) latency auditory evoked potentials (AEPs) were recorded from the scalp, ear, nose and mastoid regions of normal adult subjects using a balanced sternovertebral non-cephalic reference system. This study intended to differentiate neurogenic from myogenic components. Components judged to be n...

Although no therapeutic agent has proved to be of benefit in subacute sclerosing panencephalitis (SSPE), the use of Isoprinosine has been associated with clinical improvement in several preliminary reports. Two additional patients with SSPE are presented who had repeated serological and electroencephalographic studies during therapy with Isoprinosi...