BAER, EOG, MRI and 3-D MR angiography correlates in a case of Locked-In syndrome.

A case of Locked-in syndrome is reported with correlation of BAER and EOG with MRI for localization and identification of brain lesions, and 3-D MRA and 2-D gradient echo MR imaging, a non-invasive new diagnostic modality for confirmation and visualization of vascular pathology. There was thrombosis of the basilar artery with extensive infarct of ventral pons and lower mid-brain. The patient had ocular bobbing. This eye movement in its classical form consists of irregular vertical oscillations, the fast component being downward with complete absence of horizontal eye movements. To our knowledge, the change from ocular bobbing to upbeat nystagmus has not been previously reported in the Locked-in syndrome. Bilateral involvement of the lateral lemniscus might have contributed to its appearance in our patient.

Thymectomy for myasthenia gravis.

OBJECTIVES: To assess the change in clinical status of patients with generalized myasthenia gravis treated with thymectomy and to identify prognostic variables that may be of significance in optimizing patient selection. DESIGN: Retrospective review. Mean follow-up period was 41 months. SETTING: Large community hospital. PATIENTS: Thirty-seven patients (11 male and 26 female) with generalized myasthenia gravis who were referred for thymectomy if they were refractory to medical treatment or had a thymoma. This represents all patients undergoing thymectomy for myasthenia gravis between January 1982 and December 1991. INTERVENTIONS: Each patient underwent staging before and after thymectomy using a modified Osserman classification. Medication requirements were also recorded. All patients underwent transsternal thymectomy and complete mediastinal dissection. MAIN OUTCOME MEASURES: Changes in clinical stage and medication requirement before and after thymectomy; effect of patient age, sex, duration of disease, stage of disease, antibody status, histologic characteristics of the thymus, and duration of follow-up on outcome. RESULTS: Improvement after thymectomy was noted in all 37 patients. Complete remission was achieved in three patients (8%) and pharmacologic remission in 23 (62%). The remainder improved in stage, medication requirement, or both. Patients in preoperative stages IIb and IIc showed the greatest improvement. Age, sex, duration of disease, antibody status, histologic characteristics of the thymus, and duration of follow-up were not significant factors in assessing improvement. CONCLUSIONS: Transsternal thymectomy was found to be beneficial to all patients with generalized myasthenia gravis. Complete or pharmacologic remission was achieved in most patients (70%) following the procedure. Patients in preoperative stages IIb and IIc showed the greatest degree of postoperative improvement.

Clinical correlates of enzyme-immunoassay versus radioimmunoassay measurements of antibody against acetylcholine receptor in patients with myasthenia gravis.

Antibody against human nicotinic acetylcholine receptor [Ab(AcChR)] was measured in the sera obtained from 55 patients with myasthenia gravis (MG) using both radioimmunoassay (RIA) and enzyme-linked immunosorbent assay (ELISA). By at least one assay, 91% of the patients had elevated Ab(AcChR). We found no correlation between the amount of Ab(AcChR) measured by RIA and that measured by ELISA. Patient subpopulations defined by ELISA- or RIA-measured Ab(AcChR) were associated with different disease durations. All of those who had high Ab(AcChR) levels by both assays had experienced symptoms for less than 2 years. 87% of those with high Ab(AcChR) levels by ELISA had had MG for less than 4 years. Those patients with high Ab(AcChR) only by RIA had a mean disease duration of over 8 years. With regard to correlations of Ab(AcChR) with patient age and sex, females under 50 years of age had high levels of Ab(AcChR) by RIA, but had lower levels by ELISA, whereas men over 50 had high Ab(AcChR) levels by ELISA. Using either assay, no relationship was established between concentrations of Ab(AcChR) and the patient's functional status, previous thymectomy, or current therapy. In this study, 16% of the MG patients with elevated Ab(AcChR) would have been considered within the non-disease range of Ab(AcChR) had only the RIA been performed, thus recommending the routine use of both assays for diagnostic purposes.

Immunoenzymometric assay and radioimmunoassay measure different populations of antibody against human acetylcholine receptor.

We used a "sandwich"-type immunoenzymometric assay (IEMA) and a radioimmunoassay (RIA) to measure antibody against the human nicotinic acetylcholine receptor in serum from individuals with myasthenia gravis, with markedly different results for certain specimens, as measured by the two techniques. In some cases, antibody concentrations were high by RIA but low by IEMA; in others, the reverse was found. Such differences persisted through 30 months after thymectomy. An investigation of potential causes of this disparity suggests that high IEMA measurements reflect specific anti-receptor antibody and are not artifactual. The IEMA is recommended as an adjunct to the RIA because some patients with myasthenia gravis who have low concentrations of anti-receptor antibodies as measured by RIA have significantly above-normal concentrations of anti-receptor antibodies as measured by IEMA.