Saturday, June 15, 2024
HomeNeurologyTemporal Lobe Epilepsy

Temporal Lobe Epilepsy

Practice Essentials

Temporal lobe epilepsy (TLE) was defined in 1985 by the International League Against Epilepsy (ILAE) as a condition characterized by recurrent, unprovoked seizures originating from the medial or lateral temporal lobe. The seizures associated with this condition consist of simple partial seizures without loss of awareness, now categorized as focal aware seizures, and complex partial seizures (ie, with loss of awareness), now called focal impaired awareness seizures. Secondarily generalized seizures are now called focal to bilateral tonic-clonic seizures under the updated 2017 ILAE classication.
 Temporal lobe epilepsy is a common type of epilepsy that is sometimes difficult to diagnose, but once diagnosed it can be effectively treated with medications. Medically intractable temporal lobe epilepsy is amenable to epilepsy surgery with a very high seizure-free rate.

Signs and symptoms

Common features of temporal lobe epilepsy include the following:

Memory impairment

Aura (now called focal aware)

Auras/focal aware may be classified by symptom type, as follows:

Sensory – auditory, gustatory, hot-cold sensations, olfactory, somatosensory, vestibular, visual

Autonomic – Heart rate Change (asytole, bradycardia, palpitations, tachycardia), flushing, gastrorintestinal, pallor, piloerection, respiratory

Cognitive/psychic – Déjà vu or jamais vu, dissociation, depersonalization or derealization, forced thinking, aphasia/dysphasia, memory

Emotional/affective – agitation, aggression, anger, anxiety, fear, paranoia, pleasure, crying (dacrystic) or laughing 

Features of temporal lobe complex partial seizure may include the following:

Aura/focal ware

Motionless stare, dilated pupils, and behavioral arrest

Automatism – Oral-facial, eye blinking, alimentary, manual  or unilateral dystonic limb posturing, perserveration, vocalization/speech

Possible evolution to a secondarily generalized tonic-clonic seizure, now called bilateral tonic clonic

Postictal period that can include confusion, aphasia, or (by definition) amnesia

See Presentation for more detail.

Diagnosis

A good history and physical is tantamount for diagnosis of TLE.  Diagnostic modalities that may be considered include the following:

Magnetic resonance imaging (MRI); the neuroimaging modality of choice for temporal lobe epilepsy, especially coronal cuts

Computed tomography (CT); poor resolution compared to that of MRI, but is strong for calcified lesion(s)

Positron emission tomography (PET); useful for interictal seizure localization in surgical candidates when MRI is normal

Single-photon emission CT (SPECT); adjunctive imaging modality useful for surgical candidates, when done as ictal study 

Magnetic resonance spectroscopy( MRS); of some use in trying to evaluate lesion for neoplastic signal

Electroencephalography (EEG); indicated in all patients with suspected temporal lobe epilepsy

Magnetoencephalography (MEG); mainly used for coregistration with MRI to give magnetic source imaging in 3-dimensional space

See Workup for more detail.

Management

Older antiepileptic drugs (AEDs) used for seizure control in temporal lobe epilepsy have some long-term side effects and require lab monitoring:

Phenytoin

Carbamazepine

Valproate

Phenobarbital

Newer AEDs appear to be comparably effective but with fewer side effects and don’t requre lab monitoring for the most part:

Gabapentin

Pregabalin

Topiramate

Lamotrigine

Levetiracetam

Oxcarbazepine

Zonisamide

Lacosamide

Briviacetam

Clobazam 

Rufinamide

Perampanel

Vigabatrin (for intractable)

Felbamate (for intractable)

Nonpharmacologic treatments for temporal lobe epilepsy are as follows:

Vagus nerve stimulation (VNS; approved for treatment of intractable partial epilepsy in patients aged 4 years and older)

Responsive neurostimulation (RNS; stimulation of seizure focus when seizure occurs is the goal)

Deep brain stimulation (DBS; awating FDA approval but is available in other countries) 

Temporal lobectomy (the definitive treatment for medically intractable temporal lobe epilepsy with high seizure-free rate)

Dietary therapies are adjunctive such as ketogenic diet and Modified Atkins diet

See Treatment and Medication for more detail.

RELATED ARTICLES
- Advertisment -

Most Popular