Multiple Sclerosis (MS) is a chronic neurological condition that affects the brain and spinal cord, collectively known as the central nervous system. It involves the immune system mistakenly attacking the protective myelin sheath covering nerve fibers, leading to communication problems between the brain and the rest of the body. While MS can manifest with a wide range of symptoms, seizures can occur in individuals living with the condition, though they are not among the most common manifestations. Recognizing this connection is important for comprehensive management of MS.
The MS-Seizure Connection
Individuals with MS experience a slightly elevated risk of seizures compared to the general population. While the prevalence of epilepsy in the general U.S. population is 1.2%, it is estimated to be 2% to 5% in people with MS. This suggests that while seizures are not a universal symptom, their likelihood is increased in the context of MS.
Seizures in MS are a direct symptom of the disease process. They can sometimes be one of the initial signs of MS before a diagnosis is made. The timing of seizure onset can vary, sometimes occurring during MS flare-ups, though they can also happen independently of disease relapses.
Mechanisms Behind Seizures in MS
Pathological changes within the brain can lead to seizures in MS. Multiple sclerosis causes demyelination, which is the loss of the myelin sheath, and inflammation, leading to the formation of lesions in the brain and spinal cord. These lesions can disrupt the normal electrical signaling pathways of the brain.
Seizures arise from abnormal electrical discharges in the brain, originating in the cortex, or gray matter. While MS is primarily known as a white matter disease, there is an overlap between white and gray matter. Lesions in cortical or juxtacortical regions can directly affect the gray matter, creating areas of neuronal hyperexcitability that can trigger seizures. This disruption in signal transmission can lead to widespread disarray in brain activity, increasing the risk of abnormal electrical events.
Identifying Seizure Activity in MS
Seizures can present in various ways, and their manifestations may sometimes be subtle or mimic other MS symptoms. Common types of seizures include focal (or partial) seizures, which originate in one area of the brain, and generalized tonic-clonic seizures, which involve both sides of the brain and can cause loss of consciousness and involuntary jerking movements. Focal seizures, particularly focal aware and focal impaired awareness types, are common in MS, accounting for about 60-70% of cases.
It is important to distinguish epileptic seizures from other involuntary movements or paroxysmal symptoms common in MS, such as tonic spasms, choreoathetosis, or sudden sensory distortions, which are not epileptic in nature but can resemble seizures. Accurate observation and a thorough medical evaluation are important for proper diagnosis. Observing details like loss of consciousness, body stiffening, rhythmic jerking, confusion, or changes in awareness can help differentiate seizure activity.
Treatment Approaches for Seizures in MS
Diagnosing seizures in MS involves evaluating the individual’s clinical history and conducting tests such as an electroencephalogram (EEG), which records the brain’s electrical activity. Magnetic Resonance Imaging (MRI) is used to identify brain lesions contributing to seizure activity. Differentiating seizures from other MS-related symptoms is an important part of the diagnostic process.
Treatment for seizures in MS involves anti-seizure medications (ASMs), also known as antiepileptic drugs. The choice of medication depends on the specific seizure type and considers potential interactions with existing MS treatments. While some older ASMs are used, newer medications are preferred due to their favorable side effect profiles and limited interactions with MS disease-modifying therapies. The goal of treatment is to control seizures, and individuals work closely with a neurologist to manage their condition.