The effects of Hypericum perforatum on nerve regeneration after sciatic nerve injury have not yet been evaluated in all its aspects yet. In this experimental study, the effect of Hypericum perforatum on injured nerve tissue was histologically and biochemically investigated. Motor functional healing was surveyed by gait analysis.

Rats were divided into 3 groups: Group I (n=8) was intact control group and no intervention and treatment was applied to this group. Group II (n=16) was surgical control group and Group III (n=16) was Hypericum perforatum group. After the operation, while any treatment was performed on Group II, 30 mg/kg dose Hypericum perforatum extract was intraperitoneally administered to the Group III per day for 8 weeks from the 1^st day of post-op. Gait analysis was made to all rats for functional evaluation at 2^nd, 3^rd, 4^th, 6^th and 8^th weeks, and sciatic functional index (SFI) was evaluated. At the end of the eighth week, sciatic nerve tissue samples were taken from the sacrificed rats. Tissues were examined biochemically, histologically and immnohistochemically. Malondialdehyde (MDA) as an indicator of oxidative stress and main antioxidant enzyme [superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT)] levels were biochemically measured. The nerve degeneration and regeneration were histologically viewed, and also cell count was immnohistochemically done by having done anti-S100 staining.

It was seen that measurement results of SFI were statistically significantly difference between groups (p<0,001). In the sciatic nerve tissue samples taken from the rats, it was not determined a statistically significant difference between MDA, SOD, GPx and CAT levels detected by ELISA method (p>0,05). In the histological evaluation, it was seen that Hypericum perforatum affected positively the regeneration and immunohistochemically, it was found a statistically significant difference between the anti-S-100 positive cell numbers.

The obtained results in this study show that; Hypericum perforatum, which was intraperitoneally administered on rats subjected to nerve injury, has affected positively the nerve regeneration and it can also provide an insight to future studies.

We undertook a retrospective analysis of 306 procedures on 233 patients, with a mean age of 12 years (1 to 21), in order to evaluate the use of somatosensory evoked potential (SSEP) monitoring for the early detection of nerve compromise during external fixation procedures for limb lengthening and correction of deformity. Significant SSEP changes were identified during 58 procedures (19%). In 32 instances (10.5%) the changes were transient, and resolved once the surgical cause had been removed. The remaining 26 (8.5%) were analysed in two groups, depending on whether or not corrective action had been performed in response to critical changes in the SSEP recordings. In 16 cases in which no corrective action was taken, 13 (81.2%, 4.2% overall) developed a post-operative neurological deficit, six of which were permanent and seven temporary, persisting for five to 18 months. In the ten procedures in which corrective action was taken, four patients (40%, 1.3% overall) had a temporary (one to eight months) post-operative neuropathy and six had no deficit.

After appropriate intervention in response to SSEP changes, the incidence and severity of neurological deficits were significantly reduced, with no cases of permanent neuropathy. SSEP monitoring showed 100% sensitivity and 91% specificity for the detection of nerve injury during external fixation. It is an excellent diagnostic technique for identifying nerve lesions when they are still highly reversible.

The diagnosis of nerve injury using thermotropic liquid crystal temperature strips was compared blindly and prospectively against operative findings in 36 patients requiring surgical exploration for unilateral upper limb lacerations with suspected nerve injury. Thermotropic liquid crystal strips were applied to affected and non-affected segments in both hands in all subjects. A pilot study showed that a simple unilateral laceration without nerve injury results in a cutaneous temperature difference between limbs, but not within each limb. Thus, for detection of a nerve injury, comparison was made against the unaffected nerve distribution in the same hand.

Receiver operating characteristic curve analysis showed that an absolute temperature difference ≥ 1.0°C was diagnostic of a nerve injury (area under the curve = 0.985, sensitivity = 100%, specificity = 93.8%).

Thermotropic liquid crystal strip assessment is a new, reliable and objective method for the diagnosis of traumatic peripheral nerve injuries. If implemented in the acute setting, it could improve the reliability of clinical assessment and reduce the number of negative surgical explorations.