[10] These types of TLE are very rare due to the genetic cause or lesions such as tumor, birth defect, blood vessel abnormalities in the temporal lobe.

[10][2] The common mesial temporal lobe seizure auras include a rising epigastric feeling, abdominal discomfort, taste (gustatory), smell (olfactory), tingling (somatosensory), fear, déjà vu, jamais vu, flushing, or rapid heart rate (tachycardia).

[15][16][14]: 71  Mesial temporal lobe epilepsy arising from the language dominant hemisphere impairs verbal memory, and mesial temporal lobe epilepsy arising from the language non-dominant hemisphere impairs nonverbal memory.

[19][20][21][22][23] Hippocampal sclerosis, brain tumor, traumatic brain injury, cerebral vascular malformation, neuronal migration disorders, infections such as encephalitis and meningitis, autoimmune disease (limbic encephalitis) and genetic disorders may cause temporal lobe epilepsy.

[26] Those who experienced any sort of brain injury in their early life have a higher risk of developing epilepsy.

[27] Experimental research has shown that N-methyl-d-aspartate (NMDA) receptor activation causes neuronal cell loss, and electrical stimulation-induced animal models of temporal lobe epilepsy duplicate the cell loss pattern of temporal lobe epilepsy in humans.

[27] Repetitive seizures irreversibly damage interneurons leading to persistent loss of recurrent inhibition.

[27] The secondary epileptogenesis hypothesis is that repetitive seizures lead to interneuron loss, loss of glutamatergic principal neurons, axonal sprouting, and formation of new recurrent glutamatergic excitatory circuits leading to a more severe epilepsy.

[29]: 1318  In the normal brain, dentate granule cells block seizure spread from entorhinal cortex to the hippocampus.

[27] However, a study has shown that a similar pattern of granule cell dispersion may occur in persons without epilepsy.

[3] Magnetoencephalography may diagnose temporal lobe epilepsy by recording epileptiform discharges or seizure patterns arising from the magnetic fields of neural electrical currents.

[4] Single-photon emission computed tomography (SPECT) may show a region of decreased blood flow occurring 40-60 seconds after injection during the seizure; this reduced blood flow region may correspond to the seizure focus.

[31] CT scan is advised in emergencies when the suspected cause of epilepsy may be intracerebral hemorrhage, brain abscess, large cerebral infarction or subdural empyema.

CT scan may better demonstrate calcium containing brain abnormalities causing epilepsy such as in tuberous sclerosis and Sturge–Weber syndrome.

[34]: 751  Studies show that language dominant anterior temporal lobectomy may lead to verbal memory decline.

[16] However, study outcomes are more variable on language non-dominant anterior temporal lobectomy leading to nonverbal memory decline.

[40] Remission was more likely among those without hippocampal sclerosis, brain tumor, or focal cortical dysplasia on MRI scan.