Tolvaptan for Treatment of Syndrome of Inappropriate Antidiuretic Hormone Secretion (SIADH) in a Child with Corpus Callosum Agenesis.

Syndrome of inappropriate antidiuretic hormone secretion (SIADH) is one of the common causes of euvolemic hyponatremia (serum Na+ < 135 mEq/L) in hospitalized children. It is characterized by increased serum ADH, leading to water retention via its action on V2 receptors in the distal renal tubules. Various conditions such as pain, the postoperative state, drugs, central nervous system infections, tumors, malformations, and pneumonia can predispose a person to SIADH. The conventional treatment of SIADH includes fluid restriction and salt supplementation. Occasionally, this may fail to control hyponatremia, mandating pharmacological therapy. V2-receptor antagonists are an FDA-approved therapy for adults with euvolemic and hypervolemic hyponatremia. However, there is limited experience with their use in the pediatric population. Here, the authors present a girl with corpus callosum agenesis with severe symptomatic hyponatremia due to SIADH who was successfully managed with the V2-receptor antagonist tolvaptan.

Long-term follow-up in pediatric patients with paroxysmal hypothermia (Shapiro's syndrome).

INTRODUCTION: Shapiro syndrome (SS) is characterized by spontaneous recurrent episodes of hypothermia, hyperhidrosis and corpus callosum (CC) agenesis. Less than 60 cases have been reported to date and the pathogenic mechanism as well as the prognosis of this syndrome are still debated. We describe the clinical features and long-term follow-up of a pediatric cohort of SS patients. METHODS: We collected 13 (10 novel) pediatric cases of SS and report their long-term follow-up and neurological outcome. RESULTS: All patients experienced recurring hypothermia, with body temperature below 35 °C during the episodes, often accompanied by hyperidrosis. CC agenesis was an inconstant structural feature in the present series (2/13 patients). Seven patients received antiepileptic drugs (AEDs) or other drug therapy for a mean period of 12 months. At long-term follow-up (mean = 61 months, range: 60-96), all individuals were free from episodes of paroxysmal hypothermia independently from previous AED use or other drug therapy. CONCLUSION: Paroxysmal hypothermia, the core symptom of SS, behaved as a age-dependent feature in our cohort, supporting a good long-term prognosis for SS. A prompt diagnosis of SS is crucial to avoid unnecessary diagnostic investigations.

Early-Onset Shapiro Syndrome Variant Treated with Pizotifen: A Case Report.

Shapiro Syndrome is a rare entity defined by the triad of recurrent spontaneous hypothermia, hyperhidrosis, and agenesis of the corpus callosum. Fewer than 100 cases have been reported so far and there are only few cases without a complete agenesis of corpus callosum ("Shapiro Syndrome Variant"). In this article, we report the clinical, electroencephalographic, and neuroimaging data of a patient with early-onset Shapiro Syndrome Variant. The case study describes a 4-year-old patient with episodes characterized by generalized hyperhidrosis, hypotonia, impaired consciousness, and hypothermia with onset before the first year of age. We captured an event during which the EEG showed rhythmic low- to medium-voltage theta waves without clear epileptiform activity. Brain MRI was normal and Shapiro Syndrome Variant was hypothesized. We started treatment with pizotifen, and after 2 years, the patient showed a reduction in frequency and duration of episodes. Shapiro Syndrome, although rare, should be considered in the differential diagnosis in patients with neurovegetative symptoms which suggest epileptic attacks at first. Our case is of particular interest to specialists because Shapiro SyndromeVariant is a rare syndrome and our patient had a very early onset of symptoms.In addition, we report our experience with pizotifen therapy, which produced a good response.

KCC3 loss-of-function contributes to Andermann syndrome by inducing activity-dependent neuromuscular junction defects.

Loss-of-function mutations in the potassium-chloride cotransporter KCC3 lead to Andermann syndrome, a severe sensorimotor neuropathy characterized by areflexia, amyotrophy and locomotor abnormalities. The molecular events responsible for axonal loss remain poorly understood. Here, we establish that global or neuron-specific KCC3 loss-of-function in mice leads to early neuromuscular junction (NMJ) abnormalities and muscular atrophy that are consistent with the pre-synaptic neurotransmission defects observed in patients. KCC3 depletion does not modify chloride handling, but promotes an abnormal electrical activity among primary motoneurons and mislocalization of Na+/K+-ATPase α1 in spinal cord motoneurons. Moreover, the activity-targeting drug carbamazepine restores Na+/K+-ATPase α1 localization and reduces NMJ denervation in Slc12a6-/- mice. We here propose that abnormal motoneuron electrical activity contributes to the peripheral neuropathy observed in Andermann syndrome.

Shapiro syndrome.

We report here a case of Shapiro syndrome who presented with episodic generalized sweating, hypotension, and hypothermia. Brain magnetic resonance imaging demonstrated corpus callosum agenesis with colpocephaly. Patient was treated with Clonidine and Propranolol. This case is being reported here because only a few cases of Shapiro Syndrome are reported in world literature.

Immunodeficiency in Vici syndrome: a heterogeneous phenotype.

Vici syndrome is a rare congenital multisystem disorder characterized by agenesis of the corpus callosum, hypotonia, developmental delay, hypopigmentation, cataract, cardiomyopathy, and immunological abnormalities. Recurrent infections, mainly affecting the respiratory tract, have been reported in the majority of cases, representing an important risk factor for morbidity and mortality. The immunological phenotype of patients is extremely variable, ranging from a combined immunodeficiency to nearly normal immunity. We report on a new patient with Vici syndrome, in whom we have extensively investigated immunological features. Despite a mild impairment of the cellular compartment, a defect of humoral immunity was found, requiring treatment with intravenous immunoglobulin. A wider knowledge of immune system abnormalities of Vici syndrome will help to plan strategies for treatment and prevention of infections, such as immunoglobulin replacement and antimicrobial prophylaxis, resulting in improved survival rates.