Distal Lower Limb Research Articles

Systemic sclerosis in aquaporin-4 antibody-positive longitudinally extensive transverse myelitis

We report on the first patient with a relapsing, anti-aquaporin-4 (AQP-4) antibody-positive, longitudinally extensive transverse myelitis (LETM) who developed systemic sclerosis (SSc). A 62-year-old woman, who presented with bilateral, distal lower limb and perineal numbness, developed clinical manifestations and paraclinical features of SSc. Spinal cord imaging revealed lesions that were consistent with LETM. Patient's serum was positive for neuromyelitis optica (NMO)-IgG/AQP-4 antibodies. High-dose intravenous corticosteroids improved the neurological symptoms. The present case expands the list of autoimmune systemic diseases that occur in neuromyelitis optica spectrum disorders associated with NMO-IgG/AQP-4 antibodies.

Perforasomes

Sir: We would like to compliment Dr. Sanit and his team for proposing the concept of the perforasome.1 Mentioned in the article, the concepts of perforasome and “linking vessels” between adjacent perforasomes give evidence to our study2 in 1998 that the perforators have a chain-link vessel in the adipose layer. Based on the advanced anatomical and graphic methods, the authors propose the concept of the perforasome. We consider it to be great progress after the “angiosome” concept of Taylor; however, we have a few questions. Priority of perfusion. The authors describe two forms of linking vessels: Direct linking vessels travel within the suprafascial and adipose tissue layers. Indirect linking vessels communicate with adjacent perforators by means of recurrent flow through the subdermal plexus. There are communicating branches between them. On dynamic computed tomographic angiography, we note the recurrent flow from the subdermal plexus into a communicating branch that connects with a large direct linking vessel (Video 3). Does this video indicate that indirect linking vessels are flooded more easily than direct linking vessels? It is important to understand which type of vessel has priority of perfusion, especially when we design an adipofascial flap without skin. Pressure of perfusion. There is no detailed value of pressure mentioned in this article. We noted that high perfusion pressure through the single perforator opens multiple direct and indirect linking vessels and allows perfusion of four or five perforasomes, as shown in Figure 5. However, by clinical practice, we found that even if the flap is designed according to the linking vessel, the distal part of a long flap has a poor blood supply. Thus, we want to define the area that can be filled by a single perforator by physiologic pressure. Neurovascular axis. Our investigation and many other studies have confirmed that if the superficial sensitive nerves are incorporated in the subcutaneous adipose tissue, the perforators will give specific branches to these structures to form a paraneural vascular plexus to nourish them (i.e., a distally based sural neurofasciocutaneous flap including the sural nerve component could be designed and used for repair of soft-tissue defects in the distal lower limb). We look forward to more detailed information about how the vessels link perforators to the paraneural vasculature. When designing a flap, the surgeon has to estimate the value of taking a nerve in the flap, because he or she has to face the sensible lack of a donor site at the same time. To sum up the above arguments, we think that the anatomical study of vessels has moved from static research to dynamic research. We believe that, in the near future, researchers will be able to simulate physiologic blood flow to help surgeons design the most suitable flaps for patients. Ying-qi Zhang, M.D. Shi-min Chang, M.D. Xin Wang, M.D. Tongji Hospital Shanghai, China

PHENOTYPE OF A PATIENT WITH RECESSIVE CENTRONUCLEAR MYOPATHY AND A NOVEL BIN1 MUTATION

Centronuclear myopathies (CNM) are rare congenital myopathies characterized by centrally located nuclei in a variable number of muscle fibers. CNM are caused by mutations in myotubularin ( MTM1 ; X-linked)1 or dynamin-2 ( DNM2 ; autosomal dominant or sporadic).2 One patient with sporadic CNM harboring a ryanodine receptor-1 gene mutation was also described.3 Recently, mutations in amphiphysin-2 ( BIN1 ) were shown to cause autosomal recessive (AR) CNM in 3 consanguineous families.4 We characterize the phenotype of an adult patient with CNM with a novel BIN1 mutation. ### Case report. The male patient belonged to a Moroccan family with 5 siblings of which 1 boy died at age 1 year of unknown cause. There was no familial history of neuromuscular diseases and no known consanguinity. Pregnancy and birth were normal. He had delayed motor milestones, walked at age 3.5 years, and experienced difficulties in running and climbing stairs since childhood. He developed speech at 3.5 years of age, had mild mental retardation (IQ 70), and had ptosis since childhood. Since 11 years of age, he showed diffuse muscle atrophy and progressive muscle weakness, resulting in difficulties in walking, with frequent falls. Subsequently, he developed problems carrying weights and fatigability. At age 21 years (figure, A), he showed weakness in axial muscles (2–4/5), diffuse weakness in upper limbs (2–3/5), in proximal (3–4/5) and distal lower limbs, with ankle dorsiflexion and plantar flexion equally affected (2/5), foot eversion at 0/5 and inversion at 4/5. He had symmetric scapular winging, Gowers' sign, hyperlordosis, and waddling gait. He presented facial diplegia (figure, B), ptosis, vertical ophthalmoparesis, dysphonia, and dysarthria, without dysphagia. He presented an elongated face, high-arched palate, retrognathism, protruding ears, thin hands with long small fingers, left-sided kyphoscoliosis, bilateral pes cavus, and equinovarus. Tendon reflexes were absent and sensory testing was normal. He had no clinical …

Familial amyloid polyneuropathy: A clinico-pathologic study

In familial amyloid polyneuropathy (FAP), destruction of nerve fibres is related to accumulation of mutated transthyretin (mTTR) derived amyloid deposits (AD) in the endoneurium. Liver transplantation (LT), which removes the main source of mTTR, does not prevent deterioration of the clinical condition in all recipients. Material and methodsWe evaluated the distribution of AD in the central and peripheral nervous system in order to better understand the pathophysiology of FAP and the potential role of lesions of nerve blood vessels and of mTTR released by choroid plexuses (CP). Forty nerve biopsy specimens and 3 autopsy cases, including 7 patients who underwent liver transplantation, all from patients with symptomatic FAP and DNA mutation of the TTR gene, were included. ResultsPatients were ranged into three categories:Group 1:Patients with early neuropathic manifestations. Five patients carrying an amyloidogenic mutation closely followed to detect early neuropathic manifestations experienced paresthesiae with stockings temperature and pains deficit in two; uncertain changes in the others. Sensory nerve action potentials (SNAPs) were normal. Biopsy was performed to detect morphological changes as an indication for early therapeutic intervention. Only one patient had decreased MF and unmyelinated fiber (UF) density.Group 2:Patients with marked sensory-motor and dysautonomic polyneuropathy (35 patients). Non dissociated sensory loss prevailed in distal limbs, while sensory defect predominated on temperature and pain sensations in proximal limbs and anterior trunk. Weakness and amyotrophy predominated in distal lower limbs. Fiber loss massively predominated on UF.Group 3:Patients at terminal stage of the disease. All 3 patients had been bedbound for months with flaccid quadriplegia and non dissociated sensory deficit affecting all four limbs, up to proximal thighs, arms and anterior trunk along with severe autonomic dysfunction. There was virtually no surviving nerve fibers in distal nerves. Morphological changesAmyloid predominated around endoneurial capillaries in 37 patients, with occlusion/destruction of endoneurial capillaries in 15 nerves at late stages of the disease. Post-mortem examination showed amyloid in choroid plexuses and perivascular spaces in the brain and around blood vessels penetrating the endoneurium, following arachnoid and connective tissue septae. Destruction of endoneurial blood vessels is a late event in the natural course of FAP. Morphological findings were similar in patients who underwent liver transplantation and in those who did not. The distribution of amyloid in areas communicating with the subarachnoid space suggests that mutated TTR released in the CSF may move to the endoneurial fluid and accumulate in peripheral nerves, accounting for lack of efficacy of liver transplantation in some individuals.

Do Not Forget the Distal Lower Limb Veins in Screening Patients With Spinal Cord Injuries for Deep Venous Thromboses

In this prospective study, we aimed to document the rate and localization of deep venous thromboses in patients with spinal cord injuries. Patients with paraplegia or tetraplegia were screened by a serial color duplex sonography protocol for deep venous thrombosis within the first 36 hours after admission, at day 7, and at day 21. Sonography was performed by a complete scan including the veins below the knee. A total of 139 patients were included (19-90 years, 63.5% male). Cumulative rate of deep venous thrombosis after 3 duplex scans was 45.3% (n = 63). In 71.4% (n = 45), thromboses were localized below the knee. Because of the relevant number of distal vein thromboses, inclusion of the calf veins during screening scans is suggested. Further studies are needed to analyze the clinical benefit of diagnosing and treating distal vein thromboses.

Quinine-responsive muscle cramps in X-linked bulbospinal muscular atrophy Kennedy

Letter to the editor X-linked bulbo-spinal muscular atrophy (BSMA, Kennedy disease) is a rare motor- neuron-disease due to a CAGrepeat expansion in the androgen-receptor-gene on Xq12 [1, 2]. BSMA presents clinically with slowly progressive, amyotrophic quadruparesis, bulbar involvement, wasting, fasciculations, and gynecomastia. Muscle cramps are not infrequent in BSMA [3] but therapy is usually ineffective. The patient is a 39-year-old male with a history of postural tremor since age 12 years, dysarthria since age 15 years ubiquitous muscle cramps since age 29 years, prohibiting sleep and increasing since age 36 years, general myalgias since age 32 years, general fasciculations predominantly of the thighs since age 34 years, myoclonic jerks and dyspnea upon exercise since age 36 years, and easy fatigability upon exercise. Symptoms worsened during episodic relapses 3–4 times/year, each lasting 2–3 weeks. The family history was positive for tremor (grandfather and uncle from the mother’s side, brother), and for his other presenting symptoms (uncle from the mother’s side). The patient’s mother was symptom-free. Clinical neurologic examination at age 39 years showed dysarthria, fibrillations of the tongue, weakness of the facial muscles, weakness of head anteflexion (M5-), diffuse weakness of both upper-limbs with proximal and rightsided predominance (M4 to M5-), reduced tendon reflexes, fasciculations and myoclonic jerks on the lower-limbs, predominantly of the thighs. There was discrete wasting of the upper- and distal lower-limbs.

Inflammatory plaque with peripheral nodules: A new specific finding of cutaneous polyarteritis nodosa

Cutaneous polyarteritis nodosa commonly affects the distal lower limbs, presenting as nodules, ulcers, and livedo reticularis. We report five cases to illustrate a new specific presentation of cutaneous polyarteritis nodosa on the trunk or proximal extremities. In the acute stage, lesions were tender erythematous plaques. On palpation, 1- to 2-cm diameter subcutaneous nodules were found along the periphery. The lesions responded to dapsone, aspirin, nonsteroidal antiinflammatory drugs, or systemic steroids and healed with postinflammatory hyperpigmentation. Systemic polyarteritis nodosa did not develop in any patient after a follow-up time ranging from 9 months to 9 years. The presence of small nodules at the periphery of an inflammatory plaque was a useful clinical clue, because this prompted us to suspect cutaneous polyarteritis nodosa when we encountered similar cases later, which could be confirmed histologically. In conclusion, cutaneous polyarteritis nodosa can present as inflammatory plaques on the trunk and proximal extremities, and the presence of peripheral nodules around these plaques constitutes a useful clinical clue to its diagnosis.

Nephrogenic systemic fibrosis: the first Italian gadolinium-proven case

Nephrogenic systemic fibrosis (NSF) is a systemic disease, recently described in patients with advanced chronic kidney disease (CKD), characterized by progressive scleromyxedema-like fibrotic involvement mainly of the skin. We describe the case of a 66-year-old woman on chronic hemodialysis for end-stage renal failure, also affected by hypothyroidism, secondary hyperparathyroidism and occluding arteriopathy, for which she underwent a contrast-enhanced magnetic resonance angiography of the lower limbs in February 2007. One month later, she began complaining of progressive, painful distal lower limb stiffness, which subsequently spread to all four limbs and to the whole trunk. A deep-skin biopsy, taken from an affected area, showed gadolinium deposits. The case reported is, to best of our knowledge, the first Italian case of NSF. This diagnosis should be considered with care in CKD patients with a recent exposure to a gadolinium-based contrast agent, complaining of limb stiffness, especially in the presence of risk factors.

A Case of Central Core Disease with Distal Lower Limb Weakness - Case Report -

A Case of Central Core Disease with Distal Lower Limb Weakness - Case Report -

Distally based sural fasciomyocutaneous flap: Anatomic study and modified technique for complicated wounds of the lower third leg and weight bearing heel

The reconstruction of the distal third leg and weight-bearing heel, especially when complicated with infection and/or dead space, remains a challenge in reconstructive surgery. The distally based sural neurofasciomyocutaneous flap has been proved a valuable tool in repair of the soft tissue defects of those areas. In this report, we present the results of the anatomical study on vascular communication between the suprafascial sural neurovascular axis and the deep gastrocnemius muscle and a modified technique in clinical applications for reconstruction of the soft tissue defects in the distal lower leg and heel. Six lower limbs of fresh cadavers were injected with red gelatin and dissected. A constant vascular connection with average four musculo-fasciocutaneous perforators with diameter 0.2-0.5 mm was identified in the overlapping area between the suprafascial sural neurovascular axis and the deep gastrocnemius muscle. Based on these findings, a modified distally based sural neurofasciomyocutaneous flap including the distal gastrocnemius muscle component was designed and used for repairs of the soft tissue defects in the distal lower limb and plantar heel pad in six patients. The blood supplies of flaps comprised either the peroneal perforator and adipofascial pedicle or the peroneal perforator only. The average size of the fasciocutaneous flap was 51 cm(2), and the muscle component 17.7 cm(2). All flaps survived uneventfully. Our results suggest that this technical modification could provide wider range for applications of the distally based sural neurofasciomyocutaneous flap in repair of the soft tissue defects of the lower extremity and heel.

Management of a comminuted tibial fracture in a patient with primary lymphoedema

Multi-fragmented fractures of the distal tibia can be a diffi-cult injury to treat and when complicated by primary lym-phoedema they become a therapeutic challenge for thetrauma surgeon. Lymphoedema is described as tissue fluidaccumulation that arises as a result of impaired lymph drai-nage [12]. It is usually a chronic, unrelenting condition andcan interfere with the management of concomitant condi-tions or injuries including wound and fracture healing [2].Current management options for lymphoedema include pre-venting infection, limb positioning, exercise, compressiongarments and bandages, pneumatic pumps and lymphaticmassage.Lymphoedema praecox is the most common sub-type ofprimary lymphoedema [10] presenting between the ages of 2and 35 years old. The condition is almost ten times morecommon in women than in men and the oedema is usuallyunilateral and limited to the distal lower limb [1,11].It is well recognised that the soft tissue envelope plays animportant role in fracture healing and therefore fracturemanagementshouldincludeminimallyinvasivetechniquestolimit interference of the soft tissue. External fixators areemployedinthisregardandareoftenanexcellentsolutiontomanagement of both open and closed fractures. The Ilizarovexternal fixator has been well documented in such fracturemanagement [4,8]. It is a modular, fine wire and ring devisethat allows early loading and mobilisation [7].ToourknowledgetheuseoftheIlizarovexternalfixatorincases complicated by lymphoedema has not been describedin the English literature. We present a case of a patient withprimarylymphoedemapraecoxandacomminutedfractureofherdistaltibiatodescribeanapproachtothemanagementofthis complex dual pathology.

Recovery from acute paraplegia due to spontaneous spinal, epidural hematoma under minimal-dose acetyl-salicylic acid

Spontaneous spinal epidural hematoma (SEH) has not been reported under anti-thrombotic therapy with acetyl-salicylic acid (ASA) in a dosage of 50 mg/d. Spinal MRI, emergency laminectomy. A 77-yo, HIV-negative female under longterm treatment over three years with ASA 50 mg/d for varicositas, prescribed by her general practitioner, experienced sudden onset back pain with radiation towards both knees after getting up in the morning. One-and-a-half hours later she also developed ascending hypesthesia and weakness originating from both distal lower limbs. Three hours after onset, hypesthesia had reached the T10-level bilaterally and she had become paraplegic. There was reduced intestinal motility, stool incontinence, and urinary hesitancy. MRI of the thoraco-lumbar spine demonstrated a SEH T9-L1 indenting the dural sack and compressing the myelon. Immediately after emergency laminectomy T10-12 with micro-surgical evacuation of the clot, 12 h after onset, she could move both legs again and was able to walk with support 7 days after surgery. This case shows that SEH occurs under a minimal dose of ASA and that such patients rapidly recover upon immediate surgical decompression and evacuation of the hematoma.

Distribution pattern of infrageniculate arterial obstructions in patients with diabetes mellitus and renal insufficiency – implications for revascularization

Diabetes mellitus (DM) and renal insufficiency (RI) were shown to be associated with an obstructive lesion pattern favouring distal lower limb arterial segments in patients with peripheral arterial disease (PAD). We hypothesized that presence of DM is associated with pronounced involvement of the tibioperoneal arteries, whereas RI predominantly affects the pedal arch. A consecutive series of PAD patients (mean age 75 +/- 10 years, 40 women) with RI alone (n = 15), RI and DM (n = 25), DM alone (n = 25) and without RI or DM (n = 25) underwent diagnostic angiography. We analyzed the obstructive burden of different segments of the infrageniculate arterial tree using the Bollinger score as well as accessibility of pedal arteries for bypass surgery. In patients with DM and in patients with RI the mean total obstructive burden was higher in pedal as compared to tibioperoneal arteries (9.79 +/- 4.60 vs. 6.99 +/- 3.45, p = 0.03;10.50 +/- 5.53 vs. 6.88 +/- 4.12, p = 0.05, respectively). However, rates of patency of at least one pedal artery were significantly lower in patients with RI and RI/DM as compared to controls (47% and 48% vs. 80%, respectively; p = 0.007), whereas patency was comparable between patients with diabetes alone and controls (72% vs. 80%, ns). Rates of viability of pedal arteries as an attachment site for distal bypass was 80%, 68%, 47% and 44% in controls, patients with DM alone, RI alone and RI/DM, respectively (p = 0.0042). In contrast to previous anecdotal observations, both DM and RI are associated with a high atherosclerotic burden of the pedal arch in the present angiographic series. The presence of RI, however, is associated with a lower patency of the pedal arch as compared to the presence of DM alone, and more than fifty percent patients are unsuitable for distal bypass grafting.

Chondrolipoma of the toe

Chondrolipoma is a rare benign mesenchymoma composed of mature cartilage and adipose tissue. We present a 71-year-old man with a chondrolipoma of the great toe. On histological examination, the tumor contained both mature fat cells and chondrocytes. To our knowledge, this is the first report of a chondrolipoma on the toe. This case contributes to better awareness of an extremely rare lesion of the distal lower limb.

Aliskiren Set for Monotherapy or Combined Hypertensive Therapy

Aliskiren Set for Monotherapy or Combined Hypertensive Therapy

‘Beckung and Kyllerman reply’

‘Beckung and Kyllerman reply’ SIR–We are grateful for the valuable comments made by Dan et al.1 regarding our study on motor function in children with Angelman syndrome.2 We highly appreciate the additional information provided by Bernard Dan and Guy Cheron on advanced kinematic analysis comparing motor control in children developing normally with children with Angelman syndrome. In the clinical setting of our study we found that distal lower limb spasticity, ataxic-like gait, stiff lower limbs, and the presence of coactivation during locomotion were significantly more frequent in children with Angelman syndrome than in the comparison group of children with retardation of motor function from other causes. These results indicate that the physiology of pathological locomotion in children with Angelman syndrome is somewhat similar to that described in children with cerebral palsy (CP), and other upper motor-neuron syndromes. However, the dominant impression is of immaturity in execution, on a par with the generally low developmental level. As collaborators of the Surveillance of Cerebral Palsy in Europe (SCPE) network we apply the definition of CP as ‘a group of disorders, involving a disorder of movement and posture and of motor function, permanent but not unchanging, due to a non-progressive interference, lesion, and/or abnormality in the developing/immature brain’.3 In our opinion, motor problems in children with Angelman syndrome mainly represent immature dyscoordinated movement patterns, similar to those seen in the early stages of motor development. All children in this study functioned at a very immature gross and fine motor developmental level. We did also imply in our paper that the specific movement patterns were not purely immaturity. Signs of ataxia and spasticity were more prevalent in the Angelman syndrome group than the comparison group, which may indicate that there are additional dysfunctions specific to children with Angelman syndrome. We also found that the movement pattern was ataxic-like but differed from the dysmetria, dyssynergia, and dysequilibrium seen in individuals with cerebellar ataxia syndromes. Neurological abnormalities were mild, and, in our opinion, did not qualify for a diagnosis of CP. Difficulties experienced by children in the test probably resulted from central dyscoordination resulting in difficulties in positioning the body and interacting with the environment. Children seemed to have problems in sensory-motor integration, i.e. deficient interaction between multiple spinal and supraspinal systems. We considered that neurological abnormalities observed in children in our study with Angelman syndrome impeded motor function less than or as much as immaturity did. On the grounds mentioned above, the motor difficulties were insufficient for a diagnosis of spastic diplegic or ataxic CP, although mild neurological signs were present.

Respiratory failure in infants due to spinal muscular atrophy with respiratory distress type 1

Spinal muscular atrophy with respiratory distress type 1 (SMARD1) is a rare autosomal recessive neuromuscular disease of unknown prevalence characterized by degeneration of anterior horn alpha-motoneurons and manifesting in the first 6months of life as life-threatening irreversible diaphragmatic paralysis associated with progressive symmetrical muscular weakness (distal lower limbs mainly involved), muscle atrophy, and peripheral sensory neuropathy. Pediatric intensive care unit of tertiary care hospital. We present two new cases of SMARD1 and report two new mutations in the gene IGHMBP2 which encodes immunoglobulin mu-binding protein 2 on chromosome 11q13. SMARD1 is a poor-prognosis disease that should be considered when acute respiratory insufficiency, of suspected neuromuscular or unclear cause, develops during the first 6months of life. Diaphragmatic paralysis, manifesting as dyspnea and paradoxical respiration, is the most prominent presenting sign and diaphragmatic motility should be investigated early by fluoroscopy or ultrasound. Electromyography and nerve conduction studies revealing peripheral motor and sensory neuropathy then suggest the diagnosis which should be confirmed by genetic analysis.

P13.1 Conduction block in Charcot–Marie–Tooth type 1B (CMT1B) neuropathy

Background: On neurophysiological studies the hereditary demyelinating motor and sensory neuropathies (CMT1) usually show uniform reduction in motor conduction velocities. On the other hand, conduction block (CB) far from compression sites is typical of acquired demyelinating neuropathies. Aims: To describe a patient with CMT1 in whom neurophysiological studies disclosed marked CB outside entrapment sites. Case report:A34-year-oldwomanwith afive-year history ofmuscle cramps, right hand and distal lower limbweakness after longstanding efforts. She only startedwalking at the age of 30months but had no other motor development problem. Her father had a history of disabling demyelinating motor– sensory neuropathy. On neurological examination, she had bilateral pes cavus, slight weakness on right thumb abduction, bilateral foot dorsiflexion and hallux extension weakness (4/5); there was a generalized areflexia and distal lower limb light touch and pinprick hypostesia and few errors on postural sense testing; walking on heels was impaired. Motor conduction studies showed low velocities with prolonged latencies, with absent motor responses in feet. Partial conduction blocks were present in the median and ulnar nerves at the forearm (below elbow), more severe aftermuscular fatigue. Sensory potentialswere absent (lower limbs) or small. Laboratorial evaluation includingCSFanalysis was unremarkable. The genetic study was positive for the 233C > T mutation at the MPZ gene. Conclusion: This case illustrates the electrophysiological heterogeneity of CMT1B and adds this entity to conduction block differential diagnosis.

The G526R glycyl-tRNA synthetase gene mutation in distal hereditary motor neuropathy type V

Distal hereditary motor neuropathy (dHMN) or distal spinal muscular atrophy (dSMA) is a heterogeneous group of disorders characterized almost exclusively by degeneration of motor nerve fibers, predominantly in the distal part of the limbs. One subtype, dHMN type V (dHMN-V), is transmitted by autosomal dominant inheritance and predominantly involves the hands. It is allelic with Charcot-Marie-Tooth disease 2D (CMT2D), in which a similar phenotype is associated with sensory signs. Missense mutations in the glycyl-tRNA synthetase (GARS) gene have been recently reported in families with either dHMN-V, CMT2D, or both. The authors searched for GARS mutations in eight dHMN-V families. The authors found the G526R missense mutation in three families (16 patients) of Algerian Sephardic Jewish origin. All patients shared a common disease haplotype, suggestive of a founder effect. The clinical phenotype consists of a slowly progressive, purely motor distal neuropathy. It starts in the hands in most patients, but also in both distal upper and lower limbs or in distal lower limbs alone. The age at onset in symptomatic individuals was between the second to fourth decades, but four mutation carriers were still asymptomatic, two of whom were already age 49 years. Electrophysiology showed that the motor fibers of the median nerve were the most affected in upper limbs. Sensory nerve action potentials were normal. The age at onset of patients with the G526R mutation in the GARS gene varied widely, but the clinical and electrophysiologic presentation was uniform and progressed slowly. Glycyl-tRNA synthetase mutations are a frequent cause of familial distal hereditary motor neuropathy type V but, because of the reduced penetrance of the disease, could also account for isolated cases.

Superficial peroneal sensory and sural nerve conduction studies in peripheral neuropathy

The objective of this study was to prospectively evaluate sensory nerve conduction studies (NCS) in the distal lower limbs in the electrodiagnosis of peripheral neuropathy. We prospectively studied 316 consecutive patients with surface stimulation and recording, in comparison with 90 control subjects. A total of 310 patients were found to have lower limb sensory NCS abnormalities. In these patients, the rate of detection of peripheral neuropathy with superficial peroneal NCS (88.5%) was significantly higher ( P < 0.001) compared with sural NCS (75%). The superficial peroneal NCS appeared to have a higher detection rate for peripheral neuropathy in our study, and its study can be adjunctive to sural NCS.