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Minerva Anestesiologica Sep 2019Pupillary examination has fundamental diagnostic and prognostic values in clinical practice. However, pupillary assessment was relied until present on manual,... (Review)
Review
Pupillary examination has fundamental diagnostic and prognostic values in clinical practice. However, pupillary assessment was relied until present on manual, qualitative, examination, using manual flash penlights or lamps. Quantitative examination with the use of automated infrared video-pupillometers allows an objective assessment of several pupillary parameters and may be superior to manual subjective examination. The potential for quantitative pupillometry is multiple in the setting of critical care, for the monitoring and detection of secondary cerebral insults and to assess brainstem dysfunction and early coma outcome prognostication, and in the intra-operative anesthesiology setting, to assess analgesia and opioid requirement. Here, we describe the pupillometry technique and review recent critical care and anesthesiology studies that demonstrate the value and potential clinical utility of quantitative pupillometry as neuromonitoring bedside modality.
Topics: Analgesia; Analgesics; Anesthetics; Anthropometry; Antiemetics; Automation; Clinical Trials as Topic; Coma; Critical Care; Critical Illness; Equipment Design; Humans; Infrared Rays; Intracranial Hypertension; Multicenter Studies as Topic; Neuromuscular Blocking Agents; Prognosis; Pupil; Reflex, Abnormal; Reflex, Pupillary
PubMed: 30938123
DOI: 10.23736/S0375-9393.19.13437-2 -
Journal of Diabetes Research 2021Blink reflex provides an objective assessment of the cranial and central nervous systems. However, the relationships between body mass index, dizziness, and BR have not...
Blink reflex provides an objective assessment of the cranial and central nervous systems. However, the relationships between body mass index, dizziness, and BR have not been explored in patients with type 2 diabetes mellitus (T2DM). Moreover, R2 duration, one of the parameters of the blink reflex, has not been studied to date. In the present study, we aimed to investigate the characteristics and influencing factors of blink reflex in patients with T2DM. We included 45 healthy subjects and 105 hospitalized patients with T2DM. The relationships between these parameters and sex, age, body mass index, duration of T2DM, hemoglobin A1c, distal symmetrical polyneuropathy (DSPN), and dizziness symptoms were analyzed. The results showed that blink reflex latencies (including R1, ipsilateral R2, and contralateral R2 latency) were negatively associated with body mass index but were positively correlated with the duration of T2DM. There were no correlations between blink reflex parameters and sex, age, and hemoglobin A1c. Patients with DSPN had longer blink reflex latencies and shorter R2 durations than those without DSPN. Patients with dizziness had longer latencies (including R1, ipsilateral R2, and contralateral R2 latencies) and shorter R2 durations (including ipsilateral R2 and contralateral R2 durations) than those without dizziness. R2 duration was also a predictive factor for blink reflex abnormality. R2 latency was the most sensitive factor and the optimal predictor of dizziness. These results demonstrate that patients with T2DM with low body mass index, longer duration of T2DM, DSPN, and dizziness-related symptoms had more abnormal blink reflex parameters, indicating more serious injuries to the cranial nerves or the central nervous system.
Topics: Adult; Aged; Blinking; Body Mass Index; Cross-Sectional Studies; Diabetes Mellitus, Type 2; Dizziness; Female; Humans; Male; Middle Aged; Polyneuropathies; Reaction Time; Reflex, Abnormal
PubMed: 33791387
DOI: 10.1155/2021/2473193 -
Neurological Research and Practice Feb 2023Post-stroke dysphagia (PSD) is common and can lead to serious complications. Pharyngeal sensory impairment is assumed to contribute to PSD. The aim of this study was to...
BACKGROUND
Post-stroke dysphagia (PSD) is common and can lead to serious complications. Pharyngeal sensory impairment is assumed to contribute to PSD. The aim of this study was to investigate the relationship between PSD and pharyngeal hypesthesia and to compare different assessment methods for pharyngeal sensation.
METHODS
In this prospective observational study, fifty-seven stroke patients were examined in the acute stage of the disease using Flexible Endoscopic Evaluation of Swallowing (FEES). The Fiberoptic Endoscopic Dysphagia Severity Scale (FEDSS) and impaired secretion management according to the Murray-Secretion Scale were determined, as well as premature bolus spillage, pharyngeal residue and delayed or absent swallowing reflex. A multimodal sensory assessment was performed, including touch-technique and a previously established FEES-based swallowing provocation test with different volumes of liquid to determine the latency of swallowing response (FEES-LSR-Test). Predictors of FEDSS, Murray-Secretion Scale, premature bolus spillage, pharyngeal residue, and delayed or absent swallowing reflex were examined with ordinal logistic regression analyses.
RESULTS
Sensory impairment using the touch-technique and the FEES-LSR-Test were independent predictors of higher FEDSS, Murray-Secretion Scale, and delayed or absent swallowing reflex. Decreased sensitivity according to the touch-technique correlated with the FEES-LSR-Test at 0.3 ml and 0.4 ml, but not at 0.2 ml and 0.5 ml trigger volumes.
CONCLUSIONS
Pharyngeal hypesthesia is a crucial factor in the development of PSD, leading to impaired secretion management and delayed or absent swallowing reflex. It can be investigated using both the touch-technique and the FEES-LSR-Test. In the latter procedure, trigger volumes of 0.4 ml are particularly suitable.
PubMed: 36793109
DOI: 10.1186/s42466-023-00233-z -
Frontiers in Immunology 2021Anti-IgLON5 disease forms an interface between neuroinflammation and neurodegeneration and includes clinical phenotypes that are often similar to those of...
OBJECTIVE
Anti-IgLON5 disease forms an interface between neuroinflammation and neurodegeneration and includes clinical phenotypes that are often similar to those of neurodegenerative diseases. An early diagnosis of patients with anti-IgLON5 disease and differentiation from neurodegenerative diseases is necessary and may have therapeutic implications.
METHODS
In our small sample size study we investigated oculomotor function as a differentiating factor between anti-IgLON5 disease and neurodegenerative disorders. We examined ocular motor and vestibular function in four patients suffering from anti-IgLON5 disease using video-oculography (VOG) and a computer-controlled rotational chair system (sampling rate 60 Hz) and compared the data with those from ten age-matched patients suffering from progressive supranuclear palsy (PSP) and healthy controls (CON).
RESULTS
Patients suffering from anti-IgLON5 disease differed from PSP most strikingly in terms of saccade velocity and accuracy, the presence of square wave jerks (SWJ) (anti-IgLON5 0/4 . PSP 9/10) and the clinical finding of supranuclear gaze palsy (anti-IgLON5 1/4). The presence of nystagmus, analysis of smooth pursuit eye movements, VOR and VOR suppression was reliable to differentiate between the two disease entities. Clear differences in all parameters, although not always significant, were found between all patients and CON.
DISCUSSION
We conclude that the use of VOG as a tool for clinical neurophysiological assessment can be helpful in differentiating between patients with PSP and patients with anti-IgLON5 disease. VOG could have particular value in patients with suspected PSP and lack of typical Parkinson's characteristics. future trials are indispensable to assess the potential of oculomotor function as a biomarker in anti-IgLON5 disease.
Topics: Aged; Autoantibodies; Autoantigens; Autoimmune Diseases of the Nervous System; Cell Adhesion Molecules, Neuronal; Diagnosis, Differential; Electrooculography; Eye-Tracking Technology; Female; Humans; Male; Middle Aged; Neurodegenerative Diseases; Neuroinflammatory Diseases; Nystagmus, Pathologic; Ocular Motility Disorders; Phenotype; Reflex, Abnormal; Reflex, Vestibulo-Ocular; Retrospective Studies; Saccades; Supranuclear Palsy, Progressive; Video Recording
PubMed: 34659261
DOI: 10.3389/fimmu.2021.753856 -
The Journal of Physiology May 2021In people or animals with incomplete spinal cord injury (SCI), changing a spinal reflex through an operant conditioning protocol can improve locomotion. All previous...
KEY POINTS
In people or animals with incomplete spinal cord injury (SCI), changing a spinal reflex through an operant conditioning protocol can improve locomotion. All previous studies conditioned the reflex during steady-state maintenance of a specific posture. By contrast, the present study down-conditioned the reflex during the swing-phase of locomotion in people with hyperreflexia as a result of chronic incomplete SCI. The aim was to modify the functioning of the reflex in a specific phase of a dynamic movement. This novel swing-phase conditioning protocol decreased the reflex much faster and farther than did the steady-state protocol in people or animals with or without SCI, and it also improved locomotion. The reflex decrease persisted for at least 6 months after conditioning ended. The results suggest that conditioning reflex function in a specific phase of a dynamic movement offers a new approach to enhancing and/or accelerating recovery after SCI or in other disorders.
ABSTRACT
In animals and people with incomplete spinal cord injury, appropriate operant conditioning of a spinal reflex can improve impaired locomotion. In all previous conditioning studies, the reflex was conditioned during steady-state maintenance of a stable posture; this steady-state protocol aimed to change the excitability of the targeted reflex pathway; reflex size gradually changed over 8-10 weeks. The present study introduces a new protocol, comprising a dynamic protocol that aims to change the functioning of the reflex pathway during a specific phase of a complex movement. Specifically, we down-conditioned the soleus H-reflex during the swing-phase of locomotion in people with hyperreflexia as a result of chronic incomplete SCI. The swing-phase H-reflex, which is absent or very small in neurologically normal individuals, is abnormally large in this patient population. The results were clear. With swing-phase down-conditioning, the H-reflex decreased much faster and farther than did the H-reflex in all previous animal or human studies with the steady-state protocol, and the decrease persisted for at least 6 months after conditioning ended. The H-reflex decrease was accompanied by improvements in walking speed and in the modulation of locomotor electromyograph activity in proximal and distal muscles of both legs. These results provide new insight into the factors controlling spinal reflex conditioning; they suggest that the conditioning protocols targeting reflex function in a specific movement phase provide a promising new opportunity to enhance functional recovery after SCI or in other disorders.
Topics: Animals; Conditioning, Operant; Electromyography; H-Reflex; Humans; Locomotion; Muscle, Skeletal; Recovery of Function; Spinal Cord; Spinal Cord Injuries
PubMed: 31215646
DOI: 10.1113/JP278173 -
Journal of the American Veterinary... Apr 2022To evaluate neurological tests and expected results in inland bearded dragons (Pogona vitticeps) and generate recommendations for bearded dragon-specific neurological...
OBJECTIVE
To evaluate neurological tests and expected results in inland bearded dragons (Pogona vitticeps) and generate recommendations for bearded dragon-specific neurological examination.
ANIMALS
26 healthy adult inland bearded dragons.
PROCEDURES
A complete neurological examination utilizing tests described in both mammals and reptiles was performed on each lizard, and test feasibility and outcome were recorded.
RESULTS
Tests with poor feasibility included oculocardiac reflex (successfully completed in 62% [16/26] of animals) and voluntary ambulation and swallowing by use of a food item (0% [0/26] of animals). Tests with outcomes considered abnormal in mammals but attributable to normal bearded dragon behavior included head position (head tilt present in 12% [3/26]) and head movement (head bob present in 4% [1/26]). Many tests had absent or inconsistent outcomes, including menace response (present in 19% [5/26]), proprioceptive positioning (present in 4% [1/26] in the thoracic limbs and 0% [0/26] in the pelvic limbs), vent reflex (present in 27% [7/26]), and myotatic reflexes (biceps present in 8% [2/26]; patellar, gastrocnemius, and triceps present in 0% [0/26]). Extensor postural thrust was absent in all successfully tested animals, but a novel reflex termed the caudal thoracic extensor reflex was noted instead in all observed animals (100% [21/21]).
CLINICAL RELEVANCE
Tests with poor feasibility or inconsistent outcomes should have low priority or be excluded from neurological examinations of inland bearded dragons. Normal behaviors should be considered for head position and movement. A bearded dragon-specific neurological examination protocol derived from these findings is described and recommended in order to decrease stress and improve neurolocalization.
Topics: Animals; Lizards; Mammals; Neurologic Examination
PubMed: 35417409
DOI: 10.2460/javma.20.12.0706 -
Cureus Oct 2021Guillain-Barré syndrome (GBS) represents the main cause of flaccid paralysis worldwide. Although most cases have a typical clinical presentation of symmetric ascending...
Guillain-Barré syndrome (GBS) represents the main cause of flaccid paralysis worldwide. Although most cases have a typical clinical presentation of symmetric ascending flaccid paralysis with areflexia or hyporeflexia, this disease may present as multiple clinical entities, therefore representing a diagnostic challenge for physicians, who should consider these variants when assessing neuropathies. The pharyngeal-cervical-brachial (PCB) variant of Guillain-Barré syndrome is defined by rapidly progressive oropharyngeal and cervicobrachial weakness associated with hyporeflexia or areflexia in the upper limbs. It is present in 3% of all Guillain-Barré syndrome cases and is characterized by axonal rather than demyelinating neuropathy. We present a pharyngeal-cervical-brachial variant case in a 55-year-old male who presented to the neurological emergency department with a three-day history of progressive and continuous dysarthria, dysphagia to solids, and tongue numbness, later developing paresthesia and weakness in the upper limbs. On physical examination, slight bilateral facial weakness, limited soft palate elevation, absent gag reflex, and limited tongue lateralization were found. Additionally, weakness was found bilaterally in the upper limbs and the flexor and extensor muscles of the neck with preserved muscle strength in the lower limbs. The patient presented upper limb hyporeflexia with lower limb hyperreflexia. A lumbar puncture was performed, revealing protein levels of 35 mg/dL and no cells in the cerebrospinal fluid. Nerve conduction studies reported acute motor and sensory axonal neuropathy (AMSAN). Management of the patient consisted of IgG administration and nasogastric tube insertion.
PubMed: 34804654
DOI: 10.7759/cureus.18788 -
Journal of Applied Physiology... Dec 2022In healthy individuals, loading inspiratory muscles by brief inspiratory occlusion produces a short-latency inhibitory reflex (IR) in the electromyographic (EMG)...
In healthy individuals, loading inspiratory muscles by brief inspiratory occlusion produces a short-latency inhibitory reflex (IR) in the electromyographic (EMG) activity of scalene and diaphragm muscles. This IR may play a protective role to prevent aspiration and airway collapse during sleep. In people with motor and sensory complete cervical spinal cord injury (cSCI), who were able to breathe independently, this IR was predominantly absent. Here, we investigated the reflex response to brief airway occlusion in 16 participants with sensory incomplete cSCI [American spinal injury association impairment scale (AIS) score B or C]. Surface EMG was recorded from scalene muscles and the lateral chest wall (overlying diaphragm). The airway occlusion evoked a small change in mouth pressure resembling a physiological occlusion. The short-latency IR was present in 10 (63%) sensory incomplete cSCI participants; significantly higher than the IR incidence observed in complete cSCI participants in our previous study (14%; = 0.003). When present, mean IR latency across all muscles was 58 ms (range 29-79 ms), and mean rectified EMG amplitude decreased to 37% preocclusion levels. Participants without an IR had untreated severe obstructive sleep apnea (OSA), in contrast to those with an IR, who had either had no, mild, or treated OSA ( = 0.002). Insufficient power did not allow statistical comparison between IR presence or absence and participant clinical characteristics. In conclusion, spared sensory connections or intersegmental connections may be necessary to generate the IR. Future studies to establish whether IR presence is related to respiratory morbidity in the tetraplegic population are required. Individuals with incomplete cSCI were tested for the presence of a short latency reflex inhibition of inspiratory muscles, by brief airway occlusion. The reflex was 4.5 times more prevalent in this group compared with those with complete cSCI and is similar to the incidence in able-bodied people. Participants without this reflex all had untreated severe OSA, in contrast to those with an IR, who either had no, mild, or treated OSA. This work reveals novel differences in the reflex control of inspiratory muscles across the cSCI population.
Topics: Humans; Cervical Cord; Reflex; Muscles
PubMed: 36356259
DOI: 10.1152/japplphysiol.00113.2022 -
Journal of Central Nervous System... 2022Postural imbalance, abnormal axial posture, and axial rigidity are the characteristic features of Parkinson's disease (PD), and they are referred to as axial symptoms.... (Review)
Review
Postural imbalance, abnormal axial posture, and axial rigidity are the characteristic features of Parkinson's disease (PD), and they are referred to as axial symptoms. The symptoms are difficult to manage since they are often resistant to both L-DOPA and deep brain stimulation. Hence, other treatments that can improve Parkinsonian axial symptoms without adverse effects are required. Vestibular dysfunction occurs in PD since neuropathological changes and reflex abnormalities are involved in the vestibular nucleus complex. Galvanic vestibular stimulation (GVS), which activates the vestibular system, is a noninvasive method. This review aimed to assess the clinical effect of GVS on axial symptoms in PD. To date, studies on the effects of GVS on postural instability, anterior bending posture, lateral bending posture, and trunk rigidity and akinesia in PD had yielded interesting data, and none of the patients presented with severe adverse events, and the others had mild reactions. GVS indicated a possible novel therapy. However, most included a small number of patients, and the sample sizes were not similar in some studies that included controls. In addition, there was only one randomized controlled clinical trial, and it did not perform an objective evaluation of axial symptoms. In this type of research, vestibular contributions to balance should be distinguished from others such as proprioceptive inputs or nonmotor symptoms of PD.
PubMed: 35237093
DOI: 10.1177/11795735221081599 -
Frontiers in Neural Circuits 2022Abnormally high-amplitude hippocampal gamma activity (30-100 Hz) in behaving animals is seen after a hippocampal seizure, following injection of phencyclidine (PCP) or... (Review)
Review
Abnormally high-amplitude hippocampal gamma activity (30-100 Hz) in behaving animals is seen after a hippocampal seizure, following injection of phencyclidine (PCP) or ketamine, and transiently in a delirium stage during induction of general anesthesia. High-amplitude hippocampal gamma activity in behaving rats is associated with hyperactive behavior and impairment in sensorimotor gating and sensory gating. The medial septum is necessary for the high-amplitude gamma activity and abnormal behaviors observed following a hippocampal seizure or injection of PCP/ketamine. Glutamatergic projection of the hippocampus to the nucleus accumbens (NAC) and dopaminergic transmission in NAC is necessary for abnormal behaviors. Large hippocampal gamma waves are suggested to contribute to seizure-induced automatism following temporal lobe seizures, and the schizophrenia-like symptoms induced by PCP/ketamine. Low-amplitude gamma activity is found during general anesthesia, associated with loss of consciousness in humans and loss of righting reflex in animals. Local inactivation or lesion of the medial septum, NAC, and brain areas connected to the septohippocampal-NAC system attenuates the increase in hippocampal gamma and associated behavioral disruptions induced by hippocampal seizure or PCP/ketamine. Inactivation or lesion of the septohippocampal-NAC system decreases the dose of anesthetic necessary for gamma decrease and loss of consciousness in animals. Thus, it is proposed that the septohippocampal-NAC system serves to control consciousness and the behavioral hyperactivity and neural dysfunctions during psychosis.
Topics: Animals; Consciousness; Electroencephalography; Gamma Rays; Hippocampus; Humans; Ketamine; Psychotic Disorders; Rats; Rats, Long-Evans; Seizures; Unconsciousness
PubMed: 35874429
DOI: 10.3389/fncir.2022.895000