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PubMed1991

Auditory neglect after right frontal lobe and right pulvinar thalamic lesions.

Auditory unilateral neglect or extinction to simultaneous stimulation is reported in a right-handed male with a lesion in the right frontal lobe and in the right thalamic pulvinar area. The patient was submitted to stereotactic thalamotomy for a post-traumatic intentional ataxia in the left extremities. He was subjected to repeated tests with dichotic listening to consonant-vowel syllables under three different attentional instructions. He was also tested monaurally with the same stimulus materials as used in the dichotic test. The results showed almost complete extinction of the left ear input during dichotic presentations, despite normal hearing when tested with audiometer screening. The left ear extinction effect was independent of instructions to attend to the left or right ear input. However, during monaural presentation, correct left ear reports increased to about 85%. The results are interpreted as showing an auditory attentional neglect caused by the right frontal and pulvinar lesions.

Adult↗
PubMed1980

CT in head trauma: a review.

The diagnosis and management of head trauma has changed significantly with the availability of computed tomography. CT not only demonstrates the presence of a mass, but also delineates acute bleed from brain swelling. CT is useful in determining whether the hematoma is intracerebral or extracerebral, as well as its volume, extent, and multiplicity. CT provides the opportunity for noninvasive sequential studies in the management of the patient with severe head trauma. Sequential CT studies have also been useful in understanding the long-term effects of head trauma. CT has eliminated the need for other diagnostic studies in all but the most exceptional situations.

Adult↗
PubMed1980

Computed tomography in child abuse head trauma.

Forty-five head trauma cases from 177 child-abuse patients are reported. Intracranial injuries include acute epidural and subdural hematomas, subdural effusion, cerebral contusion, and atrophy (subdural effusion and cerebral contusion being most frequently seen). Incidence of skull fracture among the 45 patients is about 38%. Sixty-five percent of the 17 skull fracture patients also had intracranial injury, and 78% of the 28 patients with normal skulls had intracranial injury. CT should be the primary tool for evaluating child-abuse head trauma.

Brain Concussion↗
PubMed1988

Non-conscious face recognition in patients with face agnosia.

Four patients with face agnosia, a condition in which there is a failure to recognize previously known faces or faces that ought to have been learned without difficulty, were studied with an experimental paradigm in which both overt (verbal self-report) and covert (electrodermal skin conductance response) probes of recognition were used. The results showed a striking dissociation between the two indices: (1) all 4 patients generated more frequent and significantly larger-amplitude skin conductance responses to familiar faces, as compared to unfamiliar ones. This outcome contrasts with the finding that (2) none of the patients was able to give discriminatory verbal ratings of familiar versus unfamiliar faces. The positive electrodermal discrimination is interpreted as an index of the rich co-activation of records that is produced when familiar facial stimuli successfully trigger the reassembly of previously acquired representations of the physical structure of faces. The results of this co-activation, however, are unavailable to consciousness. This is seen as the consequence of lesion-related disruption of linkages between face records, on the one hand, and non-face records that contain information uniquely and unequivocally apposite to the possessor of a particular face.

Adult↗
PubMed1995

Time course of increased vulnerability of cholinergic neurotransmission following traumatic brain injury in the rat.

We have previously shown that spatial memory changes following experimental traumatic brain injury (TBI) include long-term changes that are (1) 'overt': detected by routine behavioral assessments, or (2) 'covert': undetected in the absence of a secondary pharmacological challenge, such as by the cholinergic antagonist, scopolamine. Our objective in this study was to extend this finding by characterizing the time course of recovery of overt and covert spatial memory performance following two magnitudes of experimental TBI. The Morris water maze was used to assess cognitive performance. Rats received either moderate magnitude (6 m/s, 1.77 mm deformation) or low magnitude (6 m/s, 1 mm deformation) impacts through a lateral craniectomy under isoflurane anesthesia. Sham rats underwent identical surgical procedures but were not injured. To avoid motor deficits, water maze testing started two weeks post-injury. Rats were given four trials per day for seven consecutive days. For each trial, latency to find a hidden platform was timed. On the sixth, rats were injected (i.p.) with scopolamine (1 mg/kg) 15 min prior to maze testing. The next day, rats were retested. This testing regimen was repeated, beginning 4, 6, and 10 weeks post-TBI. Results showed that, while the low-magnitude injury produced no overt spatial memory deficits, the moderate-magnitude group exhibited overt deficits during the first test regimen. Also, while both injury magnitudes produced an enhanced sensitivity to spatial memory impairment by scopolamine at two weeks post-TBI, this covert deficit persisted only in the severe group at 4, 6, and 10 weeks post-TBI. Qualitative light microscopy showed that both injury groups had graded cortical necrosis. However, underlying subcortical structures such as the hippocampus appeared intact, with no overt cellular or parenchymal damage to the neuropil. These data suggest three distinct stages of functional recovery: (1) the initial period when overt deficits are present, (2) a period following recovery from overt deficits within which covert deficits can be reinstated by a pharmacological challenge, and (3) a period following recovery from both overt and covert deficits. Covert deficits can persist long after the recovery of overt deficits and, like other neurological deficits, the rate of recovery is dependent on the magnitude of TBI. Finally, spatial memory deficits can occur in the absence of light microscopic evidence of cell death in the hippocampus.

Acetylcholine↗
PubMed1990

Predicting cognitive recovery from closed head-injury in children and adolescents.

Longitudinal data from 84 head-injured children and adolescents, who were tested at three points in the first year postinjury, were analyzed to determine the best combination of demographic, injury-related, and behavioral factors predicting cognitive performance. Dependent variables were language, memory, visuomotor, and speeded performance factor scores obtained through confirmatory factor analyses of an extensive test battery. Multiple regression analyses indicated that injury severity and the existence of previous psychological, physical, or cognitive disorders were primary for predicting acute (1 month post-hospital discharge) performance for older subjects. For younger subjects, however, parental marital status was the most important correlate of acute cognitive performance. Those residing in homes with both parents fared better than children in one-parent families. At 6 months and 1 year postinjury, the older subjects who performed most poorly initially remained the most impaired. For younger children, acute cognitive standing was also an important predictor of later performance, but parental marital status remained a crucial influence on their longer-term recovery of cognitive skills.

Adolescent↗
PubMed1991

Event-related potential assessment of attention and the orienting reaction in boxers before and after a fight.

Boxers' attention and orienting mechanisms were investigated using event-related brain potential recordings, before and after a fight. This study did not reveal any abnormalities of attention or detection processes. However, a slight deficit in the orienting reaction towards stimuli delivered in the right ear, related to a greater number of blows delivered on the left side of the head, was observed.

Adult↗
PubMed1990

Long-term sequelae of brain damage from closed head injury in children and adolescents.

A study was made of the sequelae of brain damage in young patients. Seventy patients between 4 and 18 years, admitted under the diagnosis "diffuse brain contusion", have been followed at least two years after head injury. The degree of function impairment in the fields of motor skills, cognition and behaviour was recorded. It was found that many patients with neurologically little or no function loss, nevertheless after the accident did suffer from psychosocial problems in the realm of family life, school or profession. Based on these findings, the authors recommend a consequent and systematic follow up of patients if they have been in coma for more than 1 hour, the objective being the early assessment of such dysfunctions, followed by adequate assistance.

Adolescent↗
PubMed1989

Afferent and efferent connections of the cholinoceptive medial pontine reticular formation (region of the ventral tegmental nucleus) in the cat.

Following minor concussive brain injury when there is an otherwise general suppression of CNS activity, the ventral tegmental nucleus of Gudden (VTN) demonstrates increased functional activity (32). Electrical or pharmacological activation of a cholinoceptive region in this same general area of the medial pontine tegmentum contributes to certain components of reversible traumatic unconsciousness, including postural atonia (31, 32, 45). Therefore, in an effort to examine the neuroanatomical basis of the behavioral suppression associated with a reversible traumatic unconsciousness, the afferent and efferent connections of the VTN and putative cholinoceptive medial pontine reticular formation (cmPRF) were studied in the cat using the retrograde horseradish peroxidase (HRP), HRP/choline acetyltransferase (ChAT) double-labeling immunohistochemistry, and anterograde HRP and autoradiographic techniques. Based upon retrograde HRP labeling, the principal afferents to the VTN region of the cmPRF originated from the medial and lateral mammillary nuclei, and lateral habenular nucleus, and to a lesser extent from the interpeduncular nucleus, lateral hypothalamus, dorsal tegmental nucleus, superior central nucleus, and contralateral nucleus reticularis pontis caudalis. Other afferents, which were thought to have been labeled through spread of HRP into the medial longitudinal fasciculus (MLF), adjacent paramedian pontine reticular formation, or uptake by transected fibers descending to the inferior olive, included the nucleus of Darkschewitsch, interstitial nucleus of Cajal, zona incerta, prerubral fields of Forel, deep superior colliculus, nucleus of the posterior commissure, nucleus cuneiformis, ventral periaqueductal gray, vestibular complex, perihypoglossal complex, and deep cerebellar nuclei. In HRP/ChAT double labeling studies, only a very small number of cholinergic VTN afferent neurons were found in the medial parabrachial region of the dorsolateral pontine tegmentum, although the pedunculopontine and laterodorsal tegmental nuclei contained numerous single-labeled ChAT-positive cells. Anterograde HRP and autoradiographic findings demonstrated that the VTN gave rise almost exclusively to ascending projections, which largely followed the course of the mammillary peduncle (16,21) and medial forebrain bundle, or the tegmentopeduncular tract (4). The majority of fibers ascended to terminate in the medial and lateral mammillary nuclei, interpeduncular complex (especially paramedian subnucleus), ventral tegmental area, lateral hypothalamus, and the medial septum in the basal forebrain. Labeling that joined the mammillothalamic tract to terminate in the anterior nuclear complex of the thalamus was thought to occur transneuronally. Some projections were also observed to nucleus reticularis pontis oralis and caudalis, superior central nucleus, and dorsal tegmental nucleus adjacent to the VTN...

Animals↗
PubMed1979

CT and acute head trauma.

The value of CT in the management of 500 patients with head trauma is described. In these cases CT defined the effect of edema, contusion, subdural or epidural hematoma, or hydrocephalus.

Brain Concussion↗
PubMed1985

The diagnosis of diffuse axonal injury in routine autopsy practice.

A 40-year-old pedestrian was involved in a road traffic accident. He lost consciousness immediately and remained comatose for 6 months until he died of a bronchopneumonia. Examination of the fixed brain revealed the late results of diffuse axonal injury. Not all the features were readily visible macroscopically, but required a limited number of histological sections from readily predictable sites for demonstration. Special stains played only a confirmatory role. This case illustrates some of the problems in diagnosing one of the commoner patterns of brain damage in head injury, and shows how the problem may best be approached in practice.

Accidents, Traffic↗
PubMed1988

Extravasation of plasma proteins in brain trauma.

The cellular distribution of extravasated plasma proteins in cortical contusions was studied with an immunoperoxidase method using polyclonal antibodies against human plasma albumin, alpha 1-acid glycoprotein, alpha 2-macroglobulin, alpha 1-antitrypsin, transferrin, hemopexin, haptoglobin, fibrinogen, fibronectin and immunoglobulin G. The material consisted of 24 human autopsy brains with a primary diagnosis of cerebral contusion due to blunt trauma. The time interval between injury and death ranged between minutes and 7 years. Immediately after the trauma, a complete breakdown of the blood-brain barrier (BBB) occurred with hemorrhage and extravasation of all types of plasma proteins. This was followed by spreading of edema fluid within the extracellular space in and around the wound. Uptake of extravasated protein by glial cells began on the 3rd day followed by proliferation of reactive astrocytes whose ample cytoplasm appeared to serve as a reservior for the extravasated plasma proteins. Within the reactive astrocytes, plasma proteins and S-100 protein had a similar and diffuse distribution in the immunostained sections. The plasma proteins once incorporated into the glial cells remained unchanged for several years with little sign of degradation. It is suggested that the extravasated plasma proteins subsequent to uptake and processing by the glial cells, may serve some important physiological function in wound healing.

Adolescent↗
PubMed2004

A longitudinal, controlled study of patient complaints following treated mild traumatic brain injury.

This study provided 3-month follow-up data to a previous paper that compared symptom complaints of patients with mild traumatic brain injury (MTBI) with those of non-injured control participants within 1 month of injury. The 110 MTBI patients and 118 control participants were group-matched on age, gender, education level, and socioeconomic status. As a group, MTBI patients no longer endorsed significantly more symptoms (M = 14.09, S.D. = 10.77) than did the control group (M = 12.56, S.D. = 8.46, P = .232). Only 3 of the 43 queried symptoms were endorsed by significantly more (Bonferroni-corrected P < .00116) MTBI patients than controls. Using the same Bonferroni-corrected criteria, 10 of the 43 symptoms were endorsed at a significantly higher severity level by MTBI patients. Overall, the treated MTBI group's symptom complaints diminished from baseline to 3 months post-injury, with relatively few differences remaining between the two groups.

Adolescent↗
PubMed2007

Criterion validity of the California Verbal Learning Test-Second Edition (CVLT-II) after traumatic brain injury.

The California Verbal Learning Test-Second Edition (CVLT-II) was performed by 200 participants, divided into moderate-severe traumatic brain injury (n=43), mild traumatic brain injury (n=57) and demographically matched control (n=100) groups. Participants with complicating premorbid histories or who scored below 15/16 on the CVLT-II forced choice recognition trial were excluded. There were statistically significant (p<.0001) effects of group status on the CVLT-II total recall discriminability and recognition discriminability indices. Logistic regression revealed that, in the classification of control versus moderate-severe traumatic brain injury, CVLT-II variables were accurate 66-71% overall, but false positive rates ranged from 49 to 54%. In conclusion, average scores on the CVLT-II differ meaningfully between patients with various degrees of severity of traumatic brain injury and controls, but this test should not be used in isolation to determine the presence or absence of acquired memory impairment.

Adolescent↗
PubMed2005

Amnesia, traumatic brain injury, and posttraumatic stress disorder: a methodological inquiry.

This study explored the relationship between mild traumatic brain injury (MTBI), amnesia, and posttraumatic stress disorder (PTSD). MTBI status and amnesia for the event were assessed in 307 consecutive admissions to a Level 1 Trauma Center. Amnesia did not always occur concurrently with MTBI: 18% of those with MTBI had full recall and over half had partial recall of the event. Just over 10% of participants developed PTSD by 12 months post-injury, with prevalence comparable across MTBI and non-MTBI groups. Non-significant differences in incidence of PTSD were apparent between those with full recall (9%), partial recall (14%) and no recall (7%). These data highlight the fact that PTSD may develop following trauma despite amnesia for the event, and illustrate the importance in both clinical and research settings of carefully examining the extent of amnesia.

Adolescent↗