Brain function in the minimally conscious state: a quantitative neurophysiological study.

OBJECTIVE: To explore possible EEG power spectrum and coherence differences between patients in minimally conscious state (MCS) and patients with severe neurocognitive disorders (SND), who show signs of awareness. We also try to find EEG cortical sources that differentiate between both conditions using LORETA source analysis. METHODS: We studied 16 patients with traumatic brain injury (7 MCS, 9 SND; aged 18-49) and compared EEG power spectra, coherence, and LORETA sources at rest for both groups. RESULTS: EEG power spectra revealed significant differences in the delta range of both conditions. Patients in MCS showed a notably increased power in this band, compared to SND patients. LORETA analysis showed that posterior sources of delta and theta frequencies had higher amplitude in MCS patients than in SND patients. Regarding fast frequencies, lower source magnitudes in temporal and frontal lobes were found for MCS patients. CONCLUSIONS: Our results stress the importance of fronto-temporal-parietal associative cortices within the "awareness-regions" model. Our results also suggest a relation between excess of slow wave activity and diminished level of awareness in brain injury population. SIGNIFICANCE: Neurophysiological correlates in brain damaged patients who are severely impaired could be used to assess the integrity of brain areas responsible for awareness.

Cognitive deterioration due to GH deficiency in patients with traumatic brain injury: a preliminary report.

PRIMARY OBJECTIVE: To determine whether cognitive and behavioural disorders observed in TBI patients are due to hormonal deficits or to the brain injury itself. RESEARCH DESIGN: Transversal, between-group design. METHODS AND PROCEDURES: Studied 22 severe TBI patients (GCS < 8): 11 had isolated GH deficiency and 11 did not. Prepared detailed clinical reports on patients and performed physical examinations, standard biochemical and full blood count analysis. Patients underwent neuropsychological assessment and hormonal evaluation 6 months after TBI diagnosis. RESULTS: TBI patients with GH deficiency show greater deficits in attention, executive functioning, memory and emotion than those without GH deficiency. CONCLUSIONS: Results show GH-related cognitive impairment in patients who develop GH deficiency after TBI and suggest that treatment of GH deficiency would improve cognition. The clinical importance of these findings should be established to better understand the nature, magnitude and meaning of GH-related cognitive impairment in patients who develop GH deficiency after TBI.

Consensus guidelines on screening for hypopituitarism following traumatic brain injury.

PRIMARY OBJECTIVE: The goal of this consensus statement is to increase awareness among endocrinologists and physicians treating patients with traumatic brain injury (TBI) of the incidence and risks of hypopituitarism among patients with TBI. RATIONALE: TBI poses significant risk to the pituitary gland, leading to elevated risks of diabetes, hypopituitarism and other endocrinopathies. Signs and symptoms associated with hypopituitarism often mimic the sequellae of TBI, although the severity of symptoms is not necessarily related to the severity of the injury. Patients with TBI-induced hypopituitarism may benefit both physically and psychologically from appropriate hormone replacement therapy (HRT). Participants at this unique consensus meeting attempted to define and spearhead an approach to increase awareness of the risks of TBI-induced endocrinopathies, in particular growth hormone deficiency (GHD), and to outline necessary and practical objectives for managing this condition. RECOMMENDATIONS: Systematic screening of pituitary function is recommended for all patients with moderate-to-severe TBI at risk of developing pituitary deficits. Patients with hypopituitarism benefit from appropriate hormonal replacement and prospects for rehabilitation of patients with TBI-induced hypopituitarism may be enhanced by appropriate HRT. Further exploration of this possibility requires: (1) active collaboration between divisions of endocrinology and rehabilitation at the local level to perform a screening of pituitary function in patients after TBI, (2) creation of a consultancy service by endocrine societies for use by rehabilitation centres, (3) development of continuing medical education (CME) programmes that can be offered as crossover training to the physicians who manage the care of patients with TBIs, (4) targeting of patient organizations with educational information for dissemination to patients and their families, (5) continued efforts to more clearly define the population at greatest risk of TBI-induced hypopituitarism and (6) monitor results of efficacy studies as they become available to evaluate whether and how much replacement therapy can improve the symptoms of individuals with TBI-induced hypopituitarism.

The locked-in syndrome: a challenge for therapy.

The locked-in syndrome (LIS) is a severe condition originated by a ventral pons lesion causing quadriplegia and anarthria but with a preserved consciousness. LIS seems to be a well defined clinical picture, although different problems still persist, such as the diagnosis as it is usually mistaken for akinetic mutism and a vegetative state; the unclear prognosis, because of the patient's psychological state and the lack of information and data concerning the different types of available treatment and the need for results. Rehabilitation is a challenge for physicians, new methods and techniques of specialized treatments for these patients are opening a new future that will allow us to abandon the initial pessimism. A more efficient rehabilitation of these patients depends on the intensity of the rehabilitation, the multidisciplinary approach, and duration of the treatment.

Driving with cognitive deficits: neurorehabilitation and legal measures are needed for driving again after severe traumatic brain injury.

PRIMARY OBJECTIVE: This article presents a retrospective study on a group of survivors of severe traumatic brain injury with the purpose of discerning whether post-traumatic cognitive deficits prevent them from safely resuming driving and to see if holistic neurorehabilitation improves the rate of patients fit for returning to driving. METHODS AND PROCEDURES: We studied 17 patients who had suffered severe traumatic brain injury (TBI) as measured by Glasgow Coma Scale scores. All subjects underwent a holistic, intensive and multidisciplinary neurorehabilitation program during a mean period of 10.53 months in the Centro de Rehabilitación de Daño Cerebral (CRECER)--Center for Brain Injury Rehabilitation--in Seville, Spain. Patients were divided into two different groups: drivers (patients who drove despite strong and repeated recommendations from the Center to desist from doing so when they began the rehabilitation program) and non-drivers (patients not driving at the time they began the rehabilitation program although they had a pre-injury driver's license). The FIM+FAM-Revised Scale [1] was administered both before commencing treatment and upon termination. RESULTS AND CONCLUSION: (1) Patients showing physical functionality above 80% returned to driving, regardless of their cognitive and/or emotional deficits, and against doctor recommendations. (2) Severe TBI survivors that have not been certified as fit to drive are at increased risk for driving incidents other than collisions and traffic accidents. This is illustrated by significant incidents involving some of the subjects in our study that were due to disorientation, confusion and confrontations with people or situations. (3) We found that neurorehabilitation is worthwhile; after integral and multidisciplinary neurorehabilitation more than 70% of survivors of severe TBI can return to driving with regular safety. (4) We also suggest that laws be introduced to keep not-clinically-apt patients from driving.

Executive functioning as outcome in patients after traumatic brain injury.

The present study was designed to determine how traumatic brain injury affect executive functioning, to know whether different treatments in the acute phase improve this functioning, and to check whether the severity of the neurocognitive impairment is detected by the Glasgow Outcome Scale (GOS). Ability for problem solving and executive functioning within 2 years after Traumatic Brain Injury (TBI) was examined in 35 conscious survivors. Two groups were formed. One group consisted of 13 patients who needed neurosurgery. The other group was made up of 22 patients without neurosurgical treatment. All were treated in the Neurosurgical Intensive Care Unit and in the Rehabilitation Service. The following variables were registered: Secondary Lesions, Glasgow Coma Scale (GCS), CT, subacute CT, and Glasgow Outcome Scale. Neuropsychological tests administered were Wisconsin Card Sorting Test (WCST) and the Tower of Hanoi/Sevilla. Comparing both groups' test performance (man Whitney U) we found that a severe traumatic brain injury, whatever the treatment applied in the acute phase, impairs the executive functioning of the patients; this impairment is related to acute pathophysiological events. The neurosurgical intervention does not improve the executive functioning. The Glasgow Outcome Scale does not detect more than 25% of the patients with severe impairment. It is suggested that the Tower of Hanoi/Sevilla could be a good tool to evaluate the executive functioning routinely in TBI patients as outcome. It also suggested that mild TBI patients must be referred for a complete neuropsychological examination.

The attentional system in brain injury survivors.

The present study was designed to check the model of attention proposed by Posner and Petersen (1990), in patients with traumatic brain injury. We analyzed a series of neuropsychological tests administered to these patients after they were discharged from the hospital. Scores obtained from this group were subjected to factor analysis. The results of this analysis could be characterized by four factors which accounted for 85.4% of the variance. According to our data, factor 1 (perceptual and motor speed) and factor 2 (vigilance and alertness) represent Posner's posterior attention system. Factor 3 (encoding) and factor 4 (shifting) represent Posner's anterior attention system (AAS), but we have to consider that the AAS is not only attention but is shared by other cognitive processes. The results also suggest that the attention system could be stable and could be defined independently from the type of patient and type of illness.

[Visual constructive deficits and coma depth]. / Déficits visoconstructivos y profundidad del coma.

The present study has the purpose of relating the capacities of visual retention with the Benton Visual Retention Test and the level of coma depth, which is measured with the GCS (Glasgow Coma Scale). 31 subject suffering cranioencephalic damage admitted to the intensive care unit (ICU) have been studied. GCS scores were obtained during their stay in the intensive care unit and the Benton Visual Retention Test was administered after hospital discharge. The procedure followed consists in comparing the performance of subjects with higher GCS scores to subjects with lower values when executing administration. A of form C of BVRT. We could conclude as follows: firstly that BVRT is a useful tool to detect the existence of brain damage; secondly, indexes of brain damage presence with BVRT are: a low figure in correct design, more errors, less errors in distortion and rotation; more errors in the left visual hemifield. Thirdly, the depth of coma is a good prognosis index on BVRT execution and in consequence of visuo-constructive abilities.

The computerized Tower of Hanoi: a new form of administration and suggestions for interpretation.

A computerized version of the Tower of Hanoi with a new form of administration was administered to two different groups, 15 men and 22 women, who were university students reporting normal psychological histories, and 24 traumatically brain-injured patients (20 men and 4 women). Scores on this test for both groups can be interpreted as an index of ability to solve problems and of learning strategies. Men and women scored differently on the task, i.e., women used different strategies than men to solve problems.