PubMed Health⌕ Search

Biomedical subjects

O N Markand

Publications and source records attributed to O N Markand.

At least 19 recordsLinked to original sources
PubMed2000

Near infrared spectroscopy (NIRS) distinguishes seizure types.

Near infrared spectroscopy (NIRS) is a noninvasive method for bedside measurement of cerebral oxygenation (SaO(2)). The purpose of this study was to establish differences in SaO(2)for complex partial seizures (CPS) and rapidly secondarily generalized CPS (RCPS). We studied eight adults with medically refractory epilepsy undergoing evaluation for temporal lobectomy. We continually measured cerebral SaO(2)via a Somanetic Invos 3100a cerebral oximeter, pre-ictal (5 minutes), ictal, immediate (30 seconds) post-ictal, and late post-ictal (5 minutes after ictus). Seventeen seizures (12 CPS, four RCPS and one subclinical) were recorded in eight patients. The percentage change in cerebral SaO(2)from pre-ictal to ictal periods was derived. Cerebral SaO(2)increased (percentage change, mean: 16.6, SD: 13.9) for CPS and decreased (percentage change, mean: 51.1, SD: 18.1) for RCPS. No change in cerebral oximetry was recorded for the subclinical seizure. Post-ictal (immediate and late) increase in cerebral SaO(2)was seen for 11 of the 17 seizures (nine CPS and two RCPS). Peripheral SaO(2)rose greater than 93% for all CPS and the subclinical seizure, but decreased between 78 and 84% during RCPS. These results suggest NIRS distinguishes cerebral SaO(2)patterns between CPS and RCPS. The decrease in peripheral SaO(2), however, may account for the decrease in cerebral SaO(2)seen in generalized seizures.

Adult↗
PubMed2000

Health-related quality of life outcome in medically refractory epilepsy treated with anterior temporal lobectomy.

PURPOSE: A prospective study to investigate health-related quality of life (HRQOL) outcome in patients with temporal lobe epilepsy treated with anterior temporal lobectomy (ATL). METHODS: The majority of the patients with medically refractory focal epilepsy had Quality of Life in Epilepsy-89 (QOLIE-89) assessment at the time of prolonged video/EEG monitoring as part of their presurgical evaluation. Thirty-seven patients who were not treated surgically constituted the control group, and 53 patients who underwent ATL made up the surgery group. Both control and surgery groups had HRQOL assessment repeated at approximately 1-and 2-year intervals. Repeated measures analysis of variance (ANOVA) was used to test for differences between the two groups. RESULTS: For the overall score and almost every scale, the surgery group had a higher baseline mean than the control group. Because of this baseline difference, change scores were used in further analysis. The overall score and 10 of 17 scales in QOLIE-89 showed significant HRQOL improvement after ATL, and the improvement was significant relative to score changes of the nonsurgical comparison group. Scores improved in overall QOL, emotional well-being, attention/concentration, language, social isolation, health perception, role limitations-physical, work/drive/social, health discouragement, and seizure worry. For the first five scales, there was group-time interaction; the improvement was significantly more on the 2-year than on the 1-year follow-up. When the surgery patients were divided into four categories (class IA-, completely seizure free; class IA+, seizure free with aura; class II, rare seizures; class III, worthwhile improvement in seizure control; and class IV, no improvement), the improved HRQOL in the surgery group was almost entirely contributed by the class IA- outcome patients who were totally seizure free. The class IA+ patients with continuing aurae and class II/III/IV patients had no significant improvement in their overall HRQOL scores at 1-or 2-year follow-up. CONCLUSIONS: Overall score and 10 of the 17 scales of QOLIE-89 significantly improved in patients with medically refractory temporal lobe epilepsy after ATL. For some scales, there was delay in the improvement to manifest. The HRQOL improvement was related to achieving an entirely seizure-free status (i.e., no seizures or aurae postoperatively).

Adolescent↗
PubMed1999

The contribution of life events to pseudoseizure occurrence in adults.

Life events associated with pseudoseizures were studied in 58 adults. Recent precipitants were diverse and triggered affect that was usually related to current life problems or remote trauma. Four patterns of remote and recent events were found, two related to trauma and two to inadequate emotional expression. When evaluating pseudoseizure precipitants, clinicians should consider the meaning of recent events in light of remote trauma, current life context, and dysfunctional familial patterns of handling affect.

Adaptation, Psychological↗
PubMed1997

Comparative study of interictal PET and ictal SPECT in complex partial seizures.

OBJECTIVE: To compare the sensitivity of ictal 99mTc-HMPAO single photon emission computed tomography (SPECT) with interictal 18F-fluoro-deoxyglucose positron emission tomography (PET) in localization of the epileptogenic focus in patients with medically intractable complex partial seizures (MI-CPS). MATERIAL AND METHODS: Retrospective analysis was performed on patients with MI-CPS who underwent anterior temporal lobectomy from January 1993 onwards when PET became available to us for clinical studies at the Indiana University Medical Center. There were 38 female and 29 male patients (total = 67) with MI-CPS, 10 to 55.5 years of age (mean 31) and duration of their epilepsy from 1-46 years (mean 21). Interictal PET was evaluated for evidence of focal hypometabolism and ictal SPECT for focal perfusion abnormality (hyperperfusion or hypoperfusion) by visual analysis. RESULTS: Both ictal SPECT and interictal FDG-PET studies were obtained in 36 patients with MI-CPS. PET showed definite hypometabolism in 30 and questionable hypometabolism in an additional two patients. Ictal SPECT correctly localized the seizure focus in 27 patients by demonstrating ictal hyperperfusion whereas in one the hyperperfusion was falsely localized. In an additional seven patients the ictal SPECT provided probable localization by demonstrating ictal hypoperfusion in the appropriate temporal lobe. The sensitivity of ictal SPECT and interictal PET was 34/36 and 32/36, respectively, the difference was not statistically significant (chi 2y = 0.18, DF = 1, P = 0.67). In six of the 36 patients the two tests were complementary to each other in providing localizing information. CONCLUSION: Ictal SPECT and interictal PET are equally sensitive and reliable techniques in localizing the epileptogenic focus in patients with MI-CPS. They play a critical role in providing localization in MRI negative patients allowing surgical resection to be undertaken in many without additional invasive electrographic monitoring.

Adolescent↗
PubMed1996

Diagnostic utility of video EEG monitoring in paroxysmal events.

OBJECTIVES: A retrospective study was conducted to evaluate clinical usefulness of video EEG monitoring in patients with suspected epileptic seizures. MATERIAL AND METHODS: A total of 444 patients who had diagnostic video EEG from January 1989 to December 1992 were studied after excluding those with known medically refractory focal epilepsy undergoing presurgical evaluation. Most were outpatients and had video EEG monitoring during normal working hours over 1-5 days. RESULTS: The procedure had a success rate of 73%; characteristic events were captured and categorized in 53% of the patients. Patients with an event frequency of at least one per week or those who had events characterized by motor manifestations showed a higher yield. Thirty-two percent of the patients had psychogenic seizures. Thirty-four percent of the patients had either epileptic seizures recorded during the study or showed clear-cut interictal epileptiform abnormalities providing strong evidence of underlying epileptic process. CONCLUSION: In patients with frequent paroxysmal events, a video EEG study provides diagnostically critical information. It can be performed usually as an outpatient investigation.

Adult↗
PubMed1996

Psychodynamics and psychiatric diagnoses of pseudoseizure subjects.

OBJECTIVE: The goal of this study was to determine current and lifetime rates of DSM-III-R disorders in patients with pseudoseizures and to ascertain whether trauma is associated with the occurrence of pseudoseizures. METHODS: Adult pseudoseizure patients (N = 45) were interviewed regarding seizure course and life events, and they were given the Structured Clinical Interview for DSM-III-R--Patient Version, the Structured Clinical Interview for DSM-III-R Dissociative Disorders, the Dissociative Experiences Scale, and the Personality Diagnostic Questionnaire--Revised. The pseudoseizures were diagnosed in a tertiary-care video-EEG facility. Most of the subjects (78%) were female, and the mean age of the overall patient group was 37.5 years (SD = 9.7). RESULTS: The mean duration of the subjects' seizure history was 8.3 years (SD = 8.0). Common current psychiatric diagnoses included somatoform disorders (89%), dissociative disorders (91%), affective disorders (64%), personality disorders (62%), posttraumatic stress disorder (PTSD) (49%), and other anxiety disorders (47%). The lifetime occurrence of nonseizure conversion disorders was 82%. The mean Dissociative Experiences Scale score was 20.2 (SD = 18.2). Trauma was reported by 84% of the subjects: sexual abuse by 67%, physical abuse by 67%, and other traumas by 73%. CONCLUSIONS: Pseudoseizure subjects have high rates of the psychiatric disorders found in traumatized groups; they closely resemble patients with dissociative disorders. Reclassification of conversion seizures with the dissociative disorders should be considered. Pseudoseizures often appear to express distress related to abuse reports. Clinicians should screen pseudoseizure patients for adult and childhood trauma, dissociative disorders, depression, and PTSD.

Adolescent↗
PubMed1995

Clinical correlation of periodic lateralized epileptiform discharges in children.

Fifteen children with periodic lateralized epileptiform discharges are reported and clinical and radiologic features and outcome are presented. Both structural cerebral lesions and metabolic factors were associated with periodic lateralized epileptiform discharges. Although all patients had seizures, 8 had status epilepticus. Seven patients survived and 8 patients died. Six of the 7 survivors had residual seizures. Periodic lateralized epileptiform discharges in children are associated with acute encephalopathies and there is a high incidence of subsequent epilepsy.

Adolescent↗
PubMed1994

Clinical characteristics and predictive factors in 98 patients with complex partial seizures treated with temporal resection.

OBJECTIVE: To analyze the preoperative and operative factors predictive of outcome in patients undergoing surgery for temporal lobe epilepsy. DESIGN: From 1984 to 1992, 98 patients with medically refractory temporal lobe epilepsy underwent surgery. Evaluation included the following: video electroencephalography (13 patients had intracranial recordings), head magnetic resonance imaging, interictal and ictal single photon emission computed tomography, psychometric testing, and Wada testing. Seizure-free groups and non-seizure-free groups were analyzed. Follow-up of 1 year to 8 years was available for 89 patients (mean, 3.2 years). SETTING: Indiana University Epilepsy Surgery Program, Indianapolis. OUTCOME: Sixty percent (53/89) were seizure free, 16% (14/89) had rare seizures, 13% (12/89) had worthwhile improvement, and 11% (10/89) showed no improvement. Forty-two percent of seizure-free patients had a history of febrile seizures compared with 5% of non-seizure-free patients. Ictal single photon emission computed tomography showed increased flow on the side of seizure onset in 86% of seizure-free patients compared with 62% of non-seizure-free patients. Ninety-seven percent of seizure-free patients had a pathologic diagnosis; mesial temporal structures were identified in 61%. Only 64% of non-seizure-free patients had a pathologic diagnosis, and mesial temporal structures were identified in only 36% of non-seizure-free patients. CONCLUSIONS: Eighty-nine percent (79/89) of our patients benefited from surgery. The following factors were predictive of good outcome: a history of febrile seizures; ictal single photon emission computed tomography showing increased blood flow ipsilateral to the epileptogenic zone; a pathologic diagnosis; and the presence of mesial temporal structures in the resected tissue.

Adolescent↗
PubMed1994

Brainstem auditory evoked potentials.

Brainstem auditory evoked potentials (BAEPs) have obtained widespread clinical application in assessing neurologic and audiologic problems. Seven waves (I-VII) are usually recorded in the first 10 ms following broad-band and high-intensity clicks. Latencies of waves I, III, and V, interpeak latencies of I-III, III-V, and I-V, and the amplitude ratio of wave V to wave I are common parameters evaluated for assessing clinically relevant abnormalities of BAEPs. Usually two-channel recordings are obtained: vertex (Cz) to ipsilateral ear and Cz to contralateral earlobe derivation. Evaluating different components in the two derivations helps their identification, particularly when the BAEPs are abnormal. Several technical and subject-related factors affect the amplitude and latencies of BAEP components besides lesions and dysfunctions involving the peripheral auditory structures and brainstem auditory pathways. BAEPs have maximal clinical utility in evaluating comatose patients, in patients with suspected demyelinating disorders, posterior fossa tumors, or in audiologic evaluation, especially in infants. They are also used for intraoperative monitoring of eighth-nerve and brainstem function during different types of posterior fossa surgery.

Brain Stem↗
PubMed1994

Ictal brain imaging in presurgical evaluation of patients with medically intractable complex partial seizures.

At the Indiana University Medical Center, 99 patients with medically intractable complex partial seizures (MI-CPS) had presurgical evaluation with subsequent anterior temporal lobectomy. The majority of the patients had single photon emission tomography (SPECT) performed interictally as well as during an actual epileptic seizure (ictal scan). Decreased regional cerebral perfusion (rCP) was seen in 54/94 (57%) of the interictal scans corresponding to the eventual site of the surgery. However, ictal scans provided a higher yield; increased rCP in the temporal lobe during an actual seizure was observed in 60/82 (73%) concordant to the side of surgery. SPECT is a useful, noninvasive method of localizing the epileptiform focus in patients with MI-CPS considered for resective surgery. Both interictal and ictal SPECT need to be performed; combined interictal hypoperfusion and ictal hyperperfusion in the same focal area are unique to epileptogenic lesions. Ictal SPECT studies can be performed in the majority of patients during the period of continuous video/EEG monitoring with only a little additional effort. Combining the results of functional brain imaging (interictal and ictal SPECT, PET) with clinical semiology of seizures, surface and sphenoidal EEG, magnetic resonance imaging and other non-invasive tests, anterior temporal lobectomy can be recommended in approximately two-thirds of the patients without resorting to potentially dangerous intracranial EEG monitoring.

Adolescent↗
PubMed1993

The influence of the reference electrode on CMAP configuration.

The ulnar, hypothenar compound muscle action potential often shows a double-peaked configuration in the negative phase component while the median, thenar potential has a simple dome shape. To investigate the origin of these differences we evaluated the activity at the belly and tendon electrode locations by referencing those sites to an electrode on the contralateral hand. The tendon sites are not electrically inactive. The ulnar tendon electrode contributes a large amplitude potential which corresponds to the second peak of the ulnar belly-tendon potential. The median tendon electrode contributes only a minimal component to the negative phase of the belly-tendon potential. The distribution of such potentials throughout the hand is evaluated and possible mechanisms for the presence of a tendon potential as well as the differences between ulnar and median sites are discussed.

Action Potentials↗
PubMed1992

Genetic and radiation hybrid mapping of the hyperekplexia region on chromosome 5q.

Hyperekplexia, or startle disease (STHE), is an autosomal dominant neurologic disorder characterized by muscular rigidity of central nervous system origin, particularly in the neonatal period, and by an exaggerated startle response to sudden, unexpected acoustic or tactile stimuli. STHE responds dramatically to the benzodiazepine drug clonazepam, which acts at gamma-aminobutyric acid type A (GABA-A) receptors. The STHE locus (STHE) was recently assigned to chromosome 5q, on the basis of tight linkage to the colony-stimulating factor 1-receptor (CSF1-R) locus in a single large family. We performed linkage analysis in the original and three additional STHE pedigrees with eight chromosome 5q microsatellite markers and placed several of the most closely linked markers on an existing radiation hybrid (RH) map of the region. The results provide strong evidence for genetic locus homogeneity and assign STHE to a 5.9-cM interval defined by CSF1-R and D5S379, which are separated by an RH map distance of 74 centirays (roughly 2.2-3.7 Mb). Two polymorphic markers (D5S119 and D5S209) lie within this region, but they could not be ordered with respect to STHE. RH mapping eliminated the candidate genes GABRA1 and GABRG2, which encode GABA-A receptor components, by showing that they are telomeric to the target region.

Base Sequence↗
PubMed1992

Single photon imaging computed tomography (SPECT) for localization of epileptogenic focus in patients with intractable complex partial seizures.

Interictal and ictal HIPDM-SPECT brain scans were obtained in 38 patients who eventually underwent temporal lobectomy for treatment of medically intractable complex partial seizures (CPS). Interictal studies revealed decreased regional cerebral perfusion (rCP) in the temporal lobe corresponding to the eventual site of surgery in 76% of the patients. Similarly, ictal studies demonstrated increased rCP in 91% of the patients. Of the 33 patients who had both interictal and ictal SPECT studies, 23 (70%) showed increased rCP in the ictal state and decreased rCP in the interictal state in the same temporal lobe which was subsequently removed. The SPECT scans were particularly helpful in providing confirmatory evidence for localization and in deciding to undertake temporal lobectomy in 16 patients whose EEG studies had provided less secure localization. Our experience suggests that interictal and ictal SPECT brain imaging can be easily obtained and provides reliable localizing information in the epileptic patients being considered for temporal lobectomy.

Adolescent↗
PubMed1990

Alpha rhythms.

Explore the source record for details and available documents.

Aging↗
PubMed1990

Presenting the diagnosis of pseudoseizure.

Simultaneous video-EEG monitoring has allowed pseudoseizures to be effectively diagnosed. Discussing the results of the monitoring with the patient is the 1st step in treatment. We outline a protocol for presenting the diagnosis of pseudoseizure with the goal of conveying to the patient the importance of knowing the nonepileptic nature of the spells and the need for psychiatric follow-up. The protocol also allows elicitation of sexual abuse history and the use of suggestion to aid in controlling the pseudoseizures.

Clinical Protocols↗
PubMed1990

HIPDM-SPECT brain imaging in the presurgical evaluation of patients with intractable seizures.

We report the results of interictal and ictal HIPDM-SPECT brain imaging in 34 patients who eventually underwent temporal lobectomy for treatment of medically intractable complex partial seizures. Interictal studies revealed decreased regional cerebral perfusion (rCP) in the temporal lobe corresponding to the eventual site of surgery in 73% of the patients. Similarly, ictal study demonstrated increased rCP in 93% of the patients. In 69% of the patients, the SPECT studies were able to demonstrate both increased rCP on the ictal scan and decreased rCP on the interictal scan in the same location, corresponding to the eventual site of surgery. These results suggest that interictal and ictal SPECT brain imaging can be easily obtained and provide reliable localizing information in the presurgical evaluation of patients with medically intractable epilepsy.

Adolescent↗