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Biomedical subjects

W O Tatum

Publications and source records attributed to W O Tatum.

At least 19 recordsLinked to original sources
PubMed2004

Short-term outpatient EEG video with induction in the diagnosis of psychogenic seizures.

To analyze the yield of short-term outpatient EEG video monitoring, the authors reviewed data on all patients who underwent this procedure at their center. All patients were suspected of having psychogenic nonepileptic seizures (PNES) on clinical grounds. The total number of cases of short-term outpatient EEG video monitoring was 74. In 49 (66%) cases, the suspected diagnosis of PNES could be confirmed, thereby obviating the need for prolonged inpatient EEG video monitoring.

Adolescent↗
PubMed2004

Vagus nerve stimulation for pharmacoresistant epilepsy: clinical symptoms with end of service.

PURPOSE: Limited capability exists to predict when vagus nerve stimulation (VNS) battery deterioration becomes significant. Initial models last 2-5 years. We evaluated the first 18 patients with pharmacoresistent epilepsy after reimplantation to examine the clinical course observed during VNS end of service (EOS). METHODS: Of 72 patients with VNS, 18 patients had generator replacement. EOS was estimated based on duration of use and stimulus parameters in accordance with manufacturer guidelines. Eight males and ten females had pharmacoresistent epilepsy for a mean of 17.9 years. Thirteen with localization-related epilepsy (LRE) and 5 nonverbal patients with symptomatic generalized epilepsy (SGE) failed a mean of 11.1 antiepileptic drugs (AEDs) over 21.5 years. Seven had intracranial evaluations and five failed epilepsy surgery. Reimplantation was performed after a mean of 34.4 months. Symptoms at end of service (EOS) were addressed by postoperative survey submitted at initial reprogramming within 2 weeks of reimplantation. Stimulus parameters were compared before and after surgery. RESULTS: Nine of thirteen (69.2%) verbal patients and 11 of 18 (61.1%) total patients had signs or symptoms prior to replacement, suggesting clinical EOS, and 4 of 18 (22.2%) failed interrogation denoting battery failure without symptoms; however, this did not reach significance (chi2=0.359,p=0.54). Increased seizures were the most frequent sign in 8 of 18 (44.4%), with intensification in 7 of 18 (38.9%). Irregular stimulation was detected in 5 of 18 (27.7%), with less intense stimulation in 4 of 18 (22.2%). Painful stimulation and behavioral worsening each occurred in 2 of 18 (11.1%). A subjective improvement in function after reimplantation was noted in 12 of 13 (92.3%) verbal patients, with greater intensity and consistency. Maximally tolerated reimplant current averaged -0.56 mA less. All but one (94.4%) felt surgery should be performed before clinical EOS occurred. CONCLUSIONS: We conclude that clinical signs and symptoms may arise during VNS EOS and following replacement. Seizure increase or a change in seizure pattern was most frequently observed. The tolerated reimplant current was less than the preoperative output current in most cases. Battery replacement before EOS appears desirable from a patient perspective.

Adolescent↗
PubMed2004

Diffusion-weighted imaging and status epilepticus during vagus nerve stimulation.

PURPOSE: Transient abnormalities have been reported on diffusion-weighted imaging (DWI) during status epilepticus. Vagus nerve stimulation (VNS) is a therapy for epilepsy that has previously demonstrated alteration in regional cerebral blood flow on functional neuroimaging. We describe the peri-ictal DWI abnormalities in a patient with status epilepticus. METHODS: A 21-year-old woman with pharmacoresistant localization-related epilepsy was treated with VNS and underwent brain magnetic resonance imaging (MRI) with DWI for clinical purposes. RESULTS: Transient and reversible hyperintense signal abnormalities were noted on DWI at the site of seizure onset, in addition to the thalamus and midbrain bilaterally. A concomitant decrease in the apparent diffusion coefficient mimicked ischemia, yet complete clinical, and electrographic resolution occurred following successful termination of status. CONCLUSIONS: High-energy brain MRI sequences using DWI were safely performed in our epilepsy patient with a vagus nerve stimulator who experienced status epilepticus. This case highlights the bilateral and robust involvement of subcortical structures present immediately following status epilepticus. Additionally, bilateral abnormalities in the thalamus and midbrain in addition to the region of seizure origin, were observed in our patient implanted with a vagus nerve stimulator. Modulation of regional cerebral blood flow is one potential mechanism of action for VNS in humans; therefore, these regions of involvement could reflect the effects of status epilepticus, activation or facilitation by VNS, or both.

Adult↗
PubMed2001

How many patients with psychogenic nonepileptic seizures also have epilepsy?

The proportion of patients with psychogenic nonepileptic seizures (PNES) who also have epilepsy has been reported to vary from 10% to over 50%. The authors reviewed all 32 patients diagnosed with PNES in our EEG-video monitoring unit over a period of 1 year, and only 3 (9.4%) had interictal epileptiform discharges to support a coexisting diagnosis of epilepsy. Thus, the authors believe that only a small proportion of patients with PNES have coexisting epilepsy.

Adult↗
PubMed2001

Advances in the treatment of epilepsy.

Significant advances have been made in the diagnosis and treatment of epilepsy over the past decade. With the advent of electroencephalographic video monitoring, physicians are now able to reliably differentiate epilepsy from other conditions that can mimic it, such as pseudoseizures. In addition, neuroimaging has changed the way treatment for difficult epilepsy is approached. As a result, the classification systems that have been in use since the early 1980s are currently being revised. A broader range of treatment options for epilepsy is now available. Many new antiepileptic drugs have become available in recent years, including felbamate, gabapentin, lamotrigine, topiramate, tiagabine, levetiracetam, oxcarbazepine and zonisamide. These medications offer options for patients with epilepsy whose seizures cannot be controlled using the classic agents. Several classic antiepileptic drugs have been modified and reformulated. The ketogenic diet has resurfaced as a treatment option in certain types of epilepsy. The vagus nerve stimulator, approved in 1997, represents a completely new treatment modality for patients with seizures not controlled by medications. Epilepsy surgery is now a well-documented and effective treatment for some patients with intractable epilepsy.

Anticonvulsants↗
PubMed2001

Vagus nerve stimulation and drug reduction.

The authors prospectively assessed drug reduction and patient satisfaction in 21 patients using vagus nerve stimulation (VNS) for refractory epilepsy and compared results to a case-matched control group with a mean follow-up of 13.2 months. Significant antiepileptic drug (AED) reduction occurred in 9/21 (42.9%) of VNS patients averaging 0.43 AED/patient, with dose reduction in four patients (19.0%). For 12/21 (57.1%) patients not reducing AED, dose reduction occurred in 6/21 (28.6%). Drug and dose reduction of AED is possible in patients using VNS for refractory epilepsy without loss of seizure control and with improved patient satisfaction.

Adolescent↗
PubMed2001

Postmarketing experience with topiramate and cognition.

Ideal antiepileptic drugs (AEDs) are designed to stop seizures with limited central nervous system (CNS) side effects. However, CNS-related treatment-emergent adverse events (TEAEs) often occur in patients receiving AEDs. Topiramate (TPM) is an AED proven to be safe and effective as adjunctive treatment for epilepsy patients with partial seizures. Double-blind, placebo-controlled, multicenter trials demonstrated potential effects on cognition. The P.A.D.S. (post-marketing antiepileptic drug survey) group, a cooperative group of 14 epilepsy centers that collaborate on obtaining data about new AEDs and devices, prospectively collected standardized data forms before and during treatment with TPM for epilepsy, and analyzed the postmarketing experience of CNS TEAEs with TPM. Our results from 701 treated patients show that cognitive complaints were the most common reason to discontinue TPM. The presence of complaints did have predictive value if the patient would discontinue TPM, although was not specific as to when discontinuation would occur. The spectrum of complaints in our open-label prospective multicenter postmarketing study was similar to those observed in controlled clinical trials. We were unable to demonstrate a specific population, dose titration, or concomitant AED that was at risk to discontinue treatment. We conclude that most patients treated with TPM will continue therapy beyond 6 months. Cognitive complaints and not efficacy reflect the primary reason for discontinuing therapy. Psychomotor slowing was the most common complaint, yet most patients elect to continue treatment, with "better" or "much better" ratings of both seizure and global improvement during treatment.

Adolescent↗
PubMed2001

MRI of the brain is safe in patients implanted with the vagus nerve stimulator.

Metallic devices generally represent a contra-indication for MRI scanning. Based on laboratory testing, the neuro cybernetic prosthesis (NCP) is labelled MRI compatible when used with a send and receive head coil. However, there are no published clinical data to support the safety of brain MRI in patients with the NCP. Our objective was to report clinical experience with such a population. We questioned 40 centres that had implanted the NCP system as of 10/1/99. If MRI had been performed on any vagus nerve stimulator patients, we collected information on these patients, the MRI technique used, any events noted during the scan, including both subjective reports (by the patient ), and observable (objective) changes noted by the staff. Twelve centres (30%) responded. Over a time period of 3 years, there were a total of 27 MRI scans performed in 25 patients. All scanners were 1.5 T. A head coil was used in 26 scans, and a body coil in one. The indications for the scans were diverse. Seven were related to the epilepsy, including aetiology or pre-surgical evaluation. Others were unrelated, including brain tumours, cerebral haematoma, vasculitis, headaches, and head trauma. Three scans were performed with the stimulator on, while 24 were performed with the stimulator off. One patient had a mild objective voice change for several minutes. No other objective changes were noted in any of the patients. One 11-year old reported chest pain while experiencing severe claustrophobia. Twenty-five patients denied any discomfort around the lead or the generator. We conclude that this clinical series supports the safety of routine brain MRI using a send and receive head coil in patients implanted with the NCP System.

Adolescent↗
PubMed2001

Outpatient seizure identification: results of 502 patients using computer-assisted ambulatory EEG.

Patients with epilepsy may not always be able to identify their seizures. Epilepsy management relies on patient reporting to validate whether seizures occur during treatment. The goal of this study was to assess the frequency of unreported seizures recorded during routine outpatient ambulatory EEG recording. The authors reviewed 552 records from 502 patients who underwent outpatient 16-channel computer-assisted ambulatory EEG monitoring (CAA-EEG). Seizure identification was evaluated by assessing push-button activation. Partial seizures were seen most commonly. A total of 47 of 552 records (8.5%) had partial seizures recorded on CAA-EEG, with 29 of 47 (61.7%) with electroclinical seizures identified by push-button activation. Seizures on EEG without push-button activation were analyzed separately and compared with a self-reported written diary to verify lack of recognition. A total of 18 of 47 records (38.3%) had some partial seizures that were unrecognized by the patient, and 11 of 47 records (23.4%) had seizures recognized only by the computer. The authors conclude that patients frequently have seizures outside of the hospital that go unrecognized. Underreporting of seizure frequency occurs in the outpatient setting and impacts optimal diagnosis and treatment for patients with epilepsy.

Adolescent↗
PubMed2001

Long-term EEG monitoring: a clinical approach to electrophysiology.

Long-term electroencephalographic monitoring (LTM) is the capability of recording the EEG over long periods of time and not a specific duration. Prolonged EEG recording is used primarily for epilepsy monitoring, but LTM is also used in the intensive care unit, the operating room, and in the emergency department. The purpose of LTM is to expand the limited time sampling associated with shorter "routine" EEG recording. Audiovisual monitoring may also be used in conjunction with LTM to evaluate simultaneously a specific clinical behavior that may or may not be associated with EEG alteration. This is typically performed in a hospital setting for safety and ancillary testing purposes. LTM is used most frequently in the diagnosis and management of seizures and "spells," but has also gained wider application in the evaluation of sleep disorders, cerebrovascular disease, psychiatric conditions, and movement disorders. Computer-assisted LTM systems that process, analyze, compress, and store data digitally have become widely available in clinical practice both in the hospital as well as outside the hospital when the patient is ambulatory.

Diagnosis, Differential↗
PubMed2000

Induction of psychogenic nonepileptic seizures without placebo.

The diagnosis of psychogenic nonepileptic seizures (PNES) can only be made with EEG-video monitoring. The authors describe a provocative technique without placebo. Patients with a clinical suspicion for PNES underwent an activation procedure using suggestion, hyperventilation, and photic stimulation. Of 19 inductions performed, 16 (84%) were successful in inducing the habitual episode. The authors' technique had a sensitivity comparable to those using placebo (e.g., saline injection), but does not have disadvantages.

Adult↗
PubMed1999

Ventricular asystole during vagus nerve stimulation for epilepsy in humans.

Electrical stimulation of the vagus nerve, a recently available option for patients with refractory epilepsy, has demonstrated safety and efficacy. We report four patients with refractory epilepsy who experienced ventricular asystole intraoperatively during initial testing for implantation of the vagus nerve stimulator. Acute intraoperative vagus nerve stimulation may create ventricular asystole in humans. Extracorporeal cervical vagus nerve stimulation testing with continuous EKG monitoring intraoperatively before generator implantation is warranted.

Adult↗
PubMed1998

Seizures in Klinefelter's syndrome.

This study describes the clinical spectrum of patients with Klinefelter's syndrome and seizures. Klinefelter's syndrome is a sex chromosomal abnormality and the most common cause of male hypogonadism. It is characterized by cognitive dysfunction, hypogonadism, and abnormalities of physical maturation. Neurologic impairment has been recognized, but seizures have received little attention. The authors describe three American patients and discuss nine additional patients from two European centers previously reported with Klinefelter's syndrome and seizures. The most common profile of patients with Klinefelter's syndrome and seizures includes mental retardation, behavior problems, epileptiform electroencephalograms (EEGs), and generalized tonic-clonic seizures. The seizures of six of 11 patients with epilepsy were well controlled with antiepileptic drugs. One patient had a single seizure and was not treated with medication. In patients with Klinefelter's syndrome and recurrent seizures, the electroclinical spectrum is heterogenous and outcome with antiepileptic drug treatment is favorable.

Adolescent↗
PubMed1998

Epileptic pseudodementia.

Dementia is a frequent cause of memory loss with aging. The incidence of complex partial seizures sharply rises after age 60. Complex partial seizures that occur with subtle clinical signs or loss of awareness, or occur during sleep may defy identification. We report five elderly patients fearing dementia in whom memory dysfunction was due to unrecognized complex partial seizures.

Aged↗