Non-convulsive status epilepticus presenting as acute confusional state in a young adult

BD Sharma; Amit Kumar Batra

doi:10.4103/INJMS.INJMS_8_18

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CASE REPORT

Year : 2019 | Volume : 10 | Issue : 1 | Page : 35-38

Non-convulsive status epilepticus presenting as acute confusional state in a young adult

BD Sharma¹, Amit Kumar Batra²
¹ Department of Medicine, Max Super Speciality Hospital, New Delhi, India
² Department of Neurology, Max Super Speciality Hospital, New Delhi, India

Date of Submission	09-Jul-2018
Date of Acceptance	25-Aug-2018
Date of Web Publication	17-Oct-2018

Correspondence Address:
Dr. B D Sharma
Department of Medicine, Max Super Speciality Hospital, A-108, Patparganj, New Delhi - 110 092
India

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/INJMS.INJMS_8_18

Abstract

Nonconvulsive status epilepticus (NCSE) can occur in a variety of clinical conditions and is characterized by prolonged electrographic seizures without clinically discernible seizure activity. It may be one of the most frequently missed diagnoses in patients with altered neurologic function because it is often seen in patients with other serious illnesses. For accurate diagnosis of NCSE, an alteration in baseline cognition or behavior and a concurrent epileptiform seizure pattern on electroencephalography (EEG) must be present. This case of a young adult male presented to our emergency room with an acute onset of confusional state and behavioral changes with no clue for its etiology on initial clinical or after routine investigations including CT brain until EEG picked up continuous epileptic discharges. He responded dramatically to antiepileptic drugs without any recurrence during follow-up of 4 months. Many cases like this are being diagnosed with the use of continuous EEG monitoring (cEEG) in Neurological Intensive Care Units. The advent of cEEG is instrumental in the diagnosis as well as monitoring the response to treatment of this condition with antiepileptic drugs. Increased awareness and a high index of suspicion are needed for timely diagnosis of NCSE if a patient presents with acute onset of unexplainable cognitive or behavioral change of at least 30–60 min duration. Patients with NCSE need to be managed exactly as convulsive SE, using EEG as a guide rather than clinical observations as the determinant of response to treatment.

Keywords: Confusion, epilepsy, seizure, status epilepticus

How to cite this article:
Sharma B D, Batra AK. Non-convulsive status epilepticus presenting as acute confusional state in a young adult. Indian J Med Spec 2019;10:35-8

How to cite this URL:
Sharma B D, Batra AK. Non-convulsive status epilepticus presenting as acute confusional state in a young adult. Indian J Med Spec [serial online] 2019 [cited 2023 Jun 7];10:35-8. Available from: http://www.ijms.in/text.asp?2019/10/1/35/243628

Introduction

Status epilepticus (SE) is defined as continuous seizure activity lasting more than 30 min, or two or more seizures in this duration without regaining consciousness between them. However, for clinical purposes, the “operational” definition envisages 5 min of continuous seizures or discrete seizures without recovery of consciousness between them. It is one of the most frequent neurological emergencies. The differential diagnosis of any person presenting with a sudden change in mental status should include epilepsy. SE can be divided, from a clinical viewpoint, into two main types as follows: convulsive SE (CSE) and Non-CSE (NCSE). NCSE is an underdiagnosed neurological emergency because of its versatile presentation, especially in the critical care setting. It is defined as mental status changes from baseline of at least 30–60 min duration associated with continuous or near continuous ictal discharges on EEG^[1] It is a state of electromechanical dissociation where the epileptiform discharges evident on the EEG are not accompanied by clinical manifestations other than mental status changes such as confusion, behavioral abnormalities, obtundation, coma, or barely discernible motor manifestations such as facial twitching, nystagmus, etc.^[2],[3] Sustained or recurrent change from baseline behavior or mental status should be clinically evident. The main categories of NCSE are complex partial SE and absence SE (ASE). A physician unfamiliar with this kind of patients may not be able to differentiate between baseline cognitive and behavioral functions from ictal behavioral and mental state changes. It should be suspected in patients with witnessed seizures who has unduly prolonged postictal confusion or obtundation in spite of adequate treatment for the seizures. Late-onset de novo ASE, however, has been reported in every tenth elderly patient with protracted ictal confusion.^[4] patients with late-onset de novo NCSE often have neither history of previous seizures nor other peculiar clinical features pointing to this condition.^[5] Use of continuous EEG (cEEG) monitoring in Neurological Intensive Care Units (ICUs) has resulted in increasing recognition of this clinical entity. It is instrumental in the diagnosis as well as monitoring of the response to treatment of this condition.^[6] It has particularly been used in the elderly patients who present with acute confusional state due to a variety of conditions such as vascular, metabolic or dyselectrolytemia, or sepsis to mention a few.^[7] We share our experience in managing one such case of a young adult male, who was unique in not only being young but also did not have any antecedent clinical conditions usually associated with NCSE.

Case Report

Mr. A J, a 26-years-old male presented to the emergency room (ER) of max super specialty hospital Patparganj with a history of acute confusional state and abnormal behavior for the last 12 h. Patient was in perfect health before this. Evening before he had dined out with his friends where he had consumed a few alcoholic drinks followed by mild inebriation. He slept normally through the night and woke up in the morning with a headache and one episode of nonbilious vomiting. He felt a sense of warmth in his body which got relieved with 1 tablet of paracetamol 650 mg. There was no documented fever, vomiting, or a headache during the subsequent course of his clinical illness. By the afternoon, he started behaving abnormally. He was restless, confused, and disoriented. For these complaints, he was brought to the hospital. While in ER he passed urine in the bed before he could be catheterized. On examination, the patient was afebrile, vitals were normal, he appeared alert but confused, followed simple commands, moving all the four limbs but was restless and irritable not allowing any meaningful physical examination. Patients' GCS was E4V4 M6. Pupils were bilateral 3 mm, reacting to light. No pallor, icterus, cyanosis, goiter, neck vein engorgement or pedal edema was noticed on physical examination. Plantar reflexes elicited bilateral withdrawal response. There was no nystagmus or neck stiffness but had minimal tremors of limbs. Cardiovascular and respiratory systems were normal clinically. Per abdomen there was no organomegaly. There was no focal neurological deficit. No seizure activity was noticed. The patient was shifted to the Neurology ICU with the working Diagnosis of Acute Viral Encephalitis/Substance Abuse. NCCT of the brain was normal. Urine toxic screen came out to be negative for barbiturates, benzodiazepines, cannabinoids, cocaine, opiates, and phencyclidine. MRI brain revealed edema of Splenium of Corpus Callosum on diffusion weighted imaging (DWI) with subtle evidence of diffuse white matter edema [Figure 1]. Patient was sedated with 2 mg of midazolam, I/V access was secured and was started empirically on injection acyclovir, ceftriaxone, and I/v fluids. All through this period patient remained in a confused state of mind with incoherent vocalization in response to verbal commands. Portable bedside EEG was done at this stage which revealed continuous spike and wave discharges without any clinical seizure activity [Figure 2]. Occasional twitchings of facial muscles were noticed by the EEG technician while recording his EEG. Lumbar puncture for cerebrospinal fluid (CSF) examination was done by sedating the patient. Findings of CSF examination are tabulated in [Table 1].

Figure 1: Magnetic resonance imaging brain showing edema of the splenium of the corpus callosum (arrow)

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Figure 2: First electroencephalography after admission which clinched the diagnosis of nonconvulsive status epilepticus showed continuous spike and wave discharges

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Table 1: Cerebrospinal fluid findings in the case

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CSF was negative for autoimmune encephalitis/meningitis panel. ADA levels were within normal range, and India Ink preparation for Cryptococcus was negative. CSF cytology, biochemical analysis, gram staining, and culture were negative.

Other laboratory investigations [Table 2] were all normal except for mild elevation of serum ammonia.

Table 2: Laboratory Investigations

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Based on the clinical picture, EEG and magnetic resonance imaging (MRI) findings, antiepileptic drugs (dilantin sodium and sodium valproate) and dexamethasone were started, following which patient showed progressive improvement in sensorium and within 48 h was fully conscious, oriented, and coherently communicative. However, the patient had almost total amnesia from the time of his hospitalization until he became fully conscious. Repeat EEG [Figure 3] done after 48 hours of antiepileptic drugs was normal. The patient was discharged after 1 week, and he was without recurrence of any cognitive or behavioral symptoms during the follow-up period of 4 months. Repeat MRI of the brain done after 2 months showed the complete disappearance of edema of the splenium of corpus callosum and white matter.

Figure 3: Normal electroencephalography 48 h after being treated with Antiepileptic drugs

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Discussion

In short, our patient was a young adult male who presented with an acute-onset confusional state and altered behavior without any focal neurological deficit, clinical seizures, or unequivocal clinical evidence of meningitis or encephalitis. Although he had consumed a few alcoholic drinks 10–12 h before the onset of this illness, his other friends who shared the same drinks and food had no problem of this nature. The initial suspicion of possible substance abuse was ruled out because the urine toxic screen was negative for commonly abused drugs [Table 2]. NCCT head was unremarkable. MRI brain without gadolinium showed evidence of edema of the splenium of corpus callosum with DWI restriction and subtle evidence of diffuse white matter edema, but there was no evidence of any focal pathology in the brain. CSF examination, including autoimmune panel, CSF-PCR for tuberculosis and India Ink preparation for cryptococcus were negative and were not suggestive of any definite neurological diagnosis. All the routine laboratory investigations [Table 2] were normal except mild elevation of serum ammonia (<3 times the ULN). Serology for leptospirosis was also negative. In fact, it was EEG [Figure 1] done on the 2^nd day of illness which clinched the diagnosis of NCSE. There was mild pleocytosis in the CSF with a total count of 95 cells/cmm with lymphocyte predominance, elevated CSF protein with normal glucose suggestive of an acute encephalitic illness underlying the NCSE in our patient. He was treated with intravenous acyclovir for 2 weeks and discharged on antiepileptic drugs.

Transient lesions of the splenium of corpus callosum in MRI as seen in our patient have been well documented in the literature.^[8] They have two distinct patterns, well circumscribed, small, oval lesions in the midline within the substance of the corpus callosum and more extensive ill-defined irregular lesions extending throughout the splenium and into the adjacent hemispheres (boomerang sign). The former lesions are generally seen in the setting of seizures/cessation of antiepileptic medication, whereas the larger lesion is more typical of other etiologies.

Furthermore, the mild elevation of serum ammonia observed in our patient has been well described in literature in the setting of seizure status.^[9] However, the main question in this patient, whether it was the NCSE per se or NCSE triggered by an underlying encephalitic illness which was responsible for his cognitive and behavioral state, especially in the light of CSF findings. It has long been reported that a CSF pleocytosis may be observed in 2%–20% of patients after the occurrence of one or more epileptic seizures without an identified underlying brain process. CSF pleocytosis was first reported after the occurrence of seizures in 1926 by Patterson and Levi^[10] and other reports soon followed.^[11],[12] Some of these reports suggested that CSF pleocytosis tends to follow repeated or prolonged seizures.^[13],[14] However, many of these observations were made at a time when the modalities for diagnosing brain diseases with modern neuro-imaging techniques like MRI, improved diagnostic modalities for central nervous system (CNS) infections and recognition of autoimmune encephalitis with the use of molecular techniques were not available.

A recent study and systematic literature review of literature by Carly Scramstad and Jackson^[15] reveals that seizure per se may be the cause of CSF pleocytosis only in a minority of cases. In their retrospective study in a critical care population, they identified 51 patients over a 4-year period with seizures in whom postictal CSF analyses had been done. They did not find a single case of CSF pleocytosis in which the seizures themselves were the only identified probable cause of the pleocytosis. It is well known that the prognosis of the patients with NCSE is determined by the effective management of the underlying etiology of NCSE. It is better in patients who have no identifiable organic CNS abnormality.

Mechanism of CSF pleocytosis in seizure is still not clearly understood. Although blood brain barrier (BBB) dysfunction with seizures is very well-documented, yet the available evidence does not provide an explanation for the presence of cells in the CSF.^[16]

In fact, one study showed that “neither acute-induced nor chronic seizures correlate with WBC brain parenchymal migration while albumin and IgG brain leakage is a hallmark of acute and chronic seizures,” implying thereby that BBB dysfunction with seizures is sufficient to lead to extravasation of smaller molecules, but not of larger blood components such as cells.^[17]

Conclusion

Although there is unequivocal evidence of NCSE as well as CSF pleocytosis and protein elevation suggestive of acute encephalitic illness in our patient, yet there was no characteristic evidence on MRI of herpes simplex encephalitis or any other focal neurological illness. His dramatic clinical improvement after the control of electrographic seizures supports NCSE as the primary cause of his symptoms. Quick response to anti-epileptics further lends support to the impression that it was NCSE which was responsible for the acute confusional state and behavioral manifestations in our patient, though an unspecified mild encephalitic illness and/or consumption of alcohol could have acted as background triggers for NCSE in this patient. The issue whether CSF pleocytosis can occur due to NCSE per se remains unresolved and further research on this topic is on.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

None.

Conflicts of interest

There are no conflicts of interest.

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