This presentation describes the concept of temporal plus syndrome, pseudotemporal epilepsy and paradoxical temporal lobe epilepsy and how to differentiate them from temporal lobe epilepsy.

1. Temporal plus syndrome,
Pseudotemporal epilepsy and
Paradoxical TLE
Dr Pramod Krishnan, MD (Int Med), DM Neurology (NIMHANS)
Fellowship in Epilepsy (SCTIMST) (LMU, Munich)
World Sleep Federation Certified Sleep Medicine Specialist.
Consultant Neurologist and Epileptologist
Head of the Department of Neurology,
Manipal Hospital, Bengaluru.

2. Introduction
• The notion of focality in temporal lobe epilepsy (TLE) is too simplistic
to suit the variety of temporal lobe seizure generators.
• The concept of ‘epileptogenic network’ better explains the complex
spatial organization of several distinct cortical areas generating
seizures.
• This explains the significant proportion of surgical failures in ‘temporal
lobe epilepsy’.

3. Understanding the concept
Temporal lobe epilepsy: the epileptic
generator is located within the
temporal lobe.
Investigation Observation
Clinical
features
TLE, classical features
Scalp EEG TLE
MRI brain MTS, other pathology
Invasive EEG TLE (usually not required)
Surgical results
(ATL+AH)
Excellent
MRI brain T2 Coronal showing left mesial
temporal sclerosis

4. Understanding the concept
Paradoxical TLE: The epileptic
generator is within the temporal lobe.
Investigation Observation
Clinical features TLE (may have some red flags)
Scalp EEG TLE
MRI brain Unremarkable
Invasive EEG TLE
Surgical results
(ATL+AH)
Good
Normal MRI brain T2 Coronal

5. Understanding the concept
Temporal plus epilepsy: This is
due to a complex epileptogenic
network including the temporal
lobe and neighbouring structures:
1. Orbitofrontal cortex
2. Insula
3. Frontal and parietal
operculum
4. Temporo-parieto-occipital
junction.
MRI brain showing a large left
temporo occipital FCD

6. Temporal plus epilepsy
• Unifying term for multilobar epilepsies characterised by prominent
involvement of the temporal lobe: fronto-temporal, temporo-perisylvian
and temporo-parieto-occipital epilepsies.
Investigation Observation
Clinical features Like TLE (may have red flags)
Scalp EEG (ictal and inter-ictal) Suggests TLE
MRI brain May show MTS or may be unremarkable.
Intracranial EEG Ictal onset simultaneously from temporal and adjoining
extra-temporal regions.
Two coexisting seizure types in the same patient, with
temporal and extratemporal ictal onset, respectively.

7. Onset Vs Propagation
• Seizures that start in the temporal lobe and spread rapidly to
extratemporal areas is not temporal plus epilepsy.
• The very frequent insular spread of TLE is a good example, since it can
elicit symptoms suggesting an insular involvement but does not
influence the prognosis of TLE surgery.

8. Temporal plus Vs Dual pathology
Temporal plus epilepsy Dual pathology
One contiguous epileptogenic network
involving temporal lobe and adjoining
extra-temporal structures
an extratemporal lesion coexists with
mesial temporal sclerosis, both being
epileptogenic.
Functionally and anatomically connected
network
The two foci are functionally and
anatomically separate.
Usually single seizure type Usually two seizure types
Activation of different parts of the
temporal plus epileptogenic network can
result in different seizure semiologies.
Each epileptogenic network produces a
distinct seizure semiology

9. Understanding the concept
• It is clinically silent until the
discharge propagates to temporal
lobe structures.
• Therefore it mimics TLE clinically
and on scalp EEG.
Investigation Observation
Clinical features TLE (may have some red flags)
Scalp EEG TLE
MRI brain No mesial temporal changes
Invasive EEG Extra-temporal ictal onset
Surgical results Surgical plan based on invasive
EEG.
Pseudotemporal epilepsy: The
epileptic generator is located
outside the temporal lobe.
Left Mamillary body hamartoma presenting as TLE

10. Possible locations of epileptogenic focus in pseudotemporal epilepsy
Orbitofrontal Shihabuddin et al., 2001
Anterior cingulate Madhavan et al., 2007
Posterior cingulate Koubeissi et al., 2009
Insula Cukiert et al., 1998; Isnard et al., 2000
Parietal lobe Cascino et al., 1993; Foldvary et al., 2001; Salanova et al., 1995
Occipital lobe Foldvary et al., 2001; Palmini et al., 1993
Diffuse band heterotopia Bernasconi et al., 2001
Periventricular nodular
heterotopia
Cascino et al., 1993a
Hypothalamic hamartoma Duncan et al., 1997

11. Temporal lobe epilepsy Temporal plus epilepsy
Ability to warn at onset Gustatory, Vestibular aura, Auditory illusions
Digestive aura Contralateral versive manifestations
Gestural automatisms Piloerection
Post-ictal amnesia Ipsilateral tonic motor signs
Post-ictal dysphoric state
Bilateral spikes and/or slow waves
Precentral spikes and/or slow waves
Ictal onset: anterior frontal (Fp1-F3, Fp2-F4), temporo-
parietal (T5-P3, T6-P4) or precentral (F4-C4, F3-C3)

12. J Clin Neurophysiol 2013;30: 238–246
Pseudotemporal epilepsy
(PT) 10 pts, 37 seizures
MTLE-HS (HS)
12 pts, 45 seizures
Neocortical TLE (NT)
11 pts, 41 seizures
• The ictal onset pattern and later pattern could not distinguish the three groups.
• Rhythmic temporal theta as ictal onset pattern was noted in all 3 groups.
• No significant difference in the occurrence of rhythmic temporal theta pattern
between TLE (mesial and neocortical) and pseudotemporal epilepsy.
• All pseudotemporal seizures spread to the contralateral hemisphere at some
point during the seizure.

13. Confirmation is by invasive EEG
Diagnosis of temporal plus,
pseudotemporal, paradoxical TLE
Indications for invasive EEG at a
particular centre
Protocol and extent of coverage for
intracranial EEG
Depends on red flags in history, scalp
EEG and radiology (non-specific)
Depends on subtype of temporal plus
syndrome like fronto-temporal etc.
Spatial sampling is large, and depth
electrodes are preferred.

14. Indications for intracranial EEG in ‘TLE’
Radiology red flags:
• MRI negative TLE
Red flags on scalp EEG
• Inter-ictal: Bilateral
IEDs, Precentral
IEDs
• Ictal: ictal onset over
the anterior frontal,
temporoparietal and
precentral regions
• Unclear ictal onset.
Clinical red flags:
• Aura: gustatory,
vestibular or
auditory
• Contraversive head
or eye movements.
• Ipsilateral focal
motor signs.
• Piloerection.

15. Implications of Temporal plus epilepsy
• Identification can prevent surgical failure in ‘TLE’.
• Improved surgical results due to more complete and targeted resection.
• Helps better evaluate outcomes of actual TLE patients.
• Temporal plus epilepsy may be a specific risk factor for SUDEP.
• This is because of the role played by the insular cortex in cardiovascular
function and it’s association with frequent secondarily generalized
tonic–clonic seizures, which might promote respiratory failure.

16. • Of 168 patients included, 18 (10.7%) had temporal plus epilepsy.
• Engel class I outcome at 10 years: 14.8% for temporal plus epilepsy.
• Multivariate analyses- predictors of seizure relapse:
1. Temporal plus epilepsy (P<0.001)
2. Postoperative hippocampal remnant (P = 0.001)
3. Past history of traumatic or infectious brain insult (P = 0.022)
4. Secondary generalized tonic-clonic seizures (P = 0.023).
• Risk of temporal lobe surgery failure was 5.06 (95% CI: 2.36–10.382) greater
in patients with temporal plus epilepsy than in those with unilateral TLE.

17. Conclusion
• Distinguishing TLE, pseudo TLE and temporal plus syndromes is
crucial for better surgical outcomes.
• In some cases they can be suspected clinically.
• Scalp EEG and MRI cannot distinguish these groups.
• Confirmation requires intracranial EEG.
• Surgical results are good if properly identified and resected.

18. THANK YOU