Strokes in the subinsular territory: Clinical, topographical, and etiological patterns

PubMed ID: 15623721The authors studied 11 patients with subinsular stroke (subIS) located in a deep border zone between lenticulostriate arteries and small insular cortical penetrating branches of the middle cerebral artery. The typical clinical features of subIS were motor deficits (11 patients), sensory disturbances (6 patients), transcortical motor aphasia and hypophonia (2 patients), and transient dysphagia at stroke onset (5 patients). Large artery disease and cardioembolic mechanisms may give rise to subIS by hemodynamic mechanisms

Diagnostic value of lumbar root stimulation at the early stage of Guillain-Barré syndrome

PubMed ID: 22925837Objective: The aim of this study is to investigate diagnostic value of electrical lumbar root stimulation (RS) at the laminar level in the early stage of Guillain-Barré syndrome (GBS). Methods: Fifteen patients (30 sides) and nine controls (17 sides) were included in the study. Conventional nerve conduction studies, needle electromyography, F responses and electrical lumbar RS were obtained from both groups. The needle electrical stimulation was performed at the L2-3 intervertebral level. Vastus lateralis, tibialis anterior and soleus muscles were investigated bilaterally and simultaneously in the first and fourth weeks. Results: In all patients, the amplitudes elicited by lumbar RS were significantly attenuated while the conventional electrophysiological findings were normal and/or not diagnostic in 6 of 15 patients (40%) within the first week. Motor latencies by the lumbar RS were prolonged in the patients, compared to the controls, but the results were not statistically significant. Conclusions: M-responses elicited by lumbar RS appear to be helpful in disclosing proximal conduction abnormalities of GBS early in the course. Significance: Lumbar RS seems to be a useful method in making the diagnosis of GBS early and there is no considerable side effect of this particular method. © 2012 International Federation of Clinical Neurophysiology

Diagnostic value of cauda equina motor conduction time in lumbar spinal stenosis

PubMed ID: 22418591Objective: Lumbar spinal stenosis (LSS) is a chronic degenerative disease with pain in the back, buttocks and legs aggrevated by walking and relieved after rest without associated vascular disease of lower extremities observed in patients between 50 and 60. years. Several studies, using different methods indicated an association between slowing or blocking of root-nerve conduction and LSS. None of the previous research had applied the more conceivable methods such as recording the cauda equina potentials from the lumbar level or stimulating the spinal roots within the canal using either leg nerves or muscles. In this study, electrical lumbar laminar stimulation was used to demonstrate prolongation of cauda equina motor conduction time in lumbar spinal stenosis. Methods: Twenty-one LSS patients and age matched 15 normal control subjects were included in the study. Lumbar laminar electrical stimulation from L1 and L5 vertebra levels were applied by needle electrodes. Compound muscle action potential (CMAP) from gastrocnemius muscles were recorded bilaterally. Latency difference of CMAPs obtained from L1 and L5 spine levels were accepted as the cauda equina motor conduction time (CEMCT). Results: CEMCT was significantly longer in patient group when compared to normal controls. Mean latency difference was 3.59 ± 1.07. msec on the right side, 3.49 ± 1.07. msec on the left side in LSS group, it was 1.45 ± 0.65. msec on the right side, 1.35 ± 0.68. msec on the left side on normal control group (p< 0.0001). Conclusions: The prolongation of CEMCT was statistically and individually significant in patient group. This may indicate that lower lumbosacral motor roots were locally and chronically compressed due to lumbar spinal stenosis. Lumbar spinal stenosis may have induced local demyelination at the cauda equina level. Significance: Since the prolongation of CEMCT was found only in patients with LSS, the method of laminar stimulation can be chosen for patients with uncertain diagnosis of LSS. © 2012 International Federation of Clinical Neurophysiology