Head position modulates activity in the human parietal eye fields.

For us to interact with our environment we need to know where objects are around us, relative to our body. In monkeys, a body-centered map of visual space is known to exist within the parietal eye fields. This map is formed by the modulation of retinal responses by gain fields to gaze position.

A neurocognitive account of frontal lobe involvement in orthographic lexical retrieval: an fMRI study.

The present study aimed to examine the relationship between activation induced by an orthographic lexical retrieval (OLR) task and performance across time on the standard clinical version of OLR, the Controlled Oral Word Association Test (COWAT). The number of significantly activated pixels in a frontal lobe region of interest (encompassing middle and inferior frontal gyri) were measured for the left and right cerebral hemispheres in 20 volunteers. A relationship between the pixel count and the total number of words retrieved during the COWAT was found for the left but not the right hemisphere.

APOE epsilon4 genotype is associated with an earlier onset of chronic temporal lobe epilepsy.

The authors analyzed the association between APOE epsilon4 genotype and clinical and MRI findings in 43 refractory temporal lobe epilepsy patients. The distribution of the alleles were normal. Ten patients (23%) had an APOE epsilon 4 allele and had an earlier onset of habitual seizures (with epsilon4 5 +/- 5 years; without epsilon4 15 +/- 10 years).

Occurrence of hippocampal sclerosis: is one hemisphere or gender more vulnerable?

Purpose: We analyzed a large group of patients investigated for suspected seizures to test whether gender or side are important factors in the origins of hippocampal sclerosis (HS).

Methods: We studied 996 consecutive patients (48% men, 52% women) by using standard hippocampal T2-relaxometry methods.

Results: HS was associated with a highly abnormal T2 time (< or =113 ms).

Hippocampal sclerosis: development in adult life.

Hippocampal sclerosis (HS) is the most common pathological lesion underlying intractable temporal lobe epilepsy. It is not known whether HS exists before the onset of epilepsy or whether it is caused by seizures. Its has been proposed that childhood seizures cause HS.

Hippocampal T(2) abnormalities correlate with antecedent events and help predict seizure intractability.

Introduction: We performed hippocampal T(2) relaxometry as part of a routine magnetic resonance imaging (MRI) examination in 50 normal controls and 127 consecutive patients referred because of suspected seizures.

Methods: On the basis of T(2) values in controls (100.2 +/- 4.

Presurgical evaluation of the motor hand area with functional MR imaging in patients with tumors and dysplastic lesions.

Purpose: To test an optimized functional magnetic resonance (MR) imaging procedure to depict the motor hand representation area (HRA) in patients with epilepsy lesions near the central sulcus.

Materials And Methods: Fast low-angle shot MR imaging was performed with an oblique single-section imaging technique in eight control subjects (10 hemispheres) and six patients (12 hemispheres). Three series of five activation images (obtained while subjects performed repetitive finger-to-thumb opposition movements) and five rest images were acquired.

Twins with different temporal lobe malformations: schizencephaly and arachnoid cyst.

The etiology and relationships between different forms of malformations of cortical development are poorly understood. Schizencephaly is generally regarded as unrelated to arachnoid cysts. As part of a systematic study of epilepsy in twins we observed a monozygotic twin pair discordant for temporal lobe epilepsy where the twin with epilepsy had unilateral temporal schizencephaly and periventricular heterotopia.

Anterior temporal abnormality in temporal lobe epilepsy: a quantitative MRI and histopathologic study.

Objective: To examine the nature and frequency of anterior temporal lobe (AT) abnormalities that occur in intractable temporal lobe epilepsy (TLE).

Methods: We reviewed the MR scans and clinical histories of 50 consecutive patients with intractable TLE. Histopathology was available in 42 surgically treated cases.

Hemicranial volume deficits in patients with temporal lobe epilepsy with and without hippocampal sclerosis.

Purpose: In patients with refractory temporal lobe epilepsy, studies have suggested volume deficits measured by MRI of brain structures outside the epileptogenic hippocampus. Hippocampal sclerosis (HS) is a frequent, but not obligate, finding in such patients. The present study examines the influence of the presence of HS on quantitative magnetic resonance imaging (MRI) measurements.