Right hippocampal pathology inhibits the Flynn effect in temporal lobe epilepsy.
Summary of "Right hippocampal pathology inhibits the Flynn effect in temporal lobe epilepsy."
If brain pathology impedes the mechanisms that drive the Flynn effect, the gap between the mean IQ of patient groups and the general population will increase over successive generations. We examined the IQs of a large series of patients aged between 18 and 35 years, with homogenous underlying brain pathology tested over two decades, for evidence of a Flynn effect; 381 patients with temporal lobe epilepsy and unilateral hippocampal sclerosis (n = 221 left hippocampal sclerosis, LHS; n = 160 right hippocampal sclerosis, RHS) completed the Wechsler Adult Intelligence Scales. Patients assessed between 1990 and 2000 were assessed on the Wechsler Adult Intelligence Scale-Revised (WAIS-R; n = 234). Patients assessed between 2001 and 2011 were assessed on the Wechsler Adult Intelligence Scale-Third Edition (WAIS-III; n = 147). The IQ scores were adjusted for the progressive obsolescence of norms using the following equation: adjusted IQ = recorded IQ - (estimated magnitude of Flynn effect in the normal population x years since test was normed, at the time of assessment). In the RHS group there was a significant negative correlation between the year of assessment and the adjusted Verbal IQ (r = -.18, p < .05) and adjusted Performance IQ (r = -.20, p < .01). There were no significant correlations between the adjusted IQ scores and the year of assessment in the LHS group. Our data suggest that the gap between the mean IQ in the general population and that in patients with right hippocampal pathology is widening in successive generations. The findings are discussed in relation to the current theories regarding the mechanisms that drive the Flynn effect.
Affiliation
a Department of Clinical and Experimental Epilepsy , Institute of Neurology UCL , London.
Journal Details
This article was published in the following journal.
Name: Journal of clinical and experimental neuropsychology
ISSN: 1744-411X
Pages:
Links
- PubMed Source: http://www.ncbi.nlm.nih.gov/pubmed/22897234
- DOI: http://dx.doi.org/10.1080/13803395.2012.711812
Medical and Biotech [MESH] Definitions
Anterior Temporal Lobectomy
A neurosurgical procedure that removes the anterior TEMPORAL LOBE including the medial temporal structures of CEREBRAL CORTEX; AMYGDALA; HIPPOCAMPUS; and the adjacent PARAHIPPOCAMPAL GYRUS. This procedure is generally used for the treatment of intractable temporal epilepsy (EPILEPSY, TEMPORAL LOBE).
Epilepsy, Temporal Lobe
A localization-related (focal) form of epilepsy characterized by recurrent seizures that arise from foci within the temporal lobe, most commonly from its mesial aspect. A wide variety of psychic phenomena may be associated, including illusions, hallucinations, dyscognitive states, and affective experiences. The majority of complex partial seizures (see EPILEPSY, COMPLEX PARTIAL) originate from the temporal lobes. Temporal lobe seizures may be classified by etiology as cryptogenic, familial, or symptomatic (i.e., related to an identified disease process or lesion). (From Adams et al., Principles of Neurology, 6th ed, p321)
Hippocampus
A curved elevation of gray matter extending the entire length of the floor of the temporal horn of the lateral ventricle. The hippocampus, subiculum, and DENTATE GYRUS constitute the hippocampal formation. Sometimes authors include the ENTORHINAL CORTEX in the hippocampal formation.
Cranial Fossa, Middle
The compartment containing the anterior extremities and half the inferior surface of the temporal lobes (TEMPORAL LOBE) of the cerebral hemispheres. Lying posterior and inferior to the anterior cranial fossa (CRANIAL FOSSA, ANTERIOR), it is formed by part of the TEMPORAL BONE and SPHENOID BONE. It is separated from the posterior cranial fossa (CRANIAL FOSSA, POSTERIOR) by crests formed by the superior borders of the petrous parts of the temporal bones.
Posterior Cerebral Artery
Artery formed by the bifurcation of the BASILAR ARTERY. Branches of the posterior cerebral artery supply portions of the OCCIPITAL LOBE; PARIETAL LOBE; inferior temporal gyrus, brainstem, and CHOROID PLEXUS.
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