Natural history and outcome of neonatal hypocalcemic and hypomagnesemic seizures

Syndromic and non-syndromic etiologies causing neonatal hypocalcemic seizures

BACKGROUND

The diagnosis of neonatal hypocalcemic seizures (HS) in newborns is made based on clinical signs and serum calcium level. Their etiology is broad and diverse, and timely detection and initiation of treatment is essential.

METHODS

We retrospectively reviewed 1029 patients admitted to the neonatal intensive care unit. Neonatal HS were diagnosed in 16 patients, and we compared etiologies and clinical outcomes, including clinical seizures and neurodevelopment at least over 1 year old.

RESULTS

The etiologies can be broadly categorized into 5 syndromic and 11 non-syndromic neonatal HS. Syndromic neonatal HS included 3 Digeorge syndrome, 1 Kleefstra syndrome and 1 Alström syndrome. Non-syndromic neonatal HS included 8 vitamin D deficiency, 1 hypoparathyroidism, and 2 hypoxic-ischemic encephalopathy. Patients with syndromic neonatal HS were found to have worse clinical outcomes than those with nonsyndromic HS. In eight patients with vitamin D deficiency, neurodevelopment was normal. Five of five patients (100%) with syndromic HS used two or more antiseizure drugs. However, among patients with non-syndromic neonatal HS, only one of 11 (9.1%) used more than one drug (p = 0.001).

CONCLUSION

This finding highlighted that syndromic hypocalcemic seizures in newborns have worse neurodevelopmental outcomes and are more often difficult to manage, and would benefit from a genetic diagnostic approach.

Pattern, etiological factors and determinants of mortality among sick newborns with seizures in Ilesa, Nigeria

Background:

Neonatal seizures contribute significantly to newborn morbidity and mortality particularly in developing countries including Nigeria. Unfortunately the countries with high incidence of neonatal seizures often lack the facilities to adequately diagnose, monitor and prognosticate the condition.

Objective:

We set out to determine the factors at presentation that predict death among babies admitted with clinically identifiable seizures.

Methods:

We prospectively observed consecutive neonatal admissions over a nine month period at the Wesley Guild Hospital, Ilesa, Nigeria. Babies with seizures were identified based on clinical observation. Perinatal history, examination and laboratory findings were compared between babies with seizures who survived and those that died. Multivariate regression analysis was used to determine the predictors of mortality.

Results:

Over a nine month study period, a total of 340 babies were recruited out of which 55 (16.7 percent) had clinically identifiable seizures. Fifteen (27.3 percent) of the 55 babies with clinically identifiable seizures died; while 20 (7.0 percent) of the 285 babies without seizures died. Clinically identifiable neonatal seizures contributed to 42.9 percent of the overall mortality in the neonatal unit during the study period. The risk factors for mortality among the babies with seizures were clinical seizures in the first 24 hours of life, birth asphyxia co-existing with hyponatraemia and presence of cerebral oedema (P < 0.05). The independent determinant of mortality among babies with clinical seizures was cerebral oedema (OR = 4.025; 95% CI 1.342–26.956; P = 0.019).

Conclusion:

We conclude that clinically identifiable neonatal seizures contribute significantly to neonatal mortality and presentation within 24 hours of delivery, birth asphyxia and cerebral oedema increased the risk of death in babies with seizures.

Clinical and laboratory characteristics of neonatal hypocalcemia

PURPOSE

To describe the clinical characteristics of full-term neonates with hypocalcemia and to suggest factors associated with neonatal hypocalcemia.

METHODS

The medical records of full-term neonates with hypocalcemia were reviewed. Hypocalcemia was defined as an ionized calcium (iCa) concentration of <4 mg/dL. Parathyroid hormone (PTH) insufficiency was defined as a serum PTH level of <60 pg/mL or a serum phosphorus level higher than the serum calcium level in the presence of hypocalcemia.

RESULTS

Fifty-three neonates were enrolled. The median age at diagnosis of hypocalcemia was 3 days. In all the neonates, formula feeding predominance was observed. Thirty-eight neonates (69.8%) were compatible with PTH insufficiency. The number of formula-fed neonates was significantly higher than that of breast-fed patients among neonates with PTH insufficiency (P=0.017). Intact PTH was negatively correlated with serum phosphorus levels. Twelve out of 14 neonates (85.7%) had 25-hydroxy vitamin D (25OHD) levels <20 ng/mL and 9 neonates (64.3%) had 25OHD levels <10 ng/mL. Twenty-one neonates had hypocalcemic tetany. The serum calcium and iCa concentrations of neonates with tetany were 4.2-8.3 mg/dL and 1.85-3.88 mg/dL, respectively. Three neonates showed symptomatic hypocalcemia with calcium levels over 7.5 mg/dL. Among the 16 neonates who underwent electroencephalography (EEG), 12 had abnormalities, which normalized after 1-2 months.

CONCLUSION

Formula milk feeding, PTH insufficiency and low serum vitamin D concentration are associated with the development of neonatal hypocalcemia. Symptoms such as tetany and QT interval prolongation can develop in relatively mild hypocalcemia. Moreover, transient neonatal hypocalcemia can cause transient EEG abnormalities.

The many etiologies of neonatal hypocalcemic seizures

Seizures during the neonatal period have a broad differential diagnosis. Unlike in developing countries where hypovitaminosis D and hypocalcemia constitutes a major cause of infantile seizures, the number of neonatal seizures attributed to hypocalcemia in developed countries has decreased dramatically due to the improvement of infant formulas and vitamin D supplementation. In these countries, most infants that present with hypocalcemic seizures have underlying endocrinological etiologies rather than dietary insufficiencies. Here, we describe 3 cases of neonatal seizures due to hypocalcemia. Although the symptoms and calcium concentrations at presentation were similar in all 3 cases, the course of the disease and the final diagnosis for each were distinct. The cases are presented along with a brief review of the pathophysiology, differential diagnosis, and treatment of neonatal hypocalcemia.

Electroencephalography of encephalopathy in patients with endocrine and metabolic disorders

Patients with acute alteration in mental status from encephalopathy because of underlying metabolic-toxic or endocrine abnormalities are frequently seen in the acute hospital setting. A rapid diagnosis and correction of the underlying cause is essential as a prolonged state of encephalopathy portends a poor outcome. Correct diagnosis and management remain challenging because several encephalopathies may present similarly, and further laboratory, imaging, or other testing may not always reveal the underlying cause. EEG provides rapid additional information on the encephalopathic patient. It may help establish the diagnosis and is indispensable for identifying nonconvulsive status epilepticus, an important possible complication in this context. The EEG may assist the clinician in gauging the severity of brain dysfunction and may aid in predicting outcome. This review summarizes the current knowledge on EEG findings in selected metabolic and endocrine causes of encephalopathy and highlights distinct EEG features associated with particular etiologies.

[Familial congenital hypomagnesemia revealed by neonatal convulsions]

Congenital hypomagnesemia is a rare disease, with an impact on cognitive and neurological development. We report on three familial cases of congenital hypomagnesemia, two boys and one girl who belong to the same consanguineous family. They all presented neonatal seizures and a psychomotor developmental delay. Cerebral computed tomography showed cerebral atrophy and calcifications in one case and magnetic resonance imaging found predominant cerebellar atrophy in the two other cases. All three patients also had hypocalcemia, hyperphosphoremia, and hypomagnesemia. The parathyroid hormone blood level was low in two cases and normal in the third. One 7-month old patient died. The others received a supplementation of calcium and magnesium, which normalized calcemia, phosphatemia but not magnesemia, which remained low despite high doses. They have both developed cognitive and behavioral impairments.

Neonatal hypocalcemic seizures due to excessive maternal calcium ingestion

Hypocalcemia is a common, treatable cause of neonatal seizures. A term girl neonate with no apparent risk factors developed seizures on day 5 of life, consisting of rhythmic twitching of all extremities in a migrating pattern. Physical examination was normal except for jitteriness. Laboratory evaluation was unremarkable except for decreased total and ionized serum calcium levels and an elevated serum phosphorus level. The mother had ingested 3-6 g of calcium carbonate daily during the final 4 months of pregnancy to control morning sickness. The baby's electroencephalogram showed multifocal interictal sharp waves and intermittent electrographic seizures consisting of focal spikes in the left hemisphere accompanied by rhythmic jerking of the right arm and leg. Treatment with intravenous calcium gluconate over several days resulted in cessation of seizures and normalization of serum calcium. The child has remained seizure free and is normal developmentally at 9 years of age. Hypocalcemic seizures in this newborn were likely secondary to excessive maternal calcium ingestion, which led to transient neonatal hypoparathyroidism and hypocalcemia. Inquiry about perinatal maternal medication use should include a search for over-the-counter agents that might not be thought of as "drugs," as in this case, antacids.

Neonatal hypocalcemic seizures in siblings exposed to topiramate in utero

We describe two siblings with neonatal hypocalcemic seizures whose mother took topiramate during both pregnancies. Apart from hypocalcemia, the patients had no identifiable etiology for their seizures. Although biochemical data suggested that the hypocalcemia was caused by hypoparathyroidism, no disorders typically associated with this condition were identified in the patients. We propose that topiramate exposure in utero led to hypoparathyroidism and subsequent hypocalcemia via effects on protein kinase A signaling, resulting in hypocalcemic seizures. Neonates exposed to topiramate in utero should be monitored for hypocalcemic seizures.

Pediatric hypocalcemic seizures: a case of rickets

Although cases of Vitamin D-deficient Rickets have declined since the Industrial Revolution, certain populations remain at risk. Risk factors for developing vitamin D-deficient Rickets include breast-feeding without formula or vitamin supplementation, very dark skin and inadequate exposure to sunlight. We describe a case of Rickets in a breastfed infant with dark skin who presented with hypocalcemic seizures. The pathophysiology of Rickets is briefly described along with the emergency management of infants presenting with hypocalcemic seizure.

Trace Elements and Electrolytes Homeostasis and Their Relation to Antioxidant Enzyme Activity in Brain Hyperexcitability of Epileptic Patients

Epileptogenesis is a big challenge. Various experimental and human studies suggested that the homeostasis of trace elements, electrolytes, membrane lipid peroxidation, and antioxidants is crucial for brain function, and they were directly or indirectly implicated as taking part in the pathophysiology of neuronal excitability, neuronal excitotoxicity, and seizure recurrence and its resistance to treatment with antiepileptic drugs (AEDs). In addition, AEDs can also alter the homeostasis of trace elements, electrolytes, and seriously increase membrane lipid peroxidation at the expense of protective antioxidants, leading to an increase in seizure recurrence and an idiosyncratic drug effect. Differential effects were detected among different AEDs treatments in which carbamazepine (CBZ) was found to be better anticonvulsant for the control of free radical related seizures and the level of trace elements were better regulated with CBZ than with valproate (VPA) and phenytoin (PHT) therapies. It is concluded that adequate trace elements and antioxidants supply is important for brain functions and prevention of neurological diseases and further elucidation of the pathological actions of such substances in the brain should result in new therapeutic approaches. Trace elements and antioxidant might have neuroprotective biological targeted benefits when used in epileptic patients.

Neonatal hypocalcemic seizures: case report and literature review

Seizures during the neonatal period have a broad differential diagnosis, many with a specific treatment and prognosis. In the case reported, a combination of dietary and endocrinologic abnormalities resulted in hypocalcemic seizures, which continued despite aggressive correction of serum ionized calcium levels. Serial electroencephalograms (EEG) performed during the hospitalization were markedly abnormal, and treatment with anticonvulsant drugs was considered given the persistence of seizures despite normalization of serum calcium levels. After 4 days of intravenous calcium administration, the seizure activity resolved, and the patient returned to his normal baseline level of functioning. This case highlights the clinical course of neonatal hypocalcemic seizures, EEG findings in several cases, and possible mechanisms for both hypocalcemic precipitation of seizures and anticonvulsant ineffectiveness.

Oral contraceptives do not affect magnesium in breast milk

OBJECTIVES

To study the effects of oral contraceptives on magnesium metabolism of lactating mothers.

METHODS

Serum and breast-milk magnesium were measured in three groups of mothers that were using combination pill (12), mini-pill (21), and a control group (21).

RESULTS

There was no significant effect of oral contraceptives on breast-milk magnesium.

CONCLUSIONS

The use of oral contraceptives such as the combination pill and mini-pill does not seem to affect the secretion of magnesium in breast milk.

Magnesium in human milk

Reported concentrations for magnesium in breast milk vary over a wide range (15 to 64 mg/L) with a median value of 31 mg/L and 75% of reported mean concentrations below 35 mg/L. Constitutional variables such as adolescent motherhood, gestation length, maternal undernutrition, metabolic disorders (diabetes, galactosemia), race, stage of lactation, sampling techniques (foremilk and hindmilk), as well as environmental variables such as socio-cultural diversity, smoking habits, dietary calcium and magnesium (including supplementation), vegetarianism, calciotropic agents (immunoreactive calcitonin, vitamin D), medication (hormonal contraceptives, magnesium sulfate) are critically reviewed in relation to changes in milk magnesium concentrations. Magnesium secretion into breast milk does not seem to be affected by the studied variables.