Generalized periodic discharges with triphasic morphology

Screening of toxic-metabolic encephalopathy with and without epileptic seizure with density spectral array

OBJECTIVE

Although toxic metabolic encephalopathy (TME) is clinically common, distinguishing between TME with/without epileptic findings remains challenging. We examined the efficacy of density spectral array (DSA), a form of power-spectrum electroencephalography (EEG) screening tool, for clinicians not specializing in EEG interpretation to make this distinction.

METHODS

Among 346 patients with suspected TME who underwent EEG for acute impaired consciousness (2012-2023), 149 were ultimately diagnosed with TME (mean age 68.9 ± 13.3 years) were enrolled. Using EEG data, we operationally classified DSAs based on frequency changes, as follows: 1) flame or cyclic (presence of temporal frequency change), 2) band (presence of continuous alpha-range activity), 3) gradation (alpha to delta-range activity), and 4) other patterns. The inter-rater agreement rate for DSA pattern assignment was evaluated in a double-blind manner to confirm the reasonableness of the classification. Additionally, we evaluated the sensitivity and specificity of each DSA pattern at determining the ultimate diagnostic outcomes (TME alone or TME with epileptic findings).

RESULTS

TME alone and TME with epileptic findings were 136 and 13, respectively. The inter-rater agreement for DSA classification was high among clinicians (κ = 0.72-0.92). The flame or cyclic pattern exhibited high specificity (97.1 %), but low sensitivity (23.1 %) for the diagnosis of TME with epileptic findings. Conversely, the band and gradation patterns showed a high specificity (76.9-84.6 %) for the diagnosis of TME alone.

CONCLUSIONS

Overall, our DSA classification demonstrated a high inter-rater agreement rate, indicating utility as a simple yet specific tool for distinguishing TME with and without epileptic findings.

The electroencephalogram in the diagnosis and classification of status epilepticus: a practical guide

Status epilepticus is a serious neurological emergency requiring swift recognition and treatment. Presentations with prominent motor features are easily recognised but it can be challenging to diagnose those with subtle or no motor features. Electroencephalogram (EEG) remains indispensable in diagnosing, classifying, monitoring and prognosticating of status epilepticus. There are several separate classification systems for seizures, epilepsy and status epilepticus, incorporating clinical features, causes and EEG correlates. This review focuses on using EEG in status epilepticus and provides a practical approach to diagnosis and classification aligning with the current International League Against Epilepsy and American Clinical Neurophysiology Society definitions.

Sporadic Creutzfeldt-Jakob Disease in the young (50 and below): 10-year review of United Kingdom surveillance

INTRODUCTION

Sporadic Creutzfeldt-Jakob Disease (sCJD) is the commonest human prion disease, with a median age of onset of 68 years. We characterise the clinical, investigation, and neuropathological features in young individuals with sCJD using data from UK national CJD surveillance.

METHODS

Referrals between 2011 and 2021 were examined, with definite (post-mortem confirmed) or probable sCJD cases included. Clinical features, MRI, EEG, CSF RT-QuIC, 14-3-3, PRNP sequencing and neuropathological findings were examined. We compared younger (≤ 50 years age of onset) with older individuals. Records of Non-sCJD referrals were also reviewed.

RESULTS

46 (4%) young individuals were identified (age at onset 25-50) from 1178 cases. 15 (33%) were autopsy confirmed. Psychiatric disturbance (37% vs 22%, p = 0.02) and headache (11% vs 3%, p = 0.01) at presentation, and longer disease duration (by 1.45 months, 95% CI 0.43-2.79, logrank p = 0.007) were commoner. CSF RT-QuIC showed lower sensitivity (82% vs 93%, p = 0.02). There was no difference in sensitivity of MR brain or CSF 14-3-3. There were no significant co-pathologies in autopsy-confirmed cases. For non-sCJD referrals, 41 cases were of other CJD subtypes, and 7 non-prion diagnoses.

CONCLUSIONS

Young-onset sCJD is more likely to present with neuropsychiatric symptoms and headache, longer disease duration, and lower sensitivity of RT-QuIC. These findings may be driven by the underlying molecular subtypes. Our results guide the evaluation of younger individuals presenting with rapidly progressive cognitive, neuropsychiatric, and motor decline, and emphasise the need for additional vigilance for atypical features by clinicians and CJD surveillance programmes worldwide.

The Clinical Neurophysiology of COVID-19- Direct Infection, Long-Term Sequelae and Para-Immunization responses: A literature review

The COVID-19 pandemic resulting from the SARS-CoV-2 virus is in its third year. There is continuously evolving information regarding its pathophysiology and its effects on the nervous system. Clinical neurophysiology techniques are commonly employed to assess for neuroanatomical localization and/or defining the spectrum of neurological illness. There is an evolving body of literature delineating the effects of the SARS-CoV-2 virus on the nervous system as well as para-immunization responses to vaccination against this virus. This review focuses on the use of neurophysiological diagnostic modalities in the evaluation of potential acute and long-term neurological complications in patients that experience direct infection with SARS-CoV-2 and analyzes those reports of para-immunization responses to vaccination against the SARS-CoV-2 virus. The neurophysiological modalities to be discussed include electroencephalography (EEG), evoked potentials (EPs), nerve conduction studies and electromyography (EMG/NCV), autonomic function tests, transcranial magnetic stimulation (TMS) and Transcranial Doppler ultrasound (TCD).

Neurological Emergencies in Patients Hospitalized With Nonneurological Illness

OBJECTIVE

We aimed to present neurological profiles and clinical outcomes of patients with acute neurological symptoms, which developed during hospitalization with nonneurological illness.

METHODS

We organized the neurological alert team (NAT), a neurological rapid response team, to manage in-hospital neurological emergencies. In this registry-based study, we analyzed the clinical profiles and outcomes of patients who were consulted to the NAT. We also compared the 3-month mortality of patients with acute neurological symptoms with that of patients without acute neurological symptoms.

RESULTS

Among the 85,507 adult patients, 591 (0.7%) activated the NAT. The most common reason for NAT activation was stroke symptoms (37.6%), followed by seizures (28.6%), and sudden unresponsiveness (24.0%). The most common diagnosis by the NAT neurologists was metabolic encephalopathy (45.5%), followed by ischemic stroke (21.2%) and seizures or status epilepticus (21.0%). Patients with NAT activation had high rates in mortality before hospital discharge (22.5%) and at 3 months (34.7%), transfer to intensive care units (39.6%), and length of hospital stay (43.1 ± 57.1 days). They also had high prevalence of poor functional status (78.1%) and recurrence of neurological symptoms at 3 months (27.2%). In a Cox proportional hazards model, patients with in-hospital neurological emergencies had a hazard ratio of 13.2 in terms of mortality at 3 months (95% confidence interval, 11.5-15.3; P < 0.001).

CONCLUSIONS

Occurrence of acute neurological symptoms during hospital admission was associated with high rate of mortality and poor functional status. These results call for enhanced awareness and hospital-wide strategies for managing in-hospital neurological emergencies.