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Acta Otorhinolaryngologica Italica :... Jun 2024We describe an uncharacteristic vestibular-ocular reflex (VOR) pattern, studied by video head impulse tests (VHIT) in patients suffering from unilateral isolated...
OBJECTIVE
We describe an uncharacteristic vestibular-ocular reflex (VOR) pattern, studied by video head impulse tests (VHIT) in patients suffering from unilateral isolated posterior semicircular canal (PSC) hypofunction. In these patients, we found an upward sliding of the eyes, followed by an oblique downward catch-up saccade during horizontal head impulse to the healthy side.
METHODS
We present a retrospective study of all VHIT exams presenting isolated PSC hypofunction between May 2020 and November 2022.
RESULTS
We found 37 patients, which led to the discovery of such incongruent eye movement in 19 cases; their gain data are shown and compared to the remaining 18 cases in which such an anomaly was absent. A control group of 31 healthy subjects was recruited to define the reference criteria for VHIT gain values. The correlation between the amplitude of the vertical saccade and the relative functional imbalance of the vertical semicircular canals was studied.
CONCLUSIONS
We have observed that in approximately half of the subjects with isolated CSP deficiency, there is a VOR anomaly. A possible pathophysiological explanation of the unbalanced effect of vertical semicircular canal stimulation of a labyrinth during horizontal head thrust toward the opposite side is proposed. The planar incongruity of the response of the VOR described here appears more evident at the onset of the CSP deficit. Current VHIT systems do not detect this incongruent eye reflex. They can lead to an error in gain evaluation (pseudo-deficit) of the lateral semicircular canal of the healthy side and problems in performing the test (trace rejected). In the future, software for VHIT should take into account the possibility of non-coplanar ocular responses to cephalic stimuli.
Topics: Humans; Retrospective Studies; Saccades; Semicircular Canals; Head Impulse Test; Male; Female; Middle Aged; Adult; Reflex, Vestibulo-Ocular; Aged; Young Adult
PubMed: 38712769
DOI: 10.14639/0392-100X-N2508 -
Neurology May 2024Pupillary assessment is a quintessential part of the clinical examination in neuro-intensive care patients because it provides insight into the integrity of midbrain...
Pupillary assessment is a quintessential part of the clinical examination in neuro-intensive care patients because it provides insight into the integrity of midbrain reflex arcs. Abnormal pupils, particularly anisocoria and later bilateral fixed mydriasis, are classically used to assess expansive intracranial processes because they are frequently considered early indicators of transtentorial midbrain compression due to elevated intracranial pressure. Complex ocular motor deficits mapping to the midbrain are rarely described in the setting of high transtentorial pressure. This is likely because ocular motor deficits typically occur in conjunction with decreased consciousness and corticospinal tract dysfunction reflecting advanced midbrain compromise. We present a case of left midbrain compression due to downward herniation in a patient with acute-on-chronic bilateral subdural hematoma. Ocular motor assessment demonstrated left internuclear ophthalmoplegia (INO) and an ocular tilt reaction, termed INO plus. However, pupillary, mental status, and sensorimotor examinations were unremarkable. Head magnetic resonance imaging revealed acute perforator ischemia in the left pontomesencephalic tegmentum, localizing to the ipsilateral medial longitudinal fasciculus and graviceptive oculocephalic circuits. Microvascular compromise secondary to mechanical pressure is discussed as a causative mechanism. We caution against overreliance on "telltale pupils" in suspected brainstem compression and recommend checking for other oculomotor signs.
Topics: Humans; Ocular Motility Disorders; Brain Stem; Male; Magnetic Resonance Imaging; Female; Aged
PubMed: 38701401
DOI: 10.1212/WNL.0000000000209421 -
Neurology. Clinical Practice Jun 2024Physical examination findings in athletes with sport-related concussion (SRC) are not well described in the literature. The objective of this study was to describe...
BACKGROUND AND OBJECTIVE
Physical examination findings in athletes with sport-related concussion (SRC) are not well described in the literature. The objective of this study was to describe physical examination findings during the first month following concussion in athletes, with a focus on the effect of sex, age, and time since injury.
METHODS
This was a retrospective electronic medical record (EMR) review of physical examination findings in 500 patients aged 6-24 who were initially seen within 15 days of SRC at a multidisciplinary outpatient academic concussion clinic between 2017 and 2019. A standardized concussion examination built in the EMR recorded mental status, cranial nerve, vestibulo-ocular motor screen, and balance findings for all patients. The primary outcome was the frequency of abnormal examination findings during the first 30 days postinjury, which was further analyzed by sex, age, and time since injury using mixed logistic regression models.
RESULTS
The most common abnormal examination findings overall were eyes-closed single-leg stance, vestibular-ocular reflex, visual motion sensitivity, the neck examination, and eyes-closed tandem stance. Abnormal findings were more frequent in female athletes for vestibular ocular reflex and visual motion sensitivity. The frequency of abnormal findings increased with age for vestibulo-ocular reflex, visual motion sensitivity, the neck examination, convergence testing, and eyes-open single-leg stance, whereas abnormalities decreased in frequency with age for eyes-open tandem stance and tandem gait. The frequency of abnormal findings generally decreased with time over the first 4 weeks following injury.
DISCUSSION
A comprehensive physical examination is pivotal for evaluation of athletes with concussion. These findings highlight high-yield components of the concussion examination and support use of these examination components as injury markers. Future work should investigate associations between physical examination findings and postconcussion symptoms and recovery outcomes.
CLASSIFICATION OF EVIDENCE
This retrospective cohort study provides Class IV evidence that neurologic examination with specifically designed clinical tests are helpful for diagnosis of traumatic brain injury in young athletes at age 6-24.
PubMed: 38699600
DOI: 10.1212/CPJ.0000000000200284 -
Annals of Medicine and Surgery (2012) May 2024Moyamoya disease (MMD) is a condition characterized by progressive narrowing of arteries in the brain and abnormal development of small collateral vessels. It is...
INTRODUCTION AND IMPORTANCE
Moyamoya disease (MMD) is a condition characterized by progressive narrowing of arteries in the brain and abnormal development of small collateral vessels. It is commonly found in East Asia but has never been reported in Palestine.
CASE PRESENTATION
A 2-year-old female, part of a twin born to non-consanguineous parents, presented with recurring seizures and developmental regression. The physical examination revealed signs of hypotonia, reflex abnormalities, and bilateral Babinski signs. Comprehensive laboratory tests and imaging investigations confirmed the diagnosis of MMD, marking this patient as the reported case in Palestine.
CLINICAL DISCUSSION
The diagnostic criteria for this condition were revised in 2021 to focus on findings seen in angiography and magnetic resonance angiography (MRA) scans. MMD has not been curative so far, and the management is focused on preventing complications, sometimes with surgical revascularization, including its different approaches: direct, indirect, and a combination of both.
CONCLUSION
This case highlights the importance of identifying MMD in regions where it is uncommon to be diagnosed. It emphasizes the need for diagnosis and appropriate intervention to reduce complications.
PubMed: 38694386
DOI: 10.1097/MS9.0000000000001934 -
Muscle & Nerve Jul 2024The frequency and distribution of upper motor neuron (UMN) signs in primary lateral sclerosis (PLS) are unknown. We aimed to study the spectrum of UMN signs in PLS and...
INTRODUCTION/AIMS
The frequency and distribution of upper motor neuron (UMN) signs in primary lateral sclerosis (PLS) are unknown. We aimed to study the spectrum of UMN signs in PLS and compare it with hereditary spastic paraplegia (HSP).
METHODS
We retrospectively analyzed the frequency of different UMN signs, including hyperreflexia (limbs and jaw), limb and tongue spasticity, Babinski, and Hoffman signs, in PLS patients at first observation and compared this respect to onset region and symptom duration. We also compared PLS versus HSP patients.
RESULTS
We included 34 PLS and 20 HSP patients, with a median symptom duration at first visit of 3.0 (interquartile range, IQR = 4.0) and 19.0 (IQR = 22.0) years, respectively. In PLS patients, hyperreflexia of upper (UL) (88.2%) and lower (LL) (91.2%) limbs, and LL spasticity (79.4%) were the most common findings. Spasticity of LL was significantly (p = .012) more frequent in LL-spinal onset subgroup, tongue spasticity in bulbar-onset subgroup (p = .021), and Hoffman sign in UL-spinal onset subgroup (p = .024). The PLS subgroup with shorter disease duration had a higher frequency of abnormal jaw jerk reflex (p = .037). Compared with HSP, PLS patients had a higher frequency of UL hyperreflexia (88.2% vs. 42.1%, p < .001) and UL spasticity (44.1% vs. 0.0%, p < .001). Asymmetric distribution of UMN signs was present in PLS and not in HSP.
DISCUSSION
In PLS, UL UMN signs are nearly always present and UMN sign distribution appears to be associated with onset region. At first observation, bulbar involvement, asymmetrical distribution of UMN signs and UL spasticity may indicate PLS versus HSP.
Topics: Humans; Spastic Paraplegia, Hereditary; Male; Female; Middle Aged; Adult; Retrospective Studies; Motor Neurons; Aged; Muscle Spasticity; Motor Neuron Disease
PubMed: 38687249
DOI: 10.1002/mus.28100 -
Paediatrics and International Child... Apr 2024Nitrous oxide, an inhalational anaesthetic, is popular with adolescents worldwide as an accessible recreational drug which induces a euphoric effect. However, chronic...
Nitrous oxide, an inhalational anaesthetic, is popular with adolescents worldwide as an accessible recreational drug which induces a euphoric effect. However, chronic abuse leads to serious complications such as myeloneuropathy and bone marrow suppression by inactivation of vitamin B. A 17-year-old girl presented with nitrous oxide-induced myeloneuropathy. She reported chronic nitrous oxide inhalation for 10 months and was admitted to the emergency department on account of repeated falls for 2 weeks. She also had ascending paraesthesia in both legs and urinary incontinence. Neurological examination demonstrated bilateral lower extremity weakness [motor power: proximal muscles 4/5, plantar flexion and extensor hallucis longus (EHL) 3/5], decreased sensation, proprioception and vibration of the lower extremities. Deep tendon reflexes were absent in the ankles and knees. Laboratory results demonstrated mild anaemia [Hb 11.2 g/dL (12.0-16.0), haematocrit 35.4% (36-50), MCV 89.4 fl (78-102)] with significant hypersegmented neutrophils in a peripheral blood smear. Serum vitamin B was 340 pg/mL (197-771), but serum homocysteine was increased at 65.8 µmol/L (5-15). A nerve conduction study was prolonged, and F-waves were absent from the bilateral perineal and tibial nerves, indicating diffuse demyelinating motor polyneuropathy. Magnetic resonance imaging of the whole spine demonstrated faint T2 hypersignal intensity and an inverted V-shape appearance at the posterior column of the upper thoracic cord (around T2-T6), a pathognomonic sign of vitamin B deficiency or subacute combined degeneration of the nitrous oxide-induced myeloneuropathy. A 7-day course of 1000 µg cyanocobalamin was given intramuscularly, followed by weekly doses for 4 weeks. Supplements of daily oral vitamin B, B and B (65 µg vitamin B) were administered, along with rehabilitation. At the 6-months outpatient follow-up, there were a few residual neurological abnormalities: weakness of the left EHL (grade 4/5) and an absent deep tendon reflex in the left ankle. This case emphasises the significant health consequences of chronic abuse of nitrous oxide, myeloneuropathy and megaloblastic anaemia, by inactivation of vitamin B. The myelopathy is noticeably improved by cyanocobalamin. EHL: extensor hallucis longus; MRI: magnetic resonance imaging; NCS: nerve conduction study.
PubMed: 38682882
DOI: 10.1080/20469047.2024.2344403 -
Clinical Physiology and Functional... Apr 2024It is controversial whether people with vasovagal syncope (VVS) have abnormal autonomic responses at baseline and whether specific diagnostic manoeuvres have a...
It is controversial whether people with vasovagal syncope (VVS) have abnormal autonomic responses at baseline and whether specific diagnostic manoeuvres have a diagnostic value. We investigated whether the pupillary light reflex and cardiac autonomic tests can be used to identify autonomic dysfunction in volunteers with a medical history of VVS. The study groups included 128 healthy volunteers, of whom 31 reported a history of typical VVS. The right pupil was evaluated using an automated, commercial infra-red pupillometer under strict conditions. In addition to miosis and mydriasis kinetics, pupil diameters were measured. Heart rate variability at rest and heart rate changes to standing were quantified with high-resolution electrocardiography and designated software. The demographic and clinical characteristics of both groups were statistically similar. Average constriction velocity (ACV) was significantly higher in VVS patients following a univariate analysis (3.83 ± 0.59 vs. 3.56 ± 0.73 mm/s, p = 0.042) and after correcting for potential confounders (p = 0.049). All other pupillometric and heart rate indices were comparable between groups. Patients with a history of VVS depict pupillary parasympathetic overactivity in response to light stimuli, manifested as increased ACV. The prognostic implications of this finding and the significance of using this simple clinical tool to identify patients who are at risk for developing frequent episodes of VVS or physical injuries following a syncope merits further study.
PubMed: 38678442
DOI: 10.1111/cpf.12884 -
Frontiers in Neurology 2024The pupillary light reflex (PLR) is the constriction of the pupil in response to light. The PLR in response to a pulse of light follows a complex waveform that can be...
INTRODUCTION
The pupillary light reflex (PLR) is the constriction of the pupil in response to light. The PLR in response to a pulse of light follows a complex waveform that can be characterized by several parameters. It is a sensitive marker of acute neurological deterioration, but is also sensitive to the background illumination in the environment in which it is measured. To detect a pathological change in the PLR, it is therefore necessary to separate the contributions of neuro-ophthalmic factors from ambient illumination. Illumination varies over several orders of magnitude and is difficult to control due to diurnal, seasonal, and location variations.
METHODS AND RESULTS
We assessed the sensitivity of seven PLR parameters to differences in ambient light, using a smartphone-based pupillometer (AI Pupillometer, Solvemed Inc.). Nine subjects underwent 345 measurements in ambient conditions ranging from complete darkness (<5 lx) to bright lighting (≲10,000 lx). Lighting most strongly affected the initial pupil size, constriction amplitude, and velocity. Nonlinear models were fitted to find the correction function that maximally stabilized PLR parameters across different ambient light levels. Next, we demonstrated that the lighting-corrected parameters still discriminated reactive from unreactive pupils. Ten patients underwent PLR testing in an ophthalmology outpatient clinic setting following the administration of tropicamide eye drops, which rendered the pupils unreactive. The parameters corrected for lighting were combined as predictors in a machine learning model to produce a scalar value, the Pupil Reactivity (PuRe) score, which quantifies Pupil Reactivity on a scale 0-5 (0, non-reactive pupil; 0-3, abnormal/"sluggish" response; 3-5, normal/brisk response). The score discriminated unreactive pupils with 100% accuracy and was stable under changes in ambient illumination across four orders of magnitude.
DISCUSSION
This is the first time that a correction method has been proposed to effectively mitigate the confounding influence of ambient light on PLR measurements, which could improve the reliability of pupillometric parameters both in pre-hospital and inpatient care settings. In particular, the PuRe score offers a robust measure of Pupil Reactivity directly applicable to clinical practice. Importantly, the formulae behind the score are openly available for the benefit of the clinical research community.
PubMed: 38654735
DOI: 10.3389/fneur.2024.1363190 -
Clinical Neurophysiology : Official... Jun 2024
Topics: Humans; Blinking; Electromyography
PubMed: 38640821
DOI: 10.1016/j.clinph.2024.04.001 -
The Kaohsiung Journal of Medical... Jun 2024Slow transit constipation (STC) is one of the most common gastrointestinal disorders in children and adults worldwide. Paeoniflorin (PF), a monoterpene glycoside...
Slow transit constipation (STC) is one of the most common gastrointestinal disorders in children and adults worldwide. Paeoniflorin (PF), a monoterpene glycoside compound extracted from the dried root of Paeonia lactiflora, has been found to alleviate STC, but the mechanisms of its effect remain unclear. The present study aimed to investigate the effects and mechanisms of PF on intestinal fluid metabolism and visceral sensitization in rats with compound diphenoxylate-induced STC. Based on the evaluation of the laxative effect, the abdominal withdrawal reflex test, enzyme-linked immunosorbent assay, quantitative real-time polymerase chain reaction, western blot, and immunohistochemistry were used to detect the visceral sensitivity, fluid metabolism-related proteins, and acid-sensitive ion channel 3/extracellular signal-regulated kinase (ASIC3/ERK) pathway-related molecules. PF treatment not only attenuated compound diphenoxylate-induced constipation symptoms and colonic pathological damage in rats but also ameliorated colonic fluid metabolic disorders and visceral sensitization abnormalities, as manifested by increased colonic goblet cell counts and mucin2 protein expression, decreased aquaporin3 protein expression, improved abdominal withdrawal reflex scores, reduced visceral pain threshold, upregulated serum 5-hydroxytryptamine, and downregulated vasoactive intestinal peptide levels. Furthermore, PF activated the colonic ASIC3/ERK pathway in STC rats, and ASIC3 inhibition partially counteracted PF's modulatory effects on intestinal fluid and visceral sensation. In conclusion, PF alleviated impaired intestinal fluid metabolism and abnormal visceral sensitization in STC rats and thus relieved their symptoms through activation of the ASIC3/ERK pathway.
Topics: Animals; Glucosides; Monoterpenes; Acid Sensing Ion Channels; Constipation; Rats; Male; MAP Kinase Signaling System; Rats, Sprague-Dawley; Colon; Gastrointestinal Transit; Aquaporin 3; Serotonin; Visceral Pain
PubMed: 38634140
DOI: 10.1002/kjm2.12829