The many etiologies of neonatal hypocalcemic seizures

Cerebral Hemodynamic and Metabolic Abnormalities in Neonatal Hypocalcemia: Findings from Advanced MRI

BACKGROUND AND PURPOSE

Neonatal hypocalcemia is the most common metabolic disorder, and whether asymptomatic disease should be treated with calcium supplements remains controversial. We aimed to quantify neonatal hypocalcemia's global CBF and cerebral metabolic rate of oxygen (CMRO2) using physiologic MR imaging and elucidate the pathophysiologic vulnerabilities of neonatal hypocalcemia.

MATERIALS AND METHODS

A total of 37 consecutive patients with neonatal hypocalcemia were enrolled. They were further divided into subgroups with and without structural MR imaging abnormalities, denoted as neonatal hypocalcemia-a (n = 24) and neonatal hypocalcemia-n (n = 13). Nineteen healthy neonates were enrolled as a control group. Brain physiologic parameters determined using phase-contrast MR imaging, T2-relaxation-under-spin-tagging MR imaging, and brain volume were compared between patients with neonatal hypocalcemia (their subgroups) and controls. Predictors for neonatal hypocalcemia-related brain injuries were identified using multivariate logistic regression analysis and expressed as ORs with 95% CIs.

RESULTS

Patients with neonatal hypocalcemia showed significantly lower CBF and CMRO2 compared with controls. Furthermore, the neonatal hypocalcemia-a subset (versus controls or neonatal hypocalcemia-n) had significantly lower CBF and CMRO2. There was no obvious difference in CBF and CMRO2 between the neonatal hypocalcemia-n subset and controls. CBF and CMRO2 were independently associated with neonatal hypocalcemia. The ORs were 0.80 (95% CI, 0.65-0.99) and 0.97 (95% CI, 0.89-1.05) for CBF and CMRO2, respectively.

CONCLUSIONS

Neonatal hypocalcemia with structural damage may exhibit lower hemodynamics and cerebral metabolism. CBF may be useful in assessing the need for calcium supplementation in asymptomatic neonatal hypocalcemia to prevent brain injury.

A Case of Severe Neonatal Hypocalcemia Treated With Continuous Enteral Calcium

Background/Objective

Hypocalcemia is a common, treatable cause of neonatal seizures. The rapid repletion of calcium is essential for restoring normal calcium homeostasis and resolving seizure activity. The accepted approach to administer calcium to a hypocalcemic newborn is via peripheral or central intravenous (IV) access.

Case Report

We discuss a case of a 2-week-old infant who presented with hypocalcemia and status epilepticus. The etiology was determined to be neonatal hypoparathyroidism secondary to maternal hyperparathyroidism. Following an initial dose of IV calcium gluconate, the seizure activity abated. However, stable peripheral intravenous access could not be maintained. After weighing the risks and benefits of placing a central venous line for calcium replacement, it was decided to use continuous nasogastric calcium carbonate at a rate of 125 mg of elemental calcium/kg/d. Ionized calcium levels were used to guide the course of the therapy. The infant remained seizure-free and was discharged on day 5 on a treatment regimen that included elemental calcium carbonate, calcitriol, and cholecalciferol. He remained seizure free since discharge and all medications were discontinued by 8 weeks of age.

Discussion

Continuous enteral calcium is an effective alternate therapy for restoration of calcium homeostasis in a neonate presenting with hypocalcemic seizures in the intensive care unit (ICU).

Conclusion

We propose that continuous enteral calcium be considered as an alternative approach for calcium repletion in neonatal hypocalcemic seizures, one that avoids the potential complications of peripheral or central IV calcium administration.

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.

Clinical Findings and Neurologic Outcome in Neonatal Encephalopathy With White Matter Injury Accompanied by Rotavirus

Our objective was to elucidate the clinical characteristics and neurodevelopmental outcomes in neonatal encephalopathy with characteristic white matter injury as compared with other injury patterns on magnetic resonance diffusion-weighted imaging. We conducted a retrospective study comparing clinical and laboratory findings, and neurologic outcomes between 17 newborns with diffuse lesions in the periventricular white matter and white matter tract (group I) and 22 newborns with other patterns (group II). Stool samples indicated that 16 neonates (94.1%) in group I were rotavirus-positive, whereas none in group II had rotavirus infection. Significantly lower calcium levels were found in group I than in group II ( P < .001). Moreover, a more favorable neurodevelopmental outcome was observed in group I than in group II. This study suggests that characteristic white matter injury in neonatal encephalopathy may be related to decreased calcium levels induced by rotavirus, and may have a better neurodevelopmental prognosis than other causes.

Acute Symptomatic Seizures Caused by Electrolyte Disturbances

In this narrative review we focus on acute symptomatic seizures occurring in subjects with electrolyte disturbances. Quite surprisingly, despite its clinical relevance, this issue has received very little attention in the scientific literature. Electrolyte abnormalities are commonly encountered in clinical daily practice, and their diagnosis relies on routine laboratory findings. Acute and severe electrolyte imbalances can manifest with seizures, which may be the sole presenting symptom. Seizures are more frequently observed in patients with sodium disorders (especially hyponatremia), hypocalcemia, and hypomagnesemia. They do not entail a diagnosis of epilepsy, but are classified as acute symptomatic seizures. EEG has little specificity in differentiating between various electrolyte disturbances. The prominent EEG feature is slowing of the normal background activity, although other EEG findings, including various epileptiform abnormalities may occur. An accurate and prompt diagnosis should be established for a successful management of seizures, as rapid identification and correction of the underlying electrolyte disturbance (rather than an antiepileptic treatment) are of crucial importance in the control of seizures and prevention of permanent brain damage.