Tarsal tunnel release restores sensations in sole for diabetic sensorimotor polyneuropathy

BackgroundDiabetic sensorimotor polyneuropathy (DSPN) is the commonest form of neuropathy. Loss of sensations in sole leads to diabetic foot ulcers (DFU) and its complications. Surgical decompression has been used in the treatment of diabetic peripheral neuropathy, however; its effectiveness has been questioned.Purpose of this study was to evaluate the sensory recovery in sole after tarsal tunnel decompression (TTD) in patients having DSPN.MethodsThirteen patients (Age28-70 years, average 35.57 years; 7 Males, 6 Females; 20 feet) with DSPN and positive Tinel's sign over the tarsal tunnel were included in the study. Pre and post-operative sensory tests performed on the sole included tests for touch, pain, temperature, pressure, vibration perception threshold (VPT) and two-point discrimination (2-PD). Results were classified as per British Medical Research Council (MRC) scoring system.Results–Sixteen feet were followed-up for 6 months. In all feet perception of touch, pain and pressure recovered. Temperature perception recovered in 75% feet. VPT came to normal range (16.81V) from 40.37 V and 2-PD came down to average of 6.0 mm from preoperative average of11.2 mm.MRC scale improved from S0 in 5 feet and S2 in 15 feet to S₃₊ in all 16 feet.There were no ulcers or amputation in operated limbs during follow up period of 6 months.ConclusionsTTD improves plantar sensations in diabetic neuropathy and prevents ulcers and its related complications.     

股前外侧皮瓣和腓肠神经营养血管皮瓣联合修复足部套状撕脱伤

目的 探讨吻合神经的股前外侧皮瓣和腓肠神经营养血管皮瓣联合修复足部套状逆行撕脱伤的临床效果。方法 足部套状逆行撕脱伤患者14例，男10例，女4例；年龄16-58岁，平均31岁。切取带股前外侧皮神经的股前外侧皮瓣移植至足部，将股前外侧皮神经与足底内侧神经吻合，并将足底外侧神经植人股前外侧皮瓣的足底修复区；转移腓肠神经营养血管皮瓣修复足外侧部。将腓浅神经及其分支分别与腓肠内、外侧皮神经吻合。按照Swanson等制定的周围神经损伤临床疗效评定方法，将感觉分成S1-S55级，将感觉恢复范围分为R1（〈25％）、R2（25％-50％）、R3（50％-75％）与R4（75％～100％）4级。结果 14例移植皮瓣均成活，术后外形良好。术后6个月足部感觉恢复分级：足内侧，S26足，S38足；足底，S29足，S35足；足外侧，S23足，S311足。足部感觉恢复范围：足内侧，R14足，R210足；足底，R18足、R26足；足外侧，R14足、R210足。术后9个月足部感觉恢复分级：足内侧，S37足，S47足；足底，S22足，S36足，S46足；足外侧，S38足，S46足。足部感觉恢复范围：足内侧，R25足，R38足，R41足；足底，R28足，R34足，R42足；足外侧，R25足，R37足，R42足。结论 吻合神经的股前外侧皮瓣和腓肠神经营养血管皮瓣联合修复足部套状逆行撕脱伤具有供区隐蔽、实用，受区感觉恢复理想的特点。     

Sensory neurotization of muscle: past,present and future considerations

Research has shown that temporary innervation by a sensory neuron can provide trophic support to a denervated muscle and stave off muscular atrophy until motor neuron transfer is viable. This so called ‘sensory protection’ allows for improved outcomes when motor reinnervation able to occur. The theoretical benefit of sensory neurotization is hypothesized to maintain tissue architecture of the end organ due to tropic effects of stimulation. While the literature supports direct motor neurotization from 2 to 4 months post-injury, patient factors including the location of the injury and loss of nerve can preclude this therapeutic window. When direct neurotization is not possible, or there is a long distance to traverse for reinnervation, sensory neurotization may be beneficial. The theorized trophic stimulation enabling end organ architectural maintenance provided by sensory neurotization has been shown to allow for delayed direct motor neurotization without the irreversible sequelae of prolonged denervation. This is a review of the pathogenesis of nerve injury and a literature review of sensory neurotization. An analytical search of the literature in PubMed was performed in order to find articles pertinent to the topic of sensory neurotization, including experimental data from both animal models and case reports in humans.     

Assessing Decreased Sensation and Increased Sensory Phenomena in Diabetic Polyneuropathies

Loss of sensation and increased sensory phenomena are major expressions of varieties of diabetic polyneuropathies needing improved assessments for clinical and research purposes. We provide a neurobiological explanation for the apparent paradox between decreased sensation and increased sensory phenomena. Strongly endorsed is the use of the 10-g monofilaments for screening of feet to detect sensation loss, with the goal of improving diabetic management and prevention of foot ulcers and neurogenic arthropathy. We describe improved methods to assess for the kind, severity, and distribution of both large- and small-fiber sensory loss and which approaches and techniques may be useful for conducting therapeutic trials. The abnormality of attributes of nerve conduction may be used to validate the dysfunction of large sensory fibers. The abnormality of epidermal nerve fibers/1 mm may be used as a surrogate measure of small-fiber sensory loss but appear not to correlate closely with severity of pain. Increased sensory phenomena are recognized by the characteristic words patients use to describe them and by the severity and persistence of these symptoms. Tests of tactile and thermal hyperalgesia are additional markers of neural hyperactivity that are useful for diagnosis and disease management.Altered sensation (loss or increased sensory phenomena) may be early and prominent manifestations of varieties of polyneuropathy associated with diabetes. These neuropathies may be classified into four major varieties: distal symmetric sensorimotor polyneuropathies (typical and atypical diabetic sensorimotor polyneuropathy [DSPN]); compression and entrapment varieties (median neuropathy at the wrist [carpal tunnel syndrome]); radiculoplexus neuropathies (lumbosacral [Bruns Garland syndrome], thoracic, and cervical); and cranial neuropathies (1–3). Although none of these varieties are uniquely associated with DM, all varieties are more prevalent in diabetes. Underlying mechanisms are different among these varieties (1–3).Decreased sensation and increased sensory phenomena are not being adequately evaluated in clinical medicine. Possible reasons include the following: 1) methodologies of such assessments are not sufficiently emphasized in training of health care professionals; 2) insufficient time is taken in their evaluation (i.e., to assess kind, severity, and distribution of sensation loss, let alone to assess increased sensory phenomena); 3) reference values are often not available or used; 4) standard techniques of assessment are typically not used, for example, to assess clinical sensation with cotton wool, disposable stick pins, tuning forks, or other; 5) validated quantitative sensation tests (QSTs) are generally not used; and 6) compensation for such testing is unavailable.Here we review the neurobiology underlying decreased and increased sensory phenomena occurring in diabetic polyneuropathies (DPNs) and methodologies of their assessment. Especially emphasized in this review are improved methods to screen for sensation loss of feet, with the goal of preventing ulcers and neurogenic arthropathy; use of composite scores of neuropathic signs; computer-assisted (smart) QSTs; nerve conduction (NC) measurements; and counts of intraepidermal nerve fibers as neuropathy end points for therapeutic trials of DPN severity. Also described are measures of increased sensory phenomena.     

Decompression of peripheral nerve trunks in leprosy to prevent the development and progression of deformities

Background:

Peripheral nerve involvement results in deformities in leprosy. High doses (40-60 mg) of steroids along with anti-leprosy drugs is the preferred treatment, even though 70-75% cases still develop deformity. Early surgical decompression of nerves gives better chances of preventing deformity. We have analyzed the role of early surgical decompression in such cases.

Materials and Methods:

Five hundred nerves (386 ulnar, 60 median and 54 posterior tibial) not responding to the medical treatment in 12 weeks, were undertaken for external and internal nerve trunk decompression. These cases were followed up for five to 20 years at various intervals.

Results:

The pain in nerve (neuralgia) recovered in all cases of ulnar, median and posterior tibial nerves. Full sensory recovery to pinprick and feather or cotton wool touch was seen in 50% cases of all the three nerves. Twenty percent cases maintained the preoperative levels of sensory status. Plantar ulcers healed within six months after decompression of posterior tibial nerve but six cases showed recurrence. Overall motor recovery in ulnar nerve was 89% and 70% in median nerve.

Conclusions:

The sensory recovery restores protective sensation which prevents secondary injuries. The improvement of motor power gives better function and improves the appearance, which in the absence of surgical intervention was not possible.     

靶器官前神经束交叉吻合治疗难修复的神经疾患临床与实验研究

目的: 采用靶器官前神经束交叉吻合术治疗周围和中枢神经损害或疾患造成支配的效应器官功能障碍并评价其治疗效果。方法: 采用靶器官前神经束交叉吻合11种术式, 治疗12类神经系统疾患及其并发症, 包括脊髓空洞症、脊髓圆锥或马尾神经损伤、腰骶神经根损伤、中枢或周围神经损伤等所引起的手足溃疡、骨髓炎、Charcot关节病等, 同时通过动物实验在损伤及修复后的不同时间进行功能和形态学检查。结果: 40处溃疡或骨髓炎中有30处愈合, 有效率为75%, 并且相应肌肉运动、皮肤感觉和关节活动功能得到有效恢复, 动物实验切断神经经过交叉吻合4周后可恢复正常的体感诱发电位, 并在原神经支配区皮肤神经末梢与其胞体之间形成新的通路。结论: 靶器官前神经束交叉吻合术是治疗周围和中枢神经损害或疾患后效应器官功能障碍的有效方法。     

Neuronal regeneration in denervated muscle following sensory and muscular neurotization

Background and purpose?Neurotization of denervated muscles has been shown to improve muscle bulk, but the neuronal regeneration response has not been compared previously in different surgical techniques of neurotization. Thus, using a rat model of experimental skeletal muscle denervation, we studied neuronal regeneration following sensory neurotization by two methods: sensory nerve to motor branch of muscle and direct sensory nerve implantation to muscle.

Material and methods?The lateral head of the gas-trocnemius muscle was denervated in 36 rats, of which the first 12 served as denervated controls. In the second group of 12, the sural nerve was anastomozed to the motor branch of the gastrocnemius muscle (sensory-to-motor nerve neurotization) and in the remaining 12 rats the sural nerve was split into 4 fascicles and embedded into 4 quadrants of the muscle (direct sensory nerve-to-muscle neurotization). Immunohistochemistry was used to examine nerve fibers in muscle containing the sensory neuropeptides substance P (SP) and calcitonin gene-related peptide (CGRP), and general neuronal marker protein gene product 9.5 (PGP 9.5).

Results?Semiquantitative analysis showed that, compared to the control side, the number of nerve fibers on the experimental side was highest (p < 0.01) for group III (direct sensory nerve-to-muscle neurotization) for all 3 markers. The difference was 71%, 298%, and 254% for PGP 9.5, CGRP, and SP, respectively.

Interpretation?This method may be a good option for inducing neuronal regeneration in denervated muscles, and has therapeutic implications for prevention of atrophy of denervated muscles and as an adjunct for reconstruction of soft tissue defects.     

Keller procedure for the treatment of resistant plantar ulceration of the hallux

A retrospective chart review was performed on 11 patients (13 feet) who underwent a modified Keller procedure for the treatment of recalcitrant neuropathic diabetic ulcers to the plantar aspect of the hallux between 1994 and 1998 to evaluate the postoperative results and complications. Diabetic patients with hallux rigidus, adequate vascular status, documented peripheral neuropathy, and at least 6 months of conservative care for treatment of a Wagner grade I and II ulceration were included in the study. Patients with active soft tissue infections or osteomyelitis were excluded. All primary ulcers healed within 6 months postoperatively. After 1-year of follow-up, 8 feet remained completely free of ulcers and 5 transfer ulcers occurred. Four infections developed; 3 from the surgical wound and 1 from a transfer ulcer. Based on these findings, the modified Keller procedure may be an appropriate intervention for hallux ulcerations provided the surgeon and the patient are aware of its limitations and possible outcomes.     

神经端侧吻合的腓肠神经营养血管皮瓣修复足踝部缺损的临床研究

目的利用腓肠神经皮瓣所带的腓肠神经内侧支和外侧支与创面周围的腓深神经或胫神经端侧吻合，重建皮瓣的感觉以及恢复足背外侧感觉。以解决患者足踝部感觉缺失的痛苦。方法从2000年1月至2003年5月，收治足踝部软组织缺损40例(43足)，其中A组20例(22足)直接进行腓肠神经营养血管皮瓣移植，B组20例(21足)在切取皮瓣时，在腓肠神经近端多取1～2cm腓肠神经内侧支和外侧支，在覆盖创面时，先分离出创面周围的腓浅神经或胫神经，把腓肠神经断端与腓浅神经或胫神经作端侧吻合，再按腓肠神经营养皮瓣处理。两组都在术后3、6、9个月分别进行随访，按照感觉检查分级标准把皮瓣和足背外侧感觉恢复情况分成S1～S5 5级，并按感觉恢复范围分成R1：小于25％；R2：25％～50％，R3：50％～75％，R4：75％～100％。结果术后3个月，皮瓣及足背外侧皮肤感觉恢复情况：A组，S1 18足、S2 4足、R1 22足，B组，S1 17足、S2 4足，R1 21足；两组皮瓣和足背外侧皮肤感觉恢复情况无差别、术后6个月，皮瓣及足背外侧皮肤感觉恢复情况：A组，S1 15足、S2 6足、S3 1足，R1 18足、R24足，B组，S16足、S36足、S49足，R2 4足、R3 12足、R4 5足；B组无论皮瓣及足背外侧感觉恢复的等级还是感觉恢复的范围都比A组好。术后9个月，皮瓣及足背外侧皮肤感觉恢复情况：A组，S1 14足、S2 7足、S3 1足，R1 17足、R2 5足，B组，S3 2足、S44足、S5 15足，R35足、R416足；B组皮瓣及足背外侧感觉基本恢复正常，A组感觉恢复进展不大。供体神经功能无明显影响。结论作腓肠神经营养皮瓣移植时行腓肠神经与创面周围胫神经或腓浅神经端侧吻合手术简单，对胫神经或腓浅神经无不良影响，而皮瓣和足背外侧感觉恢复较好。     

家兔再造阴茎神经植入后远期机械感觉纤维再生研究

目的 探讨机械感觉纤维在神经植入后的再生情况。方法 用单纤维放电引导技术，从机械感觉传入纤维再生检出率、快慢适应感受器的比例、再生感受器的阈值及再生纤维传导速度等方面，研究了家兔再造阴茎游离神经移植后机械感受器的再生规律。结果 术后9个月再生机械感受纤维数量接近正常水平；快适应机械感受器再生数量多，成熟度较高；慢适应感受器再生数量较少。术后9个月再生纤维传导速度及机械感觉阈值尚未达到正常。结论 家兔再造阴茎游离神经移植后快慢适应机械纤维均有功能恢复，但恢复效果不一致。     

Nerve lesions associated with limb-lengthening

BACKGROUND: Nerve injury is one of the most serious complications associated with limb-lengthening. We examined the risk, assessment, and treatment of nerve lesions associated with limb-lengthening. METHODS: We retrospectively studied the records on 814 limb-lengthening procedures. Nerve lesions were defined by clinical signs and symptoms of motor function impairment, sensory alterations, referred pain in the distribution of an affected nerve, and/or positive results of quantitative sensory testing with use of a pressure specified sensory device. RESULTS: Seventy-six (9.3%) of the limbs had a nerve lesion. Eighty-four percent of the nerve lesions occurred during gradual distraction, and 16% occurred immediately following surgery. The pressure specified sensory device showed 100% sensitivity and 86% specificity in the detection of nerve injuries. The patients in whom the lesion was diagnosed with this method, or with this method as well as with nerve conduction studies, had significantly faster recovery than did those diagnosed on the basis of clinical symptoms or nerve conduction studies alone (p = 0.02). Patients undergoing double-level tibial lengthening and those with skeletal dysplasia were at higher risk for nerve lesions (77% and 48%, respectively). Nerve decompression was performed in fifty-three cases (70%). The time between the diagnosis and the surgical decompression was strongly associated with the time to recovery (p = 0.0005). Complete clinical recovery was achieved in seventy-four of the seventy-six cases. CONCLUSIONS: Early detection based on signs and symptoms or testing with a pressure specified sensory device improves the prognosis for nerve injury that occurs during limb-lengthening. Of the methods that we used to identify neurologic compromise, testing with the pressure specified sensory device was the most sensitive. Aggressive early treatment (slowing the rate of lengthening and/or performing decompression) allows continued lengthening without incurring permanent nerve injury. When indicated, decompression of the affected nerve should be performed as soon as possible, thereby improving the chances of and shortening the time to complete recovery.     

Surgical treatment for total root avulsion type brachial plexus injuries by neurotization: A prospective comparison study between total and hemicontralateral C7 nerve root transfer

Purpose: We conducted a clinical study to evaluate the effects of neurotization, especially comparing the total contralateral C7 (CC7) root transfer to hemi‐CC7 transfer, on total root avulsion brachial plexus injuries (BPI). Methods: Forty patients who received neurotization for BPI were enrolled in this prospective study. Group 1 (n = 20) received hemi‐CC7 transfer for hand function, while group 2 (n = 20) received total‐CC7 transfer. Additional neurotization included spinal accessory, phrenic, and intercostal nerve transfer for shoulder and elbow function. The results were evaluated with an average of 6 years follow‐up. Results: Group 1 had fewer donor site complications (15%) than group 2 (45%); group 2 had significantly better hand M3 and M4 motor function (65%) than group 1 (30%; P = 0.02). There was no difference in sensory recovery. Significantly, better shoulder function was obtained by simultaneous neurotization on both suprascapular and axillary nerves. Conclusions: Total‐CC7 transfer had better hand recovery but more donor complications than hemi‐CC7. Neurotization on both supra‐scapular and axillary nerves improved shoulder recovery. © 2013 The Authors. Microsurgery published by Wiley Periodicals, Inc. Microsurgery 34:91–101, 2014.     

A touch pressure sensory assessment of the surgical treatment of the tarsal tunnel syndrome

Background

Decompressive tarsal tunnel surgery may improve dysfunctional plantar foot sensation in, patients with tarsal tunnel syndrome and peripheral neuropathy. However, quantitative sensory, assessment is lacking.

Method

Quantitative sensory threshold evaluation of 42 feet in 37 consecutive (29 non-diabetic and 8 diabetic) patients was done before and after surgical decompression for tarsal tunnel syndrome. Insensitivity was documented quantitatively (grams force) before and after surgery using a graded series of twenty Semmes–Weinstein monofilaments applied to the anatomic nerve regions of the plantar aspect of the foot.

Results

Sensory evaluation at an average of 12 months after surgery showed significant improvement, of mean sensory threshold, compared with preoperative values, for medial calcaneal, medial plantar, and lateral plantar nerves.

Conclusion

Quantitative sensory assessment with a graded series of twenty Semmes–Weinstein, monofilaments showed significant sensory improvement in the medial calcaneal, medial plantar, and, lateral plantar nerves after posterior tibial nerve decompression.     

Internal neurolysis.

One hundred seventy-eight patients diagnosed with a lower extremity nerve compression syndrome were treated conservatively using orthopedic, medical, and physical therapy modalities. Eighty-two per cent of these patients improved and recovered, and required no further care. Eighteen per cent of these patients did not recover or experience significant improvement in their sensory or motor loss. This chronic group was treated by internal neurolysis. Ninety-five per cent of this chronic group treated by internal neurolysis improved. Only 5% did not have significant prolonged relief or improvement and eventually required excision of a sensory peripheral nerve. Internal neurolysis may not be indicated in those patients who suffer from transient sensory paresthesias; conservative care and/or an external peripheral nerve decompression may suffice. Internal neurolysis is indicated in those patients who have constant sensory aberations or motor loss from a chronic peripheral nerve compression syndrome or any other nerve lesion that has not responded well to conservative care or to an external nerve decompression procedure. Internal neurolysis, in addition to conservative care regimes presented here, has been found to be effective in reversing heretofore thought to be irreversible pain syndromes in the lower extremity even when significant atrophy has already occurred.     

Management of hand palsies in isolated C7 to T1 or C8, T1 root avulsions

Thirteen patients were operated on for hand palsies in cases of C7 to T1 or C8, T1 root avulsions. Finger flexion and intrinsic function were paralyzed in all patients. Finger extension was paralyzed in 12 patients. Wrist flexion and extension were present in all patients. Tendon transfers were performed to restore the different functions. The extensor carpi radialis longus was transferred to the flexor digitorum profundus. The brachioradialis tendon was transferred to the flexor pollicis longus tendon for thumb flexion, with a tendon translocation procedure in 6 patients. Intrinsic function was reanimated with passive capsulorrhaphy techniques or other equivalent techniques in 9 patients. Extensor tenodesis was performed to restore hand opening with active wrist flexion in all patients. Moreover, sensory neurotization was performed to restore sensation on the ulnar side of the hand. All patients recovered finger flexion with an average pulp-to-palm distance of 2 cm. Finger extension occurred in 30 degrees wrist flexion. The average Kapandji score was 3. Key pinch was present in all patients. The average grip strength was 8 kg; the average key pinch was 5 kg. All patients recovered a protective sensation with a mean time of 19.5 months. Injury with C7 to T1 or C8, T1 root avulsions is a rare entity. Motor nerve surgery is not possible in these cases. However, surgery remains a challenge and may greatly improve these patients. Therefore, we propose a new tendon transfer and sensory neurotization protocol.     

Altered behavioural responses and functional recovery in rats following sciatic nerve compression and early vs late decompression

Objective: The aim of the study was to examine sensory behaviour and functional recovery in rats during nerve compression and after decompression. Compression injury is a far more common condition than nerve transection. The condition is characterised by numbness and a tingling/burning sensation, and some patients experience pain and allodynia during compression or after decompression treatment. The aetiology is in many cases unknown. Thus, further studies are of great importance for the understanding of this condition.

Methods: In the present study, behavioural responses to tactile stimulation, thermal pain, as well as functional sensorimotor behaviour were investigated in rats before, during severe compression, and after decompression. The sciatic nerve of the rats was experimentally compressed for 3 or 28 days, whereafter surgical release, i.e. decompression, of the nerve was performed and the rats were examined up to ～9 weeks.

Results: An altered behaviour was found in response to compression injury, which is mitigated after early decompression treatment.

Conclusions: These findings indicate that early intervention during severe compression injuries is of great importance for recovery and restoration of nerve function and, thus, should have an impact on clinical routines regarding treatment of compression injuries.     

Neurovascular Bundle Decompression without Excessive Dissection for Tarsal Tunnel Syndrome

Tarsal tunnel syndrome (TTS) is an entrapment neuropathy of the posterior tibial nerve and its branches in the tarsal tunnel. We present our less invasive surgical treatment of TTS in 69 patients (116 feet) and their clinical outcomes. The mean follow-up period was 64.6 months. With the patient under local anesthesia we use a microscope to perform sharp dissection of the flexor retinaculum and remove the connective tissues surrounding the posterior tibial nerve and vessels. To prevent postoperative adhesion and delayed neuropathy, decompression is performed to achieve symptom improvement without excessive dissection. Decompression is considered complete when the patient reports intraoperative symptom abatement and arterial pulsation is sufficient. The sensation of numbness and/or pain and of foreign substance adhesion was reduced in 92% and 95% of our patients, respectively. In self-assessments, 47 patients (68%) reported the treatment outcome as satisfactory, 15 (22%) as acceptable, and 7 (10%) were dissatisfied. Of 116 feet, 4 (3%) required re-operation, initial decompression was insufficient in 2 feet and further decompression was performed; in the other 2 feet improvement was achieved by decompression of the distal tarsal tunnel. Our surgical method involves neurovascular bundle decompression to obtain sufficient arterial pulsation. As we use local anesthesia, we can confirm symptom improvement intraoperatively, thereby avoiding unnecessary excessive dissection. Our method is simple, safe, and without detailed nerve dissection and it prevents postoperative adhesion.     

Experimental study of the trophic effects of reinnervation of pedicled muscle flaps]

Any transplanted muscle flap undergoes atrophy to an extent depending mainly on its innervation. Other factors such as the tension at rest and the duration of ischemia play a secondary role. An experimental study was carried out in rats to quantitatively assess the extent of atrophy according to the mode of transplant reinnervation. The gracilis muscle was used as an experimental model of pedicled flap after verifying the axial nature of its vasculature. Results were assessed after three months from a histological point of view and in terms of postoperative weight in four different groups of 13 rats. The first three groups reproduced situation encountered in clinic: intact nerve, sutured nerve, resected nerve. A graft sensory neurotization technique was implemented in the fourth group by diverting a neighboring sensory nerve. The best trophic results were obtained when the motor nerve remained continuous. The sensory neurotization technique did not significantly influence the trophic evolution after three months.     

Contribution of the distal nerve sheath to nerve and muscle preservation following denervation and sensory protection

The goal of this study was to determine the contribution of the distal nerve sheath to sensory protection. Following tibial nerve transection, rats were assigned to one of the following groups: (1) saphenous-to-tibial nerve neurorrhaphy; (2) saphenous-to-gastrocnemius neurotization; (3) unprotected controls (tibial nerve transection); or (4) immediate common peroneal-to-tibial nerve neurorrhaphy. After a 6-month denervation period and motor reinnervation, ultrastructural, histologic, and morphometric analyses were performed on the distal tibial nerve and gastrocnemius muscle cross-sections. Sensory axons neurotized to muscle maintain existing muscle integrity, as demonstrated by less fibrosis, collagenization, and fat deposition, more than unprotected muscle, and preserve the distribution pattern of fast twitch fibers. However, neurorrhaphy of the sensory nerve to the distal tibial nerve (involving the distal nerve sheath) improves existing endoneurial sheath structure, demonstrated by reduced collagen, and enhances regeneration, shown by improved axon-to-Schwann cell coupling and increased axon area. The authors conclude that sensory protection of muscle does not require the distal nerve sheath, but that preservation of the distal sheath may contribute to enhanced nerve regeneration.     

Management of cervical spinal cord trauma in Southern California.

Acute cervical spinal cord injuries were reviewed in 356 patients treated by the neurosurgical community in Southern California. Neurological recovery was compared in operated and nonoperated patients with complete and incomplete cervical myelopathies. The complications of nonsurgical and surgical therapy are identified. No neurological improvement was noted in any patient with a complete lesion who underwent early surgical decompression. In those with incomplete sensorimotor paralysis, it was difficult to document any effect of surgical decompression on neurological recovery. Patients with some degree of sensory preservation had a similar incidence of motor recovery in both surgical and nonsurgical groups. With complete sensorimotor paralysis, anterior cervical fusion within the first week of injury was associated with increased pulmonary morbidity.