What is the significance of an electroencephalogram (EEG) showing sharp waves in the left temporal region, indicating a discharging epileptiform focus, in a patient experiencing episodic right hand shaking?

From the Guidelines

The patient's episodic right hand shaking is likely caused by focal seizures originating from the left temporal region, and treatment should begin with an antiepileptic medication such as levetiracetam (Keppra) at a starting dose of 500mg twice daily, gradually increasing to 1000-1500mg twice daily as tolerated, as recommended by the most recent guidelines 1. The EEG findings of sharp waves in the left temporal region, confirmed by digital spike analysis, indicate a focal epileptogenic zone in this area. This presentation is consistent with focal seizures originating from the left motor cortex, which controls the right side of the body. Some key points to consider in the management of this patient include:

• The use of intermittent electroencephalography (EEG) to detect epileptic activity in patients with clinical seizure manifestations, as recommended by the European Resuscitation Council and European Society of Intensive Care Medicine 1.
• The potential for myoclonus to be mistaken for seizures, and the importance of distinguishing between these two conditions, as noted in the consensus summary statement of the International Multidisciplinary Consensus Conference on Multimodality Monitoring in Neurocritical Care 1.
• The recommendation to treat seizures in post-cardiac arrest patients, despite the lack of high-level evidence, as stated in the 2023 American Heart Association focused update on adult advanced cardiovascular life support 1. The patient should keep a seizure diary documenting frequency, duration, and characteristics of episodes to monitor treatment effectiveness. Triggers like sleep deprivation, alcohol, and stress should be avoided. Follow-up EEG monitoring in 3-6 months is recommended to assess treatment response. If seizures persist despite adequate medication trials, referral to an epilepsy specialist for consideration of additional treatments or surgical evaluation may be necessary. The correlation between the left temporal EEG abnormalities and right-sided symptoms follows the principle of contralateral brain control of motor function.

From the Research

EEG Findings and Epilepsy Diagnosis

• The patient's EEG shows few sharp waves in the left temporal region, indicating a discharging relatively inactive epileptiform focus within this region, as confirmed by digital spike analysis 2.
• This finding is consistent with the diagnosis of epilepsy, a heterogeneous disorder often associated with abnormal EEG findings 2.

Patient Symptoms and Epilepsy

• The patient's symptoms include episodic right-hand shaking, which may be related to the epileptiform focus in the left temporal region 2.
• Epilepsy is a common neurological condition with a worldwide prevalence of around 1%, and approximately 60% to 70% of people with epilepsy will achieve a longer-term remission from seizures 3.

Treatment Options for Epilepsy

• The patient may benefit from antiepileptic drug (AED) treatment, with options including carbamazepine, lamotrigine, and levetiracetam 3, 4.
• Levetiracetam has been shown to be effective in achieving seizure freedom, with a superior seizure-freedom rate compared to carbamazepine and lamotrigine 4.
• The choice of AED treatment should be individualized, taking into account the patient's specific needs and medical history 3, 5.

Monitoring and Follow-up

• Continuous EEG monitoring may be useful in diagnosing and treating subclinical seizures and nonconvulsive status epilepticus 2.
• Regular follow-up appointments with a healthcare provider are essential to monitor the patient's response to treatment and adjust the treatment plan as needed 5, 4.