Electrophysiological improvement following decompression surgery in tarsal tunnel syndrome

Plantar nerve conduction studies 14 months to 3.5 years after decompression surgery in 3 cases of tarsal tunnel syndrome showed an improvement in motor conduction as well as in sensory nerve conduction. This electrophysiological improvement was associated with clinical improvement. However, minor abnormalities still existed in sensory nerve conduction in all 3 cases.     

Focal conduction block in a case of tarsal tunnel syndrome

We report a case of tarsal tunnel syndrome (TTS) with focal conduction block across the tarsal tunnel (TT). A 46‐year‐old woman had pain in the left foot, sensory loss on the plantar surface, and positive Tinel sign over the TT. TTS was confirmed by magnetic resonance imaging (MRI) scan and surgery. Motor nerve conduction studies showed focal conduction block across the TT. Conduction block has rarely been reported in TTS. In this case, conduction block provides evidence for focal demyelination as the primary pathological process in TTS. Muscle Nerve, 2010     

Tarsal tunnel syndrome in a patient on long-term peritoneal dialysis: case report

Tarsal tunnel syndrome (TTS) is defined as the entrapment of the posterior tibial nerve in the tarsal tunnel of the ankle. The etiologies of tarsal tunnel syndrome are mainly the presence of a ganglion, osseous prominence with tarsal bone coalition, trauma, varicose veins, neurinoma, hypertrophy of the flexor retinaculum, or systemic disease (rheumatoid arthritis, ankylosing spondylitis). However, no specific cause can be identified in some cases. Patients with chronic renal failure tend to develop peripheral nerve entrapment and carpal tunnel syndrome is the best-known peripheral entrapment neuropathy among them. Contrary to carpal tunnel syndrome, tarsal tunnel syndrome is observed less frequently in chronic renal failure patients. The common presenting symptoms of TTS are paresthesias and/or pain in the plantar side of the foot. Motor symptoms are rarely detected. Diagnosis is made primarily by electroneuromyographic studies and physical examination. Surgery is the treatment of choice and the outcome is generally favourable. In this report, we present a patient with tarsal tunnel syndrome complicating peritoneal dialysis.     

Medial plantar neuropathy

We have described four cases of medial plantar neuropathy that was confirmed by the near-nerve sensory nerve conduction study. The common compression site in medial plantar neuropathy is at the entrance to the fibromuscular tunnel behind the navicular tuberosity, distal to the tarsal tunnel, where Tinel's sign is localized.     

Electrophysiological findings in entrapment of the median nerve at wrist and elbow

In 117 consecutive patients with carpal tunnel syndrome and 11 patients with a compression syndrome of the median nerve at elbow, motor and sensory conduction along the median and ulnar nerves and quantitative electromyography were compared with findings in 190 normal controls of the same age. In 25% of patients with carpal tunnel syndrome in whom motor conduction and EMG were normal, the lesion was located from abnormalities in sensory conduction. The fact that conduction along the same fibres was moderately slowed from digit to palm, severely slowed across the flexor retinaculum, and normal from wrist to elbow indicates that slowing was due to demyelination at the site of compression. Fifteen per cent of the patients with carpal tunnel syndrome had clinical and electrophysiological signs of ulnar involvement. In the other patients conduction along the ulnar nerve was as in 100 normal controls. Compression at the elbow was located by electromyographical findings rather than by abnormalities in conduction.     

Nerve ultrasound in electrophysiologically verified tarsal tunnel syndrome

Introduction: Tarsal tunnel syndrome (TTS) arises from tibial nerve damage under the flexor retinaculum of the fibro‐osseus tunnel at the medial malleolus. It is notoriously difficult to diagnose, as many other foot pathologies result in a similar clinical picture. We examined the additional value of nerve ultrasound in patients with tarsal tunnel syndrome confirmed by nerve conduction. Methods: We performed a retrospective analysis of nerve ultrasound changes in electrophysiologically confirmed TTS spanning our records from 2007 to 2015. Results: Nine feet with TTS were identified, all of which showed abnormal nerve ultrasound findings, which in 6 feet, led to identification of the underlying cause. Conclusions: This study shows that nerve ultrasound is abnormal in all cases of electrophysiologically verified TTS. The pattern of nerve abnormality is varied. This, and the fact that in the majority of patients causation was identified, suggests nerve ultrasound should form part of standard work‐up for TTS. Muscle Nerve 53 : 906–912, 2016     

Anomalies of ulnar nerve conduction in different carpal tunnel syndrome stages

Impairment of ulnar sensory fibers at the wrist has recently been documented in moderate/severe carpal tunnel syndrome (CTS). This has been interpreted as a consequence of compressive forces transmitted to Guyon's canal by high pressure in the carpal tunnel or comorbidity between ulnar neuropathy and CTS. The main aim of the present study was to identify any ulnar nerve conduction impairment in the early stages of CTS. The relation between ulnar and median nerve conduction in all CTS severity stages was also assessed. Ulnar nerve sensory conduction at the wrist was investigated in 580 hands with CTS. Significant changes in ulnar nerve conduction were present even in the early stages of CTS. A significant, positive correlation was also found between CTS severity and conduction abnormalities of ulnar sensory fibers. These findings make the hypothesis of comorbidity weak. Based on the above results and on reports of high pressure in Guyon's canal in CTS, ulnar nerve conduction abnormalities may be caused in part by compressive forces progressively transmitted to the canal by increasing pressure in the carpal tunnel with increasing CTS severity. This does not exclude other causative factors such as subclinical traumatic damage acting on median and ulnar fibers.     

Electrophysiological evidence of “nerve entrapment syndromes” and subclinical peripheral neuropathy in progressive systemic sclerosis (scleroderma)

We report the electrophysiological findings and the management of 5 subjects with progressive systemic sclerosis (PSS) and clinical evidence of nerve entrapment. Three had carpal tunnel syndrome (CTS), 1 bilateral CTS and right tarsal tunnel syndrome (TTS) and 1 Guyon's canal syndrome. Only 1 patient (with CTS) showed significant clinical improvement after surgical decompression; the other 4 demonstrated a slight recovery of conduction without lasting clinical relief after conventional treatment. To explain these failures we hypothesized that these entrapment syndromes were the clinical expression of underlying diffuse damage to the peripheral nervous system (PNS). The conduction values of nerves unaffected by entrapment syndromes were within normal limits, but almost all distal velocities were below the mean of controls. Such subclinical distal peripheral neuropathy was also verified in a selected sample of 17 patients with PSS, without clinical symptoms or signs of PNS involvement. In these 17 cases the mean distal sensory and motor conduction findings of the median, ulnar, sural and tibial nerves were significantly lower than those of a control group, while no significant differences were found in the more proximal tracts of the same nerves. Furthermore, 3 of the 17 patients showed classical electrophysiological evidence of TCS and TTS without any clinical symptoms. We concluded that the subjects with PSS had subclinical polyneuropathy which may become plain polyneuropathy or nerve entrapment syndromes perhaps induced by other risk factors.     

Carpal tunnel syndrome - electrodiagnostic aspects of fifty seven symptomatic hands

Electrodiagnostic data of fifty seven symptomatic extremities with carpal tunnel syndrome (CTS) are described. Practice recommendations made by American Academy of Neurology, American Association of Electrodiagnostic Medicine and American Academy of Physical Medicine and Rehabilitation regarding electrodiagnostic studies were considered while confirming CTS diagnosis by electrodiagnostic studies. Median sensory nerve conduction studies were the commonest abnormalities noted. The median orthodromic sensory latencies were prolonged in 86% and sensory nerve action potential amplitude abnormalities were seen in 82%. Prolongation of the conduction in the short segment across the wrist in the median nerve was seen in 96.5% and the difference in the conduction between median and ulnar nerve across the wrist was significant in all the 57 extremities. The median motor latencies were prolonged in 67% of hands. Higher incidence of electrodiagnostic abnormalities observed in this study might be due to inclusion of patients with severe disease.     

Sensory conduction from digit to palm and from palm to wrist in the carpal tunnel syndrome

In normal subjects the maximum and minimum conduction velocity along sensory nerve was the same from digit to palm and from palm to wrist. Severe slowing from palm to wrist in patients with the carpal tunnel syndrome was often associated with only slight slowing from digit to palm. The distal slowing is attributed to a reversible constriction of nerve fibres, an assumption supported by the recovery in distal conduction velocity as early as two and a half months after decompression. The sensory velocity from wrist to elbow was normal or supernormal, whereas the motor velocity was often slightly decreased. The exclusion of the normal segment of the median nerve distal to the flexor retinaculum made it possible to demonstrate abnormalities across the flexor retinaculum in patients with clinical signs of carpal tunnel syndrome in whom distal motor latency and sensory conduction from digit to wrist were normal.     

Long-term clinical and electrophysiological results of local steroid injection in patients with carpal tunnel syndrome

The aim of this study was to evaluate the effects of local steroid injection on both the clinical symptoms and motor and sensory conduction of the median nerve in carpal tunnel syndrome (CTS). Using a standard evaluation and treatment protocol, we prospectively studied steroid injection in 32 hands in 24 patients (mean age: 50.7 +/- 10 years; 23 women and 1 man). To determine the normal median nerve values, 42 normal controls (mean age: 39.1 +/- 10.5 years; 21 women and 21 men) were also studied. At follow-up, clinical symptom scores and signs of CTS, as well as electrophysiological variables of the median nerve, showed a significant trend towards improvement with respect to baseline values (p < 0.01). By the end of the one-year follow-up period, the symptoms had remitted completely or partially in 27 hands (84.4%). In addition to the relief of the symptoms, motor nerve conduction abnormalities had improved in 62.6% of hands, and anti-dromic sensory nerve conduction abnormalities in 62.5%. In cases where a sensory nerve action potential (SNAP) could be obtained, the efficacy of this treatment was found to be relatively higher than in cases in which SNAP was absent (p < 0.01).     

Evaluation of age, body mass index, and wrist index as risk factors for carpal tunnel syndrome severity.

To determine the role of personal variables as risk factors for carpal tunnel syndrome (CTS) and their relationship to severity of nerve conduction abnormality, we studied 210 consecutive symptomatic CTS patients and 320 controls subjects without CTS symptomatology or known systemic disorders. The CTS group was classified according to the severity of nerve conduction changes. The risk factors for CTS and its severity were assessed by means of univariate and multivariate analysis. Presence of CTS was significantly related to increase of body mass index (BMI) and wrist index. More severe nerve conduction abnormalities were associated with greater age and wrist index but not with higher BMI.     

Myopathy in acromegaly. Report of two cases

Acromegaly is often associated with neuromuscular disorders. Most of them are caused by compression of nerves with hypertrophic bone and soft tissues or complications of diabetes mellitus. Myopathy has rarely been reported in the Japanese literature. We report two cases with myopathy out of 14 cases of acromegaly. Case 1 is a 62-year-old woman who developed muscle weakness and atrophy in the shoulder girdle, pelvic girdle and femoral regions after a 10-year history of acromegaly. She showed positive Gowers' sign and normal DTRs. Basal growth hormone (GH) level in plasma was 1076 ng/ml. Electromyograms (EMG) obtained from the deltoid and rectus femoris muscles revealed typical myopathic abnormalities; an excess of small-amplitude, short-duration, polyphasic motor unit potentials. Histological examinations of the rectus femoris muscle showed diffuse atrophy of both type I and type II fibers. She also had bilateral carpal tunnel syndrome and bilateral tarsal tunnel syndrome, which were confirmed by nerve conduction studies of median nerves and posterior tibial nerves. A cranial computed tomography (CT) scan demonstrated sellar mass with suprasellar extension. She underwent transsphenoidal adenomectomy and radiation therapy. GH level lowered to 29 ng/ml, however, myopathy remained unchanged for 3 years after the surgery. Case 2 is a 38-year-old woman who had undergone partial removal of a pituitary adenoma 9 years after the onset of acromegaly. Basal GH level in plasma before the surgery had been 1694 ng/ml and was still high after the surgery (100-505 ng/ml). The patient developed proximal muscle weakness and atrophy 4 years after the surgery.(ABSTRACT TRUNCATED AT 250 WORDS)     

Do nerve conduction studies predict the outcome of carpal tunnel decompression?

Patients (n = 3336) who had been tested for suspected carpal tunnel syndrome (CTS) were contacted by postal questionnaire and their opinions sought of the overall subjective outcome of any treatments using a five-point rating scale. Operative results were compared with preoperative nerve conduction, clinical and demographic variables, and a multiple logistic regression analysis used to identify significant prognostic factors. Among 1268 surgical procedures that were identified, the overall surgical success rate was 69%. Preoperative nerve conduction study findings, greater age, lower symptom scores, longer disease duration, and male gender were significant predictors of poor outcome. Nerve conduction studies had the strongest effect, with patients with middle-grade abnormalities having better results than those with either very severe or no abnormality. Surgical carpal tunnel decompression has a significant failure rate. The preoperative nerve conduction studies account for a proportion of the total variation in outcome.     

Post-traumatic tarsal tunnel syndrome: interest of muscular MRI

INTRODUCTION: Tarsal tunnel syndrome is a compressive neuropathy of the tibial nerve with multiple causes. This syndrome is difficult to diagnose and can be missed because of its subjective symptomatology. OBSERVATION: In our patient, suspected post-traumatic tarsal tunnel syndrome was confirmed at MRI. This case highlights muscle signal anomalies caused by their denervation in the tibial nerve territory. CONCLUSION: MRI can provide supplementary information to the electromyography (EMG) and contribute to positive and etiologic diagnosis of peripheral nerve lesions.     

Forearm mixed nerve conduction velocity: questionable role in the evaluation of retrograde axonal atrophy in carpal tunnel syndrome.

The objective of this study was to determine whether forearm mixed nerve conduction velocity (Fmix) reflects the real conduction velocity of forearm motor nerve (Fmot) and forearm sensory nerve (Fsen) fibers passing through the carpal tunnel. Forearm mixed nerve conduction velocity is presumed to be indicative of the conduction velocity of the median nerve over the forearm. Therefore, Fmix is used widely to assess the causes of slowing forearm conduction velocity in carpal tunnel syndrome. However, some authors claim that Fmix comes chiefly from the undamaged fibers in carpal tunnel syndrome, and thus cannot replace Fmot or Fsen in the evaluation of retrograde axonal atrophy. Patients with clinical symptoms and signs of carpal tunnel syndrome confirmed with standard electrodiagnosis were included. Age-matched volunteers served as control subjects. Conduction velocities across the wrist and over the forearm were measured, including those of the wrist sensory (Wsen), wrist motor (Wmot), and wrist mixed nerves (Wmix); and forearm mixed (Fmix), forearm motor (Fmot), and forearm sensory nerves (Fsen). The authors compared and correlated Wsen, Wmot, and Wmix; and Fmix, Fmot, and Fsen respectively. The mean values of Wsen, Wmot, Wmix, Fmix, Fmot, and Fsen of the control subjects less those of corresponding conduction velocity of carpal tunnel syndrome patients were designated Wsen N, Wmot N, Wmix N, Fmix N, Fmot N, and Fsen N respectively and were compared and correlated again. Wrist motor nerve conduction velocity, Wsen, and Wmix were significantly lower in carpal tunnel syndrome patients, and Fmot and Fsen but not Fmix were reduced significantly when compared with control subjects. Mean wrist sensory nerve conduction velocity, Wmot N, and Wmix N; and Fsen N and Fmot N showed good correlation except for Fmix N, suggesting that Fmix reflects the conduction velocity of undamaged fibers in carpal tunnel syndrome. Forearm mixed nerve conduction velocity cannot replace Fmot or Fsen in the assessment of retrograde axonal atrophy in carpal tunnel syndrome. In the disease state, Fmix possibly represents the conduction velocity of the palmar cutaneous branch.     

Tibial nerve branching in the tarsal tunnel

To provide an anatomical basis for diagnosis and treatment of the tarsal tunnel syndrome, the relationship of the tibial nerve to the tarsal tunnel was investigated in 31 feet of 20 cadavers. The bifurcation into medial and lateral plantar nerves occurred within 1 cm of the malleolar-calcaneal axis in 90% of the feet. Seven of 11 bilateral specimens were bilaterally symmetrical in the bifurcation location; three varied within 1 cm between sides; and in the fourth cadaver, one side bifurcated at 3 cm and the other at 5 cm proximal to the axis. The calcaneal nerve showed great variability; in seven cadavers, it arose within, in eight cadavers proximal to, and in five cadavers there were multiple branches arising both proximal to and within the tarsal tunnel.     

神经肌电图检查对肘管综合征与腕尺管综合征鉴别诊断的价值

目的探讨神经肌电图检查在肘管综合征(CuTS)与腕尺管综合征(UTS)鉴别诊断中的应用价值。方法对35例单侧上肢临床症状、体征符合CuTS或UTS的患者进行尺神经、正中神经远端运动潜伏期(DML)、运动传导速度(MCV)、感觉传导速度(SCV)、波幅(AMP)及尺神经肘部寸移电位检测;尺神经、正中神经所支配的肌肉肌电图(EMG)检测。结果 35例患者中,CuTS 29例(83%),UTS 4例(11%),正常2例(6%),总异常率94%。结论神经肌电图检测可明确鉴别肘管综合征与腕尺管综合征,为临床诊断及治疗提供依据,有重要的临床应用价值。     

Ultrasonographic measurements in cubital tunnel syndrome

The cubital tunnel is the most common site of ulnar nerve entrapment. Previous ultrasound studies have demonstrated enlargement of the ulnar nerve in cubital tunnel syndrome but did not report on the cubital tunnel itself. Twenty-two individuals with cubital tunnel syndrome were evaluated with nerve conduction studies and ultrasound. The ultrasound measurement that most strongly correlated with conduction velocity was the ratio of ulnar nerve to cubital tunnel cross-sectional area with the elbow flexed. Measurement of this ratio may improve the diagnostic accuracy of ultrasound in cubital tunnel syndrome, although further investigation is needed.     

Hereditary neuropathy with liability to pressure palsy combined with schwannomas of the median and medial plantar nerves

A 42-year-old woman was surgically treated for carpal tunnel syndrome, revealing schwannoma of the median nerve. A year later, she developed a tarsal tunnel syndrome. At time of this diagnosis, hereditary neuropathy with liability to pressure palsies (HNPP) was diagnosed genetically and a schwannoma of the medial plantar nerve was treated surgically. The occurrence of HNPP and schwannomas in the same patient might be purely coincidental, but it is tempting to speculate that they share a common genetic basis.