Shoulder instability: impact of glenohumeral arthrotomography on treatment

We used arthrotomography to study the glenoid labrum in 114 patients. Sixty-nine of the patients had anatomic instability of the shoulder (including recurrent dislocation and subluxation of the shoulder), and 45 patients had functional instability of the shoulder (denoted by chronic pain, clicking of the joint, and the sensation that an unstable condition exists without the objective signs of it). Labral tears were revealed arthrotomographically in 86% of the patients with anatomic instability, while only 40% of the patients with functional instability had labral abnormalities, and these were primarily of minor severity. Fifty-six patients (44 of whom had anatomic instability; 12, functional instability) required surgery. The surgical findings were correlated with the arthrotomographic findings, and no false-positive results were revealed. However, arthrotomography demonstrated only part of the pathologic condition of two patients. These results confirm that there is a strong correlation between labral pathologic conditions and anatomic instability of the shoulder. Arthrotomographic studies have a great impact on the selection of therapy in cases of both anatomic and functional instability of the shoulder.     

The prognostic value of somatosensory and motor evoked potentials in comatose patients.

Somatosensory and motor evoked potentials (SEP and MEP) were examined in a total of 213 patients in traumatic (n = 140) and nontraumatic (n = 73) coma. It was the aim of this study to compare the prognostic value of MEP elicited by both electrical and magnetoelectric transcranial stimulation with the use of SEP alone. According to the presence or absence of responses and the duration of central conduction time, SEP and MEP obtained during Days 1 through 3 after the onset of coma were divided into four categories and correlated with the outcome of the patients, as assessed by the Glasgow Outcome Scale. Our results clearly show that in terms of prognostic value, SEP are superior to MEP, with normal findings indicating a favorable outcome and absent responses an unfavorable outcome. On the other hand, patients with normal electromyographic responses after both electrical and magnetoelectric stimulation had favorable and unfavorable outcomes about equally. Thus, unlike SEP, normal MEP do not allow any prognostic conclusions. Only the bilateral absence of MEP in response to electrical stimulation was a definitely unfavorable prognostic sign because all of these patients died. In contrast, with magnetoelectric stimulation, neither normal nor absent responses allowed any prognostic conclusions. Therefore, the prognostic value of electrically evoked motor responses is limited, and magnetoelectric stimulation cannot be recommended in this context.     

Motor evoked responses recorded epidurally in a patient with Guillain-Barré syndrome

Summary The case of a 75-year-old man with Guillain-Barré syndrome is presented. By means of transcranial electrical stimulation and epidural recording at the spinal level L2-3, distinct potentials with a latency of 21ms were obtained when the patient was tetraplegic. At the same time electromyographic responses of the thenar and anterior tibial muscles were absent following both transcranial and peripheral nerve stimulation. The patient recovered partially within 4 weeks. It is concluded that epidurally recorded motor evoked responses allow electrophysiological assessment of the descending pathways even in severe cases of Guillain-Barré syndrome and might contribute to a more accurate prediction of outcome.     

Prognostic value of somatosensory- and motor-evoked potentials in patients with a non-traumatic coma

Summary A total of 28 patients with non-traumatic coma were studied both with somatosensory- and motor-evoked potentials. While somatosensory-evoked potentials (SEP) have proved to be useful in predicting the outcome in patients with severe brain damage, the aim of this study was to find out whether the additional evaluation of motor-evoked potentials (MEP) could contribute to a better prediction of the outcome than SEP alone. Our results clearly indicate that in terms of prognostic value, SEP are superior to MEP. Nine patients with bilaterally preserved MEP died, while all of the patients with bilaterally preserved SEP and a central conduction time 6.5 ms survived, with a Glasgow outcome score of 1 to 3. Therefore, we cannot recommend the inclusion of MEP in the prognostic evaluation of patients with non-traumatic coma.     

Linkage of the MHC to familial multiple sclerosis suggests genetic heterogeneity. The Multiple Sclerosis Genetics Group

Multiple sclerosis (MS) is a demyelinating autoimmune disease of the central nervous system. While its etiology is not well understood, genetic factors are clearly involved. Until recently, most genetic studies in MS have been association studies using the case-control design testing specific candidate genes and studying only sporadic cases. The only consistently replicated finding has been an association with the HLA-DR2 allele within the major histocompatibility complex (MHC) on chromosome 6. Using the genetic linkage design, however, evidence for and against linkage of the MHC to MS has been found, fostering suggestions that sporadic and familial MS have different etiologies. Most recently, two of four genomic screens demonstrated linkage to the MHC, although specific allelic associations were not tested. Here, a dataset of 98 multiplex families was studied to test for an association to the HLA-DR2 allele in familial MS and to determine if genetic linkage to the MHC was due solely to such an association. Three highly polymorphic markers (HLA-DR, D6S273 and TNFbeta) in the MHC demonstrated strong genetic linkage (parametric lod scores of 4.60, 2.20 and 1.24, respectively) and a specific association with the HLA-DR2 allele was confirmed (TDT; P < 0.001). Stratifying the results by HLA-DR2 status showed that the linkage results were limited to families segregating HLA-DR2 alleles. These results demonstrate that genetic linkage to the MHC can be explained by the HLA-DR2 allelic association. They also indicate that sporadic and familial MS share a common genetic susceptibility. In addition, preliminary calculations suggest that the MHC explains between 17 and 62% of the genetic etiology of MS. This heterogeneity is also supported by the minority of families showing no linkage or association with loci within the MHC.