Format

Send to

Choose Destination
Ann Neurol. 2015 Jun;77(6):1060-75. doi: 10.1002/ana.24407. Epub 2015 Apr 23.

Voxel-based morphometric magnetic resonance imaging (MRI) postprocessing in MRI-negative epilepsies.

Author information

1
Epilepsy Center, Cleveland Clinic, Cleveland, OH.
2
Department of Diagnostic Radiology, Mellen Imaging Center, Cleveland Clinic, Cleveland, OH.
3
Sanford USD Medical Center, Sioux Falls, SD.
4
Department of Anatomic Pathology, Cleveland Clinic, Cleveland, OH.
5
Clinic of Neurology, Epilepsy Center, Clinical Center of Serbia, Belgrade, Serbia.
6
Department of Neurology, Westmead Hospital, Sydney, Australia.
7
Department of Neurosurgery, Cleveland Clinic, Cleveland, OH.

Abstract

OBJECTIVE:

In the presurgical workup of magnetic resonance imaging (MRI)-negative (MRI(-) or "nonlesional") pharmacoresistant focal epilepsy (PFE) patients, discovering a previously undetected lesion can drastically change the evaluation and likely improve surgical outcome. Our study utilizes a voxel-based MRI postprocessing technique, implemented in a morphometric analysis program (MAP), to facilitate detection of subtle abnormalities in a consecutive cohort of MRI(-) surgical candidates.

METHODS:

Included in this retrospective study was a consecutive cohort of 150 MRI(-) surgical patients. MAP was performed on T1-weighted MRI, with comparison to a scanner-specific normal database. Review and analysis of MAP were performed blinded to patients' clinical information. The pertinence of MAP(+) areas was confirmed by surgical outcome and pathology.

RESULTS:

MAP showed a 43% positive rate, sensitivity of 0.9, and specificity of 0.67. Overall, patients with the MAP(+) region completely resected had the best seizure outcomes, followed by the MAP(-) patients, and patients who had no/partial resection of the MAP(+) region had the worst outcome (p < 0.001). Subgroup analysis revealed that visually identified subtle findings are more likely correct if also MAP(+) . False-positive rate in 52 normal controls was 2%. Surgical pathology of the resected MAP(+) areas contained mainly non-balloon-cell focal cortical dysplasia (FCD). Multiple MAP(+) regions were present in 7% of patients.

INTERPRETATION:

MAP can be a practical and valuable tool to: (1) guide the search for subtle MRI abnormalities and (2) confirm visually identified questionable abnormalities in patients with PFE due to suspected FCD. A MAP(+) region, when concordant with the patient's electroclinical presentation, should provide a legitimate target for surgical exploration.

PMID:
25807928
PMCID:
PMC4447617
DOI:
10.1002/ana.24407
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Wiley Icon for PubMed Central
Loading ...
Support Center