Diagnosis and treatment of temporomandibular epilepsy

Post by Master, Doctor Truong Van Tri - Head of Functional Neurosurgery Unit - Department of General Surgery - Vinmec Central Park International General Hospital

Temporal lobe epilepsy affects human's emotional processing function, short-term memory. Patients with this disease will appear symptoms: excitement, fear, anxiety, ... So how is the diagnosis and treatment of temporal epilepsy?

Temporal epilepsy is the most common partial epilepsy, on average 6 out of 10 people with partial epilepsy have temporal lobe epilepsy. Seizures in temporal lobe epilepsy involve 1 or 2 temporal lobes of the brain. There are two types of temporal lobe epilepsy:
Mesial temporal epilepsy involving the medial temporal lobe structures. Seizures usually begin in the hippocampus or the area around the hippocampus. This type of epilepsy accounts for 80% of all temporal lobe epilepsy types. Lateral temporal epilepsy involves the lateral structures of the temporal lobe. Medial temporal lobe epilepsy usually begins at age 10 or 20, but can have onset at any age. Medial temporal lobe epilepsy is often associated with changes or abnormalities in the temporal lobe. One of the most common abnormalities is scarring in the medial temporal lobe, called hippocampal sclerosis. On MRI, the hippocampus on one side, or both sides, is atrophied.

Seizures in temporal lobe epilepsy may present as auras and focal cognitive impairment.
Auras are the first symptoms of a seizure. The most common manifestation is a feeling of hallucinating memories (also known as déjà-vu: a sense of familiarity with an event or environment that has not been experienced) or upset stomach. Feelings of fear, anxiety, a feeling of rising from the stomach to the chest or throat, hangover, restlessness with nausea are other common phenomena. Some people can perceive an unusual smell. This symptom is highly suggestive of the possibility that the patient has a lesion or tumor in the hippocampus. Sometimes auras can be very difficult to describe.
Focal impaired awareness seizures are also called complex partial seizures. During this type of seizure, the person may appear dazed, lose consciousness, or be confused about what is going on around them, fidgeting with their fingers, or smacking their lips. Seizures last from 30 seconds to several minutes.
There may be abnormal posture or movement of the arm. Some people slurred or lost the ability to speak, and language problems often occur if the seizure comes from the dominant temporal lobe.
Focal seizures may turn into generalized tonic-clonic seizures. Some people may also experience prolonged seizures. Seizures can be repetitive or prolonged, a condition known as status epilepticus.
Seizures in lateral temporal lobe epilepsy often begin with auditory auras, such as humming or hearing a specific sound.

Traumatic brain injury, infection (such as encephalitis or meningitis) Changes in the structure of the temporal lobe, such as a brain malformation or tumor The most common risk factor is febrile seizures . About 2 out of 3 people with temporalis epilepsy have a history of febrile seizures. Three out of four of these had febrile seizures that were either prolonged or had complex features. However, it is important to note that the majority of people with febrile seizures do not develop temporal lobe epilepsy.

Temporal lobe epilepsy is a clinical diagnosis. This means that several factors need to be combined to arrive at a diagnosis. A single test cannot diagnose temporal lobe epilepsy. Tests for epilepsy include brain MRI to look for temporal lobe abnormalities and EEG (usually spikes will be seen at the apex or anterior of the temporal lobe).

Epilepsy is a disease characterized by recurrent, often spontaneous, seizures. Without treatment, seizures can lead to fall injury, memory and cognitive impairment, or even death.
5.1. Drug Treatment The first-line treatment for epilepsy is an antiepileptic drug (AED). Many patients with temporal lobe epilepsy can control their seizures with an AED. However, about one-third of patients with epilepsy still have seizures despite multiple AEDs. If 2 appropriate AEDs, alone or in combination, have failed to control seizures, the patient is considered drug-resistant and cannot control seizures by medical alone. Treatment-resistant patients should be referred to an epilepsy center to consider the possibility of surgery to stop or reduce the frequency of seizures.
5.2. Surgery For epilepsy that cannot be controlled with medication, surgery may be an option. If an MRI shows damage to the temporal lobe and an EEG shows that seizures begin in that area, the epilepsy can be cured with surgery. If necessary, other tests to confirm the seizure focal point, such as magnetoencephalography, PET scan, SPECT, or invasive EEG may be performed. However, these are advanced tests and techniques that are not easily accessible in developing countries.
Surgery can help 70-80% of patients with temporal lobe epilepsy due to hippocampal fibrosis stop convulsions and leave no serious sequelae after surgery (Figure 2).

If surgery is not possible or ineffective, neuromodulation such as vagus nerve stimulation (Figure 3) or responsive neurostimulation may be used. . The goal of neuromodulation is to reduce the frequency of seizures (30-50%), this method very rarely helps to stop seizures.

Patients with epilepsy who do not respond to 2 or more epilepsy drugs are considered treatment-resistant epilepsy and should be evaluated in an epilepsy center to consider the possibility of surgery for the patient. Scientific evidence shows that surgery is effective in the treatment of middle temporal lobe epilepsy. Neuromodulation for the treatment of epilepsy rarely helps patients to stop convulsions, the main purpose of which is to reduce the frequency of seizures.

References:
Kyle I. Swanson et al., Epilepsy, Functional Neurosurgery, and Pain , Operative Neurosurgery, Volume 17, Issue Supplement_1, August 2019, Pages S209–S228. Epilepsy Foundation, Temporal Lobe Epilepsy , epilepsy.com