1671 DIAGNOSIS OF CEREBRAL ATROPHY IN INFANTS BY THE NEARFIELD. METHOD: A NEW TECHNIQUE IN CRANIAL SONOGRAPHY

Abstract

Cerebral atrophy in infants has been difficult to assess by cranial sonogram (CS) because the subarachnoid space has been a “blind spot” by ultrasound, yet CS is an ideal imaging method for infants as it is portable, non-radiative and unlike computed cranial tomography (CCT), requires no intravenous contrast or sedation. We present a new method of evaluating the subarachnoid space by CS in infants and correlate it with the presence of cerebral atrophy. Material & Methods: Realtime ultrasound equipment with a modified transducer was used for imaging the “nearfield”. The nearfield was defined as the first 2-3 cm from the scalp into the brain. The subaracnnoid space which can be detected within the nearfield was assessed in 25 consecutive infants who were sonogranmed for various neurologic indications. The results were correlated with CCT findings of cerebral atrophy. Results: On nearfield sonography, 3 of the 25 patients had enlargement of the subarachnoid space. All 3 patients had cerebral atrophy on CCT. 22 of the 25 patients had no enlargement of the subarachnoid space by nearfield sonography. None of the infants who had CCT showed evidence of cerebral atrophy. Enlargement of the subarachnoid space by nearfield sonography was therefore found to be most sensitive and specific for cerebral atrophy when compared to CCT. Summary: Nearfield sonography provides a simple tool for assessing the subarachnoid space and therefore the presence of cerebral atrophy. It opens the way for a non-invasive method of evaluating the degree of cerebral atrophy and its correlation with the clinical state and prognosis. Larger series using this technique seems appropriate.