From the Guidelines
Yes, a patient can be conscious and experience a focal seizure limited to one arm. Focal seizures, as described in the 2024 American Heart Association and American Red Cross guidelines for first aid 1, affect only one area of the brain and can present as jerking of only one extremity or one side of the body, with or without changes in consciousness. According to the International League Against Epilepsy (ILAE) classification, focal seizures can be further characterized by having motor onset or nonmotor onset symptoms and can also be characterized by being aware or having impaired awareness 1.
Key Characteristics of Focal Seizures
- Affect only one part of the brain
- Can manifest with symptoms restricted to a specific body part, such as one arm
- Patients often remain fully conscious and aware of what is happening
- Symptoms may include involuntary jerking or twitching movements, unusual sensations like tingling or numbness, or weakness in the affected arm
- Typically last seconds to minutes and reflect abnormal electrical activity in the part of the brain that controls arm movement (the contralateral motor cortex)
Importance of Medical Attention
If someone experiences a focal seizure for the first time, they should seek medical attention promptly as it could indicate an underlying neurological condition requiring evaluation with tests like EEG or brain imaging. Treatment usually involves anti-seizure medications, with dosing tailored to the individual 1.
Treatment Options
- Anti-seizure medications such as levetiracetam (Keppra), carbamazepine (Tegretol), or lamotrigine (Lamictal)
- Dosing tailored to the individual
- Evaluation with tests like EEG or brain imaging to determine the underlying cause of the seizure.
From the Research
Focal Seizures and Consciousness
- Focal seizures can be classified into two types: Focal Impaired Consciousness Seizures (FICS) and Focal Aware Conscious Seizures (FACS) 2
- FACS are characterized by preserved consciousness during the seizure, and can manifest as focal seizures limited to one arm, such as focal akinetic seizures 3
- Focal akinetic seizures are a type of FACS that involve ictal paresis of the contralateral arm during preserved consciousness, and are likely due to epileptic activation of negative motor areas 3
Clinical Evidence
- A study published in 1999 documented three patients with focal akinetic seizures, which were characterized by ictal paresis of the contralateral arm during preserved consciousness, using EEG and video recordings 3
- The study suggested that focal akinetic seizures are probably due to epileptic activation of negative motor areas, and can occur in patients with frontal or central foci 3
- Another study published in 2021 compared the efficacy and tolerability of different anti-seizure medications for focal epilepsy, but did not specifically address the question of consciousness during seizures 4
- A 2021 study compared the clinical effectiveness and cost-effectiveness of lamotrigine, levetiracetam, and zonisamide for focal epilepsy, and found that lamotrigine was superior to levetiracetam and zonisamide in terms of time to 12-month remission and time to treatment failure 5
Seizure Classification
- The ILAE 2010 report does not classify focal seizures, but instead uses descriptors to distinguish focal seizures with versus without impaired consciousness 2
- The classification of focal seizures into FICS and FACS is based on the level of consciousness during the seizure, and can be useful for distinguishing between different types of focal seizures 2
- Focal akinetic seizures are a type of FACS that can be documented using EEG and video recordings, and are characterized by ictal paresis of the contralateral arm during preserved consciousness 3