Mesial temporal sclerosis (MTS) is a common cause of structural epilepsy, particularly linked to focal seizures originating in the temporal lobe. It affects a specific area deep within the brain, often leading to recurring seizures.
Understanding Mesial Temporal Sclerosis
Mesial temporal sclerosis (MTS) describes scarring and neuronal cell loss in the deep part of the brain’s temporal lobe, most notably affecting the hippocampus and, at times, the amygdala. These structures play a role in memory formation and emotional processing. MTS is strongly associated with temporal lobe epilepsy (TLE), with 70% to 80% of individuals with TLE showing some degree of MTS.
The onset of seizures related to MTS typically occurs around age 10 to 20, though it can manifest at any age. While the exact cause is not always clear, several factors are thought to contribute to its development. These include prolonged febrile seizures in childhood, brain injury, infections, and a lack of oxygen to the brain. Genetic predispositions may also play a role in some instances. Identifying MTS usually involves magnetic resonance imaging (MRI) scans, which can reveal characteristic findings such as reduced hippocampal volume and abnormal signal intensity in the affected area.
Treatment Approaches
Treatment for mesial temporal sclerosis primarily focuses on managing and reducing seizures. The initial approach involves medical management through anti-seizure medications. These medications aim to control seizure activity, but they address the symptoms rather than reversing the underlying brain scarring. For many individuals with MTS, however, seizures can become drug-resistant, meaning medications alone are not sufficient to achieve seizure freedom.
When medications are ineffective, surgical options are often considered, offering a more direct intervention for drug-resistant epilepsy. Resective surgery, such as anterior temporal lobectomy (ATL), is a common procedure where the portion of the temporal lobe identified as the seizure origin is removed. Another approach is selective amygdalohippocampectomy (SAH) specifically targets the hippocampus and amygdala. Minimally invasive techniques, such as laser interstitial thermal therapy (LITT), are also available, using heat to ablate the affected brain tissue. The goal of these surgical interventions is to achieve seizure freedom.
Defining “Cure” and Long-Term Outcomes
In MTS, “cure” typically means sustained seizure freedom after effective treatment. While the underlying scar tissue is not reversed, successful surgery can eliminate the source of seizures, allowing individuals to live without them.
Surgical outcomes for MTS show a high probability of achieving long-term seizure freedom. Studies show that 58% to 80% of patients undergoing anterior temporal lobectomy (ATL) achieve seizure freedom. For laser interstitial thermal therapy (LITT), seizure freedom rates are reported between 55% and 65%, though long-term data are still emerging. While many patients achieve seizure freedom, the probability of remaining seizure-free can gradually decline over many years; for example, approximately 56% remain seizure-free 10 years after being seizure-free for the first year post-surgery.
Surgery, while effective, can be associated with certain changes. Some individuals may experience cognitive changes, such as a decline in verbal memory, particularly after left-sided temporal lobectomy. However, improvements in memory functions linked to the non-operated side can also occur. Despite these potential changes, successful surgery often leads to improvements in overall quality of life.
Living with Mesial Temporal Sclerosis
Living with mesial temporal sclerosis, whether seizures are controlled or ongoing, involves continuous attention to health and lifestyle. Ongoing neurological care is important, including regular follow-ups with healthcare professionals. Adherence to prescribed treatment plans, whether medication or post-surgical monitoring, plays a role in maintaining well-being.
Adjustments to daily habits can also contribute to managing the condition and improving quality of life. Maintaining adequate sleep, for example, is often advised, as sleep deprivation can be a seizure trigger. Managing stress through various techniques and incorporating regular physical activity can also support overall health. Engaging with support groups and utilizing mental health resources can provide valuable assistance in navigating the challenges associated with epilepsy.