María del Rosario Domínguez-Morales

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 syndrome looking for a therapy.

A review of the scientific literature on locked-in syndrome (LIS) is offered. The clinical features, diagnosis and prognosis of LIS are reviewed, and methods regarding the differential diagnosis of LIS with severe disorders of consciousness are considered. Effective treatment, physiotherapy, and methods of communication are reviewed. Although progress in the field of communication for patients with LIS is promising, it is concluded that there are new possibilities to be pursued and that a more positive outlook in the area of professional care of the patients, as well as more extensive imaginative research will facilitate new and positive strategies for this syndrome.

Survey: The locked-in syndrome: a syndrome looking for a therapy

The locked-in syndrome (LIS) is a very severe condition caused by a primary vascular or traumatic injury to the brainstem, normally corresponding to a ventral pons lesion due to an obstruction of the basilar artery, and characterized by upper motor neuron quadriplegia, paralysis of lower cranial nerves, bilateral paresis of horizontal gaze and anarthria, and with preserved consciousness. Patients who have suffered this pontine lesion generally have preserved vertical eye movements and movement of the eyelids (blinking), this being their only means of responding to the outside world. A survey was conducted of 44 people diagnosed with LIS, all of them belonging to the Association of Locked-in Syndrome (ALIS) of France. Results of this survey showed that LIS was equally frequent in men and women (51.2% vs. 48.1%) and had occurred at any age between 22-77 years of age (normally between 41-52 years, the mean age being 46.79 years). The average time that transpired post-insult was 71.35 months. The principal cause of LIS was stroke (86.4%), with traumatic brain injury (TBI) being a distant second cause with an incidence of only 13.6%. The diagnosis of LIS was usually made around the middle of the second month after onset (mean of 78.76 days). The principal treatments, when present, were pharmacological and physiotherapy. However, 47.1% of the patients were not receiving treatment of any kind at the time of the survey. Neuropsychologically, 86% had a good attentional level, 97.6% were temporally oriented and 76.7% could read; 18.6% reported memory problems and 24% showed visual deficit (found mainly in patients with LIS originated by TBI); 47.5% reported a good mood state and 12.5% reported feeling depressed; 61.1% reported having sexual desire, but only 30% maintained sexual relations; 78% were capable of emitting sounds and 65.8% could communicate without technical aid; 73.2% enjoyed going out and 81% met with friends at least twice a month. Only 14.3% participated in social activities and 23.8% watched television regularly. Nearly 100% of the patients reported being sensitive to touch to any part of their bodies. This survey suggests diagnostics and rehabilitation procedures.

Epidemiology of Traumatic Brain Injury and Subarachnoid Hemorrhage

Incidence rates of traumatic brain injury are high in both industrialized and non-industrialized countries and have been estimated variously to be between 150–250 cases per 100,000 population per year. The estimated incidence rates for subarachnoid hemorrhage (SAH) are between 10 to 25 cases per 100,000 population per year. Seasonal variation in the occurrence of subarachnoid hemorrhage has been reported in studies from different countries, with significant seasonal variations and peak periods for aneurysmal SAH differing widely. A differential racial distribution for SAH has been found as well as a higher mortality rate for women than for men. The cognitive and behavioral consequences of TBI and SAH are significant and affect the quality of life of patients and their families. Recent publications have informed of hypopituitary deficits in patients sustaining TBI or SAH. It is not clear whether the cognitive deficits found in these patients are due to the consequences of the brain injury itself or are related to the hypopituitary deficits. There is a need for research distinguishing the differential cognitive and behavioral effects of the brain injury and the endocrinological deficits in these patients, and for developing adequate treatment.

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.

Delta–alpha ratio correlates with level of recovery after neurorehabilitation in patients with acquired brain injury

OBJECTIVE To explore the relationship between three QEEG global indexes and their association with functional outcome after neurorehabilitation in non-acute acquired brain injury (ABI) patients (traumatic brain injury and stroke). METHODS Twenty-one adult ABI patients in post-acute phase were studied. Delta-alpha ratio (DAR), Power Ratio Index (PRI) and Mean Brain Symmetry Index (mBSI) were calculated from resting-state EEG taken at admission. These indexes and other clinical variables were correlated with functional recovery achieved after six months of neurorehabilitation. RESULTS DAR showed the highest strength of association with the functional outcome measure (rho=-0.65, P=0.002). The other QEEG indexes and clinical variables showed modest non-significant correlations. A posteriori group analysis showed higher DAR in patients with poor recovery as compared to good recovery patients. CONCLUSIONS Functional recovery after neurorehabilitation appears to be associated with a number of clinical and neurophysiological variables. Among the latter, the ratio between delta and alpha may play a significant role in predicting and monitoring functional rehabilitation outcome. SIGNIFICANCE Neurophysiological assessment of ABI patients may be an important tool in monitoring and predicting outcomes after neurorehabilitation.

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 drivers 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.

Synchronization between the anterior and posterior cortex determines consciousness level in patients with traumatic brain injury (TBI)

Survivors of traumatic brain injury (TBI) often suffer disorders of consciousness as a result of a breakdown in cortical connectivity. However, little is known about the neural discharges and cortical areas working in synchrony to generate consciousness in these patients. In this study, we analyzed cortical connectivity in patients with severe neurocognitive disorder (SND) and in the minimally conscious state (MCS). We found two synchronized networks subserving consciousness; one retrolandic (cognitive network) and the other frontal (executive control network). The synchrony between these networks is severely disrupted in patients in the MCS as compared to those with better levels of consciousness and a preserved state of alertness (SND). The executive control network could facilitate the synchronization and coherence of large populations of distant cortical neurons using high frequency oscillations on a precise temporal scale. Consciousness is altered or disappears after losing synchrony and coherence. We suggest that the synchrony between anterior and retrolandic regions is essential to awareness, and that a functioning frontal lobe is a surrogate marker for preserved consciousness. This article is part of a Special Issue entitled: Brain Integration.

Efficient learning produces spontaneous neural repetition suppression in prefrontal cortex.

Our study focuses on the physiological effects of repetition on learning and working memory using an adaptation of Lurias Memory Word-Task (LMWT). We assess the hemodynamic response in dorsolateral prefrontal cortex (DLPFC) of 13 healthy subjects while completing LMWT. Free word recalls were acquired at the beginning, middle and end of the task. Behavioral results showed that all subjects could recall the complete word list by the 10th trial, which was considered as successful task accomplishment. We observed an attenuation of stimulus-evoked neural activity in prefrontal neurons. Our findings show that the temporal integration of efficient verbal learning is mediated by a mechanism known as neural repetition suppression (NRS). This mechanism facilitates cortical deactivation in DLPFC once learning is successfully completed. This cortical reorganization is interpreted as a progressive optimization of neural responses to produce a more efficient use of neural circuits. NRS could be considered one of the natural mechanisms involved in the processes of memory learning.

A QEEG index of level of functional dependence for people sustaining acquired brain injury: The Seville Independence Index (SINDI)

Primary objective: To find an easy-to-use, valid and reliable tool for evaluating the level of functional dependence of an individual with brain damage who seeks a diagnosis of his/her functional dependence in daily activities. Methods: Eighty-one patients with acquired brain injury (ABI) in post-acute phase, 40 traumatic brain injury (TBI) and 41 cerebral vascular accident (CVA), were assessed using quantitative electroencephalography (QEEG) and grouped according to the FIM + FAM scale. Discriminant analysis was performed on QEEG variables to obtain a discriminant function with the best discriminative capacity between functionality groups. Results: Discriminant analysis showed classification accuracy of 100% in the training set sample and 75% in an external cross-validation sample; 100% sensitivity and 100% specificity were reached. Coherence measures were the most numerous variables in the function. Conclusions: These results point out that the discriminant function may be a useful tool in objective evaluations of patients seeking a diagnosis of their level of dependence and that it could be included in current functionality assessment protocols.