Somatosensory evoked potentials in the evaluation of lumbosacral radiculopathy.

We performed lower extremity somatosensory evoked potential (SEP) studies in 59 patients with signs or symptoms suggestive of lumbosacral radiculopathy and compared them with results of myelography with post-myelogram CT (myelogram/CT), MRI, and other electrodiagnostic studies. Of 38 patients with abnormal myelogram/CTs, 32 had abnormal SEPs, while 11 demonstrated EMG abnormalities. All 21 patients with normal myelogram/CTs had normal SEPs. SEP improved electrodiagnostic sensitivity in patients with weakness or reflex changes as well as in those with sensory deficits only. SEP was less sensitive in patients in whom spinal stenosis was the only radiographic finding. MRI generally corresponded well with the results of myelogram/CT and SEP but overestimated the significance of disk bulges in some patients. SEP is useful in the electrodiagnostic evaluation of lumbosacral radiculopathy, particularly when EMG is nondiagnostic.

Imaging of postnatal maturation of the skull base.

The skull begins to form when mesenchyme thickens and condenses around the developing brain. At the skull base, most of this mesenchyme derives from neural crest, and some arises from general head mesenchyme. This article reviews the patterns for maturation of the ossification, sutures, and synchondroses in the occipital, the sphenoid, and the orbitoseptal regions, and reports additional data derived from specific study of CT scans of the skull base in children and young adults.

Blunt trauma to the carotid arteries.

Carotid artery dissection is a rare occurrence in the trauma patient. Two cases of blunt trauma resulting in carotid artery dissection are reported. Initial recognition by clinicians is often difficult because of the diverse clinical manifestations, the delay in presentation, and the associated multi-organ system injuries that accompany carotid artery dissection. Because the diagnosis of carotid injury is rarely suspected in patients with neurological deficits, the first diagnostic test performed is usually computed tomography (CT) of the head. Angiography should be strongly considered when the following occur: (a) Neurologic deficits are incompatible with CT findings; (b) there is monoparesis or hemiparesis with a normal mental status examination; (c) there is severe cervical trauma with an abnormal neurological exam; or (d) a basilar skull fracture is present in a patient with an abnormal mental status exam. Once diagnosed, the management of carotid artery dissection is complex and no generalized guidelines have been established.

Intraspinal masses: efficacy of plain spine radiography.

Plain spine radiographs from 31 patients with pathologically proven intraspinal tumors were analyzed retrospectively by an experienced pediatric radiologist unfamiliar with the cases in order to evaluate the applicability and reliability of the radiographic signs commonly used for diagnosis. Interpediculate distances (IPDs) were graphed onto standard curves to assess whether graphic analysis aided in diagnosis. In this group of patients, no single radiographic criterion permitted better than 40% true-positive diagnosis. False-positive diagnoses were made in 0-10% of cases, depending on the sign employed. Use of multiple roentgen signs in conjunction achieved 55% true-positive and 3% false-positive diagnoses, while use of graphed IPDs alone achieved 57% true-positive and 11% false-positive diagnoses. Addition of graphed IPDs to visual inspection of the radiographs led to detection of 6 tumors (19%) not otherwise appreciated, but tripled the false-positive rate from 3 to 10%.