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Biomedical subjects

R Kuzniecky

Publications and source records attributed to R Kuzniecky.

At least 19 recordsLinked to original sources
PubMed1995

Proton nuclear magnetic resonance spectroscopic imaging of human temporal lobe epilepsy at 4.1 T.

We performed proton magnetic resonance spectroscopic imaging (MRSI) at high magnetic field (4.1 T) to study N-acetylaspartate, creatine, and choline levels in the brains of normal control subjects and patients with intractable temporal lobe epilepsy. We compared the results of MRSI to those of other presurgical techniques to determine the sensitivity of this method in the lateralization of the epileptic focus. The normal hippocampal creatine-N-acetylaspartate ratio was 0.71 +/- 0.14 with no differences between left and right. Using the mean control hippocampal creatine-N-acetylaspartate ratio plus 2 standard deviations to identify statistically significant changes, we found lateralizing metabolic abnormalities corresponding to the operated temporal lobe in all patients. Four patients (40%) had contralateral abnormalities, and 2 of them had bilateral independent seizure onset confirmed by intracranial electroencephalographic studies. Statistically significant increases in the choline-N-acetylaspartate ratio in comparison to healthy volunteers were observed in 8 of the 10 patients. With the creatine-N-acetylaspartate ratio, MRSI demonstrated a 100% sensitivity compared to magnetic resonance imaging, which identified pathology in 70% of the patients. These findings suggest that proton MRSI yields a distinctive metabolic profile in patients with temporal lobe epilepsy and is sensitive in detecting bilateral metabolic abnormalities in some patients. These preliminary findings suggest that MRSI is more sensitive than magnetic resonance imaging in the lateralization of epileptic foci in temporal lobe epilepsy.

Adult↗
PubMed1995

Frontal and central lobe focal dysplasia: clinical, EEG and imaging features.

The authors studied 11 patients with developmental malformations and seizures originating from the frontal and central regions. Patients with centrally located seizures had primary involvement of the face or mouth; clonic activity involving the limb was also seen. Seizures among those with frontal lesions were primarily unilateral or bilateral tonic motor. Secondary generalized tonic-clonic seizures preceded by focal manifestations occurred infrequently in those with central localization, but were not rare in the frontal group. MRI revealed abnormalities in 10 patients, nine of whom underwent surgical resection with good results. Focal cortical dysplasia may be the underlying epileptogenic abnormality in young patients with clinical features suggestive of central or frontal cortical involvement.

Adolescent↗
PubMed1995

Discordant occurrence of cerebral unilateral heterotopia and epilepsy in monozygotic twins.

Cerebral developmental malformations are increasingly recognized as a cause of epilepsy. Magnetic resonance imaging (MRI) has advanced our understanding of these disorders and their relation to epilepsy. We report the occurrence of discordant unilateral heterotopia and epilepsy in monozygotic twins. The affected individual developed intractable focal seizures at age 16 years. Mild cognitive difficulties had been present in early life. Evaluation showed right hemisphere EEG epileptogenic abnormalities, and the MRI scan showed massive right hemisphere heterotopia. EEG and MRI examinations in the patient's twin brother were normal. These findings suggest that the development of some developmental brain malformations and epilepsy is strongly influenced by nongenetic factors such as an environmental insult.

Adult↗
PubMed1994

Familial diffuse cortical dysplasia.

Two brothers are described with a syndrome characterized by mental retardation, atypical absence, atonic and generalized tonic-clonic seizures, and bilateral symmetrical slow spike and wave discharges on electroencephalograms. Magnetic resonance imaging revealed dysplastic cortex probably representing pachygyria primarily over the parietal regions bilaterally in both patients. The presence of an identical clinical, electroencephalographic, and cortical developmental abnormality on imaging studies in these brothers suggests that a genetic mechanism may play a role in some developmental disorders of the cerebral cortex.

Adult↗
PubMed1994

Infantile spasms: an early epileptic manifestation in some patients with the congenital bilateral perisylvian syndrome.

We report four patients with infantile spasms and the congenital bilateral perisylvian syndrome. Onset of spasms occurred during the first 6 months of life. Response to corticotropin treatment was prompt and resulted in resolution of seizures in all patients. Epilepsy developed in the four children after an interval of 2 to 12 years. Developmental outcome was variable; three were severely restricted and one was married and lived independently. Imaging studies revealed bilateral perisylvian lesions characteristic of polymicrogyria. Infantile spasms may be the presenting seizure type in some patients with the congenital bilateral perisylvian syndrome.

Adolescent↗
PubMed1994

The epileptic spectrum in the congenital bilateral perisylvian syndrome. CBPS Multicenter Collaborative Study.

We studied the frequency, clinical and EEG characteristics, and outcome of the epileptic syndrome in 31 patients with a congenital neurologic syndrome characterized by pseudobulbar palsy, cognitive deficits, and bilateral perisylvian polymicrogyria. Seizures were present in 27 of 31 patients (87%) and usually began between the ages of 4 and 12 years; they commonly consisted of atypical absence, atonic/tonic, and generalized tonic-clonic seizures. Partial attacks were present in 26%. EEG demonstrated generalized spike and wave abnormalities and, less frequently, multifocal discharges, predominantly in centro-parietal regions. Seizures were poorly controlled in 65%, with the remaining patients well controlled. Seven patients underwent callosotomy, which resulted in seizure improvement. This study indicates that the epileptic spectrum in this syndrome is broad but follows predictable patterns. Callosotomy is a valuable treatment strategy in those with intractable drop attacks.

Adolescent↗
PubMed1994

The congenital bilateral perisylvian syndrome: imaging findings in a multicenter study. CBPS Study Group.

PURPOSE: To describe the neuroimaging findings and the clinical features in patients with the congenital bilateral perisylvian syndrome. PATIENTS AND METHODS: Evaluation including history, general and neurologic examinations, electroencephalogram, chromosomal studies, and imaging data were reviewed in 31 patients. Pathologic material was available in two patients. RESULTS: All patients had similar neurologic dysfunction, primarily pseudobulbar paresis. Dysarthria and severe restriction of tongue movements were present in all. Motor milestones were delayed in 75% of the patients and language milestones in all. Mild to moderate intellectual deficits were documented in 75% of patients (full-scale IQ = 70). Pyramidal signs were observed in 70%. Seizures were present in 87% and were intractable to medical therapy in half of this group. MR revealed bilateral perisylvian and perirolandic malformations with exposure of the insula. The malformations were symmetrical in 80% of cases. Pathologic correlation revealed four layered polymicrogyria in the affected areas. CONCLUSIONS: The congenital bilateral perisylvian syndrome is a homogeneous clinical-radiologic entity. The underlying abnormality is probably polymicrogyria.

Adolescent↗
PubMed1993

Congenital bilateral perisylvian syndrome: study of 31 patients. The CBPS Multicenter Collaborative Study.

Advances in neuroimaging techniques have enabled the recognition of developmental malformations of the brain during life. Careful correlation of clinical and imaging features has identified several new syndromes. We have studied 31 patients with a congenital neurological syndrome characterised by pseudobulbar palsy, cognitive deficits, and bilateral perisylvian abnormalities on imaging studies. All patients had diplegia of the facial pharyngeal, and masticatory muscles, of variable severity. Some patients had slight dysarthria, whereas others were unable to speak. 85% of patients had mental retardation, ranging from mild to severe. Epilepsy was present in 27 (87%) and commonly consisted of atypical absence, atonic/tonic, tonic-clonic seizures, and, less frequently, partial attacks. Seizures were poorly controlled in 55%. Magnetic resonance imaging showed bilateral perisylvian cortical malformations consistent with polymicrogyria, confirmed at necropsy. Division of the corpus callosum in several patients resulted in seizure improvement. This congenital bilateral perisylvian syndrome can be clinically diagnosed and confirmed by imaging studies. Further studies are necessary to elucidate its cause.

Adolescent↗
PubMed1993

Predictive value of magnetic resonance imaging in temporal lobe epilepsy surgery.

The predictive value of magnetic resonance imaging (MRI) was assessed by a prospective study of 34 patients selected for surgical treatment of temporal lobe epilepsy. The MRIs were interpreted using standardized visual diagnostic criteria and the imaging findings were correlated with the surgical outcome. Lateralized MRI abnormalities were found in 25 (74%) of 34 patients. Significant associations were found between either the presence of a restricted foreign-tissue lesion or hippocampal atrophy and an excellent surgical outcome. An abnormal MRI had an 82% predictive value and a normal MRI had a 56% predictive value for surgical success. A history of febrile convulsions and the presence of hippocampal atrophy best predicted outcome (predictive value, 86%). These results suggest that specific MRI findings in candidates for temporal lobe epilepsy surgery are predictive of surgical outcome. The information provided by MRI may be of value for counseling patients prior to surgical intervention.

Adolescent↗
PubMed1993

Ictal single-photon emission computed tomography demonstrates localized epileptogenesis in cortical dysplasia.

We investigated the use of ictal single-photon emission computed tomography (SPECT) in 2 children with intractable epilepsy. Ictal scalp electroencephalographic studies failed to localize the epileptic focus and interictal data demonstrated widespread lateralized abnormalities. Ictal SPECT studies with technetium 99m-hexamethylpropyleneamineoxime demonstrated focal areas of hyperperfusion in the frontal lobes. Resection of the abnormal areas shown by SPECT was carried out despite evidence of large areas of epileptogenesis demonstrated by scalp and subdural electroencephalographic studies. Pathological material revealed cortical dysplasia. Ictal SPECT provides functional evidence for localized epileptogenesis in focal cortical dysplasia.

Cerebral Cortex↗
PubMed1993

Epilepsia partialis continua due to cortical dysplasia.

We describe a child with progressive neurologic deterioration and epilepsia partialis continua of the right extremities. Magnetic resonance imaging suggested cortical dysplasia of the left frontal region including the central sensorimotor cortex. Subdural grid recordings showed widespread ictal activity and frequent interictal discharges from the motor cortex. A tailored resection was performed, and histologic analysis confirmed cortical dysplasia. This case demonstrates that cortical dysplasia may be the underlying cause in some cases of childhood epilepsia partialis continua of the progressive type.

Astrocytes↗
PubMed1992

In vivo 31P nuclear magnetic resonance spectroscopy of human temporal lobe epilepsy.

We performed localized 31P nuclear magnetic resonance (NMR) 1H-image-guided in vivo spectroscopy to study regional high-energy phosphate levels in the brains of normal controls and in patients with intractable unilateral temporal lobe epilepsy. We did not observe differences in intracellular pH between controls and patients. The phosphocreatine/inorganic phosphate ratio was reduced by 50% in the epileptogenic temporal lobe compared with controls (p less than 0.005) and by 35% when compared with the unaffected contralateral temporal lobe (p less than 0.05). We did not observe differences in the ratio of phosphomonoesters to phosphodiesters between controls and patients. These findings suggest that in vivo 31P NMR spectroscopy yields a distinctive interictal metabolic profile in patients with intractable unilateral temporal lobe epilepsy and may permit noninvasive lateralizing evidence of the seizure focus.

Adolescent↗
PubMed1991

Hippocampal sclerosis in temporal lobe epilepsy demonstrated by magnetic resonance imaging.

The value of magnetic resonance imaging in the detection of hippocampal sclerosis has been controversial. We studied 10 patients aged 22.5 +/- 6.0 years with intractable temporal lobe epilepsy selected because of a history of a prolonged childhood convulsion, which is characteristic of a group of patients in whom hippocampal sclerosis is a constant finding. All 10 patients showed reduction in size of one hippocampus associated with increased signal intensity on T2-weighted magnetic resonance images. These changes were reliably detected on coronal spin-echo images, perpendicular to the long axis of the hippocampus. Appreciation of the normal imaging anatomy of the hippocampus allowed correct interpretation of the relative changes in signal intensities of the hippocampus and adjacent temporal horn on sequential echo images. The side of the abnormal hippocampus on magnetic resonance imaging accorded with the electroencephalographic localization in all 10 patients, and with the lateralization of the early convulsions in all 6 patients where this was known. Temporal lobectomy was performed in all 10 patients. Hippocampal sclerosis was confirmed in the 3 patients in whom hippocampal tissue was available for histological examination. The value of this technique was reinforced by the excellent postoperative results, with 80% being seizure free at a mean follow-up time of 33 +/- 4 months.

Adolescent↗
PubMed1991

Cortical dysplasia in temporal lobe epilepsy: magnetic resonance imaging correlations.

Cortical dysplasia has been documented in histological specimens surgically removed for treatment of refractory temporal lobe epilepsy. We studied 10 patients with cortical dysplasia and complex partial seizures who underwent temporal lobectomy. Magnetic resonance imaging revealed abnormalities in 5 of the patients who had microscopically detectable major abnormalities. Magnetic resonance imaging revealed an abnormal cortical-white matter architectonic pattern in 2 patients with moderate cortical dysplasia. In the remaining 3 patients, magnetic resonance imaging findings were unremarkable. These observations suggest that magnetic resonance imaging is sensitive in the detection of certain dysplastic lesions in temporal lobe epilepsy. Preoperative identification of these abnormalities by magnetic resonance imaging may permit early and optimal surgical treatment in patients with refractory epilepsy.

Adolescent↗
PubMed1990

Surgical treatment of epilepsy: initial results based upon epidural electroencephalographic recordings.

We describe our initial results in 50 consecutive patients who had investigation for possible surgical treatment of intractable focal epilepsy. Forty-three were investigated using intracranial epidural or foramen ovale electrodes. Forty-five had cortical resection (43 temporal, one frontal, and one parietal). Thirty-two patients who had resection have been followed up for 6 months to 4 years, and 29 (90%) have had good results. Our findings suggest that epidural recordings are valuable in patients with epilepsy who are being considered for surgical resection. They offer an alternative to depth intracerebral investigations in the majority of patients.

Adolescent↗