Safety and Efficacy of Percutaneous Morton Neuroma Cryoneurolysis Under Ultrasound Guidance.

PURPOSE: To assess the technical success, safety and early efficacy of Morton neuroma (MN) cryoneurolysis. MATERIALS AND METHODS: Retrospective review of 54 consecutive patients with MN treated with cryoneurolysis after failure of conservative treatment, from September 2022 to June 2023. Outcomes measurements included technical success (defined a successful ultrasound-guided placement of the cryoprobe), procedural safety according to Cirse classification and change in 6 months post-procedure by pain numeric rating scale (pNRS). RESULTS: A total of 59 MN were treated during 55 procedures. Mean procedure duration was 47 min, all patients were discharged 2 h after the intervention. Technical success was 98.1%. No Cirse grade 3, 4 or 5 complication was reported. Three grade 2 complication occurred, including two chilblain-type lesions and one bone insufficiency fracture. At 6 months post-procedure, pNRS score was significantly decreased (2.7 ± 2.2 vs 7.1 ± 1.1) (p < 0.0001), with a mean score decrease of 4.1points. Thirty-two patients (60.4%) reported a complete pain relief, 15 (28.3%) a partial pain relief and 6 (11.3%) no pain relief, or increased pain. CONCLUSION: Cryoneurolysis seems to be safe for the treatment of Morton neuroma. Six-month pain relief is promising and needs to be confirmed at long term.

Radiolunate arthrodesis and scaphoidectomy combined to Sauvé-Kapandji procedure as treatment of wrist osteoarthritis: Clinical and radiological results.

OBJECTIVE: The aim of this study was to analyze clinical and radiological results for 1-stage radiolunate arthrodesis and scaphoidectomy associated to the Sauvé-Kapandji procedure, to alleviate pain and conserve wrist motion. METHODS: Seven patients (8 wrists) with symptomatic osteoarthritis of the radiolunate and distal radioulnar joints were treated from 1999 to 2016. Mean age at surgery was 49 years and M/F sex ratio was 6/1. Etiologies were distal radial intra-articular malunion for 6 patients and bilateral gouty arthritis for 1. The procedure was performed by a dorsal approach in a single step. Pain was assessed on visual analogue scale (VAS). Pre- and post-operative active flexion-extension and pronation-supination were compared. The secondary endpoint was onset of postoperative complications. RESULTS: At a mean 71 months' follow-up (range, 30-168 months), there was significant reduction in pain (VAS, 0.5/10; p < 0.0001). Motion results were satisfactory, with 32° flexion, 39° extension, for a non-significant decrease of 11° and 5° respectively; pronation and supination were significantly increased, by a mean 23° and 30° respectively. Three wrists (37.5%) required a second surgery. There were no cases of surgical site infection or non-union. CONCLUSION: Radiolunate arthrodesis and scaphoidectomy combined to Sauvé-Kapandji procedure was an effective solution for the treatment of symptomatic radiolunate and distal radioulnar osteoarthritis. LEVEL OF EVIDENCE: IV.

Multiple sources of metabolic disturbance in ETHE1-related ethylmalonic encephalopathy.

Ethylmalonic encephalopathy (EE) is a rare metabolic disorder caused by dysfunction of ETHE1, a mitochondrial dioxygenase involved in hydrogen sulfide (H2S) detoxification. Patients present in infancy with psychomotor retardation, chronic diarrhea, orthostatic acrocyanosis and relapsing petechiae. High levels of lactic acid, ethymalonic acid (EMA) and methylsuccinic acid (MSA) are detected in body fluids. Several pathways may contribute to the pathophysiology, including isoleucine, methionine and fatty acid metabolism. We report on a 15-month-old male presenting with typical EE associated with a homozygous ETHE1 mutation. We investigated oral isoleucine (150 mg/kg), methionine (100 mg/kg), fatty acid loading tests and isoleucine-restricted diet (200 mg/day) for any effects on several metabolic parameters. Before loading tests or specific dietary interventions, EMA, C4-C5 acylcarnitines and most acylglycines were elevated, indicating functional deficiency of short chain acyl-CoA (SCAD) as well as all branched acyl-CoA dehydrogenases. Excretion of EMA and n-butyrylglycine increased following each of the loads, and isoleucine led to increased levels of derivative metabolites. An isoleucine-restricted diet for 8 days corrected some of the abnormalities but led to no obvious clinical improvement and only partial effects on EMA. A principal component analysis supports the inference that these dietary conditions have consistent effects on the global metabolic profile. Our results suggest that multiple pathways modulate EMA levels in EE. They might all interact with H2S toxicity. Prolonged dietary interventions involving the restriction for branched aminoacids, fatty acids and methionine could be discussed as auxiliary therapeutical strategies in EE.

Cardiomyopathies in propionic aciduria are reversible after liver transplantation.

OBJECTIVE: To evauluate the relationship between propionic acidemia (PA) and cardiomyopathy. STUDY DESIGN: We retrospectively compared clinical and metabolic results of patients with PA with and without cardiomyopathy. RESULTS: Of 26 patients with PA who survived the first year of age, a dilated cardiomyopathy developed in 6 (group 1) at a median age of 7 years (range, 5-11 years). They were compared with 14 patients without cardiomyopathy for whom data were available (group 2). Their median age at the time of the study was 11 years (range, 3-21 years). PA was diagnosed in the neonatal period in 5 of 6 patients in group 1 and 11 of 14 patients in group 2. All patients received similar medical treatment. Two patients in group 1 died of cardiac arrest. In 2 patients, the cardiomyopathy was reversed during the year after orthotopic liver transplantation (OLT). In 2 other patients, OLT was contraindicated because of severe heart disease. The number of metabolic distress episodes was similar in both groups. Excretion of propionate metabolites in urine did not correlate with the occurrence of cardiomyopathy. CONCLUSION: Dilated cardiomyopathy, a frequent complication of PA, develops independent of any specific metabolic profile and is reversible after OLT.

CC2D2A mutations in Meckel and Joubert syndromes indicate a genotype-phenotype correlation.

Meckel-Gruber syndrome (MKS) is a lethal fetal disorder characterized by diffuse renal cystic dysplasia, polydactyly, a brain malformation that is usually occipital encephalocele, and/or vermian agenesis, with intrahepatic biliary duct proliferation. Joubert syndrome (JBS) is a viable neurological disorder with a characteristic "molar tooth sign" (MTS) on axial images reflecting cerebellar vermian hypoplasia/dysplasia. Both conditions are classified as ciliopathies with an autosomal recessive mode of inheritance. Allelism of MKS and JBS has been reported for TMEM67/MKS3, CEP290/MKS4, and RPGRIP1L/MKS5. Recently, one homozygous splice mutation with a founder effect was reported in the CC2D2A gene in Finnish fetuses with MKS, defining the 6th locus for MKS. Shortly thereafter, CC2D2A mutations were also reported in JBS. The analysis of the CC2D2A gene in our series of MKS fetuses, identified 14 novel truncating mutations in 11 cases. These results confirm the involvement of CC2D2A in MKS and reveal a major contribution of CC2D2A to the disease. We also identified three missense CC2D2A mutations in two JBS cases. Therefore, and in accordance with the data reported regarding RPGRIP1L, our results indicate phenotype-genotype correlations, as missense and presumably hypomorphic mutations lead to JBS while all null alleles lead to MKS.

Structural insights on pathogenic effects of novel mutations causing pyruvate carboxylase deficiency.

Pyruvate carboxylase (PC), a key enzyme for gluconeogenesis and anaplerotic pathways, consists of four domains, namely, biotin carboxylase (BC), carboxyltransferase (CT), pyruvate carboxylase tetramerization (PT), and biotin carboxyl carrier protein (BCCP). PC deficiency is a rare metabolic disorder inherited in an autosomal recessive way. The most severe form (form B) is characterized by neonatal lethal lactic acidosis, whereas patients with form A suffer chronic lactic acidosis with psychomotor retardation. Diagnosis of PC deficiency relies on enzymatic assay and identification of the PC gene mutations. To date, six mutations of the PC gene have been identified. We report nine novel mutations of the PC gene, in five unrelated patients: three being affected with form B, and the others with form A. Three of them were frameshift mutations predicted to introduce a premature termination codon, the remaining ones being five nucleotide substitutions and one in frame deletion. Impact of these mutations on mRNA was assessed by RT-PCR. Evidence for a deleterious effect of the missense mutations was achieved using protein alignments and three-dimensional structural prediction, thanks to our modeling of the human PC structure. Altogether, our data and those previously reported indicate that form B is consistently associated with at least one truncating mutation, mostly lying in CT (C-terminal part) or BCCP domains, whereas form A always results from association of two missense mutations located in BC or CT (N-terminal part) domains. Finally, although most PC mutations are suggested to interfere with biotin metabolism, none of the PC-deficient patients was biotin-responsive.

What's new in metabolic and genetic hypoglycaemias: diagnosis and management.

Hypoglycaemia in children can be a life-threatening situation that needs to be assessed rigorously in order to treat efficiently and avoid relapse that can be responsible for cerebral damage. The diagnosis of impairment in glucose homeostasis requires the knowledge of the mechanisms regulating blood glucose concentration. The clinical history and presentation, when available, especially the timing of hypoglycaemia with respect to the last meal and some simple clinical and biological tests may allow diagnosing the vast majority of patients presenting with hypoglycaemia. Recently, new metabolic and endocrinologic genetic causes of hypoglycaemia have been identified that may give new insight to the complex mechanisms of glucose regulation and thus contribute to the discovery of new genes regulating glucose homeostasis. New diagnostic tests such as the 18-fluoro-Dopa PET-scan have also been recently developed.

CEP290 mutations are frequently identified in the oculo-renal form of Joubert syndrome-related disorders.

Joubert syndrome-related disorders (JSRDs) are a group of clinically and genetically heterogeneous conditions that share a midbrain-hindbrain malformation, the molar tooth sign (MTS) visible on brain imaging, with variable neurological, ocular, and renal manifestations. Mutations in the CEP290 gene were recently identified in families with the MTS-related neurological features, many of which showed oculo-renal involvement typical of Senior-Loken syndrome (JSRD-SLS phenotype). Here, we performed comprehensive CEP290-mutation analysis on two nonoverlapping cohorts of JSRD-affected patients with a proven MTS. We identified mutations in 19 of 44 patients with JSRD-SLS. The second cohort consisted of 84 patients representing the spectrum of other JSRD subtypes, with mutations identified in only two patients. The data suggest that CEP290 mutations are frequently encountered and are largely specific to the JSRD-SLS subtype. One patient with mutation displayed complete situs inversus, confirming the clinical and genetic overlap between JSRDs and other ciliopathies.

The Meckel-Gruber syndrome gene, MKS3, is mutated in Joubert syndrome.

Joubert syndrome (JS) is an autosomal recessive disorder characterized by cerebellar vermis hypoplasia associated with hypotonia, developmental delay, abnormal respiratory patterns, and abnormal eye movements. The association of retinal dystrophy and renal anomalies defines JS type B. JS is a genetically heterogeneous condition with mutations in two genes, AHI1 and CEP290, identified to date. In addition, NPHP1 deletions identical to those that cause juvenile nephronophthisis have been identified in a subset of patients with a mild form of cerebellar and brainstem anomaly. Occipital encephalocele and/or polydactyly have occasionally been reported in some patients with JS, and these phenotypic features can also be observed in Meckel-Gruber syndrome (MKS). MKS is a rare, autosomal recessive lethal condition characterized by central nervous system malformations (typically, occipital meningoencephalocele), postaxial polydactyly, multicystic kidney dysplasia, and ductal proliferation in the portal area of the liver. Since there is obvious phenotypic overlap between JS and MKS, we hypothesized that mutations in the recently identified MKS genes, MKS1 on chromosome 17q and MKS3 on 8q, may be a cause of JS. After mutation analysis of MKS1 and MKS3 in a series of patients with JS (n=22), we identified MKS3 mutations in four patients with JS, thus defining MKS3 as the sixth JS locus (JBTS6). No MKS1 mutations were identified in this series, suggesting that the allelism is restricted to MKS3.