Neurovascular Compression-Induced Intracranial Allodynia May Be the True Nature of Migraine Headache: an Interpretative Review.

PURPOSE OF REVIEW: Surgical deactivation of migraine trigger sites by extracranial neurovascular decompression has produced encouraging results and challenged previous understanding of primary headaches. However, there is a lack of in-depth discussions on the pathophysiological basis of migraine surgery. This narrative review provides interpretation of relevant literature from the perspective of compressive neuropathic etiology, pathogenesis, and pathophysiology of migraine. RECENT FINDINGS: Vasodilation, which can be asymptomatic in healthy subjects, may produce compression of cranial nerves in migraineurs at both extracranial and intracranial entrapment-prone sites. This may be predetermined by inherited and acquired anatomical factors and may include double crush-type lesions. Neurovascular compression can lead to sensitization of the trigeminal pathways and resultant cephalic hypersensitivity. While descending (central) trigeminal activation is possible, symptomatic intracranial sensitization can probably only occur in subjects who develop neurovascular entrapment of cranial nerves, which can explain why migraine does not invariably afflict everyone. Nerve compression-induced focal neuroinflammation and sensitization of any cranial nerve may neurogenically spread to other cranial nerves, which can explain the clinical complexity of migraine. Trigger dose-dependent alternating intensity of sensitization and its synchrony with cyclic central neural activities, including asymmetric nasal vasomotor oscillations, may explain the laterality and phasic nature of migraine pain. Intracranial allodynia, i.e., pain sensation upon non-painful stimulation, may better explain migraine pain than merely nociceptive mechanisms, because migraine cannot be associated with considerable intracranial structural changes and consequent painful stimuli. Understanding migraine as an intracranial allodynia could stimulate research aimed at elucidating the possible neuropathic compressive etiology of migraine and other primary headaches.

Fetal head-down posture may explain the rapid brain evolution in humans and other primates: An interpretative review.

Evolutionary cerebrovascular consequences of upside-down postural verticality of the anthropoid fetus have been largely overlooked in the literature. This working hypothesis-based report provides a literature interpretation from an aspect that the rapid evolution of the human brain has been promoted by fetal head-down position due to maternal upright and semi-upright posture. Habitual vertical torso posture is a feature not only of humans, but also of monkeys and non-human apes that spend considerable time in a sitting position. Consequently, the head-down position of the fetus may have caused physiological craniovascular hypertension that stimulated expansion of the intracranial vessels and acted as an epigenetic physiological stress, which enhanced neurogenesis and eventually, along with other selective pressures, led to the progressive growth of the anthropoid brain and its organization. This article collaterally opens a new insight into the conundrum of high cephalopelvic proportions (i.e., the tight fit between the pelvic birth canal and fetal head) in phylogenetically distant lineages of monkeys, lesser apes, and humans. Low cephalopelvic proportions in non-human great apes could be accounted for by their energetically efficient horizontal nest-sleeping and consequently by their larger body mass compared to monkeys and lesser apes that sleep upright. One can further hypothesize that brain size varies in anthropoids according to the degree of exposure of the fetus to postural verticality. The supporting evidence for this postulation includes a finding that in fossil hominins cerebral blood flow rate increased faster than brain volume. This testable hypothesis opens a perspective for research on fetal postural cerebral hemodynamics.

Chronic pain and local pain in usually painless conditions including neuroma may be due to compressive proximal neural lesion.

It has been unexplained why chronic pain does not invariably accompany chronic pain-prone disorders. This question-driven, hypothesis-based article suggests that the reason may be varying occurrence of concomitant peripheral compressive proximal neural lesion (cPNL), e.g., radiculopathy and entrapment plexopathies. Transition of acute to chronic pain may involve development or aggravation of cPNL. Nociceptive hypersensitivity induced and/or maintained by cPNL may be responsible for all types of general chronic pain as well as for pain in isolated tissue conditions that are usually painless, e.g., neuroma, scar, and Dupuytren's fibromatosis. Compressive PNL induces focal neuroinflammation, which can maintain dorsal root ganglion neuron (DRGn) hyperexcitability (i.e., peripheral sensitization) and thus fuel central sensitization (i.e., hyperexcitability of central nociceptive pathways) and a vicious cycle of chronic pain. DRGn hyperexcitability and cPNL may reciprocally maintain each other, because cPNL can result from reflexive myospasm-induced myofascial tension, muscle weakness, and consequent muscle imbalance- and/or pain-provoked compensatory overuse. Because of pain and motor fiber damage, cPNL can worsen the causative musculoskeletal dysfunction, which further accounts for the reciprocity between the latter two factors. Sensitization increases nerve vulnerability and thus catalyzes this cycle. Because of these mechanisms and relatively greater number of neurons involved, cPNL is more likely to maintain DRGn hyperexcitability in comparison to distal neural and non-neural lesions. Compressive PNL is associated with restricted neural mobility. Intermittent (dynamic) nature of cPNL may be essential in chronic pain, because healed (i.e., fibrotic) lesions are physiologically silent and, consequently, cannot provide nociceptive input. Not all patients may be equally susceptible to develop cPNL, because occurrence of cPNL may vary as vary patients' predisposition to musculoskeletal impairment. Sensitization is accompanied by pressure pain threshold decrease and consequent mechanical allodynia and hyperalgesia, which can cause unusual local pain via natural pressure exerted by space occupying lesions or by their examination. Worsening of local pain is similarly explainable. Neuroma pain may be due to cPNL-induced axonal mechanical sensitivity and hypersensitivity of the nociceptive nervi nervorum of the nerve trunk and its stump. Intermittence and symptomatic complexity of cPNL may be the cause of frequent misdiagnosis of chronic pain.

Mechanism of Origin of Positive Tissue Pressure During Negative-Pressure Wound Therapy.

This report provides a simplified insight into the previously unexplained physical mechanism of the origin of local positive tissue pressure during negative-pressure wound therapy (NPWT). A chain of 2 spring model could be used to show the biomechanical interaction between the NPWT dressing and the adjacent body tissues. It is important to assume that the application of NPWT dressing to the body surface creates a new closed compartmentalized volume. Air suction generates local positive pressure within the dressing due to unopposed atmospheric load, which in turn leads to compression of the adjacent tissues and induction of positive pressure there. Analysis of the biomechanical events during NPWT implies the possibility of tissue injury by positive pressure and suggests clinical alertness in regard to the balance between the size of the NPWT dressing and suction pressure as well as further related research.

Negative Pressure Wound Therapy: Supra-Physiological or Just Physical Effects of Positive Pressure?

This communication provides a new insight into the unexplained physiology of beneficial effects of negative pressure wound therapy (NPWT). Possible mechanisms of beneficial effects of NPWT in failing replantation and free tissue transfer are discussed. Positive pressure generated by NPWT as well as its draining action creates exudate-free tight tissue-to-tissue interface, which may enhance neovascularization.

Hook nail treatment - a bulky palmar flap as an alternative to the "antenna" procedure and to the thenar flap for fingertip coverage.

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Relativity of the Conventional Hand Tendon Zones and the Actual Glide Zones of Tendon Injury and Repair: A Need for Concept Reappraisal.

The conventional hand tendon zones and subzones do not reflect the actual lengths covered by the involved locus of the tendon during full digital and wrist motion, which warrant reappraisal of the tendon zone concept. Because of the tendon excursions many lacerations should be regarded as multiple zone injuries. Furthermore, the length-spans of glide of the distal tendon stump and of the tendon junction (i.e. the glide zones of tendon injury and repair, respectively) are mostly not of the same length because, due to pulley release and bulkiness of the tenorrhaphy, the glide zone of tendon repair is shorter than that of tendon injury. Therefore, it would be practical to notate the glide zones of the lacerated tendon by indicating the anatomic position of the distal tendon stump and tendon junction in full extension and flexion. This data can be provided separately or along with the conventional tendon zones, e.g. II (A4-C2) or II-III (A2-PA), where A, C, and PA stand for the annular, cruciform, and palmar aponeurosis pulleys, respectively. The conventional tendon zone classification could be improved with a tendon glide zone concept. Documentation of the actual excursions of the distal tendon stump and of the tenorrhaphy interface would prevent misinterpretation of the actual level of tendon injury and repair.

History of plastic surgery: Art, philosophy, and rhinoplasty.

The 200th anniversary of K. F. Graefe's "Rhinoplasty," E. Zeis' naming of the specialty of plastic surgery in 1838, and the continuing discussion on what is plastic surgery have prompted this historical-conceptual review with a semantic insight into the meaning of the word "plastic." A literature search has revealed that this term contains dual aspects: artistic and philosophical. The progressive development of these two connotations can be traced from their origin in the ceramics and the myths of ancient Greeks to their metamorphoses in fine arts, science, and philosophy of plasticity of the modern day. Although the names of plastic procedures and the title of the specialty carry both the artistic and philosophical features, the philosophical notion is less evident. This article underlines the importance of etymology in the interpretation of the concept of plastic surgery.

Self-regulated frequent power pinch exercises: A non-orthotic technique for the treatment of old mallet deformity.

The utilization of an orthotic device to treat a mallet finger injury is common practice. This author describes a different approach to treating patients with an old mallet finger injury. The incorporation of frequent, self-regulated exercises without the use of an orthosis is described.--Victoria Priganc, PhD, OTR, CHT, CLT, Practice Forum Editor.

Is diagrammatic goniometry feasible for finger ROM evaluation and self-evaluation?

BACKGROUND: While "diagrammatic" evaluation of finger joint angles using two folded paper strips as goniometric arms has been proposed and could be an alternative to standard goniometry and a means for self-evaluation, the measurement differences and reliability are unknown. QUESTIONS/PURPOSES: This study assessed the standard and diagrammatic finger goniometry performed by an experienced examiner on patients in terms of (1) intragoniometer and intergoniometer (ie, intrarater) differences and reliability; (2) interrater differences and reliability relative to patients' diagrammatic self-evaluation; and (3) the interrater differences related to patient's hand dominance. METHODS: Sixty-one patients without previous training self-evaluated active extension of all joints of the fifth finger of one hand once using two rectangular strips of paper. A practitioner used a goniometer and a diagram to perform parallel evaluations once in 12 patients and three times in 49 patients. The diagrams were scanned and measured. All evaluations and proportions of differences between the paired measurements of 5° or less were combined for analysis. RESULTS: Intrarater intraclass correlation coefficients (ICC) based on the second and third practitioner's trials for the proximal interphalangeal joint were greater than 0.99. Reliability was poor when calculations involved the first measurement of the practitioner (ICCs < 0.38). Interrater reliability was poor regardless of the practitioner's trial (ICCs < 0.033). The proportions of the absolute differences of 5° or less between all paired practitioner's measurements were similar. The proportions of the acceptable differences between paired practitioner's and patients' measurements were nonequivalent for the interphalangeal joints. The interrater differences did not depend on patients' handedness. CONCLUSIONS: In experienced hands both techniques produce clinically comparable reliability, but patients' performance in extempore diagrammatic self-evaluation is inadequate. Further studies are necessary to explore whether appropriate training of patients can improve consistency of diagrammatic self-evaluation.

Reliability of the standard goniometry and diagrammatic recording of finger joint angles: a comparative study with healthy subjects and non-professional raters.

BACKGROUND: Diagrammatic recording of finger joint angles by using two criss-crossed paper strips can be a quick substitute to the standard goniometry. As a preliminary step toward clinical validation of the diagrammatic technique, the current study employed healthy subjects and non-professional raters to explore whether reliability estimates of the diagrammatic goniometry are comparable with those of the standard procedure. METHODS: The study included two procedurally different parts, which were replicated by assigning 24 medical students to act interchangeably as 12 subjects and 12 raters. A larger component of the study was designed to compare goniometers side-by-side in measurement of finger joint angles varying from subject to subject. In the rest of the study, the instruments were compared by parallel evaluations of joint angles similar for all subjects in a situation of simulated change of joint range of motion over time. The subjects used special guides to position the joints of their left ring finger at varying angles of flexion and extension. The obtained diagrams of joint angles were converted to numerical values by computerized measurements. The statistical approaches included calculation of appropriate intraclass correlation coefficients, standard errors of measurements, proportions of measurement differences of 5 or less degrees, and significant differences between paired observations. RESULTS: Reliability estimates were similar for both goniometers. Intra-rater and inter-rater intraclass correlation coefficients ranged from 0.69 to 0.93. The corresponding standard errors of measurements ranged from 2.4 to 4.9 degrees. Repeated measurements of a considerable number of raters fell within clinically non-meaningful 5 degrees of each other in proportions comparable with a criterion value of 0.95. Data collected with both instruments could be similarly interpreted in a simulated situation of change of joint range of motion over time. CONCLUSIONS: The paper goniometer and the standard goniometer can be used interchangeably by non-professional raters for evaluation of normal finger joints. The obtained results warrant further research to assess clinical performance of the paper strip technique.

A technique of direct tracing for recording digital range of motion.

This report describes a technique for recording range of motion of digital joints. The technique involves tracing digital outlines with an angled marker on a sheet of paper attached to a special interray pad. A complete dorsal silhouette of the entire ray can be obtained by mounting the pad and the paper astride the palm parallel to the ray of the digit being evaluated. Fabrication and use of the equipment is described. This silhouetting system could be an alternative to wire tracing in visualizing tendencies of dynamics of digital range of motion.