Temporal Lobe Epilepsy
With our previous articles, many of you might now have an idea of what epilepsy is and how to categorize it. Among the different types of epilepsies, let’s learn about the commonest and one of the most interesting types of epilepsies, Temporal Lobe Epilepsy. Before getting into the diagnosis and treatment of the disease, let us dive into the functions of the temporal lobe.
Temporal lobe: Your Memory Center
The temporal lobe is the second largest lobe among the 4 major lobes in the brain. It is located on either side of the head, behind the ears. The main functions of the temporal lobe center around auditory stimuli, memory, and emotion. The temporal lobe’s role in auditory stimuli includes perceiving sounds, assigning meaning to those sounds, and remembering sounds. In memory formation, the temporal lobe acts to form visual memory and long-term memory. Apart from this the temporal lobe also helps in the perception of speech and recognition of language.
What causes Temporal Lobe Epilepsy?
Temporal lobe epilepsy can be caused by many different factors. Trauma to the temporal lobe, strokes, infections like meningitis or encephalitis, or inflammation of the temporal region like autoimmune encephalitis can lead to Temporal lobe epilepsy. Also, facing a febrile seizure during childhood that had lasted for more than 30min can cause scarring of the temporal lobe which would eventually lead to recurrent temporal lobe seizures in the future.
How does Temporal Lobe Epilepsy Present?
Temporal lobe epilepsy can occur with or without losing awareness. Most temporal lobe epilepsies are preceded by an aura. An aura is an unusual sensation that you feel before a seizure starts. The aura usually lasts from a few seconds to 1-2 minutes. Aura can range from a sudden sense of joy or fear, a sudden sense of strange odor or taste to a sudden rising sensation in the abdomen like riding a rollercoaster. The patient may also experience a familiar feeling (deja vu) or everything not familiar at all (jamais vu) before the onset of the seizure. Temporal lobe seizures usually last from 30 seconds to 2 minutes. Temporal lobe seizures are depicted through many symptoms like Staring into space” or a blank stare, repetitive behaviors and movements (called automatisms) of your hands (such as fidgeting, picking motions), eyes (excessive blinking), and mouth (lip-smacking, chewing, swallowing), confusion of the patient. Also, as the speech area in the temporal lobe is affected it can lead to a brief loss of ability to speak, read, or comprehend speech or the patient may speak nonsensical words. In some cases, seizures that started from one temporal lobe may rapidly move around to the other lobe or the whole brain. This is result in generalized body shaking which is known as bilateral tonic-clonic seizures (previously known as grand mal seizures).
How to Diagnose Temporal Lobe Epilepsy?
Like other diseases taking a detailed history with examination can help with the diagnosis. Taking a video during a seizure attack would provide a part of the needed history. Additionally, investigations can be done to arrive at the diagnosis. MRI of the brain can detect any tumors or structural anomalies in the brain. Epilepsy protocol MRI which is a specific MRI for epilepsy can be done to diagnose temporal lobe epilepsy. Thin cuts through the temporal lobe are recorded which an experienced neuroradiologist may be able to read. Furthermore, an EEG test can be done, which is a brainwave examination where wires are attached to the brain and brain activity is recorded. Through abnormal readings of brain activity, temporal lobe seizures can be detected.
What are Available Treatment Options for Temporal Lobe Epilepsy?
Nowadays with the advancement in medicine, there are several treatment options available for epileptic patients. Usage of anti-epileptic drugs is the commonest method used. There are different anti-epileptic drugs used namely, Levetiracetam (Keppra), Valproic acid, and Lamotrigine. Dosage and drugs used differ according to the patient. Although Keppra is one of the most commonly used anti-epileptic medications, it can cause worsening of psychiatric symptoms. Therefore, Keppra is not prescribed for patients with pre-existing psychiatric conditions like PTSD, Depression, and Anxiety or has a family history of anxiety or depression. Valproic acid and Lamotrigine are better options for such patients. Sometimes medical treatment may not work due to drug-resistant epilepsy. In these instances, surgical treatments can be used where a small portion of the brain in which the seizure originates is cut out which is usually the site of a tumor, brain injury, or malformation. There are other treatment methods available such as Responsive neurostimulation (RNS) where a device is implanted over the seizure area which stimulates the brain when seizures are detected. Other devices include Vagus Nerve Stimulation (VNS) or Deep Brain Stimulation (DBS). Apart from these methods, laser ablation (LITT) is used to treat epilepsy is under clinical trials. With time it may be one of the main treatment options for epilepsy.
To summarize, temporal lobe epilepsy is the commonest type of epilepsy where the patient presents with many symptoms like unusual speech and staring into space. These symptoms may be preceded by aura. To diagnose temporal lobe epilepsy MRI, EEG can be used. To treat epilepsy, there are medical interventions and surgical interventions available.