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Journal of Experimental Orthopaedics Dec 2023Fractures around the elbow are often challenging to treat and in most cases require an extensive approach. Since the development of elbow arthroscopy, most authors have... (Review)
Review
Fractures around the elbow are often challenging to treat and in most cases require an extensive approach. Since the development of elbow arthroscopy, most authors have pointed out the potential advantages of a less invasive technique that can be useful for visualization and reduction of the articular fragments with an eventual percutaneous fixation. Arthroscopic techniques provide a limited exposure that may lead to a faster wound healing, lower rate of complications and thus, better recovery of range of motion. However, elbow arthroscopy is also a demanding technique, especially in a swollen and fractured joint, and it is not exempt of risks. The overall rate of complications has been rated from 1.5% to 11% and nerve injury rates from 1.26-7.5%.The objective of this review is to present the arthroscopic setup and general surgical technique for the management of elbow trauma and to define some clear indications. Patient positioning and operating room display is key in order to obtain success. In addition to the arthroscopic equipment, fluoroscopy is almost always necessary for percutaneous fixation and precise preparation is mandatory. In the last decade, literature regarding new portals or surgical tips for arthroscopic treatment of elbow fractures have been published.The main indications for fracture arthroscopic-assisted fixation are those articular fractures involving the coronoid, distal humerus shear fractures in the coronal plane (trochlear and capitellum fractures) and, more controversially, those affecting the radial head. The treatment of these type of fractures all arthroscopically is exponentially demanding as it might also require ligament repair. For coronoid fractures, it can be useful in Morrey type II and III, and O´Driscoll anteromedial facet fractures associated to a posteromedial instability pattern that also require a repair of the LCL. Although excellent results have been published, comparative series are scarce. Radial head fractures can also be approached arthroscopically in simple non-comminute fractures that can be fixed percutaneously.In conclusion, arthroscopy of the elbow is an excellent tool to better understand and visualize articular fractures of the elbow. However, despite the advances in surgical technique, whether it improves clinical and radiological results is still to be proven.
PubMed: 38133719
DOI: 10.1186/s40634-023-00710-z -
Biomedicines Jul 2023The superior cerebellar artery (SCA) arises from the distal part of the basilar artery and passes by the oculomotor, trochlear, and trigeminal nerves. SCA is known to... (Review)
Review
The superior cerebellar artery (SCA) arises from the distal part of the basilar artery and passes by the oculomotor, trochlear, and trigeminal nerves. SCA is known to play a crucial role in the development of trigeminal neuralgia. However, due to its anatomical variability, it may also trigger other neurovascular compression (NVC), including hemifacial spasm, oculomotor nerve palsy, and ocular neuromyotonia. Additionally, it may be associated with ischemic syndromes and aneurysm development, highlighting its clinical significance. The most common anatomical variations of the SCA include duplication, a single vessel origin from the posterior cerebral artery (PCA), and a common trunk with PCA. Rarely observed variants include bifurcation and origin from the internal carotid artery. Certain anatomical variants such as early bifurcation and caudal course of duplicated SCA trunk may increase the risk of NVC. In this narrative review, we aimed to examine the impact of the anatomical variations of SCA on the NVCs based on papers published in Pubmed, Scopus, and Web of Science databases with a snowballing approach. Our review emphasizes the importance of a thorough understanding of the anatomical variability of SCA to optimize the management of patients with NVCs associated with this artery.
PubMed: 37509648
DOI: 10.3390/biomedicines11072009 -
Biomedicines Feb 2023Various complications of pituitary neuroendocrine tumors (PitNET) are reported, and an intratumor hemorrhage or infarct underlying pituitary apoplexy (PA) represents an... (Review)
Review
Various complications of pituitary neuroendocrine tumors (PitNET) are reported, and an intratumor hemorrhage or infarct underlying pituitary apoplexy (PA) represents an uncommon, yet potentially life-threatening, feature, and thus early recognition and prompt intervention are important. Our purpose is to overview PA from clinical presentation to management and outcome. This is a narrative review of the English-language, PubMed-based original articles from 2012 to 2022 concerning PA, with the exception of pregnancy- and COVID-19-associated PA, and non-spontaneous PA (prior specific therapy for PitNET). We identified 194 original papers including 1452 patients with PA (926 males, 525 females, and one transgender male; a male-to-female ratio of 1.76; mean age at PA diagnostic of 50.52 years, the youngest being 9, the oldest being 85). Clinical presentation included severe headache in the majority of cases (but some exceptions are registered, as well); neuro-ophthalmic panel with nausea and vomiting, meningism, and cerebral ischemia; respectively, decreased visual acuity to complete blindness in two cases; visual field defects: hemianopia, cranial nerve palsies manifesting as diplopia in the majority, followed by ptosis and ophthalmoplegia (most frequent cranial nerve affected was the oculomotor nerve, and, rarely, abducens and trochlear); proptosis (N = 2 cases). Risk factors are high blood pressure followed by diabetes mellitus as the main elements. Qualitative analysis also pointed out infections, trauma, hematologic conditions (thrombocytopenia, polycythemia), Takotsubo cardiomyopathy, and T3 thyrotoxicosis. Iatrogenic elements may be classified into three main categories: medication, diagnostic tests and techniques, and surgical procedures. The first group is dominated by anticoagulant and antiplatelet drugs; additionally, at a low level of statistical evidence, we mention androgen deprivation therapy for prostate cancer, chemotherapy, thyroxine therapy, oral contraceptives, and phosphodiesterase 5 inhibitors. The second category includes a dexamethasone suppression test, clomiphene use, combined endocrine stimulation tests, and a regadenoson myocardial perfusion scan. The third category involves major surgery, laparoscopic surgery, coronary artery bypass surgery, mitral valvuloplasty, endonasal surgery, and lumbar fusion surgery in a prone position. PA in PitNETs still represents a challenging condition requiring a multidisciplinary team from first presentation to short- and long-term management. Controversies involve the specific panel of risk factors and adequate protocols with concern to neurosurgical decisions and their timing versus conservative approach. The present decade-based analysis, to our knowledge the largest so far on published cases, confirms a lack of unanimous approach and criteria of intervention, a large panel of circumstantial events, and potential triggers with different levels of statistical significance, in addition to a heterogeneous clinical picture (if any, as seen in subacute PA) and a spectrum of evolution that varies from spontaneous remission and control of PitNET-associated hormonal excess to exitus. Awareness is mandatory. A total of 25 cohorts have been published so far with more than 10 PA cases/studies, whereas the largest cohorts enrolled around 100 patients. Further studies are necessary.
PubMed: 36979658
DOI: 10.3390/biomedicines11030680 -
Ideggyogyaszati Szemle Jul 2022This study analyzed the relationship of trochlear nerve with neurovascular structures using craniometric measurements. The study was aimed to understand the course of...
BACKGROUND AND PURPOSE
This study analyzed the relationship of trochlear nerve with neurovascular structures using craniometric measurements. The study was aimed to understand the course of trochlear nerve and minimize the risk of injury during surgical procedures.
METHODS
Twenty trochlear nerves of 10 fresh cadavers were studied bilaterally using endoscopic assistance through the view afforded by the lateral infratentorial-supracerebellar, and the combined presigmoid-subtemporal transtentorial approaches. Trochlear nerves were exposed bilaterally taking seven parameters into consideration: the distance between the cisternal segment of trochlear nerve and vascular structures (superior cerebellar artery/SCA; posterior cerebral artery/PCA), the origin of the trochlear nerve in the brain stem, the angle in the level of tentorial junction, length, diameter, and length of nerve in the cisternal segment.
RESULTS
We identified the brain stem and cisternal segments of the trochlear nerve. The lateral infratentorial supracerebellar approach allowed the exposure of the cisternal segments (crural and ambient cisterns), including the origin of the nerve in the brain stem. The combined presigmoid-subtemporal transtentorial approaches provided visualization of the cisternal segment of the nerve and the free edge of the tentorium. In this study, the mean length and width of the trochlear nerve in the cisternal segment were 30.3 and 0.74 mm, respectively. Length of the trochlear nerve from its origin to its dural entrance was 37.2 mm, tentorial dural entrance angle of the trochlear nerve and exit angle of the trochlear nerve from the brain stem were 127.0 degrees and 54 degrees, PCA to trochlear nerve in mid ambient cistern and SCA to trochlear nerve in mid ambient cistern were 7.3 mm and 6.8mm.
CONCLUSION
Trochlear nerve is vulnerable to injury during the surgical procedures. Therefore, it is necessary to have a sufficient knowledge of the anatomy of cisternal segment and its relationship with adjacent neurovascular structures. The anatomical and craniometric data can be helpful in middle and posterior fossa surgery in minimizing the potential injury of the trochlear nerve.
Topics: Brain; Brain Stem; Cadaver; Endoscopes; Humans; Trochlear Nerve
PubMed: 35916610
DOI: 10.18071/isz.75.0241 -
Eye (London, England) Feb 2015We review ocular motor cranial nerve palsies in childhood and highlight many of the features that differentiate these from their occurrence in adulthood. The clinical... (Review)
Review
We review ocular motor cranial nerve palsies in childhood and highlight many of the features that differentiate these from their occurrence in adulthood. The clinical characteristics of cranial nerve palsies in childhood are affected by the child's impressive ability to repair and regenerate after injury. Thus, aberrant regeneration is very common after congenital III palsy; Duane syndrome, the result of early repair after congenital VI palsy, is invariably associated with retraction of the globe in adduction related to the innervation of the lateral rectus by the III nerve causing co-contraction in adduction. Clinical features that may be of concern in adulthood may not be relevant in childhood; whereas the presence of mydriasis in III palsy suggests a compressive aetiology in adults, this is not the case in children. However, the frequency of associated CNS abnormalities in III palsy and the risk of tumour in VI palsy can be indications for early neuroimaging depending on presenting features elicited through a careful history and clinical examination. The latter should include the neighbouring cranial nerves. We discuss the impact of our evolving knowledge of congenital cranial dysinnervation syndromes on this field.
Topics: Abducens Nerve; Abducens Nerve Diseases; Child; Child, Preschool; Eye Diseases; Humans; Nerve Regeneration; Oculomotor Nerve; Oculomotor Nerve Diseases; Trochlear Nerve; Trochlear Nerve Diseases
PubMed: 25572578
DOI: 10.1038/eye.2014.292 -
Continuum (Minneapolis, Minn.) Aug 2014This article offers a pragmatic roadmap to the practicing neurologist on how to approach the patient with double vision. Strategies of history taking and examination... (Review)
Review
PURPOSE OF REVIEW
This article offers a pragmatic roadmap to the practicing neurologist on how to approach the patient with double vision. Strategies of history taking and examination techniques are reviewed, followed by a broad overview of the causes of diplopia organized by neuroanatomic localization. Diplopia may be the first symptom of serious vision or life-threatening neurologic disease, and its correct localization and diagnosis are therefore essential. The systems responsible for ocular movement and alignment in the vertical and horizontal plane include complex supranuclear circuitry, brainstem nuclei, cranial nerves III, IV, and VI, and their respective neuromuscular junctions and target muscles. Disruption at any point within this system or within the vestibular afferents that govern eye movement in response to head movements may therefore produce diplopia, leading to a broad differential diagnosis for the patient with diplopia. With a careful history and examination, the neurologist should be able to observe the patterns of diplopia that reveal the site of dysfunction, thus generating a shorter localization-specific list of possible etiologies. Examination of ocular motility including smooth pursuit and saccadic function, followed, if necessary, by testing designed to uncover misalignments of the eyes, including cover and Maddox rod testing, are primary components of the efferent neurologic examination. Further testing designed to detect myasthenia (eg, lid testing and fatigable upgaze) and orbital disease (eg, measuring proptosis, testing for resistance to retropulsion) may be necessary.
RECENT FINDINGS
Recent advances in the diagnosis of diplopia include the observation that vertical diplopia from skew deviation is more likely to improve with supine positioning than that caused by trochlear nerve palsies. Advances in the field of ocular myasthenia include the observation of decreased conversion to the generalized form with treatment with either steroids or thymectomy, although these conclusions need to be confirmed by prospective, randomized trials. Rarely, pure ocular myasthenia may be associated with the muscle-specific tyrosine kinase (MuSK) antibody.
SUMMARY
With proper skills, the neurologist can elucidate the localization of diplopia, even in cases of complex ocular misalignment, and generate a management plan that can address the underlying disease, and, in many cases, ameliorate or cure the diplopia.
Topics: Aged; Diagnosis, Differential; Diplopia; Female; Humans; Magnetic Resonance Imaging; Neurologic Examination; Ophthalmoscopes; Visual Pathways
PubMed: 25099102
DOI: 10.1212/01.CON.0000453310.52390.58 -
Brain Structure & Function Sep 2021Extraocular motoneurons initiate dynamically different eye movements, including saccades, smooth pursuit and vestibulo-ocular reflexes. These motoneurons subdivide into...
Extraocular motoneurons initiate dynamically different eye movements, including saccades, smooth pursuit and vestibulo-ocular reflexes. These motoneurons subdivide into two main types based on the structure of the neuro-muscular interface: motoneurons of singly-innervated (SIF), and motoneurons of multiply-innervated muscle fibers (MIF). SIF motoneurons are thought to provoke strong and brief/fast muscle contractions, whereas MIF motoneurons initiate prolonged, slow contractions. While relevant for adequate functionality, transmitter and ion channel profiles associated with the morpho-physiological differences between these motoneuron types, have not been elucidated so far. This prompted us to investigate the expression of voltage-gated potassium, sodium and calcium ion channels (Kv1.1, Kv3.1b, Nav1.6, Cav3.1-3.3, KCC2), the transmitter profiles of their presynaptic terminals (vGlut1 and 2, GlyT2 and GAD) and transmitter receptors (GluR2/3, NMDAR1, GlyR1α) using immunohistochemical analyses of abducens and trochlear motoneurons and of abducens internuclear neurons (INTs) in macaque monkeys. The main findings were: (1) MIF and SIF motoneurons express unique voltage-gated ion channel profiles, respectively, likely accounting for differences in intrinsic membrane properties. (2) Presynaptic glutamatergic synapses utilize vGlut2, but not vGlut1. (3) Trochlear motoneurons receive GABAergic inputs, abducens neurons receive both GABAergic and glycinergic inputs. (4) Synaptic densities differ between MIF and SIF motoneurons, with MIF motoneurons receiving fewer terminals. (5) Glutamatergic receptor subtypes differ between MIF and SIF motoneurons. While NMDAR1 is intensely expressed in INTs, MIF motoneurons lack this receptor subtype entirely. The obtained cell-type-specific transmitter and conductance profiles illuminate the structural substrates responsible for differential contributions of neurons in the abducens and trochlear nuclei to eye movements.
Topics: Abducens Nerve; Animals; Eye Movements; Ion Channels; Macaca; Motor Neurons; Oculomotor Muscles; Reflex, Vestibulo-Ocular; Trochlear Nerve
PubMed: 34181058
DOI: 10.1007/s00429-021-02315-7 -
JNMA; Journal of the Nepal Medical... Jul 2021Tolosa-Hunt Syndrome is a rare disease characterized by painful ophthalmoplegia affecting third, fourth, and/or sixth cranial nerve caused by non-specific inflammation...
Tolosa-Hunt Syndrome is a rare disease characterized by painful ophthalmoplegia affecting third, fourth, and/or sixth cranial nerve caused by non-specific inflammation in the cavernous sinus or superior orbital fissure of unknown etiology. We presented a 67-year-old female with Tolosa-Hunt Syndrome. She had a right-sided headache and periorbital pain with double vision. Examination showed right-sided ptosis, right-sided trochlear and abducens nerve palsy, and partial right-sided oculomotor nerve palsy with hypoesthesia in the area of the ophthalmic division of the trigeminal nerve. Magnetic resonance imaging of head and orbit showed altered signal intensity changes in the optic nerve and lateral rectus muscle. After steroid therapy, pain and ptosis were significantly improved in 72 hours. Tolosa-Hunt Syndrome is a diagnosis of exclusion, with clinical presentation, normal investigations, magnetic resonance imaging findings, and response to steroid therapy crucial in making the diagnosis.
Topics: Aged; Blepharoptosis; Female; Humans; Magnetic Resonance Imaging; Pain; Tolosa-Hunt Syndrome
PubMed: 34508416
DOI: 10.31729/jnma.5700