L. A. Hayman

A guide to the isolated dilated pupil.

The poorly reactive and dilated pupil observed in a comatose patient is often thought to represent an acute third nerve palsy owing to brain herniation or aneurysm. In the well patient, however, the isolated dilated pupil is unlikely to be owing to a third nerve palsy. It is more commonly owing to other benign causes such as local iris sphincter abnormalities, pharmacologic dilation, tonic pupil syndrome, or sympathetic irritation. This article presents a diagnostic flowchart to help the primary care physician analyze this problem and prevent costly and unnecessary imaging of these patients.

Spinal disease in neurologically symptomatic HIV-positive patients.

Abstract We review the MRI findings of human immunodeficiency virus (HIV)-positive patients with “spinal” symptoms and review the literature. In 23 consecutive HIV-positive patients presenting with acute neurologic complaints thought to be referable to the spine, we reviewed spinal MRI, medical charts, and laboratory, pathologic, and autopsy data. In the early stages of HIV infection, the common causes of spinal complaints (i. e., degenerative spine and disc disease) predominated. However, pathology may be missed without contrast-enhanced MRI of the spine. In more advanced cases, the differential diagnosis includes one or more neoplastic and/or infectious causes which require contrast-enhanced MRI for detection. In these cases, normal cerebrospinal fluid findings should not preclude contrast-enhanced MRI of the spine. Imaging of the brain may also be indicated in cases when the spinal study is negative.

Surgical anatomy of the temporal bone: an atlas.

Abstract This atlas demonstrates the usefulness of reconstructed high-resolution CT for planning temporal bone surgery. The first part focuses on a sagittal plane, the second on a rotated longitudinal plane, and the third on a rotated transverse plane. We believe knowledge of temporal bone anatomy in these planes facilitates surgical planning by showing anatomic relationships and providing a customized map for each patient. This decreases the likelihood of surgical mishap and improves teaching.

Conservative management of extra-axial hematomas diagnosed by CT.

Abstract Our purpose was to assess the role of serial CT in recently traumatized patients with clinically stable extra-axial intracranial hematomas (EACH) and a midline shift of less than 0.5 cm. A retrospective review of 91 imaging studies in 41 patients (with 45 EACH) was done to assess the time between trauma and CT; the presence and type of skull fracture; the volume, type, and location of the EACH; the presence of associated edema and/or contusion. Over a 19-day follow-up, 11 % of the dense EACH increased in volume and 27 % decreased. An adjacent skull fracture was seen most frequently in patients with a decrease in EACH volume. Clinical data remain the key to determining the need for neurosurgical intervention in patients with EACH. Follow-up CT afforded no data which altered the medical management of these patients. However, it may be said to have alerted the clinician to an increase in the size of the EACH in 11 % of cases, which could mandate close observation of this group.

Triple-dose contrast-enhanced images in neurologically symptomatic HIV-positive patients

Abstract Our purpose was to determine whether triple-dose delayed contrast-enhanced images would improve lesion detection in patients with symptomatic human immunodeficiency virus (HIV) infection. We reviewed 33 MRI studies on 29 patients. Single-dose immediate T 1-weighted spin-echo (1x-T 1) images were compared with delayed triple-dose images (D3x-T 1). Two neuroradiologists decided which technique showed more lesions, increased lesion conspicuity and/or altered the radiologic diagnosis. The D3x-T 1 technique improved lesion detection in 14 of 29 patients (48 %). In two patients (7 %), the improvement changed the radiologic diagnosis by showing new meningeal lesions.