Orthopaedic manifestations of congenital indifference to pain with anhidrosis (Hereditary Sensory and Autonomic Neuropathy type IV)

Fifteen-minute consultation: Approach to a child with congenital insensitivity to pain

The hereditary sensory and autonomic neuropathies (HSANs) are a group of rare genetic disorders characterised by variable phenotypic expression affecting both sensory and autonomic dysfunction. Diagnosing these conditions can be a challenge as the presenting symptoms can be diverse and may overlap. This often leads to a delay in referral and diagnosis.Pain is often used by clinicians as a marker for systemic diseases. The key feature of HSAN conditions is the absence of pain perception and its consequences such as unexplained injuries. When a child presents with an unexplained injury, a diagnosis of non-accidental injuries must be considered, but rarely HSAN could be a possibility.The diagnosis of HSANs in children is both important and rare. This article aims to discuss an approach to the diagnosis and management of HSANs.

From the Destruction of Two Lumbar Segments to Thoracic-Lumbar-Pelvic Fusion: A Case Caused by Congenital Insensitivity to Pain with Anhidrosis and Literature Review

BACKGROUND

Congenital insensitivity to pain with anhidrosis (CIPA) with Charcot arthropathy is a rare combination in orthopaedic clinical practice. The experience dealing with such patients is limited. Here with this case of approximately 10 years follow-up, we wish to shed light on the choices of strategies of surgeries and alerting clinicians with post-surgery complications. The possible underlying reasons for the recurrent Charcot arthropathies as well as strategies for peri-operative management for such surgical cases are also discussed.

CASE PRESENTATION

The patient underwent a surgery to correct her severe kyphosis caused by CIPA-related Charcot spine. Multiple post-surgery complications occurred during her follow-up, including hardware migration, adjacent segment disease (ASD), and loosening pedicle screws. Five revision surgeries were conducted consequently. From the limited experience on the management of CIPA-related Charcot spine, surgical correction is still the first-line treatment.

CONCLUSIONS

Of all the 16 cases reviewed (including our case), loosening pedicle screws, hardware migration, and ASDs are the common post-surgery complications. Large-scale removal of damaged vertebrae and subsequent reconstruction are not recommended, which might increase the risk of hardware migration. A 360° long-segment fusion might be of help to reduce the risk of ASDs. In the meantime, comprehensive management including careful nursing, proper rehabilitation exercises, and treatments targeting bone mineral metabolism is also critical.

Case of bilateral hip joint Charcot arthropathy in a paediatric patient

An adolescent girl came with swelling of both thighs with difficulty in walking for a few months. Based on clinical, and radiological evaluation and nerve conduction studies, she was diagnosed to be having bilateral hips Charcot's arthropathy due to hereditary sensory autonomic neuropathy type 4. Other common causes of Charcot arthropathy were ruled out. The patient was conservatively managed and parents were educated about preventive measures. Through this case report, we want to highlight the myriad number of manifestations and clinical presentations of a child presenting with hereditary sensory autonomic neuropathy type 4.

Genetic pain loss disorders

Genetic pain loss includes congenital insensitivity to pain (CIP), hereditary sensory neuropathies and, if autonomic nerves are involved, hereditary sensory and autonomic neuropathy (HSAN). This heterogeneous group of disorders highlights the essential role of nociception in protecting against tissue damage. Patients with genetic pain loss have recurrent injuries, burns and poorly healing wounds as disease hallmarks. CIP and HSAN are caused by pathogenic genetic variants in >20 genes that lead to developmental defects, neurodegeneration or altered neuronal excitability of peripheral damage-sensing neurons. These genetic variants lead to hyperactivity of sodium channels, disturbed haem metabolism, altered clathrin-mediated transport and impaired gene regulatory mechanisms affecting epigenetic marks, long non-coding RNAs and repetitive elements. Therapies for pain loss disorders are mainly symptomatic but the first targeted therapies are being tested. Conversely, chronic pain remains one of the greatest unresolved medical challenges, and the genes and mechanisms associated with pain loss offer new targets for analgesics. Given the progress that has been made, the coming years are promising both in terms of targeted treatments for pain loss disorders and the development of innovative pain medicines based on knowledge of these genetic diseases.

A 5-Year-Old Palestinian Bedouin Girl with Repeated Self-Induced Injuries to the Digits, a Diagnosis of Congenital Insensitivity to Pain, and Anhidrosis

BACKGROUND Congenital insensitivity to pain with anhidrosis (CIPA), also referred to as hereditary sensory and autonomic neuropathy type IV, is a rare autosomal recessive disease caused by mutations in the NTRK1 gene. The inability to feel pain and temperature often leads to repeated severe and unintentional self-inflicted injuries; these can result in severe complications, as patients heal slowly from skin and bone injuries. This case report describes a 5-year-old Palestinian girl with self-inflicted injury to the digits, a dislocated distal inter-phalangeal joint of the left big toe, and a diagnosis of CIPA. CASE REPORT A 5-year-old girl, a daughter of related Palestinian Bedouin parents, presented with a chronic unhealed wound over the planter surface of the left foot. Painless repetitive minor traumata over the same area badly affected wound healing and this led to wound dehiscence and dislocation of the distal inter-phalangeal joint of the left big toe. Surgical fixation of the dislocated joint along with intravenous antibiotics and close follow-up resulted in eventual improvement and near complete wound healing despite the obviously slow healing process. The girl also displayed evidence of unintentional self-inflicted injury, which within the overall clinical context warranted a clinical suspicion of CIPA. This was confirmed by genetic testing for the presence of a homozygous frameshift mutation in the NTRK1 gene (c.1842_1843insT; p.Pro615Serfs*12). CONCLUSIONS This case report shows that a physician should have a low threshold of suspicion to investigate for CIPA when managing children with multiple unintentional self-inflicted injuries, anhidrosis, and pain insensitivity, mainly through genetic testing to detect mutations in the NTRK1 gene.

Prostaglandins and Bone

Prostaglandins (PGs) are highly bioactive fatty acids. PGs, especially prostaglandin E₂ (PGE₂), are abundantly produced by cells of both the bone-forming (osteoblast) lineage and the bone-resorbing (osteoclast) lineage. The inducible cyclooxygenase, COX-2, is largely responsible for most PGE₂ production in bone, and once released, PGE₂ is rapidly degraded in vivo. COX-2 is induced by multiple agonists - hormones, growth factors, and proinflammatory factors - and the resulting PGE₂ may mediate, amplify, or, as we have recently shown for parathyroid hormone (PTH), inhibit responses to these agonists. In vitro, PGE₂ can directly stimulate osteoblast differentiation and, indirectly via stimulation of RANKL in osteoblastic cells, stimulate the differentiation of osteoclasts. The net balance of these two effects of PGE₂ in vivo on bone formation and bone resorption has been hard to predict and, as expected for such a widespread local factor, hard to study. Some of the complexity of PGE₂ actions on bone can be explained by the fact that there are four receptors for PGE₂ (EP1-4). Some of the major actions of PGE₂ in vitro occur via EP2 and EP4, both of which can stimulate cAMP signaling, but there are other distinct signaling pathways, important in other tissues, which have not yet been fully elucidated in bone cells. Giving PGE₂ or agonists of EP2 and EP4 to accelerate bone repair has been examined with positive results. Further studies to clarify the pathways of PGE₂ action in bone may allow us to identify new and more effective ways to deliver the therapeutic benefits of PGE₂ in skeletal disorders.

A 10-year follow-up of asymptomatic Charcot hip joints caused by CIPA syndrome (congenital insensitivity to pain with anhidrosis) with failure of any surgical reconstructive treatment

Congenital insensitivity to pain with anhidrosis (CIPA) is a rare genetic disorder. Patients with CIPA lack among other things the protective sensation of pain. Orthopaedic manifestations are fractures, infections and hip joint dislocation. We report a 10-year follow-up of late developing hip dysplasia with CIPA and the result of several reconstructive surgical procedures. The final outcome was asymptomatic Charcot hip joints with superior migration and dislocation of both hips without pain. In conformance with the literature standard operative techniques in these rare cases usually seem to fail. A multidisciplinary conservative approach with close observation and activity modification is the proposed treatment of choice.

Key concepts in children's footwear research: a scoping review focusing on therapeutic footwear

BACKGROUND

Reports suggest that children with mobility impairment represent a significant proportion of the population living with a disability. Footwear is considered to be the key extrinsic factor affecting children's gait and footwear modifications have been historically postulated to assist with locomotory difficulty. Although therapeutic footwear has been considered within the literature, there is a lack of consistency on terminology and paucity on the overall understanding. A scoping review was performed to chart the key concepts in children's footwear and to establish the range of studies that considered therapeutic footwear.

METHODS

A systematic search of MEDLINE, CINAHL, PubMed, SPORTdiscus, and Scopus electronic databases was performed using MeSH headings and free text terms in relation to children's footwear. All studies that used footwear as an intervention in children aged 9 months to 18 years with the outcome measures including design, fit, and the effects on development and health were included. Studies were charted by textual narrative synthesis into research groupings dependent on the topics discussed and the methods used in the studies.

RESULTS

The search yielded a total of 5006 articles with 287 of these articles meeting the inclusion criteria. Two overarching areas of research were identified; articles that discussed footwear design and those that discussed the effects of footwear. Eight further general groupings were charted and apportioned between the overarching areas and therapeutic footwear was charted into three subgroupings (corrective, accommodative and functional).

CONCLUSION

Children's footwear has become an increasing area of research in the past decade with a shift towards more empirical research, with most of the included articles examining biomechanical and anthropometric aspects. However, children's therapeutic footwear has not shared the same recent impetus with no focused review and limited research exploring its effects. Empirical research in this area is limited and there is ambiguity in the terminology used to describe therapeutic footwear. Based on the findings of this review the authors suggest the term children's therapeutic footwear be used as the standard definition for footwear that is designed specifically with the purpose to support or alleviate mobility impairment in childhood; with subgroupings of corrective, accommodative and functional dependent on the intended therapeutic role.

Heterotopic ossifications and Charcot joints: Congenital insensitivity to pain with anhidrosis (CIPA) and a novel NTRK1 gene mutation

Congenital insensitivity to pain with anhidrosis (CIPA), also known as hereditary sensory and autonomic neuropathy type IV (HSAN-IV), is a rare and severe autosomal recessive disorder. We report on an adult female patient whose clinical findings during childhood were not recognized as CIPA. There was neither complete anhidrosis nor a recognizable sensitivity to heat. Tumorlike swellings of many joints and skeletal signs of Charcot neuropathy developed in adolescence which, together with a history of self-mutilation, led to a clinical suspicion of CIPA confirmed by identification of a novel homozygous variant c.1795G > T in the NTRK1 gene in blood lymphocytes. Both parents were heterozygous for the mutation. The variant predicts a premature stop codon (p.Gly599Ter) and thus represents a pathogenic variant; the first reported in the Southeastern European population.

Office-Based Anesthetic and Oral Surgical Management of a Child With Hereditary Sensory Autonomic Neuropathy Type IV: A Case Report

Hereditary sensory and autonomic neuropathy type IV (HSAN IV), or congenital insensitivity to pain with anhidrosis, is an exceptionally rare genetic disorder that results in the complete loss of pain and temperature sensation as well as anhidrosis. Anesthetic management of these patients can be difficult because of significantly increased risks during general anesthesia. Literature on perioperative anesthetic management is typically written in the context of a hospital setting. As such, our case presents a unique report on the anesthetic management of a HSAN IV patient who presented for extraction of 2 teeth in an office-based setting. In determining how to safely manage the procedure, we decided against general anesthesia as we lacked the facilities and equipment to safely handle previously reported complications. We were successful in providing sedation with nitrous oxide in oxygen and applying 20% benzocaine topical ointment on the surgical site in lieu of administering general anesthesia. We had an anesthesiologist present and obtained intravenous access prior to the surgery to help manage any complications. This report provides support that simple dental extractions can be accomplished safely in the HSAN IV patient in the office-based setting, thereby avoiding unnecessary risk.

Charcot spinal arthropathy in patients with congenital insensitivity to pain: a report of two cases and review of the literature

Charcot spine, or neuropathic spinal arthropathy, involves the progressive destruction of the spinal joint due to the lack of normal protective sensations and proprioception. A rare cause of Charcot spine is congenital insensitivity to pain, which is an absent or abnormal response to painful stimuli. There are few case reports describing this condition, and long-term follow-up data are limited. The presentation and treatment of two patients with Charcot spine secondary to congenital insensitivity to pain are described. Both cases were characterized by lumbar involvement and were treated with circumferential decompression and an extended lumbo-pelvic fusion construct. The cases described here demonstrate stable neurological status at 1.5 and 5 years follow-up. Patient characteristics, pre- and post-operative imaging, operative approach, and outcomes are described. The literature regarding this rare condition is also reviewed, with an emphasis on operative management and outcomes. Surgical management is traditionally complicated by a high rate of hardware failure and adjacent segment degeneration. The current review highlights the importance of prompt and aggressive management following diagnosis of Charcot spine, as well as extended follow-up.