Mononeuropathy in sickle cell anemia: anatomical and pathophysiological basis for its rarity

Prevalence of orofacial alterations in patients with sickle-cell disease: Systematic review and meta-analysis

OBJECTIVE

The aim of this study was to identify the prevalence of orofacial alterations in sickle-cell disease (SCD) and to compare it with the general population.

STUDY DESIGN

This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guidelines. The search was conducted on PubMed, Embase, Scientific Electronic Library Online, Web of Science, Cochrane Library, gray literature, and references of the included articles.

RESULTS

A total of 770 records were found, and 28 studies were selected. In SCD, the prevalence of decreased bone density was 57% (95% CI: 35%-80%), with Q: P < .01 and I² = 95%; for stepladder pattern was 30% (IC: 13%-47%), Q: P < .01 and I²: 93%; for delayed eruption was 20% (95% CI: 6%-34%), with Q: P < .01 and I² = 86, Q: P < .01 and I² = 99%; and for malocclusion, 66% (95% CI: 39%-92%), Q: P < .01 and I² = 98%. A high risk of bias was observed in relation to the sample size of the studies. A limited number of articles compared the prevalence of orofacial alterations in patients with SCD and healthy individuals.

CONCLUSIONS

Decreased bone density, malocclusion, orofacial pain, tooth necrosis, eruption delay, periodontal disease, and neuropathies may be present in patients with SCD with variable prevalence.

Epidemiology of Stroke in Sickle Cell Disease

Sickle cell disease is the most common cause of stroke in childhood, both ischaemic and haemorrhagic, and it also affects adults with the condition. Without any screening or preventative treatment, the incidence appears to fall within the range 0.5 to 0.9 per 100 patient years of observation. Newborn screening with Penicillin prophylaxis and vaccination leading to reduced bacterial infection may have reduced the incidence, alongside increasing hydroxyurea prescription. Transcranial Doppler screening and prophylactic chronic transfusion for at least an initial year has reduced the incidence of stroke by up to 10-fold in children with time averaged mean of the maximum velocity >200 cm/s. Hydroxyurea also appears to reduce the incidence of first stroke to a similar extent in the same group but the optimal dose remains controversial. The prevention of haemorrhagic stroke at all ages and ischaemic stroke in adults has not yet received the same degree of attention. Although there are fewer studies, silent cerebral infarction on magnetic resonance imaging (MRI), and other neurological conditions, including headache, epilepsy and cognitive dysfunction, are also more prevalent in sickle cell disease compared with age matched controls. Clinical, neuropsychological and quantitative MRI screening may prove useful for understanding epidemiology and aetiology.

Upper limb peripheral neuropathy in sickle cell anemia: MR neurography appearances

Sickle cell anemia is an inherited disorder with many systemic complications. Peripheral neuropathy related to this disorder has been sparsely reported. We report an interesting case of upper limb peripheral neuropathy from sickle cell disease with emphasis on MR neurography appearances and electrophysiology correlation.

Do We Store Packed Red Blood Cells under "Quasi-Diabetic" Conditions?

Red blood cell (RBC) transfusion is one of the most common therapeutic procedures in modern medicine. Although frequently lifesaving, it often has deleterious side effects. RBC quality is one of the critical factors for transfusion efficacy and safety. The role of various factors in the cells’ ability to maintain their functionality during storage is widely discussed in professional literature. Thus, the extra- and intracellular factors inducing an accelerated RBC aging need to be identified and therapeutically modified. Despite the extensively studied in vivo effect of chronic hyperglycemia on RBC hemodynamic and metabolic properties, as well as on their lifespan, only limited attention has been directed at the high sugar concentration in RBCs storage media, a possible cause of damage to red blood cells. This mini-review aims to compare the biophysical and biochemical changes observed in the red blood cells during cold storage and in patients with non-insulin-dependent diabetes mellitus (NIDDM). Given the well-described corresponding RBC alterations in NIDDM and during cold storage, we may regard the stored (especially long-stored) RBCs as “quasi-diabetic”. Keeping in mind that these RBC modifications may be crucial for the initial steps of microvascular pathogenesis, suitable preventive care for the transfused patients should be considered. We hope that our hypothesis will stimulate targeted experimental research to establish a relationship between a high sugar concentration in a storage medium and a deterioration in cells’ functional properties during storage.

Neuropathic Pain and Sickle Cell Disease: a Review of Pharmacologic Management

PURPOSE OF REVIEW

Sickle cell disease (SCD) remains among the most common and severe monogenic disorders present in the world today. Although sickle cell pain has been traditionally characterized as nociceptive, a significant portion of sickle cell patients has reported neuropathic pain symptoms. Our review article will discuss clinical aspects of SCD-related neuropathic pain, epidemiology of neuropathic pain among individuals with SCD, pain mechanisms, and current and future potential pharmacological interventions.

RECENT FINDINGS

Neuropathic pain in SCD is a complicated condition that often has a lifelong and significant negative impact on life; therefore, improved pain management is considered a significant and unmet need. Neuropathic pain mechanisms are heterogeneous, and the difficulty in determining their individual contribution to specific pain types may contribute to poor treatment outcomes in this population. Our review article outlines several pharmacological modalities which may be employed to treat neuropathic pain in SCD patients.

Review/overview of pain in sickle cell disease

Sickle cell disease (SCD) is a highly complex inherited disorder of hemoglobin structure. Although the molecular lesion is a single-point mutation, the sickle gene is pleiotropic in nature causing multiple phenotypic expressions that constitute the various complications of the disease. Its manifestations could be acute, chronic, nociceptive, neuropathic that could occur singly or in various combinations. Pain continues to be the major factor of SCD phenotypic complications and the most common cause of admissions to the Emergency Department and/or the hospital. Although progress has been made in understanding the pathophysiology of SCD as well as in developing curative therapies such as hematopoietic stem cell transplantation and gene therapy, effective pain management continues to lag behind. Palliative therapies continue to be the major approach to the management of SCD and its complications. The advent of hydroxyurea made partial success in preventing the frequency of vaso-occlusive crises and l-glutamine awaits post-trial confirmation of benefits. The search for additional pharmacotherapeutic agents that could be used singly or in combination with hydroxyurea and/or l-glutamine awaits their dawn hopefully in the near future. The purpose of this review is to describe the various manifestations of SCD, their pathophysiology and their current management. Recent impressive advances in understanding the pathophysiology of pain promise the determination of agents that could replace or minimize the use of opioids.

Ischemic Monomeric Neuropathy in a Woman with Sickle Cell Anaemia

Sickle cell disease is an inherited haemoglobinopathy that can affect multiple organs and systems. The most common neurological complication in sickle cell disease is stroke and silent cerebral infarcts. Peripheral nervous system involvement has been described but is exceedingly rare. Herein, we describe the case of a young woman who presented with acute flaccid paralysis and sensory loss of the left lower extremity in the context of a painful vasoocclusive crisis which resolved rapidly after receiving an emergency automated red cell exchange transfusion.

Medication- and toxin-induced neurologic syndromes

Patients who present with mixed clinical neurologic signs and symptoms can be sorted into groups based on the symptom format. Targeted physical examination and evaluation of laboratory results can help quickly segment patients into groups for further workup or admission. The possibility of medication- or toxin-induced neurologic causes must be considered. Medication- and toxin-induced neurologic syndrome is a combination of several symptoms that are induced either by the exposure to or withdrawal of various medications or by toxins, and the symptoms are sometimes difficult to fit into a nice, neat diagnostic package.

Mononeuropathy multiplex in sickle cell disease: a complication in need of recognition

Peripheral nervous system involvement is rare in sickle cell disease. A review of the literature has uncovered only a few reports of nerve deficit in association with sickle cell disease, and often a clear relationship between the neuropathy and the anemia is absent. Mononeuropathy resulting from peripheral nerve infarction, as a complication of sickle vaso-occlusive crisis, seemingly is uncommon and, to our knowledge, has been reported only once. We report two patients who developed acute mononeuropathy multiplex in the setting of sickle cell pain crisis. The clinical and electrodiagnostic findings were consistent with a multifocal nerve disorder resulting from an ischemic process caused by a sickle cell vaso-occlusive crisis. We describe the clinical course, electrophysiological findings, diagnosis, and management of these patients. We also analyze the anatomic and pathophysiological basis of this disorder and offer a possible clinical explanation for its infrequent and exceptional diagnosis.

Sickle cell pain: a critical reappraisal

Sickle cell pain includes 3 types: acute recurrent painful crises, chronic pain syndromes, and neuropathic pain. The acute painful crisis is the hallmark of the disease and the most common cause of hospitalization and treatment in the emergency department. It evolves through 4 phases: prodromal, initial, established, and resolving. Each acute painful episode is associated with inflammation that worsens with recurrent episodes, often culminating in serious complications and organ damage, such as acute chest syndrome, multiorgan failure, and sudden death. Three pathophysiologic events operate in unison during the prodromal phase of the crisis: vaso-occlusion, inflammation, and nociception. Aborting the acute painful episode at the prodromal phase could potentially prevent or minimize tissue damage. Our hypothesis is that managing these events with hydration, anti-inflammatory drugs, aggressive analgesia, and possibly vasodilators could abort the crisis and prevent or minimize further damage. Chronic pain syndromes are associated with or accompany avascular necrosis and leg ulcers. Neuropathic pain is not well studied in patients with sickle cell disease but has been modeled in the transgenic sickle mouse. Management of sickle cell pain should be based on its own pathophysiologic mechanisms rather than borrowing guidelines from other nonsickle pain syndromes.

Peripheral nervous system involvement in patients with sickle cell disease

BACKGROUND AND PURPOSE

Peripheral nervous system involvement is rare in sickle cell disease (SCD). The aim of this study is to determine the peripheral nerve involvement electrophysiologically in SCD patients without clinically evident neurological signs, symptoms and to determine the relationship between the frequency of sickle cell crisis and peripheral neuropathy.

METHODS

Fifty-one patients with SCD and fifty-one healthy controls were enrolled to the study. Conventional electrophysiological studies of peripheral nerves were performed to all subjects. The data about the frequency of sickle cell crisis were obtained.

RESULTS

Peripheral nervous system involvement was detected in ten (19.6%) patients. Five (9.8%) patients had sensorimotor axonal neuropathy, two (3.9%) sensory axonal neuropathy, one (2%) patient had ulnar sensory neuropathy and two (3.9%) had median sensory neuropathy. Sural nerve sensorial action potential was unobtainable in eight (15.7%) patients and prolonged F latencies were observed in three (5.9%). The frequency of neuropathy was higher in SCD patients when compared with the controls. The frequency of sickle cell crisis was not significantly correlated with peripheral neuropathy.

CONCLUSION

Subclinical peripheral nerve involvement may be seen in SCD patients. Electrophysiological examinations are recommended in routine examination to diagnose early neuropathy in SCD patients without neurologic symptoms.

Pain Management of Sickle Cell Disease

Management of sickle cell disease continues to be primarily palliative, including supportive, symptomatic, and preventive approaches to therapy. There are three major types of sickle cell pain: acute, chronic, and neuropathic pain. The acute painful episode is the insignia of the disease and the most common cause of hospitalization. Its management entails the use of nonpharmacologic and pharmacologic modalities. Pain management should follow certain principles that include an assessment stage, treatment stage, reassessment stage, and adjustment stage. Chronic sickle cell pain may be due to certain complications of the disease, such as leg ulcers and avascular necrosis; intractable chronic pain may be due to central sensitization. Management of chronic pain should take a multidisciplinary approach.

Transient forearm conduction block in the median nerve

We present two cases referred for electrophysiological confirmation of carpal tunnel syndrome (CTS). Initial nerve conduction studies were normal. Approximately 20 min into the examination, both patients developed sensory symptoms and weakness in the distal median nerve territory while the elbow was extended and forearm supinated. Further studies demonstrated complete conduction block across the forearm in the median motor and sensory nerve fibers. When measurable, conduction velocities remained normal or were modestly slow. Complete clinical and electrophysiological recovery occurred within 2 min following forearm pronation, suggesting that dysfunction was probably due to focal transient ischemia. Patients describing increased sensory symptoms during routine electrophysiological assessments for CTS should be investigated to rule out the possibility of a more proximal abnormality.

"Pseudo-conduction block" in vasculitic neuropathy

The predominant electrophysiologic feature of vasculitic mononeuropathy multiplex is axonal loss. Electrophysiologic findings interpreted as conduction block have, however, also been reported to occur in neuropathy secondary to necrotizing vasculitis. We report 3 patients with mononeuropathy multiplex and biopsy proven vasculitis in whom eight nerves met criteria for conduction block. In each circumstance, serial study demonstrated conversion of the electrophysiologic findings to those most consistent with severe axonal loss. "Conduction block" in vasculitic mononeuropathy multiplex is secondary to focal axonal conduction failure presumably related to infarctive axonal injury. The term conduction block should be used with caution in this disorder and only if serial studies demonstrate findings consistent with this electrophysiologic diagnosis.

Isolated weakness of the extensor hallucis longus in a patient with hereditary spherocytosis

A 24-year-old woman with a history of hereditary spherocytosis and oral contraceptive use presented with a spontaneous, isolated loss of great toe extension. She had clinical and electrodiagnostic evidence of a localized lesion affecting the nerve supply to the extensor hallucis longus (EHL). Full clinical recovery was apparent within 6 months with nonoperative therapy. Isolated EHL weakness may occur as a rare neurologic complication of procedures such as high tibial osteotomies, but, to our knowledge, this has not been reported in the absence of trauma or surgery. While the coexistence of hereditary spherocytosis and a peripheral neuropathy may have been purely coincidental, it is plausible that the isolated lesion in this patient was due to ischemic changes from underlying rheologic conditions, possibly in association with a variation in the neural or nutrient vessel supply to the EHL.

Mandibular nerve neuropathy in sickle cell disease. Local factors

An instance of permanent neuropathy that affected the mandibular nerve after a vaso-occlusive crisis in a patient with homozygous sickle cell disease and G6PD deficiency. A local factor of molar periapical inflammation may have provoked this phenomenon.