Search PubMed⌕ Search

Biomedical subjects

F W Sharbrough

Publications and source records attributed to F W Sharbrough.

At least 73 records · Page 4Linked to original sources
PubMed1993

Facial asymmetry, hippocampal pathology, and remote symptomatic seizures: a temporal lobe epileptic syndrome.

We performed a prospective study of neuroimaging studies and temporal lobe pathology in 13 patients with facial asymmetry and intractable partial epilepsy of temporal lobe origin. The 13 patients, derived from 50 consecutive patients with nonlesional medically refractory partial epilepsy, were deemed appropriate candidates for an anterior temporal lobectomy. The facial weakness occurred exclusively, or was most prominent, during emotional expression, ie, spontaneous smiling. The temporal lobe of seizure origin, demonstrated by ictal long-term EEG monitoring, was always contralateral to the side of weakness. All 13 patients had a history of early childhood neurologic disease, eg, complex febrile seizure or bacterial meningitis. Hippocampal formation atrophy was present in all the epileptic temporal lobes by MRI-based volume studies. Twelve of the 13 patients subsequently received an anterior temporal lobectomy, and mesial temporal sclerosis was present in all the surgically excised temporal lobes. Ten of the 12 patients have been seizure-free during short-term follow-up. Facial asymmetry may occur in patients with partial epilepsy related to remote symptomatic seizures and mesial temporal sclerosis.

Adolescent↗
PubMed1993

Gelastic seizures and hypothalamic hamartomas: evaluation of patients undergoing chronic intracranial EEG monitoring and outcome of surgical treatment.

We retrospectively studied 12 consecutive patients with gelastic seizures and hypothalamic hamartomas who, because of intractable epilepsy, underwent chronic intracranial EEG monitoring or epilepsy surgery. All patients had medically refractory seizures that included laughter as an ictal behavior (gelastic seizures). The hypothalamic hamartomas were identified with neuroimaging studies (12 of 12) and by pathologic verification (four of 12). Associated clinical features included behavioral disorders (n = 5), developmental delay (n = 4), and precocious puberty (n = 2). Interictal extracranial EEG predominantly showed bi-hemispheric epileptiform changes suggesting a secondary generalized epileptic disorder. Intracranial EEG recordings, performed in eight patients, indicated the apparent focal onset of seizure activity (anterior temporal lobe [n = 7] and frontal lobe [n = 1]). None of the seven patients who underwent a focal cortical resection, however, experienced a significant reduction in seizure tendency. An anterior corpus callosotomy, performed in two patients with symptomatic generalized epilepsy, resulted in a worthwhile reduction in drop attacks. Results of this study may modify the surgical strategies in patients with gelastic seizures and hypothalamic hamartomas.

Child↗
PubMed1993

New-onset seizures in critically ill patients.

We studied causes of new-onset seizures in 55 patients admitted to medical and surgical intensive care units between 1981 and 1991. In one-third of the patients, sudden withdrawal of narcotic agents was associated with tonic-clonic seizures. In another third, acute metabolic changes, predominantly severe hyponatremia (sodium < or = 125 mEq/l), accounted for new-onset seizures. In eight patients, drug toxicity (antibiotics and antiarrhythmic agents) predisposed to seizures. Only five patients had previously unrecognized structural CNS abnormalities that were manifested by focal or generalized tonic-clonic seizures. In six patients, the cause remained unknown. Twenty-four patients had recurrent seizures despite treatment with standard antiepileptic drugs. Status epilepticus occurred in four patients. Outcome was poor in only 34% of the patients, particularly in those with metabolic causes. Sudden withdrawal of narcotic drugs may be a significant cause of new-onset seizures in patients with life-threatening disorders.

Adult↗
PubMed1993

MRI hippocampal volumes and memory function before and after temporal lobectomy.

We investigated the relationship between preoperative MRI hippocampal volumes and clinical neuropsychological memory test data obtained before and after temporal lobectomy and amygdalohippocampectomy for intractable epilepsy in 44 left (LTL) and 36 right (RTL) temporal lobectomy patients. In LTL patients, the difference (right minus left hippocampal volume) between hippocampal volumes (DHF) was significantly (p < 0.001) correlated (r = 0.61) with postoperative verbal memory change as measured by a delayed memory percent retention score from the Wechsler Memory Scale-Revised, Logical Memory subtest. DHF was also positively associated with postoperative memory for abstract geometric designs in LTL patients (r = 0.49, p < 0.005). Resection of a relatively nonatrophic left hippocampus was associated with poorer verbal and visual memory outcome. In RTL patients, larger right adjusted (for total intracranial volume) hippocampal volume was associated with decline in visual-spatial learning, but not memory, following surgery. MRI hippocampal volume data appear to provide meaningful information in evaluating the risk for memory impairment following temporal lobectomy.

Adult↗
PubMed1993

Neurocognitive efficiency following left temporal lobectomy: standard versus limited resection.

Decreased memory and learning efficiency may follow left temporal lobectomy. Debate exists as to whether the acquired deficit is related to the size of the surgical resection. This study addresses this question by comparing changes in cognitive performance to the extent of resection of both mesial temporal structures and lateral cortex. The authors retrospectively reviewed 47 right-handed patients who underwent left temporal lobectomy for medically intractable seizures. To examine the effects of the extent of mesial resection, the patients were divided into two groups: those with resection at the anterior 1 to 2 cm of mesial structures versus those with resection greater than 2 cm. To examine the effects of the extent of lateral cortical resection, patients were again divided into two groups: those with lateral cortex resections of 4 cm or less versus those with resections greater than 4 cm. Statistical analyses showed no difference in cognitive outcome between the groups defined by the extent of mesial resection. Likewise, no difference in cognitive outcome was seen between the groups defined by the extent of lateral cortical resection. Associated data analyses did, however, reveal a negative correlation of cognitive change with patient age at seizure onset. These results showed that the neurocognitive consequences of extended mesial resections were similar to those of limited mesial resections, and that the neurocognitive consequences of extended lateral cortical resections were similar to those of limited lateral cortical resections. The risk of cognitive impairment depends more on age at seizure onset than on the extent of mesial or lateral resection.

Adult↗
PubMed1993

Traditional and computerized assessment procedures applied to the evaluation of memory change after temporal lobectomy.

After establishing that 40 temporal lobectomy patients (20 right, 20 left) demonstrated the same pattern of memory compromise as has been reported in prior studies, we examined the sensitivity of computerized tests of everyday memory skills to the cognitive change associated with temporal resection. Multiple cognitive deficits occur after left, but not after right, temporal lobectomies. Memory impairment after surgery is not limited to traditionally structured memory tests but is also evident on tasks designed to simulate activities of daily life.

Journal Article↗
PubMed1992

Magnetic resonance image-based hippocampal volumetry: correlation with outcome after temporal lobectomy.

We developed a magnetic resonance imaging (MRI)-based technique for measuring the volume of the hippocampal formation. In this study, the relationship between volumes of the hippocampal formation and outcome (i.e., postoperative seizure control) after anterior temporal lobectomy for intractable epilepsy was analyzed in 50 consecutive patients in whom the surgical specimen did not contain an epileptogenic mass lesion. Outcome was classified as either satisfactory or unsatisfactory. A significant relationship was found between outcome and volume of the operated hippocampal formation (p = 0.012), as well as a derived volumetric measure (nonoperated minus operated volume of the hippocampal formation) (p = 0.004). The association between outcome and nonoperated volume was borderline (p = 0.057). Thirty-four (97%) of 35 patients in whom the volumetric study and electroencephalography (EEG) concordantly lateralized the seizure disorder had satisfactory postoperative seizure control. Conversely, only 7 (42%) of 12 patients in whom the volume study was nonlateralizing and 1 (33%) of 3 in whom the EEG and volume study were discordant has a satisfactory outcome. We regard our MRI-based study of hippocampal formation volume as a noninvasive surrogate for the identification of moderate or severe mesial temporal sclerosis. The technique is a useful adjunct in a multidisciplinary, preoperative epilepsy evaluation when T2-weighted MRIs do not reveal an epileptogenic mass lesion. The reasons for the usefulness of this imaging technique are: (1) It is an independent source of information on seizure lateralization, (2) it will provide information as to expected postoperative outcome, and (3) it may aid in appropriately selecting patients for invasive preoperative monitoring studies.

Adult↗
PubMed1992

MRI in the presurgical evaluation of patients with frontal lobe epilepsy and children with temporal lobe epilepsy: pathologic correlation and prognostic importance.

We performed magnetic resonance imaging (MRI) using a high-field strength magnet (1.5 T) in two series of 53 patients with intractable partial epilepsy of frontal lobe or temporal lobe origin who subsequently received ablative surgery for their seizure disorder. In the first series of patients the pathologic correlation and prognostic importance of an MRI-identified lesion in the frontal lobe were assessed. Twenty-five percent of the patients with negative MRI studies and 67% of patients with neuroimaging abnormalities restricted to the frontal lobe, were seizure-free at a minimum duration of follow-up of 1 year. None of the patients with a multilobar MRI-detected abnormality was seizure-free postoperatively. In the second study the sensitivity and specificity of MRI-based hippocampal volumetry was determined in pediatric patients with partial epilepsy of temporal lobe origin unrelated to foreign-tissue pathology. Hippocampal formation atrophy in the epileptic temporal lobe was identified in 63% of patients. The sensitivity and specificity of hippocampal volumetry was 100% in patients with mesial temporal sclerosis. The presence of an MRI-detected epileptogenic lesion in the frontal lobe and hippocampal formation atrophy in the temporal lobe may correlate with the underlying pathology and affect the identification of potential candidates for epilepsy surgery.

Adolescent↗
PubMed1992

Surgical outcome in computer-assisted stereotactic resection of intra-axial cerebral lesions for partial epilepsy.

A retrospective analysis was performed in 30 patients who underwent computer-assisted stereotactic resection of intra-axial mass lesions with intractable partial epilepsy. Mean follow-up was 4.1 years (2-5.5), mean age 21 years (3-45) and mean duration of seizures 8.4 years (1-26). Pathology consisted of vascular malformations in 11, glial neoplasms in 11, cortical dysplasia in 4 and gliosis in 3, and no diagnostic abnormality was found in 2 patients. The location of the lesions in some cases may have precluded a standard craniotomy and cortical resection, e.g. precentral gyrus (5), post-central gyrus (5) and deep-seated left posterior temporal region (4). Operative morbidity involved 3 patients who developed motor or language deficits. Four patients were lost to follow-up. Thirteen patients out of 26 (50%) were class I, 3 (12%) were class II, 4 (15%) were class III and 6 (23%) were class IV. These findings suggest that stereotactic lesion resection in selected cases (e.g. where lesions are located in eloquent brain regions) can be useful in providing a histological diagnosis of the epileptogenic foci and result in a favorable reduction in seizure activity without the need for a standard cortical resection.

Adult↗
PubMed1992

Identification of the epileptic focus: magnetic resonance imaging.

Magnetic resonance imaging (MRI) is the most sensitive and specific structural imaging technique available to demonstrate focal epileptogenic lesions in patients with intractable partial epilepsy. MRI may be useful in the selection of candidates for surgical treatment of epilepsy. The studies may also assist in the implantation of depth electrodes and in the stereotactic resection of epileptogenic lesions. More recent applications of this neuroimaging modality in the surgical treatment of epilepsy include pre-operative hippocampal formation of volume measurements and postoperative quantitative determinations of cortical resections.

Brain↗
PubMed1991

Magnetic resonance imaging-based volume studies in temporal lobe epilepsy: pathological correlations.

We performed a prospective study correlating magnetic resonance imaging volume measurements of the hippocampal formation with histopathology in 24 patients with intractable partial epilepsy who subsequently underwent an anterior temporal lobectomy for their seizure disorder. Patients with mass lesions verified pathologically were excluded from this study. In 71% of patients, quantitative hippocampal formation atrophy correctly lateralized the temporal lobe of seizure origin; in 29%, the volume study was indeterminant. The severity of the pathological alterations in the hippocampus correlated with the hippocampal formation volume determination. Mesial temporal sclerosis was identified in the surgically excised temporal lobe in 15 patients. The magnetic resonance imaging volume studies indicated hippocampal atrophy in the temporal lobe resected in 14 of the 15 patients. Magnetic resonance imaging-based volume measurements of the hippocampal formation increase the diagnostic yield of magnetic resonance imaging scanning in patients with intractable partial epilepsy related to mesial temporal sclerosis.

Adolescent↗
PubMed1991

Epileptiform electroencephalographic abnormalities in liver transplant recipients.

We retrospectively studied patients who had undergone orthotopic liver transplantation and who also had electroencephalography to determine whether epileptiform changes were associated with a poor neurological outcome. Study groups were 36 patients who died after transplantation (141 electroencephalograms) and underwent neuropathological examination, 11 who died (18 electroencephalograms) but did not have autopsy, and a third group of 34 (62 electroencephalograms) who remained alive. Epileptiform activity was seen in electroencephalograms of 14 of the patients who died (11 from the autopsy group) and in 2 of those who remained alive. All had multiple epileptiform abnormalities and clinical or subclinical seizures. The incidence of epileptiform activity after orthotopic liver transplantation was fivefold higher in the nonsurvivors. Serious cerebral structural changes were found in 10 of the 11 patients who underwent autopsy. Epileptiform activity in the electroencephalograms of patients who had undergone orthotopic liver transplantation indicates a poor prognosis. It should alert the clinician to investigate further for potentially treatable causes.

Adolescent↗
PubMed1991

Seizure-associated speech arrest in elderly patients.

Recurrent, brief episodes of speech arrest associated with bifrontal electroencephalographic seizure activity developed in three ill elderly patients. The seizures ceased after the initiation of antiepileptic drug therapy and the correction of metabolic abnormalities. The cause of the seizure activity remains unknown, but a possible mechanism may be a transient epileptogenic cortical dysfunction that predominantly affects the frontal lobes as a result of concomitant metabolic alterations.

Aged↗
PubMed1991

Surgery for focal epilepsy in the older patient.

Eight of the 237 patients who received a surgical procedure for intractable partial epilepsy at the Mayo Clinic during a 3-year period were 50 years of age or older. All patients had disabling partial seizures of several years in duration that were refractory to antiepileptic drug medication. A neuroimaging-identified epileptogenic lesion prompted referral for surgical treatment in three patients. The only clinically significant morbidity associated with surgery in the eight patients was a transient exacerbation of an aphasia in a patient who underwent a left frontal corticectomy. All eight patients had a favorable seizure outcome, and three patients postoperatively are seizure free. Epilepsy surgery may be an appropriate alternate therapy for select patients in the sixth decade of life or older with medically refractory partial seizures.

Aging↗