Russian-American "Blind Care Foundation"

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New York University School of Medicine

A private university in the public service


NEUROMETRIC EVALUATION SERVICE

DEPARTMENT OF PSYCHIATRY

530 First Avenue, Suite 7D

New York, NY 10016

(212) 263-6287       Fax: (212)263-6457

 

Patient Name: Larry Vidimsky                    DOB: 01/31/96                       DOT: 04/13/07

Patient ID: 17303                                                                                        Referred by: Dr. Gulati

 

Reason for examination: Evaluation of visual capabilities

 

This Neurometric evaluation included a twenty minute recording of eyes closed, resting EEG recorded from standardized electrode positions over 19 brain regions while the subject sat blindfolded, initially at rest (condition A) and then while trying to read while his eyes were covered with a blindfold (condition B). After visual inspection of each EEG record, two minutes of artifact-free data were selected from A and from B for quantitative (QEEG) analysis.

 

 In addition, in both conditions A and B:

                      Visual evoked potentials (VEPs) were elicited by binocular visual pattern reversal stimuli.

 

QEEG findings:

          The EEG in condition A was of relatively low amplitude. The QEEG shows the frequency distribution expected from a normal child 11.2 years of age, when recorded at rest with eyes closed and essentially all quantitative values were well within normal limits. There was the expected peak at 10.53 Hz in the middle of the so-called “alpha” frequency band, with maximum values as expected in the visual cortical regions. The generators of this frequency were shown by three–dimensional source localization to be in the bilateral occipital and temporal gyri and the bilateral inferior frontal cortex. 

        The EEG in condition B shows a completely different frequency distribution characterized by very large electromyogram activity (EMG) in all regions of the prefrontal cortex and the anterior temporal lobes. The QEEG reveals a great anterior excess of beta activity in those regions. There are large peaks of beta activity (133-18 Hz in the periorbital, dorsolateral and mesial prefrontal cortex, consistent with wrinkling the forehead and squinting the eyes. There are no signs of activation in the visual associations regions (posterior temporal and parietal cortex) or in the primary visual (occipital) cortex. The generators of these beta frequencies were shown by three–dimensional source localization to be in the bilateral prefrontal and temporal regions associated with jaw clenching and forehead-eyelid muscle contraction, but there was no sign of activation of the readings required to mediate reading or visual scene analysis.

          Strong, normal VEPs were elicited by the pattern reversing visual field in the eyes open condition A, with morphology and topographic distribution as expected from a normal child when  tested with open eyes. Inexplicably, a strong and well replicated VEP was detected in the occipital regions in two replicated trials with the eyes blindfolded, in condition B. Copies of these VEPs are provided herewith.

 

Interpretation:

        The conventional EEG, QEEG and brain imaging all indicate strong activation of the frontalis, obicularis and temporalis muscles during the periods when the child was attempting to read. There was no indication that the brain regions concerned with processing visual information were activated during these endeavors in condition B.

        Perfectly clear, morphologically and topographically normal visual evoked potentials were elicited in with eyes open as well as blind-folded.  We found no evidence from brain imaging that indicated any input to the visual regions while blindfolded. 

 

E. Roy John, Ph.D.

Neurometrician

 

Sandlin Lowe III

Clinical Associates



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