Early-Onset Autosomal Dominant Myopathy with Vacuolated Fibers and Tubular Aggregates but No Periodic Paralysis, in a Patient with the c.1583G>A (p.R528H) mutation in the CACNA1S Gene.

Dominant mutations in CACNA1S gene mainly causes hypokalemic periodic paralysis (PP)(hypoPP). A 68-year-old male proband developed a progressive proximal weakness from the age of 35. Muscle biopsy showed atrophic fibers with vacuoles containing tubular aggregates. Exome sequencing revealed a heterozygous p.R528H (c.1583G>A) mutation in the CACNA1S gene. CACNA1S-related HypoPP evolving to persistent myopathy in late adulthood is a well-known clinical condition. However, isolated progressive myopathy (without PP) was only exceptionally reported and never with an early onset. Reporting a case of early onset CACNA1S-related myopathy in a patient with no HypoPP we intend to alert clinicians to consider it in the differential diagnosis of younger adult-onset myopathies especially when featuring vacuolar changes.

A novel CACNA1S gene variant in a child with hypokalemic periodic paralysis: a case report and literature review.

BACKGROUND: The CACNA1S gene encodes the alpha 1 S-subunit of the voltage-gated calcium channel, which is primarily expressed in the skeletal muscle cells. Pathogenic variants of CACNA1S can cause hypokalemic periodic paralysis (HypoPP), malignant hyperthermia susceptibility, and congenital myopathy. We aimed to study the clinical and molecular features of a male child with a CACNA1S variant and depict the molecular sub-regional characteristics of different phenotypes associated with CACNA1S variants. CASE PRESENTATION: We presented a case of HypoPP with recurrent muscle weakness and hypokalemia. Genetic analyses of the family members revealed that the proband had a novel c.497 C > A (p.Ala166Asp) variant of CACNA1S, which was inherited from his father. The diagnosis of HypoPP was established in the proband as he met the consensus diagnostic criteria. The patient and his parents were informed to avoid the classical triggers of HypoPP. The attacks of the patient are prevented by lifestyle changes and nutritional counseling. We also showed the molecular sub-regional location of the variants of CACNA1S which was associated with different phenotypes. CONCLUSIONS: Our results identified a new variant of CACNA1S and expanded the spectrum of variants associated with HypoPP. Early genetic diagnosis can help avoid diagnostic delays, perform genetic counseling, provide proper treatment, and reduce morbidity and mortality.

Arterial blood gas analysis aids early differential diagnosis and treatment of primary and secondary hypokalaemic periodic paralysis.

This study aimed to examine changes in electrolytes and acid-base status in primary and secondary hypokalaemic periodic paralysis (HypoPP), which will help early differential diagnosis of HypoPP. A total of 64 HypoPP patients were enrolled and relevant data from clinical records was collected. Overall, 64 patients (mean age 28.2±7.3 years) of which 58(91%) were males, with 39, 11 and 14 patients, respectively, diagnosed as primary HypoPP, thyrotoxic HypoPP, and other secondary HypoPPs at discharge, were assessed. Those with HypoPP secondary to conditions other than hyperthyroidism were more likely to develop acid-base imbalance (p<0.001); they had higher pH (p=0.046) and HCO3 levels (p=0.014) at baseline, and needed a higher dose of potassium supplement before the serum potassium level returned to normal (p=0.007) and a longer time to regain full muscle strength (p=0.004), compared with those with primary or thyrotoxic HypoPP. Emergent arterial blood gas analysis may aid early differential diagnosis of patients with primary and secondary HypoPP.

Childbirth with epidural analgesia in a pregnant woman with hypokalemic periodic paralysis.

Familial hypokalaemic periodic paralysis (FHPP) is an uncommon genetic disease characterized by muscle weakness associated with hypokalaemia. Episodes are precipitated by drugs, stress, metabolic diseases, hypothermia or infection. We report the case of a 38-year-old pregnant women with FHPP who underwent epidural analgesia for labour. Pregnant women with FHPP require multidisciplinary management involving an anaesthesiologist, a gynaecologist and a paediatrician. It is important to maintain normothermia, prevent hyperventilation, monitor electrolytes, avoid glucose infusions and medications that cause hypokalaemia, and administer potassium supplements when required. Locoregional techniques should be preferred over general anaesthesia. Early epidural analgesia reduces the risk of pain that could trigger an episode of FHPP. In the case of general anaesthesia, drugs that can cause malignant hyperthermia should be avoided, and short-acting non-depolarizing neuromuscular blockers with blockade-depth monitoring should be used.

Anaesthesia challenges of a parturient with paramyotonia congenita and terminal filum lipoma presenting for labour and caesarean section under epidural anaesthesia - a case report.

BACKGROUND: Paramyotonia congenita is a rare autosomal dominant myopathy which presents with periodic weakness due to cold and exercise. It is caused by mutations of the SCN4 gene which encodes the sodium channel in skeletal muscles. CASE PRESENTATION: We report a full term obstetric patient with both paramyotonia congenita and terminal filum lipoma who presents for induction of labour followed by an emergency caesarean section performed under epidural anesthesia. Her recovery is subsequently complicated by a 3-day history of postpartum paraparesis attributed to hypokalemic periodic paralysis. CONCLUSION: We describe the perioperative anesthesia considerations and challenges in this case with a review of the current literature. This case report highlights the importance of early proactive and collaborative multidisciplinary approach, maintaining normal temperature and electrolytes with a heightened vigilance for muscle-related perioperative complications.

The clinical and genetic heterogeneity analysis of five families with primary periodic paralysis.

To explore the clinical and genetic characteristics of five families with primary periodic paralysis (PPP). We reviewed clinical manifestations, laboratory results, electrocardiogram, electromyography, muscle biopsy, and genetic analysis from five families with PPP. Five families with PPP included: hypokalemic periodic paralysis type 1 (HypoPP1, CACNA1S, 1/5), hypokalemic periodic paralysis type 2 (HypoPP2, SCN4A, 2/5), normokalemic periodic paralysis (NormoPP, SCN4A, 1/5), and Andersen-Tawil syndrome (ATS, KCNJ2, 1/5). The basic clinical manifestations of five families were consistent with PPP, presenting with paroxysmal muscle weakness, with or without abnormal serum potassium. ATS was accompanied by ventricular arrhythmias, and skeletal and craniofacial anomalies, developing with a permanent fixed myopathy later. The electromyography showed diffuse myopathic discharge, and muscle biopsy showed tubular aggregates. Genetic testing revealed five families with PPP carried CACNA1S (R1242S), SCN4A (R675Q, T704M), and KCNJ2 (R218Q) respectively. The novel heterozygous R1242S mutation in CACNA1S caused a conformational change in the protein structure, and the amino acid of this mutation site was highly conserved among different species. SCN4A mutations led to two phenotypes of HypoPP2 and NormoPP. PPPs are autosomal dominant disorders of ion channel dysfunction characterized by episodic flaccid muscle weakness secondary to abnormal sarcolemmal excitability. PPPs are caused by mutations in skeletal muscle calcium channel CaV1.1 gene (CACNA1S), sodium channel NaV1.4 gene (SCN4A), and potassium channels Kir2.1, Kir3.4 genes (KCNJ2, KCNJ5), including HypoPP1, HypoPP2, NormoPP, HyperPP, and ATS, which have significant clinical and genetic heterogeneity. Diagnosis is based on the characteristic clinical presentation then confirmed by genetic testing.

Paralisia Periódica Hipocalêmica Tireotóxica: relato de caso / Thyrotoxic Hypokalemic Periodic Paralysis: case report

A paralisia periódica hipocalêmica tireotóxica é uma complicação rara do hipertireoidismo. Caracteriza-se por episódios de fraqueza muscular recorrente, associado à tireotoxicose e hipocalemia. Ocorre frequentemente em pacientes do sexo masculino e de origem asiática. Nesse contexto, o objetivo deste estudo é descrever o relato de caso de um paciente acometido por paralisia periódica hipocalêmica tireotóxica com redução acentuada da qualidade de vida e internações recorrentes devido a quadro agudo de tetraparesia flácida ascendente associado a hipocalemia grave por não adesão ao tratamento do hipertireoidismo. A paralisia periódica hipocalêmica tireotóxica apresenta evolução favorável quando reconhecida e tratada com controle inicial dos sintomas para normalização sérica do potássio e posterior resolução do quadro tireotóxico.

Thyrotoxic hypokalemic periodic paralysis is a rare complication of hyperthyroidism. The issue has been characterized by episodes of recurrent muscle weakness associated with thyrotoxicosis and hypokalemia. It occurs most often in male patients of Asian origin. This study aims on describing the case report of a patient affected by thyrotoxic hypokalemic periodic paralysis with intense reduction in life quality and recurrent hospitalizations due to ascending acute flaccid tetraparesis associated with severe hypokalemia due to non-adherence to treatment of hyperthyroidism. Thyrotoxic hypokalemic periodic paralysis presents a favorable evolution when identified and treated with initial symptom control for serum potassium normalization and subsequent resolution of the thyroid toxicity.

[A novel mutation of SCN4A gene causes hypokalemic periodic paralysis in a Chinese family].

Objective: To report a Chinese family with hypokalemic periodic paralysis (HOKPP) and investigate the clinical and pathogenic gene characteristics of the family. Methods: The clinical, electrophysiological and pathological data of the proband of the family were analyzed, and the information of the family was investigated in detail. The peripheral venous blood of the six members of the family was collected and their genomic DNA was extracted. The genes related to periodic paralysis analysis of the proband were performed by the second generation sequencing. The pathogenicity of the mutant protein was respectively analyzed by the bioinformatics software SIFT, Polyphen2 and Mutation Tasker. The cosegregation analysis of phenotype and genotype of the family was performed by the first generation sequencing. Results: There were 3 patients in the family with the onset age of 21 to 42 years old. All the patients manifested with vomiting as the first symptoms, then presented with muscle weakness accompanied by muscle soreness. The muscle weakness gradually relieved in 3 to 5 days. Creatine kinase (CK) of the proband significantly increased. Electromyographic exercise test was positive, however, electromyography and muscle pathological analysis were normal. The genes related to periodic paralysis analysis of the proband found a novel mutation (c.2458A>T (p.N.820Y)) of SCN4A gene which was located in the conservative region. The function analysis showed it was a pathogenic mutation. Moreover, the first generation sequencing confirmed that the mutation was cosegregated with patients in the family. Meanwhile, it was found that the proband's son carried the same mutation, but without any symptom, indicating that he was a pre-symptomatic patient. Conclusions: Vomiting can be one of the symptoms of the patients with HOKPP. The novel mutation of SCN4A gene c.2458 A>T is the pathogenic mutation of the family. Patients with periodic paralysis should be tested for blood potassium and genes as early as possible to facilitate early diagnosis and genetic counseling.

Síndrome de Sjögren primario que debuta con polimiositis mitocondrial, neuropatía axonal y parálisis hipopotasémica: reporte de caso / Onset of primary Sjögren syndrome with mitochondrial polymyositis, axonal neuropathy, and hypokalaemic paralysis: Case report

RESUMEN El síndrome de Sjögren es una entidad multisistémica de naturaleza autoinmune, clásicamente considerada una exocrinopatía debido a la alta frecuencia de síntomas secos (queratoconjuntivitis seca, xerostomía) como resultado de infiltración poliglandular por linfocitos autorreactivos. Sin embargo, menos del 10% de estos pacientes puede iniciar con manifestaciones extraglandulares severas, traducidas en peores desenlaces a largo plazo. Se presenta el caso de una gestante que inició con síndrome de debilidad aguda proximal relacionada con miositis con enfermedad mitocondrial e hipopotasemia severa, en el contexto de acidosis tubular renal distal, como manifestación extraglandular de síndrome de Sjögren primario. Se discuten brevemente manifestaciones neurológicas de esta entidad, incluyendo aquellas secundarias a trastornos metabólicos precipitados por compromiso autoinmune.

ABSTRACT Sjögren's syndrome is a multisystemic autoimmune disorder. It is classically considered as an exocrine disease, given the high frequency of dry symptoms (keratoconjunctivitis sicca, xerostomia) as a result of poly-glandular infiltration by autoreactive lymphocytes. However, less than 10% of these patients can onset with severe extra-glandular manifestations, resulting in worse long-term outcomes. The case of a pregnant woman is presented, who debuted with acute proximal weakness syndrome related to myositis with mitochondrial pathology and severe hypokalaemia in the context of distal renal tubular acidosis, as an extra-glandular manifestation of primary Sjögren's syndrome. Neurological manifestations of this condition are briefly discussed, including those secondary to metabolic disorders precipitated by autoimmune compromise.

Potassium losing, aldosterone producing adrenocortical carcinoma: a rare presentation.

Adrenocortical carcinomas (ACCs) are rare malignancies with an incidence of one to two per million per year. Aldosterone-producing ACCs (APACs) are extremely rare with an incidence less than 1%. We describe a rare case of APAC, presenting with episodic lower-limb weakness and hypertension. Our patient was found to have serum aldosterone levels of 20.8 ng/dL (2.5-15.2) with persistent hypokalaemia and a 9.7×8.3×7.7 cm right adrenal mass, which was suspicious of malignancy on evaluation. He underwent a complete surgical resection which confirmed the diagnosis of ACC and normalised his aldosterone and potassium levels. He was then subjected to postoperative chemotherapy. Postoperative adjuvant chemotherapy with mitotane has a role in preventing recurrence.

First-Onset Hypokalemic Periodic Paralysis Following Surgery for Myxopapillary Ependymoma.

BACKGROUND: Hypokalemic periodic paralysis is a rare skeletal muscle channelopathy characterized by intermittent episodes of acute flaccid paralysis with associated hypokalemia. We present here the case of a first-onset hypokalemic periodic paralysis triggered by lumbar spinal surgery for tumor resection. CASE DESCRIPTION: A 37-year-old male without any known prior medical conditions presented with a first-onset attack of hypokalemic paralysis 1.5 days after lumbar spinal surgery for myxopapillary ependymoma. Initially, the patient presented paraparesis mimicking a spinal cord compression, and while en route for imaging there was an abrupt onset of flaccid paralysis with significant respiratory distress. The emergency blood tests revealed extreme hypokalemia with a serum potassium of 1.42 mm/L. The patient was transferred to the intensive care unit, intubated, sedated, and administered intravenous reperfusion with an infusion dose of 20 mEq/hour potassium in a solution of 5% mannitol. Following reperfusion, the patient recovered completely in 12 hours. Renal potassium hyperexcretion and hyperthyroidism were excluded by laboratory tests. The diagnosis was confirmed by genetic tests showing mutation of the CACNA1S gene. CONCLUSIONS: To the best of our knowledge, this is the first described case with the first onset triggered by a neurosurgical intervention and the second case following any kind of surgery. Neurosurgeons should consider hypokalemic periodic paralysis when encountering a rapidly evolving tetraparesis, even in an apparently healthy patient.

Tumors masquerading as neurological diseases: A caution for clinicians in planning diagnosis and treatment.

INTRODUCTION: Neurological diseases can be due to direct diseases of the central nervous system (CNS) or peripheral nervous system (PNS) or be a bystander syndrome of systemic diseases. Treatment options depend on the cause. Toxic, metabolic and nutritional, and immune-mediated consequences of clinically occult neoplasms produce a spectrum of neurological diseases, recognition of which has therapeutic and prognostic importance. PATIENTS AND METHODS: Children, as well as adults who presented to the authors in the last 5 years with neurological diseases and later their diseases could be diagnosed or attributed to neoplasms which were occult, were included for the study. OBSERVATION: 28 patients were seen by the authors in the last 5 years with neurological manifestation and hidden tumor. Maximum incidence was in the age of above 60 years followed by the age group of 21-40 years. The commonest neurological presentation was muscle and nerve in adults and seizure in children. DISCUSSION: Short duration, rapid progression, severe weight loss, and poor response to treatment given for nontumor associated neurological syndrome are the red flags which point to the diagnosis. CONCLUSION: Seizures and psychosis formed the commonest features in children, muscle and nerve in adults. Short duration, rapid progression, and resistance to treatment are the markers for possible underlying neoplasm.

Reconhecimento da paralisia periódica hipocalêmica tireotóxica na emergência: relato de caso e revisão da literatura / Recognizing thyrotoxic hypokalemic periodic paralysis on emergency settings: a case report and literature revie

A paralisia periódica hipocalêmica tireotóxica é uma complicação inusitada do hipertireoidismo, porém é considerada urgência endocrinológica e ainda frequentemente subdiagnosticada. Sua apresentação clínica consiste na tríade de défice de potássio, tireotoxicose e fraqueza muscular ­ sendo esse último sintoma comum em diversas patologias. Realizamos uma revisão bibliográfica e destacamos, por meio do relato de caso, a importância do diagnóstico precoce dessa doença, possibilitando uma evolução favorável ao paciente, independente de sua etnia, sexo ou região geográfica. Atentamos ainda ao tratamento da doença, que, apesar de sua simplicidade, acarreta muitos equívocos.

The thyrotoxic hypokalemic periodic paralysis is a rare complication of hyperthyroidism, but is considered an endocrinological urgency, and yet frequently underdiagnosed. Its clinical presentation consists of potassium deficit, thyrotoxicosis, and muscular weakness, with the latter symptom being very common in several pathologies. We performed a bibliographic review and highlight, through a case report, the importance of the early diagnosis of this disease to allow favorable progression to the patient, regardless of ethnicity, sex, or geographical region. We also reinforce the importance of the disease treatment which, despite its simplicity, leads to many mistakes.

33-year-old man • flaccid paralysis in limbs • 30-lb weight loss • thyromegaly without nodules • Dx?

Flaccid paralysis in arms and legs. 30-lb weight loss in previous month. Thyromegaly without nodules. Dx?

Coexistence of myasthenia gravis with hypokalemic periodic paralysis: a rare presentation.

Bilateral symmetrical weakness of acute onset is not very uncommon and the differential varies widely from life-threatening neurological illnesses to metabolic and electrolyte derangements. We report the case of a young female with severe muscle weakness, respiratory distress and hypokalemia who required immediate intubation on arrival to emergency department. During hospital course, even after normalisation of serum potassium and some improvement in limb weakness, patient failed multiple attempts of extubation because of type II respiratory failure. Subsequently, acetyl cholinesterase antibodies were checked which came out positive, and diagnosis of myasthenia gravis and hypokalemic periodic paralysis was made. She was successfully extubated after intravenous pulse steroids, pyridostigmine and plasmapheresis. Patient was finally discharged home on oral steroids, pyridostigmine and azathioprine. In a patient presenting with hypokalemic weakness, the suspicion of a second disorder should be very high if weakness fails to resolve following correction of hypokalemia.