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Cureus Apr 2024Hyponatremia is an adverse effect of many antiseizure medications (ASMs). It occurs with interference with the normal balance of electrolytes within the body. Various... (Review)
Review
Hyponatremia is an adverse effect of many antiseizure medications (ASMs). It occurs with interference with the normal balance of electrolytes within the body. Various risk factors associated with the development of hyponatremia in patients taking these medications include age, gender, dosage, and combinations with other drugs. ASMs such as carbamazepine (CBZ), oxcarbazepine (OXC), and valproic acid have a higher risk of hyponatremia. Hyponatremia induced by an antiseizure medication can occur through various mechanisms depending on the drug's specific mechanism of action. Hyponatremia can be a potentially fatal side effect. Patients taking these medications need to be monitored closely for the signs and symptoms of hyponatremia. Acute hyponatremia, defined as developing in <48 hours, is more likely to show symptoms than chronic hyponatremia. Signs of acute hyponatremia include delirium, seizures, decerebrate posturing, and cerebral edema with uncal herniation. Chronic hyponatremia, defined as developing in >48 hours, can cause lethargy, dizziness, weakness, headache, nausea, and confusion. Hyponatremia is associated with longer hospital stays and increased mortality. Treatment varies based on the degree of severity of hyponatremia. Choosing a treatment option should include consideration of the drug causing the electrolyte disturbance, the patient's risk factor profile, and the severity of symptoms as they present in the individual patient. Healthcare providers should be aware of hyponatremia as a potential side effect of ASMs, the signs and symptoms of hyponatremia, the different treatment options available, and the potential complications associated with rapid correction of hyponatremia.
PubMed: 38707045
DOI: 10.7759/cureus.57535 -
Scientific Reports Apr 2024Several neurologic diseases including spinal cord injury, Parkinson's disease or multiple sclerosis are accompanied by disturbances of the lower urinary tract functions....
Several neurologic diseases including spinal cord injury, Parkinson's disease or multiple sclerosis are accompanied by disturbances of the lower urinary tract functions. Clinical data indicates that chronic spinal cord stimulation can improve not only motor function but also ability to store urine and control micturition. Decoding the spinal mechanisms that regulate the functioning of detrusor (Detr) and external urethral sphincter (EUS) muscles is essential for effective neuromodulation therapy in patients with disturbances of micturition. In the present work we performed a mapping of Detr and EUS activity by applying epidural electrical stimulation (EES) at different levels of the spinal cord in decerebrated cat model. The study was performed in 5 adult male cats, evoked potentials were generated by EES aiming to recruit various spinal pathways responsible for LUT and hindlimbs control. Recruitment of Detr occurred mainly with stimulation of the lower thoracic and upper lumbar spinal cord (T13-L1 spinal segments). Responses in the EUS, in general, occurred with stimulation of all the studied sites of the spinal cord, however, a pronounced specificity was noted for the lower lumbar/upper sacral sections (L7-S1 spinal segments). These features were confirmed by comparing the normalized values of the slope angles used to approximate the recruitment curve data by the linear regression method. Thus, these findings are in accordance with our previous data obtained in rats and could be used for development of novel site-specific neuromodulation therapeutic approaches.
Topics: Animals; Cats; Male; Spinal Cord; Electric Stimulation; Spinal Cord Stimulation; Urinary Bladder; Decerebrate State; Urinary Tract; Urethra; Urination; Epidural Space
PubMed: 38670988
DOI: 10.1038/s41598-024-54209-3 -
IDCases 2023We report a case of a 32-year-old male with a history of type 1 diabetes, inhaled drug use, and alcohol use disorder, who presented with encephalopathy, holocranial...
We report a case of a 32-year-old male with a history of type 1 diabetes, inhaled drug use, and alcohol use disorder, who presented with encephalopathy, holocranial headaches, neck pain, confusion, and generalized tonic-clonic seizures. The patient initially presented at a rural community hospital with a fever and was found to be in diabetic ketoacidosis (DKA). He was also hemodynamically stable but stuporous, prompting intubation to protect his airway. Despite initial treatment measures, his neurological condition worsened and he remained ventilator-dependent. Key findings include a high glucose level, presence of ketones, and evidence of drug use. Blood cultures showed no growth, but his febrile state persisted. Cerebrospinal fluid (CSF) analysis revealed mild pleocytosis, hyperglycorrhachia but normal protein, with no growth. Neuroimaging showed right hemispheric slowing on EEG and diffusion restriction in the right frontal lobe on MRI. The patient's neurological status worsened on the second day of admission, manifesting as sluggish pupillary reflexes, right third nerve palsy, and decerebrate posturing. Emergent MRI suggested cerebral edema, leading to initiation of hypertonic saline. This case highlights the diagnostic challenges and critical management considerations in a patient with multiple comorbidities presenting with unexplained neurological deterioration, emphasizing the importance of a comprehensive and timely approach to diagnosis and treatment.
PubMed: 37415782
DOI: 10.1016/j.idcr.2023.e01821 -
Neuromodulation : Journal of the... Jun 2024Implantation of stimulating electrodes into the basement of the vertebral spinous process allows the electrodes to be quickly and stably fixed relative to the spinal...
OBJECTIVES
Implantation of stimulating electrodes into the basement of the vertebral spinous process allows the electrodes to be quickly and stably fixed relative to the spinal cord. Using this approach, we have previously shown the selectivity of rat muscle activation during transvertebral stimulation (TS). In this work, we investigated the TS to induce forward stepping of the cat's hindlimbs in comparison with epidural stimulation (ES).
MATERIALS AND METHODS
TS was performed with an electrode placed in the VL3-VL6 vertebrae in five decerebrated cats. ES was performed on the same cats in L5-L7 segments. Kinematic parameters of stepping were recorded in addition to electromyographic activity of musculus (m.) iliopsoas (IP), m. tibialis anterior (TA), and m. gastrocnemius lateralis (GL) of both hindlimbs.
RESULTS
With VL3-VL4 TS, all five animals were capable of bipedal forward stepping, whereas VL5 and VL6 TS led to the forward stepping in 3 of 5 and 1 of 5 animals, respectively. Well-coordinated muscle activity led to a high level of intra- and interlimb coordination. Kinematic parameters of TS-induced stepping were similar to those obtained with ES. The TS of the VL3 vertebra causes the frequency lock with the integer multiple of the stimulation frequency. Similarly to the rat model, TS-evoked muscle responses were site specific. They were minimal during VL3 TS and were maximal during VL4-VL5 TS (IP) and VL5-VL6 TS (TA, GL).
CONCLUSIONS
The obtained results support hypotheses about the location of the central pattern generators in the upper lumbar spinal segments. The proposed approach of electrode placement is surgically easier to perform than is ES. This approach is useful for studying site-specific neuromodulation of the spinal sensorimotor networks and for investigating new strategies of locomotor recovery in animal models.
Topics: Animals; Cats; Decerebrate State; Electromyography; Muscle, Skeletal; Hindlimb; Biomechanical Phenomena; Spinal Cord Stimulation; Electrodes, Implanted; Electric Stimulation; Male; Female; Lumbar Vertebrae
PubMed: 36567242
DOI: 10.1016/j.neurom.2022.11.009 -
American Journal of Physiology.... Feb 2023We investigated the role played by bradykinin 2 (B2) receptors in the exaggerated exercise pressor reflex in rats with a femoral artery ligated for 72 h to induce...
We investigated the role played by bradykinin 2 (B2) receptors in the exaggerated exercise pressor reflex in rats with a femoral artery ligated for 72 h to induce simulated peripheral artery disease (PAD). We hypothesized that in decerebrate, unanesthetized rats with a ligated femoral artery, hindlimb arterial injection of HOE-140 (100 ng, B2 receptor antagonist) would reduce the pressor response to 30 s of electrically induced 1 Hz hindlimb skeletal muscle contraction, and 30 s of 1 Hz hindlimb skeletal muscle stretch (a model of mechanoreflex activation isolated from contraction-induced metabolite production). We hypothesized no effect of HOE-140 in sham-operated "freely perfused" rats. In both freely perfused ( = 4) and "ligated" ( = 4) rats, we first confirmed efficacious B2 receptor blockade by demonstrating that HOE-140 injection significantly reduced ( < 0.05) the peak increase in mean arterial pressure (peak ΔMAP) in response to hindlimb arterial injection of bradykinin. In subsequent experiments, we found that HOE-140 reduced the peak ΔMAP response to muscle contraction in ligated ( = 14; control: 23 ± 2; HOE-140: 17 ± 2 mmHg; = 0.03) but not freely perfused rats ( = 7; control: 17 ± 3; HOE-140: 18 ± 4 mmHg; = 0.65). Furthermore, HOE-140 had no effect on the peak ΔMAP response to stretch in ligated rats ( = 14; control: 37 ± 4; HOE-140: 32 ± 5 mmHg; = 0.13) but reduced the integrated area under the blood pressure signal over the final ∼20 s of the maneuver. The data suggest that B2 receptors contribute to the exaggerated exercise pressor reflex in rats with simulated PAD, and that contribution includes a modest role in the chronic sensitization of the mechanically activated channels/afferents that underlie mechanoreflex activation.
Topics: Rats; Animals; Reflex; Muscle, Skeletal; Receptors, Bradykinin; Rats, Sprague-Dawley; Bradykinin; Muscle Contraction; Peripheral Arterial Disease; Blood Pressure; Femoral Artery; Hindlimb
PubMed: 36534589
DOI: 10.1152/ajpregu.00274.2022 -
Journal of Orthopaedic Case Reports Apr 2022Isolated cerebral fat embolism syndrome (FES) is a rare complication that occurs within the first 3 days of the initial insult. We report a case of multiple long bone...
INTRODUCTION
Isolated cerebral fat embolism syndrome (FES) is a rare complication that occurs within the first 3 days of the initial insult. We report a case of multiple long bone fractures with isolated cerebral FES, despite undergoing early total care with definitive fixation.
CASE PRESENTATION
A 22-year-old female presented with type IIIA open femur shaft fracture on the right side (AO 32B2), closed femur shaft fracture (AO 32B2), comminuted patella fracture on the left side (AO 34C3), and undisplaced mandible fracture. She had a normal sensorium with a Glasgow Coma Scale (GCS) of E4V5M6. A whole body computed tomography (CT) scan was done to rule out other injuries. All initial scans were normal. After about 6 h in the ICU, she was noticed to have disconjugate gaze and was answering in monosyllables. A repeat CT scan of the brain was normal. The early total care and definitive fixation with titanium intramedullary nails for femur fractures and tension band wiring for patella was done under general anesthesia. On 1st post-operative day (POD), her GCS dropped to E1VTM1. On the 3rd POD, she developed decerebrate rigidity and generalized tonic clonic seizures. Fundoscopic examination showed multiple fat globules along the vessel in the entire field of both eyes. Since there were no other signs of FES in the lungs or on the skin, an MRI brain was done which revealed a hyperintensive starfield pattern on diffusion-weighted images, suggestive of cerebral fat embolism (CFE). At 4 weeks, her upper limb and lower limb muscle power improved. By 2 months, she was mobilized with support. Her Mini-Mental State Examination showed no cognitive impairment. At the latest follow-up at 1 year, her fractures are completely healed and she has no neurological or functional impairment.
CONCLUSION
We must always suspect isolated cerebral FES as a diagnosis in polytrauma patients even when the classical findings are not present. MRI compatible implants have to be used as far as possible as MRI may be required to confirm the diagnosis of CFE. The early total care with definitive fixation and supportive treatment helped us in this patient's complete recovery without cognitive impairment.
PubMed: 36380992
DOI: 10.13107/jocr.2022.v12.i04.2750 -
Frontiers in Veterinary Science 2022Debates around fishes' ability to feel pain concern : do reactions to tissue damage indicate evaluative consciousness (conscious affect), or mere nociception? Thanks to... (Review)
Review
Debates around fishes' ability to feel pain concern : do reactions to tissue damage indicate evaluative consciousness (conscious affect), or mere nociception? Thanks to Braithwaite's discovery of trout nociceptors, and concerns that current practices could compromise welfare in countless fish, this issue's importance is beyond dispute. However, nociceptors are merely necessary, not sufficient, for true pain, and many measures held to indicate sentience have the same problem. The question of whether fish feel pain - or indeed anything at all - therefore stimulates sometimes polarized debate. Here, we try to bridge the divide. After reviewing key consciousness concepts, we identify "red herring" measures that should not be used to infer sentience because also present in non-sentient organisms, notably those lacking nervous systems, like plants and protozoa (P); spines disconnected from brains (S); decerebrate mammals and birds (D); and humans in unaware states (U). These "S.P.U.D. subjects" can show approach/withdrawal; react with apparent emotion; change their reactivity with food deprivation or analgesia; discriminate between stimuli; display Pavlovian learning, including some forms of trace conditioning; and even learn simple instrumental responses. Consequently, none of these responses are good indicators of sentience. Potentially more valid are aspects of working memory, operant conditioning, the self-report of state, and forms of higher order cognition. We suggest new experiments on humans to test these hypotheses, as well as modifications to tests for "mental time travel" and self-awareness (e.g., mirror self-recognition) that could allow these to now probe sentience (since currently they reflect perceptual rather than evaluative, affective aspects of consciousness). Because "bullet-proof" neurological and behavioral indicators of sentience are thus still lacking, agnosticism about fish sentience remains widespread. To end, we address how to balance such doubts with welfare protection, discussing concerns raised by key skeptics in this debate. Overall, we celebrate the rigorous evidential standards required by those unconvinced that fish are sentient; laud the compassion and ethical rigor shown by those advocating for welfare protections; and seek to show how precautionary principles still support protecting fish from physical harm.
PubMed: 35573409
DOI: 10.3389/fvets.2022.788289 -
The Journal of Physiology May 2022Mechanical and metabolic signals associated with skeletal muscle contraction stimulate the sensory endings of thin fibre muscle afferents, which, in turn, generates...
Mechanical and metabolic signals associated with skeletal muscle contraction stimulate the sensory endings of thin fibre muscle afferents, which, in turn, generates reflex increases in sympathetic nerve activity (SNA) and blood pressure (the exercise pressor reflex; EPR). EPR activation in patients and animals with heart failure with reduced ejection fraction (HF-rEF) results in exaggerated increases in SNA and promotes exercise intolerance. In the healthy decerebrate rat, a subtype of acid sensing ion channel (ASIC) on the sensory endings of thin fibre muscle afferents, namely ASIC1a, has been shown to contribute to the metabolically sensitive portion of the EPR (i.e. metaboreflex), but not the mechanically sensitive portion of the EPR (i.e. the mechanoreflex). However, the role played by ASIC1a in evoking the EPR in HF-rEF is unknown. We hypothesized that, in decerebrate, unanaesthetized HF-rEF rats, injection of the ASIC1a antagonist psalmotoxin-1 (PcTx-1; 100 ng) into the hindlimb arterial supply would reduce the reflex increase in renal SNA (RSNA) evoked via 30 s of electrically induced static hindlimb muscle contraction, but not static hindlimb muscle stretch (model of mechanoreflex activation isolated from contraction-induced metabolite-production). We found that PcTx-1 reduced the reflex increase in RSNA evoked in response to muscle contraction (n = 8; mean (SD) ∫ΔRSNA pre: 1343 (588) a.u.; post: 816 (573) a.u.; P = 0.026) and muscle stretch (n = 6; ∫ΔRSNA pre: 688 (583) a.u.; post: 304 (370) a.u.; P = 0.025). Our data suggest that, in HF-rEF rats, ASIC1a contributes to activation of the exercise pressor reflex and that contribution includes a novel role for ASIC1a in mechanosensation that is not present in healthy rats. KEY POINTS: Skeletal muscle contraction results in exaggerated reflex increases in sympathetic nerve activity in heart failure patients compared to healthy counterparts, which likely contributes to increased cardiovascular risk and impaired tolerance for even mild exercise (i.e. activities of daily living) for patients suffering with this condition. Activation of acid sensing ion channel subtype 1a (ASIC1a) on the sensory endings of thin fibre muscle afferents during skeletal muscle contraction contributes to reflex increases in sympathetic nerve activity and blood pressure, at least in healthy subjects. In this study, we demonstrate that ASIC1a on the sensory endings of thin fibre muscle afferents plays a role in both the mechanical and metabolic components of the exercise pressor reflex in male rats with heart failure. The present data identify a novel role for ASIC1a in evoking the exercise pressor reflex in heart failure and may have important clinical implications for heart failure patients.
Topics: Acid Sensing Ion Channels; Animals; Blood Pressure; Heart Failure; Hindlimb; Male; Muscle Contraction; Muscle, Skeletal; Rats; Rats, Sprague-Dawley; Reflex
PubMed: 35343594
DOI: 10.1113/JP282923