Tibial Nerve

Posterior tibial nerve—monitor flexion of the big toe and foot... 

The nerve fibers most vulnerable to -hexane exposure in rats were the branches of the tibial nerve serving the calf muscles of the hind limbs, followed in order by the plantar nerve branches supplying the flexor digitorum brevis muscle, and then sensory plantar nerve branches innervating the digits. As... 

In a 10-month study, monkeys exposed to 1,000 ppm 2-hexanone had abnormal results in electrodiagnostic tests (Johnson et al. 1977). There was a progressive and statistically significant decrease in the maximum motor conduction velocity of the sciatic-tibial nerves starting at 4 months of exposure and a decrease in the maximum conduction velocity of the ulnar nerves starting at 1 month. Decreased amplitude of evoked muscle action potential was also seen at 1,000 ppm. 

Results of 100 ppm exposure were similar to those of controls except for a statistically significant decreased response in the ulnar nerve at the 1 and 3 month measurements and in the sciatic-tibial nerve only at 9 and 10 months. Recovery to pre-exposure values for motor-conduction velocities took 2 months for the 100 ppm group and 6 months for the 1,000 ppm group. 

The effect of hemodilution with colloids on somatosen-sory-evoked potentials in non-premedicated volunteers has been reported (9). In seven subjects, blood (20 ml/kg within 30 minutes) was removed and simultaneously replaced by gelatine 3% or etherified starches 6%. After 30 minutes, blood was retransfused. Median and posterior tibial nerve somatosensory-evoked potentials were recorded from the cortex, second cervical vertebra, Erb s point, and first lumbar vertebra. Hemodilution with gelatine or etherified starches or retransfusion did not affect somatosensory-evoked potentials, provided normovolemic conditions were maintained. 

Loss of all sensation and strength after chemical neurolysis occurred in the distribution of the posterior tibial nerve after mixed sensorimotor block of this nerve, in this case after five blocks of the nerve or its motor branches over several years. Some strength and partial sensation returned after surgical lysis of excessive fibrous tissue at the site where the injection had been performed (27). 

Chemoneurectomy with aqueous phenol injection in 116 selected patients with spastic cerebral palsy, in whom 246 peripheral nerves were blocked, caused complications in 11 patients (28). Five patients, in whom the posterior tibial nerve was blocked, developed paresthesia one had complete loss of sensation, which recovered spontaneously after a couple of days and three had pain at the site of injection or in the distribution of the injected nerve, lasting for a few days to a month. In another study there was a 3% complication rate in 98 blocks (29), while adverse effects occurred in nine of 150 blocks, with muscle weakness in eight cases and painful paresthesia in one (30). 

Intramuscular injection of phenol can cause pain and swelling in the muscle (33,34). Sometimes, a firm nodular swelling develops in the calf 1-3 weeks after intramuscular neurolysis (35), particularly when larger quantities of phenol are injected into the intramuscular branches of the tibial nerve. This can usually be avoided by limiting the quantity of phenol injected to the minimum necessary and by applying cold packs to the injected area after the procedure. 

Petrillo CR, Knoploch S. Phenol block of the tibial nerve for spasticity a long-term follow-up study. Int Disabil Stud 1988 10(3) 97-100. 

Bain, J.R., Mackinnon, S.E. and Hunter, D.A. (1989) Functional evaluation of complete sciatic, peroneal, and posterior tibial nerve lesions in the rat. Plast. Reconstr. Surg. 83 129- 136. 

Nerve conduction in organophosphorus-induced delayed neuropathy (OPIDN) was studied using adult white leghorn hen.s treated with ui-2-t -cresyl pho.sphate or di- -butyl-2,2-dichlorovinyi phosphate (Robertson et al, 1987). Refractoriness was decreased in the tibial nerve but it was incrca.sed in the sciatic nene, and the. strength-duration threshold was elevated for both nerves. However, it is not known how these changes are related to the mechanism of OPIDN,... 

Three of the 52 electrodes placed for lower extremity stimulation experienced changes in the responses of the muscles. One of these was due to a disconnection at the connector site between the implant and the electrode lead. This was repaired and the electrode continued to function without further problems. The remaining two electrodes (biceps femoris and tibial nerve) were not replaced, as they did not impact function for the subjects involved. 

About half of the untreated or long-standing diabetics develop peripheral neuritis. The symptoms are diffuse aches and pains without the signs of peripheral nerve involvement, a typical bilateral sciatica with abolition of the achillian reflexes, severe ataxia with intentional tremor in the leg reminiscent of tabes dorsalis (pseudotabes peripherica), and severe neuritis of a single nerve, for example, the ulnar or anterior tibial nerve resulting in paralysis and sensory loss. 

Nervous system In a retrospective study to analyse the incidence of peripheral neuropathy in 157 patients with continuous sciatic nerve block in the popliteal fossa, three patients with an associated common superficial peroneal and sural nerve injury were identified via clinical and electromyographical studies [21 ]. In 44% percent of the patients US guidance was combined with a nerve stimulator technique. The authors conclude that methodological bias or technical problems (lateral vs posterior approach, US guidance) may account for the higher (1.9%) than average (0-0.5%) rate of peripheral neuropathy. It is of note that anatomically the common superficial peroneal and sural nerves were more affected than the tibial nerve, possibly due to their superficial location. 

Before injection, fhe participants were given an ultrasound-guided posterior tibial nerve block with 2% lidocaine. Primary outcomes were pain, as measured by the foot health status questionnaire (0-100 point scale), and plantar fascia thickness, measured by ultrasoxmd at 4, 8, and 12 weeks. Reduction in pain at 4 weeks favoured the dexa-methasone group by 10.9 points, Between-group differences for pain scores af 8 and 12 weeks were not statistically significant. Plantar fascia thickness measured at 4 weeks favoured the dexamethasone group by -0.35 mm. At 8... 

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