RESUMEN
OBJECT: The authors sought to determine the impact of early temporal lobectomy (in patients younger than age 17 years) on intellectual functioning. The efficacy of temporal lobectomy for treating seizures is well established and the procedure is becoming more acceptable as a treatment for children whose seizures are intractable. However, cognitive outcomes of temporal lobectomy in children and adolescents are largely unreported. The present study takes advantage of a unique multicenter collaboration to examine retrospectively intellectual functioning in a large sample of children who underwent temporal lobectomy. METHODS: Intellectual functioning was assessed before and after temporal lobectomy for treatment of medication-resistant seizures in 82 patients at eight centers of epilepsy surgery. All children underwent standard presurgical examinations, including electroencephalography-video monitoring, magnetic resonance (MR) imaging, and neuropsychological testing, at their respective centers. Forty-three children underwent left temporal lobectomy and 39 underwent right temporal lobectomy. For the entire sample, there were no significant declines in intelligence quotient (IQ) following surgery. Children who underwent left temporal lobectomy demonstrated no significant loss in verbal intellectual functioning and improved significantly in nonverbal intellectual functioning. Children who underwent right temporal lobectomy did not demonstrate significant changes in intellectual functioning. Although group scores showed no change in overall IQ values, an analysis of individual changes revealed that approximately 10% of the sample experienced a significant decline and 9% experienced significant improvement in verbal functioning. Significant improvement in nonverbal cognitive function was observed in 16% of the sample and only 2% of the sample showed significant declines. Risk factors for significant decline included older patient age at the time of surgery and the presence of a structural lesion other than mesial temporal sclerosis on MR imaging. CONCLUSIONS: The present study provides preliminary data for establishing the risk of cognitive morbidity posed by temporal lobectomy performed during childhood. With respect to global intellectual functioning, a slight improvement was significantly more likely to occur than a decline. However, there were several patients in whom significant declines did occur. It will be necessary to study further the factors associated with such declines. In addition, further study of more specific cognitive functions, particularly memory, is needed.
Asunto(s)
Cognición , Epilepsia del Lóbulo Temporal/psicología , Epilepsia del Lóbulo Temporal/cirugía , Inteligencia , Lóbulo Temporal/cirugía , Adolescente , Análisis de Varianza , Niño , Epilepsia del Lóbulo Temporal/diagnóstico , Femenino , Humanos , Masculino , Estudios Retrospectivos , Riesgo , Factores de Riesgo , Resultado del TratamientoRESUMEN
We recently demonstrated statistically significant correlations between presurgical memory impairment and hippocampal volumetric cell densities (in CA3 and the hilar area only) for patients with idiopathic left temporal lobe epilepsy who exhibited marked hippocampal neuron loss. In the present research we determine whether the same relationship exists for patients with structural lesions, in whom hippocampal neuron loss was minimal. Rank-order correlations of verbal memory test results (ie, Long Term Retrieval score of the verbal Selective Reminding Test, Percent Retention index of the Logical Memory subtest of the Wechsler Memory Scale) and hippocampal volumetric cell densities (subfields CA1, CA2, CA3, the hilar area, and the granule layer of area dentata) were computed for 22 patients with structural lesions and medically refractory epilepsy of temporal lobe onset (11 left, 11 right). There were statistically significant correlations between Long Term Retrieval and the volumetric cell density of CA1 (r = 0.62, p < 0.05) and between percent retention and the volumetric cell density of CA2 (r = 0.60, p < 0.05) for patients with left hemisphere lesions. No other correlations were found for patients with left or right temporal lobe lesions.
Asunto(s)
Epilepsia del Lóbulo Temporal/complicaciones , Epilepsia del Lóbulo Temporal/patología , Hipocampo/patología , Trastornos de la Memoria/etiología , Neuronas/patología , Aprendizaje Verbal , Adulto , Recuento de Células , Muerte Celular , Femenino , Humanos , Masculino , Trastornos de la Memoria/psicología , Memoria a Corto Plazo , Recuerdo Mental , Retención en PsicologíaRESUMEN
Forty-eight patients with temporal lobe epilepsy completed measures of narrative recall and list learning prior to surgery. The intracarotid amytal procedure (IAP) established that 13 patients were right hemisphere dominant for speech and 35 (18 left foci, 17 right foci) were left hemisphere dominant. Hippocampal volumetric neuron densities were measured after surgery. The left hippocampal neuron densities in subfields CA3 and the hilar area were significantly correlated with list learning ability and percent retention for narrative recall only for left hemisphere speech dominant patients with left seizure foci. No significant correlations between measures of neuron volume and memory were found for the left hemisphere speech dominant patients with right seizure foci or the right hemisphere speech dominant patients with left seizure foci. This suggests that the right hemisphere of right speech dominant patients mediates verbal memory as well as speech. This conclusion is supported by patterns of correlations among measures of verbal memory that differed for patients undergoing resection of the dominant hemisphere versus those undergoing resection of the nondominant hemisphere. However, it is premature to conclude that the cerebral organization of cognitive functions of right hemisphere speech dominant patients is equivalent albeit reversed from that of left hemisphere speech dominant patients. Right hemisphere speech dominant patients with left temporal foci differed from left hemisphere speech dominant patients with right temporal foci with respect to the patterns of correlations between measures of verbal memory and intelligence as well as the level of intellectual ability that they demonstrated.
Asunto(s)
Corteza Cerebral/fisiopatología , Dominancia Cerebral/fisiología , Recuerdo Mental/fisiología , Habla/fisiología , Aprendizaje Verbal/fisiología , Adulto , Amobarbital , Mapeo Encefálico , Epilepsia del Lóbulo Temporal/fisiopatología , Epilepsia del Lóbulo Temporal/cirugía , Femenino , Hipocampo/fisiopatología , Humanos , Inteligencia/fisiología , Masculino , Complicaciones Posoperatorias/fisiopatología , Escalas de WechslerRESUMEN
We examined the efficacy of a memory difference score (DS: right minus left hemisphere memory) during the Wada test (intracarotid amobarbital procedure, IAP) for predicting seizure laterality and postoperative seizure outcome in 70 left speech dominant patients from two epilepsy centers. DS > or = 2, after addition of 1 point to the left hemisphere injection score to account for aphasia, were noted in 71.4% of patients and correctly predicted surgery side for 98.0% of these patients. The DS related significantly to seizure outcome at 1-year follow-up (p < 0.002) and correctly predicted 80% of patients who were seizure-free. Patients whose DS did not correctly predict seizure laterality more frequently required invasive studies to establish seizure onset. The relationship of the DS to laterality did not differ significantly by class of IAP memory stimuli. When seizures originate from the temporal lobe, the IAP memory DS predicts seizure laterality by assessing the functional adequacy of the involved hemisphere and is predictive of seizure control.
Asunto(s)
Amobarbital , Epilepsia/cirugía , Lateralidad Funcional , Memoria , Complicaciones Posoperatorias/prevención & control , Convulsiones/prevención & control , Adolescente , Adulto , Amobarbital/administración & dosificación , Arteria Carótida Interna , Niño , Preescolar , Epilepsia/diagnóstico , Epilepsia/fisiopatología , Femenino , Estudios de Seguimiento , Humanos , Inyecciones Intraarteriales , Masculino , Pronóstico , Factores de TiempoRESUMEN
OBJECTIVE: To contrast the neuropsychological profiles of Parkinsonian patients, before and after fetal ventral mesencephalic tissue transplantation. DESIGN: Case series of personally examined patients. SETTING: Patients were evaluated by neurologists, neurosurgeons, and neuropsychologists as outpatients at a university hospital. PATIENTS: Fetal mesencephalic tissue was implanted in the right caudate nucleus of three patients and both nuclei of one patient. These patients were evaluated prior to surgery and at 12, 24, and 26 months postoperatively. RESULTS: Factor analysis of the test battery identified four statistically orthogonal test clusters. No statistically significant changes were identified postoperatively for clusters assessing verbal cognitive ability, nonverbal cognitive ability, and information-processing speed. An improvement of verbal memory cluster index was observed 12 months after surgery, and the improvement reached the level of statistical significance at 24 months after surgery. However, the verbal memory of all patients declined between 24 and 36 months after surgery. CONCLUSIONS: Fetal tissue transplantation to one or both caudate nuclei did not permanently arrest cognitive dysfunction. Although there is some evidence of improved cognitive ability after transplantation, it is improbable that normal cognitive function can be restored by this procedure because the impairments of cognitive ability associated with Parkinson's disease do not appear to originate solely from dopamine deficiency.
Asunto(s)
Trasplante de Tejido Encefálico , Trastornos del Conocimiento/psicología , Trasplante de Tejido Fetal , Mesencéfalo/trasplante , Enfermedad de Parkinson/psicología , Enfermedad de Parkinson/cirugía , Adulto , Núcleo Caudado/trasplante , Femenino , Lateralidad Funcional , Humanos , Masculino , Persona de Mediana Edad , Pruebas NeuropsicológicasRESUMEN
Twenty-two patients with intractable complex partial seizures (CPS) were treated with temporal lobectomy. Eighteen of 22 (82%) are seizure-free while receiving medication, with a mean follow-up time of 4 years. In each case, the clinical seizure pattern, interictal and ictal scalp EEG, magnetic resonance imaging (MRI), neuropsychological testing, and results of the intracarotid amobarbital procedure (IAP) converged to indicate a localized abnormality. None of the patients in this series had mass lesions, vascular malformations, or cortical scars, but 18 of 22 had hippocampal atrophy on MRI and 20 had hippocampal sclerosis (HS) on pathologic examination. We believe it is possible, on the basis of the preoperative evaluation described, to identify a population of epileptic patients who will do very well postoperatively. Such patients do not require invasive EEG monitoring, and they represent approximately 20% of the patients treated surgically in our epilepsy unit in the past several years.
Asunto(s)
Electroencefalografía , Epilepsia Parcial Compleja/cirugía , Lóbulo Temporal/cirugía , Adolescente , Adulto , Amobarbital , Epilepsia Parcial Compleja/diagnóstico , Epilepsia Parcial Compleja/patología , Femenino , Estudios de Seguimiento , Lateralidad Funcional , Hipocampo/patología , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Narcoterapia , Pruebas Neuropsicológicas , Pronóstico , Esclerosis/diagnóstico , Esclerosis/patología , Lóbulo Temporal/patología , Resultado del TratamientoRESUMEN
Fifty-eight left speech dominant adults with medically refractory epilepsy originating from the temporal lobe (28 left, 30 right) were examined using the verbal Selective Reminding Test before and after anteromesiotemporal lobectomy. After neuron density in the excised hippocampal tissue was established, a median split procedure was performed to distinguish patients with severe neuron loss (13 left, 16 right) from those with only mild or moderate neuron loss (15 left, 14 right). The memory of patients with severe left hippocampal neuron loss did not decrease significantly postoperatively. Patients with mild or moderate left hippocampal neuron loss experienced significant verbal memory decrease postoperatively. The magnitude of the verbal memory decrease was not related to recurrence of seizures after operation. Patients undergoing right anteromesiotemporal lobectomy exhibited significant improvements in verbal memory, regardless of the condition of the excised hippocampal tissue. The degree of hippocampal neuron loss determines to a great extent the severity of the verbal memory decrease that follows dominant anteromesiotemporal lobectomy.
Asunto(s)
Afasia/diagnóstico , Epilepsia del Lóbulo Temporal/cirugía , Lateralidad Funcional , Hipocampo/patología , Trastornos de la Memoria/diagnóstico , Complicaciones Posoperatorias/diagnóstico , Lóbulo Temporal/cirugía , Adulto , Afasia/etiología , Afasia/patología , Recuento de Células , Electroencefalografía , Epilepsia del Lóbulo Temporal/patología , Humanos , Trastornos de la Memoria/etiología , Trastornos de la Memoria/patología , Neuronas/patología , Pruebas Neuropsicológicas , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/patología , Recurrencia , Índice de Severidad de la EnfermedadRESUMEN
Lateralization of speech dominance was established using amobarbital for 22 patients with vascular malformations lateralized to the left cerebral hemisphere. Patients' histories were negative for clinically evident neurological events (e.g., seizures or hemorrhage) prior to adulthood. The vascular lesions were categorized as high flow arteriovenous malformations (AVMs) (n = 4), low flow AVMs (n = 6), cavernous hemangiomas (n = 10), or venous angiomas (n = 2) by reviewing angiographic findings and surgical pathology for those patients whose lesions were excised. Three of the malformations encroached upon primary language areas. The frequency of right hemisphere speech dominance was not significantly elevated in comparison with the normal population, even though the incidence of nonright-handedness was. Ninety-five percent of the patients were left hemisphere dominant for speech: only one patient, with a parietal lobe cavernous hemangioma, was found to be right hemisphere dominant for speech. This malformation did not involve the primary language areas. These findings suggest that vascular malformations do not affect speech dominance as readily as other neurological diseases, but frequently affect manual dominance.
Asunto(s)
Daño Encefálico Crónico/fisiopatología , Dominancia Cerebral/fisiología , Malformaciones Arteriovenosas Intracraneales/fisiopatología , Habla/fisiología , Adolescente , Adulto , Amobarbital , Daño Encefálico Crónico/diagnóstico , Daño Encefálico Crónico/psicología , Mapeo Encefálico , Neoplasias Encefálicas/diagnóstico , Neoplasias Encefálicas/fisiopatología , Neoplasias Encefálicas/psicología , Diagnóstico por Imagen , Femenino , Lateralidad Funcional/fisiología , Hemangioma/diagnóstico , Hemangioma/fisiopatología , Hemangioma/psicología , Hemangioma Cavernoso/diagnóstico , Hemangioma Cavernoso/fisiopatología , Hemangioma Cavernoso/psicología , Humanos , Malformaciones Arteriovenosas Intracraneales/diagnóstico , Malformaciones Arteriovenosas Intracraneales/psicología , Masculino , Persona de Mediana EdadRESUMEN
The intracarotid amobarbital procedure (IAP) was conducted with a profoundly deaf young man prior to right anteromedial temporal lobectomy for pharmacologically refractory partial complex seizures. The IAP required considerable modification in order to take into account the use of varying sign language methods and related issues. Visual memory, American Sign Language, signed English, and finger-spelling functioning were all assessed. The patient manifested left hemisphere dominance for all these abilities, performing well under right hemisphere anesthesia. In contrast, no ability to function on these tasks was detectable when the left hemisphere was anesthetized. This demonstrates that an intact left temporal lobe and related structures are sufficient to support sign language functioning. The development of a deaf adaptation of the IAP is of methodological significance, as the IAP is thereby rendered accessible for deaf patients.
Asunto(s)
Amobarbital , Sordera/fisiopatología , Dominancia Cerebral/fisiología , Epilepsia Parcial Compleja/cirugía , Pruebas Neuropsicológicas , Lengua de Signos , Adulto , Arteria Carótida Interna , Métodos de Comunicación Total , Electroencefalografía , Epilepsia Parcial Compleja/fisiopatología , Lateralidad Funcional/fisiología , Humanos , Inyecciones Intraarteriales , Masculino , Recuerdo Mental/fisiología , Reconocimiento Visual de Modelos/fisiología , Complicaciones Posoperatorias/fisiopatología , Psicocirugía , Lóbulo Temporal/fisiopatología , Lóbulo Temporal/cirugíaRESUMEN
After almost 100 years of sporadic, and marginally successful, studies of neural transplantation in animals, we are now on the threshold of a clinical treatment of the damaged brain. The initial studies of neural transplantation have focused on Parkinson's disease, primarily as a model for a more general strategy of "repair by cellular replacement." Parkinson's is known to result from the loss of a small population of cells that produce the essential neuromodulator, dopamine, for much of the brain. Further, the disease is improved significantly, during the early part of its course, by chemical augmentation of dopamine activity through drug therapies, such as L-dopa. Finally, the disease is often fatal in spite of the best medical treatments, therefore justifying more radical therapeutic experiments. If transplantation of brain cells can be accomplished successfully in humans, as it has been in animals, then replacement of a small population of dopamine-producing cells in Parkinson's disease should have important functional effects and possibly reverse the course and symptoms of the disease. Other useful applications will surely follow for conditions affecting millions of people for whom medicine now has only palliative and ineffective treatments. Just as Parkinson's disease is a model clinical condition for testing cellular replacements, fetal neural tissue transplants are also a first step for a broader strategy of molecular and cellular therapies. Fetal cells are, in many respects, the best replacements one could imagine, since precursor cells have the capacity to develop into every cell found in the adult. So, the best replacement for a dopamine neuron would likely be a precursor dopamine neuron or "neuroblast." Animal research through 1985 had demonstrated the unique properties of such fetal cells, but survivability after transplantation had not been attained with primate or human neural tissue. Our programs developed techniques to transplant monkey fetal neural tissue, to cryopreserve it, and to reverse functional effects of the neurotoxin, MPTP, in monkeys. This technique was applied to the collection and preservation of human tissue, and preliminary successful results have been obtained in patients with idiopathic Parkinson's disease. Others have reported success with different techniques in two MPTP-Parkinsonian patients and a small number of patients with idiopathic disease. If the most dramatic improvements can be replicated consistently and the benefits last for a reasonable period without complications, a clinical treatment might develop using "random-source" fetal cadaver cells.
Asunto(s)
Trasplante de Tejido Encefálico , Enfermedad de Parkinson Secundaria/cirugía , Enfermedad de Parkinson/cirugía , Animales , Trasplante de Tejido Fetal , HumanosRESUMEN
This study evaluated the memory and intellectual function of 32 adults following minimal brain injury. All patients had a Glasgow Coma Scale score of 15 upon evaluation in the Emergency Room, negative findings on radiographic examination, and negative history of prior neurologic disease or injury. Seventeen of these had experienced a loss of consciousness. Patients suffering a loss of consciousness postinjury obtained significantly lower mean verbal intelligence quotients than those obtained by patients who remained conscious following their accidents. Both groups exhibited memory impairments. This could indicate that loss of consciousness predicts intellectual impairment, but not degree of memory dysfunction. An alternative interpretation of these data is that patients referred for examination after a head injury that did not involve a loss of consciousness included a disproportionate number of patients from upper socioeconomic levels who have greater access to medical delivery systems or greater sophistication regarding cognitive function.
Asunto(s)
Lesiones Encefálicas/complicaciones , Trastornos de la Memoria/etiología , Inconsciencia/complicaciones , Adulto , Trastornos del Conocimiento/etiología , Femenino , Estudios de Seguimiento , Humanos , Pruebas de Inteligencia , Masculino , Trastornos de la Memoria/psicología , Estudios Retrospectivos , Factores Socioeconómicos , Factores de Tiempo , Inconsciencia/etiologíaRESUMEN
Fifty-nine patients with temporal-lobe epilepsy (28 left, 31 right) completed the Boston Naming Test (BNT), verbal subtests of the Wechsler Adult Intelligence Scale-Revised, and the Logical Memory Subtest of the Wechsler Memory Scale (WMS) before surgery. Performances by patients with left temporal seizure foci were significantly more impaired than those of patients with right seizure foci on the WMS Logical Memory subtest and the BNT. After surgical removal of the mesial temporal lobe structures, two blinded observers established volumetric cell densities for hippocampal subfields CA1, CA2, CA3, the hilar area, and the granule cell layer of area dentata. Statistically significant correlations existed only between percent retention scores and hippocampal neuron loss in CA3 and the hilar area for patients with left temporal seizure foci. None of the other dependent measures was significantly correlated with hippocampal neuron density in any subfield. These results support the hypothesis that certain verbal memory impairments are attributable to hippocampal damage specifically, and not to temporal lobe damage in general.
Asunto(s)
Hipocampo/patología , Inteligencia/fisiología , Lenguaje , Memoria/fisiología , Aprendizaje Verbal/fisiología , Adulto , Epilepsia del Lóbulo Temporal/patología , Epilepsia del Lóbulo Temporal/cirugía , Hipocampo/cirugía , Humanos , Neuronas/fisiología , Lóbulo Temporal/patología , Lóbulo Temporal/cirugía , Escalas de WechslerRESUMEN
Magnetic resonance images (MRIs) were obtained from 25 patients with medically refractory epilepsy of temporal lobe origin (12 on the left, 13 on the right) and 14 right-handed control subjects. The hippocampi and temporal lobes were traced by computer on successive coronal images and the resulting measurements of area were summed for each region. The left and right hippocampi were symmetrical in the control subjects; however, for patients the hippocampus was smaller on the side of the seizure focus. Moreover, the left-right hippocampal ratio significantly differentiated the control subjects from each patient group. The left temporal lobe was significantly smaller than the right in control subjects. The epileptics' temporal lobes were smaller on the side of the seizure focus, compared to the temporal lobes in the control subjects. MRI hippocampal measurements were compared to hippocampal neuronal densities obtained postoperatively. Significant correlations were obtained between the ratio (side ipsilateral to focus/side contralateral to focus) of MRI hippocampal measurements and neuronal densities in all hippocampal subfields except CA2. Prior to surgery, patients were administered the Wechsler Memory Scale and the verbal Selective Reminding Test. Significant correlations existed between MRI measurements of the left hippocampus and the Wechsler logical memory percent retention scores and between the left temporal lobe measurements and the verbal Selective Reminding Test scores for patients with seizure foci in the left temporal lobe.
Asunto(s)
Epilepsia del Lóbulo Temporal/patología , Hipocampo/patología , Imagen por Resonancia Magnética , Lóbulo Temporal/patología , Adolescente , Adulto , Atrofia , Recuento de Células , Dominancia Cerebral , Epilepsia del Lóbulo Temporal/psicología , Femenino , Humanos , Masculino , Memoria/fisiología , Persona de Mediana Edad , Pruebas NeuropsicológicasRESUMEN
The presence of somatotopic organization in the human supplementary motor area (SMA) remains a controversial issue. In this study, subdural electrode grids were placed on the medial surface of the cerebral hemispheres in 13 patients with intractable epilepsy undergoing evaluation for surgical treatment. Electrical stimulation mapping with currents below the threshold of afterdischarges showed somatotopic organization of supplementary motor cortex with the lower extremities represented posteriorly, head and face most anteriorly, and the upper extremities between these two regions. Electrical stimulation often elicited synergistic and complex movements involving more than one joint. In transitional areas between neighboring somatotopic representations, stimulation evoked combined movements involving the body parts represented in these adjacent regions. Anterior to the supplementary motor representation of the face, vocalization and speech arrest or slowing of speech were evoked. Various sensations were elicited by electrical stimulation of SMA. In some cases a preliminary sensation of "urge" to perform a movement or anticipation that a movement was about to occur were evoked. Most responses were contralateral to the stimulated hemisphere. Ipsilateral and bilateral responses were elicited almost exclusively from the right (nondominant) hemisphere. These data suggest the presence of combined somatotopic organization and left-right specialization in human supplementary motor cortex.
Asunto(s)
Corteza Motora/fisiología , Adolescente , Adulto , Mapeo Encefálico , Estimulación Eléctrica , Epilepsia/diagnóstico , Epilepsia/fisiopatología , Femenino , Lateralidad Funcional , Humanos , Imagen por Resonancia Magnética , Masculino , Corteza Motora/patología , Sensación/fisiología , Habla/fisiologíaRESUMEN
The intracarotid amobarbital sodium (Amytal) procedure (IAP) was performed for 46 patients with temporal lobe epilepsy (21 with left seizure foci; 25 with right seizure foci). After anteromedial temporal lobectomy, neuronal densities were established for hippocampal subfields CA1, CA2, and CA3; the hilum; and the dentate granule cell layer. Intracarotid amobarbital procedure memory results were related to CA3 neuronal loss only. Patients who did not demonstrate memory after injection contralateral to the seizure focus had significantly fewer cells in CA3 than patients who did. Additionally, a significant correlation was observed between the intracarotid amobarbital procedure memory examination raw score after injection contralateral to the seizure focus and CA3 cell density. Using chi 2 analysis, significant differences were documented in the frequency with which memory was demonstrated after injection contralateral to the seizure focus for groups of patients classified by degree of CA3 neuronal loss. This finding supports prior research showing subfield specificity in some memory processes.
Asunto(s)
Amobarbital , Hipocampo/patología , Trastornos de la Memoria/patología , Neuronas/patología , Pruebas Neuropsicológicas , Adolescente , Adulto , Amobarbital/administración & dosificación , Hipocampo/cirugía , Humanos , Inyecciones Intraarteriales , Memoria , Lóbulo Temporal/cirugíaRESUMEN
Thirty-five patients with medically refractory epilepsy localized to the temporal lobe (18 left, 17 right) completed the verbal Selective Reminding Test before surgery. Verbal memory impairments existed before surgery regardless of the lateralization of the seizure focus, but patients with left temporal seizure foci were significantly more impaired. After surgical removal of the mesial temporal lobe structures, 2 blinded observers established volumetric cell densities for hippocampal subfields CA1, CA2, CA3, the hilar area, and the granule cell layer of the area dentata. Statistically significant correlations existed between presurgical memory impairment and cell counts (in CA3 and the hilar area, only) for patients with left temporal seizure foci. These findings support the hippocampal model of memory and complement prior research documenting the memory impairments present after surgical removal of the mesial temporal structures.
Asunto(s)
Hipocampo/patología , Trastornos de la Memoria/patología , Tractos Piramidales/patología , Aprendizaje Verbal , Adolescente , Adulto , Recuento de Células , Epilepsia del Lóbulo Temporal/patología , Epilepsia del Lóbulo Temporal/psicología , Humanos , Trastornos de la Memoria/psicologíaRESUMEN
Language impairments were reviewed retrospectively in patients who underwent partial or total corpus callosum section for medically refractory secondary generalized epilepsy. Postoperatively, four of 32 patients had clinically significant language impairments that were not present prior to the operation. All involved primarily verbal output (speech and writing) and spared verbal comprehension. Written language skills (reading and spelling), verbal memory, and verbal reasoning abilities were impaired to varying degrees. These impairments were associated with crossed cerebral dominance. Three patients with severe difficulties after surgery were right hemisphere-dominant for speech and were right-handed. One left hemisphere speech-dominant, left-handed patient was agraphic after surgery, but spoke normally. It is concluded from these data and from other reports in the literature that three syndromes of language disturbance may follow callosotomy. The first, involving speech difficulty but but sparing writing, is attributable to buccofacial apraxia. The second involves speech and writing difficulties and occurs in right hemisphere-dominant right-handed patients. The third involves dysgraphia with intact speech and occurs in left hemisphere-dominant left-handed patients.
Asunto(s)
Cuerpo Calloso/cirugía , Dominancia Cerebral/fisiología , Trastornos del Lenguaje/etiología , Complicaciones Posoperatorias , Adolescente , Adulto , Afasia/fisiopatología , Niño , Preescolar , Femenino , Estudios de Seguimiento , Lateralidad Funcional/fisiología , Humanos , Lactante , Trastornos del Lenguaje/fisiopatología , Masculino , Complicaciones Posoperatorias/fisiopatología , Estudios RetrospectivosRESUMEN
Eighteen uncontrolled epileptic patients had neuropsychological evaluation before and after partial or total corpus callosotomy. In patients with early-onset seizures and signs of severe unilateral CNS dysfunction, callosotomy produced no deficits and several improvements. All patients whose language-dominant hemisphere did not control their dominant hand had impairments in some aspect of speech and language function after callosotomy. In some patients, unilateral deterioration of motor function was observed, and was associated with mild to moderate dysfunction in the contralateral hemisphere (ie, memory impairment or preexisting hemiparesis). Postoperative deficits occurred with partial, as well as total, section.