Experience with a Noninvasive Protocol for Anteromedial Temporal Lobectomy: 138 Consecutive Patients with Nonlesional Temporal Lobe Epilepsy

Shearwood McClelland III MD, Tina T Shih MD, Lawrence J Hirsch MD, Carl W Bazil MD, PhD, Marla J Hamberger PhD, Guy M McKhann II MD, Robert R Goodman MD, PhD


Departments of Neurological Surgery and Neurology, Columbia College of Physicians and Surgeons, New York, New York. 



Objective: Anteromedial temporal lobectomy (AMTL) is an established treatment for medically refractory temporal lobe epilepsy (TLE).  Evaluations often use intracranial electrodes to identify seizure onsets.  Experience with noninvasive evaluations in nonlesional patients (few centers reporting greater than 50 patients) has provided limited information concerning efficacy and morbidity.  To expand this knowledge, we review an experience with a large patient series. 

Methods: From 1/1992-12/2003, AMTL (75 left, 63 right; 69 males, 69 females) was performed (by RRG) on 138 consecutive nonlesional TLE patients based on noninvasive evaluation (technique described by Spencer et al.; Neurosurgery 15:667-671, 1984). Mean age was 35.6 years (S.D. +- 12.3 years; range: 8-64). 

Results: 134 patients had a hippocampal MRI abnormality on the side of presumed seizure onset.  121 patients had minimum follow-up of 12 months. Using a modified Engel outcome scale, 95 (78.5%) were class I; 18 (14.9%) class II; 4 (3.3%) class III (greater than 75% seizure reduction), and 4 (3.3%) class IV (less than 75% improvement) at last follow-up.  Morbidity (138 patients) included: 16 partial quadrantinopsias (11.6%), 6 transient depressions, 4 subtotal hemianopsias (2.9%; 1 associated with dyslexia and 1 with subcortical infarct and transient hemiparesis), 4 transient diplopias (2.9%), 1 chronic subdural hematoma, 1 trapped temporal horn, 1 transient psychosis, and 1 deep vein thrombosis (0.7%).  No patients had persisting significant motor deficit, disabling dysnomia/dysphasia, amnestic syndrome or mortality. 

Conclusion: A noninvasive protocol for AMTL in a large consecutive series of nonlesional TLE patients produced seizure control comparable to reported experiences with invasive protocols.