Non-convulsive status epilepticus in a patient with hypocalcemia

Non-convulsive status epilepticus possibly induced by a rapid correction of severe hyperkalemia: a case report and literature review

BACKGROUND

Patients with chronic kidney disease frequently develop neurological complications including confusion and altered consciousness. Non-convulsive status epilepticus, which is characterized by a change in behavior and/or mental process accompanied by epileptiform discharges on electroencephalogram in the absence of convulsive seizures, is one of the overlooked causes of altered consciousness. The incidence and precise pathophysiological mechanism of non-convulsive status epilepticus in patients with kidney disease, and especially in patients with electrolyte disturbances, remains unknown. We recently treated an older patient with chronic kidney disease and severe hyperkalemia in whom non-convulsive status epilepticus developed following a correction of severe hyperkalemia.

CASE PRESENTATION

An 82-year-old male was admitted to our hospital at midnight because of weakness of all four limbs (Day 1). He underwent urgent hemodialysis for severe hyperkalemia (9.84 mEq/L) and his serum potassium concentration decreased to 4.97 mEq/L. He regained full consciousness and his limb weakness improved on the morning of Day 2, but he became confused in the evening. Electroencephalogram revealed repeated low-voltage ictal discharges in the right occipital region and a diagnosis of non-convulsive status epilepticus was made. Following medication with fosphenytoin and phenytoin, the patient became fully alert and orientated on Day 8.

CONCLUSION

We speculate that a rapid correction of hyperkalemia was the possible cause of non-convulsive status epilepticus development. To our knowledge, this is the first report of non-convulsive status epilepticus from a potassium abnormality. We described a case of this condition in detail and summarized 78 previous case reports of non-convulsive status epilepticus with kidney disease or electrolyte disturbances.

Recommandations Formalisées d’Experts SRLF/SFMU : Prise en charge des états de mal épileptiques en préhospitalier, en structure d’urgence et en réanimation dans les 48 premières heures (A l’exclusion du nouveau-né et du nourrisson)

La Société de réanimation de langue française et la Société française de médecine d’urgence ont décidé d’élaborer de nouvelles recommandations sur la prise en charge de l’état mal épileptique (EME) avec l’ambition de répondre le plus possible aux nombreuses questions pratiques que soulèvent les EME : diagnostic, enquête étiologique, traitement non spécifique et spécifique. Vingt-cinq experts ont analysé la littérature scientifique et formulé des recommandations selon la méthodologie GRADE. Les experts se sont accordés sur 96 recommandations. Les recommandations avec le niveau de preuve le plus fort ne concernent que l’EME tonico-clonique généralisé (EMTCG) : l’usage des benzodiazépines en première ligne (clonazépam en intraveineux direct ou midazolam en intramusculaire) est recommandé, répété 5 min après la première injection (à l’exception du midazolam) en cas de persistance clinique. En cas de persistance 5 min après cette seconde injection, il est proposé d’administrer la seconde ligne thérapeutique : valproate de sodium, (fos-)phénytoïne, phénobarbital ou lévétiracétam. La persistance avérée de convulsions 30 min après le début de l’administration du traitement de deuxième ligne signe l’EMETCG réfractaire. Il est alors proposé de recourir à un coma thérapeutique au moyen d’un agent anesthésique intraveineux de type midazolam ou propofol. Des recommandations spécifiques à l’enfant et aux autres EME sont aussi énoncées.

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.

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.

Perioperative changes in cortical excitability, mood, and quality of life in patients with primary hyperparathyroidism: a pilot study using transcranial magnetic stimulation

OBJECTIVE

Serum calcium (Ca(2)(+)) and parathyroid hormone (PTH), amongst others, modify cortical excitability. Alterations in cortical excitability were shown in patients with epilepsy as well as hyper- or hypoparathyroidism. In patients with primary hyperparathyroidism (pHPT), preoperative elevated serum calcium and parathyroidectomy (PTx) may affect mood and quality of life. We hypothesized that perioperative changes in Ca(2)(+) and PTH in pHPT will affect cortical excitability and improve subjective health.

DESIGN AND METHODS

Transcranial magnetic stimulation (TMS) was performed before and after surgery in 15 pHPT patients. We measured resting motor threshold, cortical silent period (CSP), short intracortical inhibition, and intracortical facilitation. Health questionnaires were administered before, 1 day and 6 months after PTx, along with the disease-specific Pasieka's parathyroid assessment of symptoms (PAS), which was, to our knowledge, its first use in German.

RESULTS

SURGERY WAS SUCCESSFUL IN ALL PATIENTS. TMS-MEASUREMENTS REMAINED UNCHANGED WHEN ANALYZING ALL PATIENTS IN THIS PILOT STUDY. POSTOPERATIVELY, DEPRESSION DECLINED (P=0.05) AND QUALITY OF LIFE IMPROVED SIGNIFICANTLY (P=0.001) IN THE SF-36-SUBSCALES: vitality, social functioning, mental health and subjective health transition (post-hoc analysis). The PAS proved early relief of disease-specific symptoms (P<0.001).

CONCLUSIONS

We found unchanged cortical excitability comparing pre- and post-PTx in this pilot study. Mood and quality of life improved postoperatively. The German PAS is valuable in detecting disease-specific changes early after PTx.

Reading epilepsy as the initial symptom of idiopathic hypoparathyroidism

Reading epilepsy is a rare form of reflex epilepsy that occurs exclusively during reading. In this report, we describe a patient in whom seizure was the initial symptom of idiopathic hypoparathyroidism. A 31-year-old man experienced seizures three times in different bookshops while browsing. Chvostek's sign was observed. Serum calcium and parathyroid hormone levels were decreased. Brain computed tomography revealed symmetrical calcification at the dentate nuclei of the cerebellum and the basal ganglia. The interictal electroencephalography was normal. There was no photoparoxysmal response. After amelioration of serum calcium level with oral administration of vitamin D, seizure attacks ceased without antiepileptic drugs. This case is, to our knowledge, the first report of reading epilepsy associated with hypocalcemia due to idiopathic hypoparathyroidism. The psychological stress of reading at bookshops without buying might have triggered seizures under CNS hyperexcitability due to hypocalcemia.

Nonconvulsive status epilepticus

Nonconvulsive status epilepticus (NCSE) refers to a prolonged seizure that manifests primarily as altered mental status as opposed to the dramatic convulsions seen in generalized tonic-clonic status epilepticus. There are 2 main types of NCSE, each of which has a different presentation, cause, and expected outcome. In the first type of NCSE, patients present with confusion or abnormal behavior, suggesting the diagnosis of absence status epilepticus (ASE) or complex partial status epilepticus (CPSE). The second type of NCSE (subtle status epilepticus [SSE]) must be considered in comatose patients who present after a prolonged generalized tonic-clonic seizure and who may have only subtle motor manifestations of a seizure, such as facial or hand twitchings. Whereas the morbidity and mortality in patients with prolonged ASE or CPSE is low, the mortality associated with SSE can exceed 30% if the seizure duration is greater than 60 minutes.

Neurologic presentations of acid-base imbalance, electrolyte abnormalities, and endocrine emergencies

Accurate identification of nervous system dysfunction is vital in the assessment of any multisystem disorder. The neurologic manifestations of acid-base disturbances, abnormal electrolyte concentrations, and acute endocrinopathies are protean and typically determined by the acuity of the underlying derangement. Detailed history and physical examination may guide appropriate laboratory testing and lead to prompt and accurate diagnosis. Neurologic manifestations of primary and secondary systemic disorders are frequently encountered in all subspecialties of medicine. This article focuses on key neurologic presentations of respiratory and metabolic acid-base derangements and potentially life-threatening endocrinopathies.

Tonic-clonic seizures in a patient with primary hypoparathyroidism: a case report

Hypoparathyroidism, a life threatening disorder, occurs when insufficient parathyroid hormone is produced to maintain extracellular calcium levels within the normal range. The acute clinical signs and symptoms of hypoparathyroidism are the same as those of hypocalcemia, ranging from tingling to intractable generalized tonic-clonic seizures; therefore, it can be mistaken for epilepsy. We report the case of a 36-year-old man who presented two tonic-clonic seizures, characterized by sudden loss of consciousness with a fall and diffuse tonic contractions and clonic jerks. At first diagnosis of epilepsy was established and therapy with valproate was commenced. In the following days, the patient presented typical signs of hypocalcemia and the diagnosis of hypoparathyroidism was made. In the 4 months follow up, antiepileptic drug therapy was reduced until suspension and calcium supplementation was initiated. We briefly review the most recent reports in the literature.

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.

Neurologic manifestations of electrolyte disturbances

Electrolyte disturbances occur commonly and are associated with a variety of characteristic neurologic manifestations involving both the central and peripheral nervous systems. Electrolyte disturbances are essentially always secondary processes. Effective management requires identification and treatment of the underlying primary disorder. Since neurological symptoms of electrolyte disorders are generally functional rather than structural, the neurologic manifestations of electrolyte disturbances are typically reversible. The neurologic manifestations of serum sodium, potassium, calcium, and magnesium disturbances are reviewed.