Dopamine/BDNF loss underscores narcosis cognitive impairment in divers: a proof of concept in a dry condition

PURPOSE

Divers can experience cognitive impairment due to inert gas narcosis (IGN) at depth. Brain-derived neurotrophic factor (BDNF) rules neuronal connectivity/metabolism to maintain cognitive function and protect tissues against oxidative stress (OxS). Dopamine and glutamate enhance BDNF bioavailability. Thus, we hypothesized that lower circulating BDNF levels (via lessened dopamine and/or glutamate release) underpin IGN in divers, while testing if BDNF loss is associated with increased OxS.

METHODS

To mimic IGN, we administered a deep narcosis test via a dry dive test (DDT) at 48 msw in a multiplace hyperbaric chamber to six well-trained divers. We collected: (1) saliva samples before DDT (T0), 25 msw (descending, T1), 48 msw (depth, T2), 25 msw (ascending, T3), 10 min after decompression (T4) to dopamine and/or reactive oxygen species (ROS) levels; (2) blood and urine samples at T0 and T4 for OxS too. We administered cognitive tests at T0, T2, and re-evaluated the divers at T4.

RESULTS

At 48 msw, all subjects experienced IGN, as revealed by the cognitive test failure. Dopamine and total antioxidant capacity (TAC) reached a nadir at T2 when ROS emission was maximal. At decompression (T4), a marked drop of BDNF/glutamate content was evidenced, coinciding with a persisting decline in dopamine and cognitive capacity.

CONCLUSIONS

Divers encounter IGN at - 48 msw, exhibiting a marked loss in circulating dopamine levels, likely accounting for BDNF-dependent impairment of mental capacity and heightened OxS. The decline in dopamine and BDNF appears to persist at decompression; thus, boosting dopamine/BDNF signaling via pharmacological or other intervention types might attenuate IGN in deep dives.

[Unconsciousness and clouded awareness]

Stupor and coma are clinical states in which patients have impaired responsiveness or are unresponsive to external stimulation and are either difficult to arouse or are unarousable. The term stupor refer to states between alertness and coma. An alteration in arousal represents an acute life-threatening emergency, requiring prompt intervention for preservation of life and brain function.

Morgagni hernia with respiratory failure aggravated by noninvasive positive pressure ventilation: a case report and overview of the literature

An elderly woman diagnosed with multiple myeloma (MM) in 2007 had improved with chemotherapy. She had severe kyphosis and a diaphragmatic hernia (DH), but no respiratory symptoms. In 2011, because of thoracic deformity and emaciation, we advised her to continue the previously prescribed domiciliary noninvasive positive pressure ventilation (NPPV) therapy for chronic type II respiratory failure. However, she refused to continue NPPV. She was later admitted for deterioration in respiratory status and carbon dioxide (CO2) narcosis. We believed her low adherence to domiciliary NPPV caused CO2 narcosis; hence, we advised her to continue domiciliary NPPV and she complied. In May 2012, the now 79-year-old patient was admitted for acute exacerbation of chronic respiratory failure and CO2 narcosis. Chest imaging suggested that DH had caused a deterioration of her status. She underwent laparoscopic diaphragmatic hernia repair. Operative findings revealed a retrosternal hernia sac, and she was diagnosed as having a Morgagni hernia (MH). Her respiratory status subsequently improved. We hypothesize that NPPV increased intra-abdominal pressure, thereby worsening the MH and exacerbating respiratory failure. We believe that clinicians should be cautious when prescribing NPPV for MH patients.

Predictors of five days mortality in diabetic ketoacidosis patients: a prospective cohort study

AIM

to determine the role of serum lactate and diabetic ketoacidosis (DKA) severity as predictors for five-days mortality in DKA patients.

METHODS

a prospective cohort study was conducted in DKA patients admitted to emergency department (ED) at Cipto Mangunkusumo Hospital, Jakarta, Indonesia, during 2007-2008 periods. Predictors for 5 days mortality in DKA patients in this study including serum lactate and DKA severity (plasma glucose, arterial blood pH, serum bicarbonate, osmolality, anion gap, and alteration in sensorium) at admission. Cox's Proportional Hazard Regression Analysis was used to determine independent predictors for 5-days mortality among study population.

RESULTS

sixty patients with diabetic ketoacidosis were enrolled in the study; in which 24 (40%) patients were died within 5 days after admission. In the multivariate analysis, the lactate level 4 mmol/L (HR, 3.09; 95% CI, 1.36-7.05) and altered in sensorium stuporous/comatose (HR, 3.38; 95% CI, 1.45-7.87) were identified as independent predictors for 5-days mortality in DKA adult patients.

CONCLUSION

lactate level 4 mmol/L and altered in sensorium stuporous/comatose can be used to predict 5-days mortality in adult patients with DKA.

Altered mental status in older patients in the emergency department

Altered mental status is a common chief compliant among older patients in the emergency department (ED). Acute changes in mental status are more concerning and are usually secondary to delirium, stupor, and coma. Although stupor and coma are easily identifiable, the clinical presentation of delirium can be subtle and is often missed without actively screening for it. For patients with acute changes in mental status the ED evaluation should focus on searching for the underlying etiology. Infection is one of the most common precipitants of delirium, but multiple causes may exist concurrently.

[Familial hemiplegic migraine type 2: two paediatric case reports]

INTRODUCTION

Familial hemiplegic migraine is a rare subtype of migraine with aura that includes, as it progresses, a motor defect together with visual or sensory symptoms or speech disorders. It may be associated to symptoms such as basilar migraine, coma and convulsions. Familial hemiplegic migraine type 2 accounts for 25% of them.

CASE REPORTS

Two patients, who started at the age of 4 years with episodes of motor deficits or seizures, together with an important sensory disorder that lasted for hours, which were sometimes triggered by banal traumatic injuries. A detailed description of the clinical and developmental features, as well as the studies conducted, is provided. The genetic study revealed mutations in gene ATP1A2: in one case this consisted in a nucleotide substitution in exon 18 (G2501A) that had already been reported, while in the other case there was a previously unknown change (c.381+3 G>T) in intron 4.

CONCLUSIONS

We recommend that this condition should be suspected when a disagreement between the duration or the severity of the seizures and the duration and characteristics of the ensuing stupor is detected.

Physical and physicochemical factors effecting transport of chlorohydrocarbon gases from lung alveolar air to blood as measured by the causation of narcosis

This systematic investigation examines gas transport in the lung for two sets of chlorohydrocarbons (CHCs): the chloromethanes (C1) and chloroethanes (C2). The C1 series includes chloromethane, methylene chloride, chloroform, and carbon tetrachloride, and the C2 series includes chloroethane, 1,2-dichloroethane, 1, 1, 2-trichloroethane, and 1, 1, 2, 2-tetrachloroethane. Most CHC gases cause narcosis. The comprehensive narcosis work of Lehmann and colleagues on CHCs was used as a basis for the narcosis endpoint in the present examination. The sites for narcosis are located in the brain (midline cortex and posterior parietal area), the spine, and at many peripheral nerve sites. Central nervous system (CNS) exposure executes a multisite, neural transmission set of inhibitions that promotes rapid loss of consciousness, sensory feeling, and current and stored memory while providing temporary amnesia. Absorption into the system requires dissolution into many lipid membranes and binding to lipoproteins. Lipophilicity is a CHC property shared with many anesthetics according to the Meyer-Overton Rule. Many structurally different lipid chemicals produce the narcosis response when the lipid concentration exceeds -67 mM. This suggests narcotic or anesthetic dissolution into CNS membranes until the lipid organization is disrupted or perturbed. This perturbation includes loading of Na(+)- and K(+)-channel transmembrane lipoprotein complexes and disrupting their respective channel functional organizations. The channel functions become attenuated or abrogated until the CHC exposure ceases and CHC loading reverses. This investigation demonstrates how the CHC physical and chemical properties influence the absorption of these CHCs via the lung and the alveolar system on route to the blood. Narcosis in test animals was used here as an objective biological endpoint to study the effects of the physical factors Bp, Vp, Kd (oil: gas) partition, Henry's constant (HK), and water solubility (S%) on gas transport. Narcosis is immediate after gas exposure and requires no chemical activation only absorption into the blood and circulation to CNS narcotic sites. The three physical factors Bp, K(d) (oil: air), and S% vary directly with unitary narcosis (UN) whereas Vp and HK vary inversely with UN in linear log-log relationships for the C2 series but not for the C1 series. Physicochemical properties of C1 series gases indicate why they depart from what is usually assumed to be an Ideal Gas. An essential discriminating process in the distal lung is the limiting alveolar film layer (AFL) and the membrane layer of the alveolar acini. The AFL step influences gas uptake by physically limiting the absorption process. Interaction with and dissolution into aqueous solvent of the AFL is required for transport and narcotic activity. Narcotics or anesthetics must engage the aqueous AFL with sufficient strength to allow transport and absorption for downstream CNS binding. CHCs that do not engage well with the AFL are not narcotic. Lipophilicity and amphipathicity are also essential solvency properties driving narcotics' transport through the alveolar layer, delivery to the blood fats and lipoproteins, and into critical CNS lipids, lipoproteins, and receptor sites that actuate narcosis. AFL disruption is thought to be strongly related to a number of serious pulmonary diseases such acute respiratory distress syndrome, infant respiratory distress syndrome, emphysema, chronic obstructive pulmonary disease, asthma, chronic bronchitis, pneumonia, pulmonary infections, and idiopathic pulmonary fibrosis. The physical factors (Bp, Vp, Kd [oil: gas] partition, Henry's constant, and water solubility [S%]) combine to affect a specific transport through the AFL if lung C > C(0) (threshold concentration for narcosis). The degree of blood CHC absorption depends on dose, lipophilicity, and lung residence time. AFL passage can be manipulated by physical factors of increased pressure (kPa) or increased gas exposure (moles). Molecular lipophilicity facilitates narcosis but lipophilicity alone does not explain narcosis. Vapor pressure is also required for narcosis. Narcotic activity apparently requires stereospecific processing in the AFL and/or down-stream inhibition at stereospecific lipoproteins at CNS inhibitory sites. It is proposed that CHCs likely cannot proceed through the AFL without perturbation or disruption of the integrity of the AFL at the alveoli. CHC physicochemical properties are not expected to allow their transport through the AFL as physiological CO(2) and O(2) naturally do in respiration. This work considers CHC inspiration and systemic absorption into the blood with special emphasis on the CHC potential perturbation effects on the lipid, protein liquid layer supra to the alveolar membrane (AFL). A heuristic gas transport model for the CHCs is presented as guidance for this examination. The gas transport model can be used to study absorption for other gas delivery endpoints of environmental concern such as carcinogens.

Modified electroconvulsive therapy for recurrent major depressive disorder in a meningioma patient: a case report of clinical experience

Electroconvulsive therapy (ECT) is primarily indicated for mood disorders and schizophrenia. Clinicians may encounter cases in which ECT is administered to patients with various kinds of complications. However, to our knowledge, no detailed medical guideline is available about the indications for ECT in psychiatric illness complicated with a concomitant brain tumor, which is one of the most likely physical complications that can directly affect ECT. We report a case in which 3 courses of modified ECT (m-ECT) were successfully administered without any neurological deterioration to a patient, who was frequently hospitalized for recurrent depressive disorder with stupor. We did not undertake any additional measures for reducing adverse events derived from the meningioma during m-ECT. In this report, we discuss the relation between brain tumor and depression.

Acute alcohol intoxication

Acute alcohol intoxication is a clinically harmful condition that usually follows the ingestion of a large amount of alcohol. Clinical manifestations are heterogeneous and involve different organs and apparatuses, with behavioral, cardiac, gastrointestinal, pulmonary, neurological, and metabolic effects. The management of an intoxicated patient occurs mainly in the emergency department and is aimed at stabilizing the clinical condition of the patient, depending on his/her clinical presentation. One specific drug that is useful in the treatment of acute alcohol intoxication is metadoxine, which is able to accelerate ethanol excretion. In patients presenting an acute alcohol intoxication, alcohol-related disorders should be detected so that the patient can be directed to an alcohol treatment unit, where a personalized, specific treatment can be established.

Cerebral subarachnoid blood migration consecutive to a lumbar haematoma after spinal anaesthesia

We report the case of a woman who received spinal anaesthesia for peripheral vascular surgery of the lower limbs and subsequently developed a spinal subarachnoid haematoma. Interestingly, low back pain was the only symptom of this spinal subarachnoid haemorrhage. During the following days, blood migrated from the spinal haematoma towards the cerebral subarachnoid spaces. The patient presented with stupor, nausea and vomiting that resolved within 2 weeks with conservative treatment.

Nonconvulsive status epilepticus causing prolonged stupor after intraventricular hemorrhage: report of a case

We describe the case of an octogenarian woman who experienced a severe alteration of mental state due to non-convulsive status epilepticus (NCSE) complicating an intraventricular hemorrhage. Our report emphasizes that NCSE may be the cause of unexplained neurological deterioration in elderly patients with acute brain injury.