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An objective clinical assessment of facial nerve function is described in terms of a facial nerve function index (FNFI). This index is useful in monitoring the return of facial nerve function in patients with facial nerve palsies.
PURPOSE: To clarify the relationship between allodynia and the sprouting of myelinated fibers, we examined whether the administration of nerve growth factor (NGF) affected the paw withdrawal response to non-noxious mechanical stimuli and the sprouting of myelinated fibers into lamina II of the spinal dorsal horn, using a chronic constriction injury model of the sciatic nerve. METHODS: Mechanical allodynia was determined as the threshold of the withdrawal response stimulated by von Frey filaments. Sprouting was examined using horseradish peroxidase conjugated to the B fragment of cholera toxin (B-HRP). NGF was continuously infused into the site of nerve injury for 14 days after nerve ligation. RESULTS: With vehicle infusion, significantly increased responsiveness to mechanical stimuli was observed on postoperative days (PODs) 5, 7, and 14 after ligation, compared with before surgery, and B-HRP-positive fibers were newly localized in lamina II on PODs 7 and 14. Infusion of NGF reduced the responsiveness to mechanical stimuli on 5, 7, and 14 PODs and B-HRP-positive fibers in lamina II on PODs 7 and 14. CONCLUSION: We propose that the suppression of the increased responsiveness to mechanical stimuli produced by NGF could be related to the disappearance of B-HRP-positive fibers in lamina II.
A bilateral study for locating the dorsal root filaments of specific nerves was accomplished from the twelfth thoracic to the coccygeal level and this using 26 fetal and 8 adult specimens. After laminectomy from the thoracic to coccygeal levels, incision of the dural sac permitted visualisation of the dorsal root filaments, the successive rootlets corresponding to each segmental level (T12 to Co1 ) were counted with the aid of a binocular microscope where they penetrated the spinal medulla at the posterior sulcus. Statistical evaluation shows that for each dorsal nerve the average number of root filaments is greater on the right compared with the left. Numbering the dorsal nerve root filaments in the cephalo -caudal direction allows to assert with 99% probability up to the L5 level and with 95% probability up to the S1 level that one is at a given spinal level of the respective segmental range; caudal-cephalic direction numbering permits to affirm with 99% probability up to the S1 level and 95% probability up to the L4 level that one is at a given spinal level of the respective segmental range.
Non-immunosuppressed Swiss mice inoculated with 5000 M. leprae in each hind foot pad were subjected to nerve conduction velocity studies followed by light and electron microscopy and fibre tease of both sciatic nerves at sequential time intervals from the 4th to the 24th month. The conduction velocity was standardized for basal temperature of 35 degrees C and uninoculated mice were used as controls. Progressive changes were noted in conduction velocity from the 6th post inoculation month and correlated with the ultrastructural changes which were first observed at the 4th month. Fibre teasing showed predominent segmental demyelination.
This is a relatively specialised technique aimed more at enhancing the skills of doctors regularly performing local anaesthetic blocks. It is a useful device for confirming the location of major nerves and plexuses proximally, but not necessary for most peripheral nerve blocks.
Nerve injuries about the shoulder in athletes are being recognized with increasing frequency. Prompt and correct diagnosis of these injuries is important to treat the patient and to understand the potential complications and natural history so as to appropriately counsel athletes. This 2-part article is a review and an overview of the current state of knowledge regarding some of the more common nerve injuries seen about the shoulder in athletes.
Pheochromocytoma (PC12) cells have been found to differ from dorsal root ganglionic cells with respect to the modulation of the beta nerve growth factor (beta NGF) binding properties elicited by alpha NGF and gamma NGF. In contrast to our previous results with intact dorsal root ganglionic cells in which only high-affinity binding was blocked, alpha NGF and gamma NGF were found to block competitively all steady-state binding of iodinated beta NGF to PC12 cells at both 37 and 0.5 degrees C. The EC50 that was found for the alpha NGF displacement was 9-10 microM, and the gamma NGF effect had an EC50 of 200 nM, in the predicted range based upon the apparent Kd for dissociation of the alpha beta or the beta gamma complex in solution. The concurrence of the binding EC50 and the Kd for each complex indicates that the formation of alpha beta or beta gamma complexes in solution competes with the process of PC12 receptor binding with 125I-beta NGF. Experiments were carried out examining the dissociation kinetics following the addition of excess unlabeled beta NGF or alpha NGF at both 37 and 0.5 degrees C. Three dissociation components were observed with alpha NGF, in contrast to the two normally found with beta NGF. Lowering the chase temperature to 0.5 degrees C changed the relative contributions made by each component without dramatically changing any of the rate constants. The "slow" receptor was further examined by the dependence on 125I-beta NGF concentration of the slowest component with a chase of either excess alpha NGF or excess gamma NGF at 0.5 degrees C.(ABSTRACT TRUNCATED AT 250 WORDS)
A method for the automatical determination of the amplitude, the transmission time, the conduction velocity and the refractory period of sural nerve was evaluated by help of HISTOMAT-S/MULTI 20 computer. The results of the automatical analysis were compared with those of the conventional method in 50 healthy control persons. There was no significant difference between the dates. Accuracy and correctness were exactly in the same range, but the investigation time of the analysis by help of a computer is much shorter.
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PURPOSE: The effect of high-dose radiation therapy on facial nerve grafts is controversial. Some authors believe radiotherapy is so detrimental to the outcome of facial nerve graft function that dynamic or static slings should be performed instead of facial nerve grafts in all patients who are to receive postoperative radiation therapy. Unfortunately, the facial function achieved with dynamic and static slings is almost always inferior to that after facial nerve grafts. In this retrospective study, we compared facial nerve function in irradiated and unirradiated nerve grafts. METHODS AND MATERIALS The medical records of 818 patients with neoplasms involving the parotid gland who received treatment between 1974 and 1997 were reviewed, of whom 66 underwent facial nerve grafting. Fourteen patients who died or had a recurrence less than a year after their facial nerve graft were excluded. The median follow-up for the remaining 52 patients was 10.6 years. Cable nerve grafts were performed in 50 patients and direct anastomoses of the facial nerve in two. Facial nerve function was scored by means of the House-Brackmann (H-B) facial grading system. Twenty-eight of the 52 patients received postoperative radiotherapy. The median time from nerve grafting to start of radiotherapy was 5.1 weeks. The median and mean doses of radiation were 6000 and 6033 cGy, respectively, for the irradiated grafts. One patient received preoperative radiotherapy to a total dose of 5000 cGy in 25 fractions and underwent surgery 1 month after the completion of radiotherapy. This patient was placed, by convention, in the irradiated facial nerve graft cohort. RESULTS: Potential prognostic factors for facial nerve function such as age, gender, extent of surgery at the time of nerve grafting, preoperative facial nerve palsy, duration of preoperative palsy if present, or number of previous operations in the parotid bed were relatively well balanced between irradiated and unirradiated patients. However, the irradiated graft group had a greater proportion of patients with pathologic evidence of nerve invasion (p = 0.007) and unfavorable type of nerve graft (p = 0.04). Although the irradiated graft cohort had more potentially negative prognostic factors, there was no difference in functional outcome (H-B Grade III or IV) between irradiated and unirradiated graft patients. H-B Grades III, IV, V, and VI were the best postoperative facial nerve functions achieved in 35%, 39%, 13%, and 13% of patients, respectively. The patient with preoperative radiotherapy never recovered any facial nerve function (H-B Grade VI). Median time to best facial nerve function after surgery was longer in the irradiated patients (13.1 vs. 10.8 months), but this was not statistically significant (p = 0.10). Presence of preoperative facial nerve palsy (p = 0.005), duration of preoperative palsy (p = 0.003), and age greater than 60 years at the time of grafting (p = 0. 04) were all negative prognostic factors for achieving a functional facial nerve on univariate analysis. Analysis of age as a continuous variable (p = 0.12) and pathologic evidence of nerve invasion (p = 0. 1) revealed a trend toward negative prognostic factors. Gender, number of previous operations in the parotid bed, extent of surgery at the time of nerve grafting, and type of grafting procedure were not significant prognostic factors. Whether radiotherapy was delivered less than 6 weeks after nerve grafting or more than 6 weeks had no impact on achievement of a functional facial nerve. CONCLUSION: Negative prognostic factors for achieving a functional facial nerve in our series include the presence of preoperative facial nerve palsy, duration of preoperative palsy, and age greater than 60 years. Radiotherapy was not a negative prognostic factor. Comparing irradiated and unirradiated grafts revealed no difference in best facial nerve function achieved, despite the presence of a greater proportion of negative prognostic factors in
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The energy-dependent uptake of (3H)-dopamine (DA), (3H)-norepinephrine (NE) and (3H)-serotonin (5-HT) was measured in synaptosomes isolated from either the whole cerebral hemispheres or the striata of gerbils after cerebral ischemia. Ischemic stroke was induced in the Mongolian gerbil by left common carotid ligation. Uptake values in the affected hemisphere (expressed as a percent of the corresponding control hemisphere) were 32.6% for DA, 35.1% for NE, and 52.0% for 5-HT, 16 hours after stroke. The differential reduction in uptake of the catecholamines relative to 5-HT was significant (p less than 0.005). This differential persisted when measures were made on isolated striata from the ischemic and control hemispheres. In the latter measurements, uptake of DA was 20.7% of control and uptake of 5-HT was 44.7% of control. Uptake of both DA and NE were significantly reduced in animals exhibiting milder circling behavior, while uptake of 5-HT was not. There was no significant reduction of uptake in animals subjected to left common carotid ligation not exhibiting signs of stroke. These studies indicate a selective sensitivity of catecholamine nerve terminals to damage in ischemic stroke.