W. R. K. Smoker

MRI in familial multiple sclerosis

We obtained cranial MRIs of 76 individuals from 13 MS multiplex families. Thirty-one MS patients and 45 normal family members participated in the study. Twenty-eight of the 31 individuals with definite or probable MS had multiple white matter lesions by MRI. Thirty-five normal family members had normal MRIs, and 10 had abnormal studies. Four normal individuals under age 50 had abnormal MRIs. Three had multiple white matter lesions. The 4th had a single small white matter lesion in the left centrum semiovale. Six normal individuals over age 50 had multiple white matter lesions. Although diffuse white matter lesions in individuals over age 40 should be interpreted with caution, these lesions in individuals under age 40 with no history of underlying medical illness are suggestive of demyelination. The results of the present study indicate that subclinical MS may be present in apparently normal members of multiplex families.

The Radiologic Assessment of Trigeminal Neuropathy

The clinical and radiologic records of 76 patients with trigeminal neuropathy and an abnormal imaging study (CT and/or MR) were analyzed retrospectively. The trigeminal nerve (cranial nerve V) was divided into proximal (brainstem, preganglionic, gasserian ganglion, and cavernous sinus) and distal (extracranial V1, V2, and V3) segments. Lesions were organized according to segments and correlated with the type and distribution of clinical symptoms or signs. The purpose of the study was to (1) determine the efficacy of clinical localization of cranial nerve V lesions, (2) compare CT and MR for cranial nerve V imaging, (3) develop an MR protocol for effective cranial nerve V imaging, and (4) construct a differential diagnosis by anatomic segment for lesions of cranial nerve V. Clinical localization was found to be extremely inaccurate. CT was not as sensitive as MR for lesions involving the basal cisterns and skull base and will not detect the most common brainstem lesions (small infarcts and multiple sclerosis plaques). The MR protocol developed does not rely heavily on clinical localization. On the basis of lesions found in this series, a differential diagnosis by segment was developed. Patients with cranial nerve V symptoms should undergo MR imaging according to the protocol provided in this article. CT is not as effective as MR in imaging some cranial nerve V segments. Clinical localization is inaccurate.

Carotid thrombosis following neck irradiation

Therapeutic irradiation may accelerate atherosclerosis, increasing the risk of vascular stenosis or occlusion several to many years following radiation. However, intimal damage following irradiation may result earlier in thrombosis without stenosis. This report discusses three cases of carotid occlusion that occurred within 3 years of moderate dose irradiation. Angiographic studies showed that occlusion occurred in the absence of atherosclerotic stenosis. A review of the literature supports the conclusion that people who receive neck irradiation are at risk not only for the delayed development of diffuse atherosclerosis but also for thrombotic occlusion within months to several years. We suggest that patients who develop neurological symptoms or signs following neck irradiation, regardless of age, dose of radiation, or interval since radiation, should be evaluated for carotid or vertebral artery disease.

The tailored CT evaluation of persistent facial nerve paralysis

The clinical, radiographic, and pathologic records of 39 patients with peripheral facial nerve dysfunction seen from October 1981 through July 1984 are reviewed. The extent of preradiologic clinical localization of suspected lesions and their subsequent pathologic confirmation is correlated to the number, sequence, and type of radiographic evaluations performed.