Howard M. Eisenberg

Dimensions of cognition measured by the tower of London and other cognitive tasks in head‐injured children and adolescents

To determine the factor structure of executive functioning in head‐injured (n = 81) and normal children (n = 102), we administered tests of concept formation and problem solving, plus planning, verbal fluency, design fluency, memory (to evaluate semantic organization), and response modulation using a Go/No‐Go task. The children who sustained closed head injury (CHI) were divided into subgroups who sustained severe (n = 39) and mild/moderate (n = 42) injury. The CHI groups and normal controls were also grouped according to age at the time of testing (6–8, 9–12, and 13–16). The principal components analysis disclosed a five‐factor solution that accounted for 79% of the variance: Conceptual‐Productivity (Factor 1), Planning (Factor 2), Schema (Factor 3), Cluster (Factor 4), and Inhibition (Factor 5). Age had a significant effect on Factors 1, 2, and 5, whereas severity of CHI affected Factors 1,2,4, and 5. Using hierarchial regression in which the Glasgow Coma Scale score, age, and their interaction were ent...

Frontal Lobe Changes after Severe Diffuse Closed Head Injury in Children

IN VIEW OF the pathophysiology and biomechanics of severe closed head injury (CHI) in children, we postulated that the frontal lobes sustain diffuse injury, even in the absence of focal brain lesions detected by magnetic resonance imaging (MRI). This study quantitated the morphological effects of CHI on the frontal lobes in children who sustained head trauma of varying severity. The MRI findings of 14 children who had sustained severe CHls (Glasgow Coma Scale score of ≤8) were compared with the findings in a matched group of 14 children having sustained mild head injuries (Glasgow Coma Scale score of 13-15). The patients ranged in age from 5 to 15 years at the time of their MRls, which were acquired at least 3 months postinjury. MRI findings revealed no focal areas of abnormal signal in the frontal lobes. Volumetric analysis disclosed that the total prefrontal cerebrospinal fluid increased and the gray matter volume decreased in the patients with severe CHI, relative to the mildly injured comparison group. Gray matter volume was also reduced in the orbitofrontal and dorsolateral regions of the brains of children with severe CHI, relative to the children who sustained mild head trauma. These volumetric findings indicate that prefrontal tissue loss occurs after severe CHI in children, even in the absence of focal brain lesions in this area. Nearly two-thirds of the children who sustained severe CHls were moderately disabled after an average postinjury interval of 3 years or more, whereas 12 of the 14 patients with mild CHls attained a good recovery (2 were moderately disabled) by the time of study. Although this initial study of brain morphometry after CHI in children was not designed to isolate the contribution of frontal lobe damage to residual disability, further research involving a larger sample is in progress to address this issue.

Radiosurgery for cerebral arteriovenous malformations: Assessment of early phase magnetic resonance imaging and significance of gadolinium-DTPA enhancement

PURPOSE To evaluate the initial changes within the nidus of arteriovenous malformations (AVMs) and to assess the reaction to the brain tissue surrounding AVMs after radiosurgery by serial magnetic resonance (MR) imaging. METHODS AND MATERIALS Twenty-one patients, treated using 60Co gamma knife unit with cerebral AVMs, were retrospectively evaluated. Forty-seven follow-up MR images of the 21 patients were performed including 10 patients with two or more serial gadolinium enhanced studies (Gd-MR). Two or more sequential MR angiographies (MRA) were obtained in 13 patients. Three-dimensional (3D) time-of-flight MRA and two-dimensional (2D) phase contrast MRA were used in 13 patients for evaluating the flow changes of AVMs. The follow-up period after radiosurgery ranged from 3 to 30 months (average 10.8 months) and the interval time of MRI ranged from 34 days to 13 months (average 4.9 months). RESULTS Reduction of nidus size was observed in 14 of 21 patients (67%) between 4 to 13 months on spin echo (SE) images. Complete obliteration was observed on SE images in 4 of these 14 patients; three were confirmed by conventional angiography. New hyperintense areas surrounding the nidus on T2s-weighted images (T2WI) developed in 9 of the 14 patients who showed nidus reduction between 5 to 17 months after radiosurgery; in three patients, size of the hyperintense area started to decrease between 6 to 7 months after its appearance. Probable radiation necrosis of pons developed in one patient 26 months after radiosurgery. The irradiated area within the AVM nidus was significantly enhanced in 8 of the 10 patients who underwent Gd-MR. The degrees of enhancement within the nidus increased with time in 7 of the 10 patients. Overall, total enhancement of irradiated areas was observed in four of the 10 patients; in three of the four, the enhancement decreased in size and degree, indicating nidus reduction. In three patients who had a partial volume irradiation within the nidus, the enhancing areas corresponded with the exact portions of irradiated volume. The nidus reduction was observed in 7 of the 13 patients on MRA during 5 to 13 months after radiosurgery. MRA was more useful compared to SE images in four of the seven patients in evaluating the size change of AVM nidus, feeding arteries, and draining veins. CONCLUSION Magnetic resonance imaging and MRA were useful in assessing the progress of nidus reduction. T2-weighted imaging was sensitive to radiation-induced reaction in and around the AVM nidus. The enhancement within the AVM nidus on Gd-MR may represent the initial sign of nidus reduction and demonstrates the exact location of irradiation in the nidus. The changes of the enhancement pattern are presumed to represent the processes of nidus reduction and irradiated reaction within the AVM nidus.

The Relative Durations of Coma and Posttraumatic Amnesia after Severe Nonmissile Head Injury: Findings from the Pilot Phase of the National Traumatic Coma Data Bank

Publisher Summary This chapter discusses the relative durations of coma and post-traumatic amnesia after severe nonmissile head injury. Neurosurgeons have widely adopted Glasgow coma scale (GCS) measure to assess the acute impairment of consciousness and duration of coma after head injury. This advance in the assessment of impaired consciousness has permitted a direct measurement of coma apart from the transitional, post-comatose stage of disturbed consciousness characterized by confusion, disorientation, and anterograde and retrograde amnesia. The analysis of individual components of the GCS score also failed to demonstrate a significant effect for hemispheric lateralization of mass lesion. It is conceivable that concomitant diffuse or multifocal trauma to the brain in severe head injury obscures the effects of hemispheric lateralization of injury on the disturbance of impaired consciousness that has been reported for acute vascular insult and intra-carotid amytal injection.

Reversible Amnesia Associated with a Left Temporal Hematoma in a Case of Right Temporal Complex Partial Seizures

Summary: We report the case of a 44‐year‐old woman with complex partial seizures (CPS) of right frontotemporal origin who developed generalized amnesia after undergoing intracranial electrode implantation complicated by left hippocampal hemorrhage. Serial memory testing disclosed recovery from the amnesic disorder, while repeated magnetic resonance imaging (MRI) showed resolution of her left hippocampal hemorrhage in a 2‐month period. A second intracarotid amytal procedure confirmed the capability of her left temporal region to support memory. Consequently, aright orbitofrontotemporal lobectomy was performed without complication.