Neurosurgery notes/Functional/Seizure/Semiology/Temporal lobes epilepsies

Temporal lobes epilepsies

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Semiology

Numbers

  • Most common focal epilepsy foci (60%).

Most seizures originate

  • Mesial temporal structures
    • Amygdala
      • Roles in emotion and autonomic and olfactory systems.
    • Hippocampal formation.
      • Roles in memory and experiential phenomena.
  • Uncinate Fits:
    • Focus:
      • Anterior aspect of the temporal lobe (uncus, parahippocampal gyrus, amygdala region, and piriform cortex)
    • Unpleasant olfactory hallucinations.

Clinical features

  • Auras (simple partial seizures)
    • Auras of right temporal origin are more commonly remembered than those from the left.
    • Auras often gradually evolve to complex (LOC) partial seizures.
  • Complex partial seizures are the hallmarks of temporal lobe seizures.
    • Patients evolving to complex partial seizures may become amnestic for the aura.
  • Common auras are:
      • Rising epigastric sensation
      • Most common aura
      Fear
      • Common
      • Must be distinguished from panic attacks.
      Experiential auras
      • Dreamy states,
      • Déjà vu:
        • Already seen
        • An individual feels as though they have already experienced a current situation, despite knowing that they haven’t
      • Jamais vu
        • Never seen
        • A psychological phenomenon that involves a temporary feeling of unfamiliarity with a familiar situation, object, or person
      Sensory auras
      • Smells, which have reliable localization but are actually quite rare.
        • Uncinate fits
          • Are characterized by seizure activity involving portions of the anterior aspect of the temporal lobe resulting in unpleasant olfactory hallucinations.
          • The structures most often implicated include the uncus, parahippocampal gyrus, the region of the amygdala and adjoining tissue, and the piriform cortex
      • Other sensory manifestations that are not localizing
        • Cephalic sensation,
        • Numbness,
        • Tingling,
        • Hearing music or phrases.
        • Spread of the seizures to the secondary sensory area that sits in the posterior operculum may produce unusual distributions of sensory symptoms that may be ipsilateral or bilateral.
      Autonomic symptoms
      • Changes in heart rate,
      • Piloerection,
      • Urinary urgency.
      Simple auditory
      • Buzzing, roaring, and muffling
      • Usually arise from the temporal neocortex on the superior temporal gyrus near Heschl’s gyrus.
      Complex visual phenomena
      • Usually occur from the posterior temporal lobe near the occipital lobe.
      Automatism
      • Oroalimentary automatisms
        • Lip smacking, chewing, or swallowing along with gestural automatisms such as picking or fumbling movements.
      • Proximal automatisms
        • Involving frontal lobes
        • Bicycling or thrashing.

Spread

  • Secondarily, generalized tonic-clonic seizures may also occur
    • Typically infrequently.