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Mild traumatic brain injury (mTBI) is a common medical condition affecting all age groups with the greatest occurrence in young and elderly patients. Research in recent years has proved that mTBI is not as a benign and fully reversible injury as previously thought implying the firmly established term „brain concussion". Repeated mTBI may result in a broad spectrum of cognitive impairment and even dementia. Some patients with frequent mTBI were described as having a histopathologically well-defined chronic traumatic encephalopathy (CTE). An accumulation of the tau protein was found in the brain tissue of these patients, which is typically present in other neurodegenerative diseases. A small percentage of patients with mTBI suffer from serious intracranial complications which may, if undetected, lead to severe neurological sequelae or even death. Thus, the aim of this consensus statement is to change the attitude toward patients with mTBI. The proposal introduces the extent of the initial neurological examination and lists risk factors indicating performance of a head CT and criteria for inpatient observation including monitored parameters. Furthermore, presented recommendations aim to decrease the long-term sequelae of mTBI and suggest algorithms of care in the Czech Republic. The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manu­script met the ICMJE "uniform requirements" for biomedical papers. [ABSTRACT FROM AUTHOR]

Neurological complications of hypoglycemia often include seizures and fasting is a predisposing factor for seizures to occur. The mechanisms involved are unknown. In rats, insulin administration induces hypoglycemia, which may lead to generalized seizures with barrel rotations as a hallmark. Here we compared the incidence of barrel rotations in fasted and nonfasted rats. Further, we investigated the role of the substantia nigra pars reticulata (SNR) in control of barrel rotations using localized bilateral microinfusions of GABA(A) or GABA(B) receptor agonists (muscimol or baclofen, respectively) or an N-methyl-D-aspartate (NMDA) receptor antagonist (AP7). The incidence of barrel rotations was significantly higher in fasted compared to nonfasted rats. SNR infusions of muscimol were ineffective, while both baclofen and AP7 significantly decreased occurrence of barrel rotations. These data suggest that during hypoglycemia, the SNR seizure controlling system has different properties than in seizure models not involving a metabolic stress.

GABAergic activation of substantia nigra pars reticulata (SNR) at postnatal day (PN) 15 has sex-specific features on seizure control in vivo and electrophysiological responses in vitro. In males, the GABA(A)-receptor agonist muscimol has proconvulsant effects and induces depolarizing responses. In females, muscimol has no effect on seizures and evokes hyperpolarizing responses. We determined the time period during which sex hormones must be present to produce the sex-specific muscimol effects on seizures and their influence on SNR GABA(A) receptor-mediated postsynaptic currents. Exposure to testosterone or its metabolites (estrogen or dihydrotestosterone) during PN0-2 in females or males castrated at PN0 was sufficient to produce proconvulsant muscimol effects but did not affect the in vitro GABA responses, which remained hyperpolarizing. The data suggest that the PN0-2 period is critical for the development of the seizure-controlling SNR system; the hormonal effect on seizure control is independent from their effect on GABA conductance.

The substantia nigra pars reticulata (SNR) plays important roles in movement and, in an age- and sex-dependent manner, in seizure control. GABAergic synaptic transmission is critical in both normal development and seizures. In many neuronal types it is excitatory early in development and later switches to the mature hyperpolarizing type. We assessed the time course of the switch of GABAA receptor-mediated postsynaptic currents (PSCs) in anterior SNR neurons of male and female developing rats using the gramicidin perforated patch clamp technique. The switch occurred in males around postnatal day (PN) 17 and in females around PN10. This sex dimorphism may play a role in several other recognized sex differences in the development of SNR and in its regulatory role in seizures.