Fascicular Involvement Research Articles

Ultra high-frequency ultrasound of fascicles in the ulnar and radial nerves.

Ultra high-frequency ultrasound (UHFUS) has been demonstrated to allow easy visualization and quantification of median and digital nerve fascicles; however, there is a lack of normative data for other upper limb nerves. The purpose of this study was to use UHFUS to establish normative reference values and ranges for fascicle count and density within selected upper extremity nerves. Twenty-one healthy volunteers underwent sonographic examination of the ulnar, superficial branch of the radial, and radial nerves on one upper limb using UHFUS with a 48 MHz linear transducer. The number of fascicles in each peripheral nerve and fascicle density were assessed. The mean fascicle number and fascicle density for each of the measured nerves was ulnar nerve at the wrist 11.7 and 2.0, ulnar nerve at the elbow 9.2 and 1.1, superficial branch of the radial nerve 7.3 and 2.5, and radial nerve at the spiral groove 4.2 and 0.8. A single significant association was observed between CSA and fascicle number in the ulnar nerve at the wrist (p = .023, r = 0.66). Neither fascicle number nor density could be predicted by age, sex, height, weight, or body mass index. UHFUS may help to establish a baseline of normative data on upper limb nerves that are not frequently biopsied due to their mixed motor and sensory functions and has the potential for increased understanding of nerve fascicular anatomy to improve diagnostic accuracy of focal nerve lesions, particularly those with selective fascicular involvement.

Fascicular Involvement of the Median Nerve Trunk in the Upper Arm: Manifestation as Anterior Interosseous Nerve Syndrome With Unique Imaging Features.

Selective fascicular involvement of the median nerve trunk above the elbow leading to anterior interosseous nerve (AIN) syndrome is a rare form of peripheral neuropathy. This condition has recently garnered increased attention within the medical community owing to advancements in imaging techniques and a growing number of reported cases. In this article, we explore the topographical anatomy of the median nerve trunk and the clinical features associated with AIN palsy. Our focus extends to unique manifestations captured through MRI and ultrasonography (US) studies, highlighting noteworthy findings, such as nerve fascicle swelling, incomplete constrictions, hourglass-like constrictions, and torsions, particularly in the posterior/posteromedial region of the median nerve. Surgical observations have further enhanced the understanding of this complex neuropathic condition. High-resolution MRI not only reveals denervation changes in the AIN and median nerve territories but also illuminates these alterations without the presence of compressing structures. The pivotal roles of high-resolution MRI and US in diagnosing this condition and guiding the formulation of an optimal treatment strategy are emphasized.

Parsonage-Turner Syndrome: Fascicular Involvement and Focal Constriction.

Parsonage-Turner Syndrome: Fascicular Involvement and Focal Constriction.

Common Peroneal Neuropathy Caused by Intraneural Ganglion Cyst, Electrophysiological Findings Related to Fascicular Involvement and Operative Findings in Two Cases

Foot drop can occur as a manifestation of a number of pathological and clinical conditions and is a fairly common disability encountered in electrodiagnostic clinics. This report describes two cases of atraumatic foot drop. Both cases were electrophysiologically diagnosed as common peroneal neuropathy around the fibular head. Radiographic and surgical findings confirmed intraneural ganglion cyst of common peroneal nerve and the surgical resection was performed. Although the radiographic and surgical findings were compatible with the lesion of common peroneal nerve, the precise analysis of the electrophysiologic findings could differentiate the fascicular involvement in two cases. Keywords: Common peroneal neuropathy; Electrodiagnosis; Intraneural ganglion cyst

Atypical Carpal Tunnel Syndromes Related to Selective Fascicular Involvement of the Median Nerve and Concurrent Recurrent Median Motor Neuropathy

Atypical Carpal Tunnel Syndromes Related to Selective Fascicular Involvement of the Median Nerve and Concurrent Recurrent Median Motor Neuropathy

Somatotopic Fascicular Lesions of the Brachial Plexus Demonstrated by High-Resolution Magnetic Resonance Neurography.

The aim of this study was to evaluate whether high-resolution brachial plexus (BP) magnetic resonance neurography (MRN) is capable of (1) distinguishing patients with compressive neuropathy or noncompressive plexopathy from age- and sex-matched controls, (2) discriminating between patients with compressive neuropathy and noncompressive plexopathy, and (3) detecting spatial lesion patterns suggesting somatotopic organization of the BP. Thirty-six patients (50.9 ± 12.7 years) with clinical symptoms, nerve conduction studies, and needle electromyography findings suggestive of brachial plexopathy and 36 control subjects matched for age and sex (50.8 ± 12.6 years) underwent high-resolution MRN of the BP. Lesion determination and localization was performed by 2 blinded neuroradiologists at the anatomical levels of the plexus trunks and cords. By applying defined criteria of structural plexus lesions on high-resolution MRN, all patients were correctly rated as affected, whereas 34 of 36 controls were correctly rated as unaffected by independent and blinded reading from 2 neuroradiologists with overall good to excellent interrater reliability. In all cases, plexopathies with a compressive etiology (n = 12) were correctly distinguished from noncompressive plexopathies with inflammatory origin (n = 24). Pathoanatomical contiguity of lesion from trunk into cord level allowed recognition of distinct somatotopical patterns of fascicular involvement, which correlated closely with the spatial distribution of clinical symptoms and electrophysiological data. Brachial plexus MRN is highly accurate for differentiating patients with symptomatic plexopathy from healthy controls and for distinguishing patients with compressive neuropathy and noncompressive plexopathy. Furthermore, BP MRN revealed evidence for somatotopic organization of the BP. Therefore, as an addition to functional information of electrodiagnostic studies, anatomical information gained by BP MRN may help to improve the efficiency and accuracy of patient care.

Pupil-sparing Isolated Fascicular Third Cranial Nerve Palsy due to Infarction: Report of a Case and Literature Review

Because of their anatomic proximity, pupillary and inferior rectus functions are linked in most cases of fascicular oculomotor palsy, with either sparing or involvement of both. A 40-year-old woman presented with painless binocular diplopia and left ptosis. Examination additionally showed limitations of the adduction and depression in the presence of normal supraduction and intact pupillary function in the left eye. Findings of other neurological neuro-ophthalmologic examination were normal. A magnetic resonance imaging revealed a diffusion restriction in the left dorsomedial midbrain. An ischemic lesion restricted to the oculomotor fascicles can cause inferior rectus palsy in the presence of pupillary sparing, which should be differentiated from a microvasculopathic lesion involving the subarachnoid portion of the oculomotor nerve.

Pattern of Fascicular Involvement in Midportion Achilles Tendinopathy at Ultrasound

Background:The Achilles tendon is composed of fascicles from the soleus and gastrocnemius muscles, which are identifiable as discrete components at anatomical dissection.Hypothesis:The pattern of fascicular involvement in Achilles tendinopathy may be characterized at ultrasound, and this characterization is reliable between different observers.Study Design:Cross-sectional diagnostic study.Level of Evidence:Level 3.Methods:One hundred cases of Achilles tendinopathy were retrospectively evaluated by 2 blinded musculoskeletal radiologists. Using a short-axis anatomical map, each case was categorized as involving the fascicular territories of the medial head of gastrocnemius, lateral head of gastrocnemius, soleus, or combinations of these, or as indeterminate.Results:Both radiologists agreed on the fascicular involvement pattern in 93 of 100 cases; 20 involved only medial gastrocnemius territories, 8 lateral gastrocnemius, 15 soleus, 3 medial and lateral gastrocnemius, 21 medial gastrocnemius and soleus, 9 soleus and lateral gastrocnemius, and 16 the entire tendon, and 1 case was classified as indeterminate. In 7 cases, the interpretations were discordant. The kappa value was calculated as 0.92 (95% CI, 0.86-0.98) in keeping with a high level of interobserver agreement.Conclusion:As assessed at ultrasound, most cases of Achilles tendinopathy involve the medial head of gastrocnemius and/or soleus fascicles.Clinical Relevance:The provided observational data will increase understanding of patterns of Achilles tendinopathy.

Radiofrequency catheter ablation of idiopathic left anterior fascicular ventricular tachycardia in children.

Idiopathic ventricular tachycardia of left anterior fascicular origin (IVT-LAF) is a rare condition, and radiofrequency catheter ablation (RFCA) therapy has not been reported in children. This study aimed to evaluate the procedures and outcomes of RFCA for pediatric IVT-LAF. Pediatric IVT-LAF cases for which RFCA was performed between June 2006 and May 2012 at our hospital were reviewed. Of 537 pediatric cases of RFCA, 6 had IVT-LAF; 4 had anterior fascicular involvement only, while 2 had both anterior and posterior fascicular involvement. All 6 of them underwent RFCA at the median age of 8.8 years (range 4.3-14.3 years). RFCA was successful in all patients, but 4 had recurrence and underwent 1-3 additional sessions of RFCA. In a total of 10 RFCA sessions, the overall recurrence rate was 50%. The site of RFCA was determined on the basis of detection of diastolic potential during ventricular tachycardia (7 sessions) or isolated delayed potential during sinus rhythm (1) or by pace mapping (2). During the median follow-up period of 33 months, no further recurrence was reported except for 1 patient, who had a recurrence and was scheduled for additional session at the time of this report. Major complications included 1 case of complete atrioventricular block and 1 case of complete left bundle branch block. Despite a high recurrence rate and a few complications, RFCA of the site of isolated delayed potential or diastolic potential, if applied cautiously, is a possible treatment of choice for pediatric IVT-LAF.

Ancient schwannoma of the median nerve­a case report and review of the literature of nerve tumors

Schwannomas are known as neurilemmonas, the most common benign tumor of the peripheral nerve's neural sheath, arising from the Schwann cells derived from the neural crest. They are the commonest tumor of the peripheral nerves, 5% of which occur in the adults. 19% of the tumors occur in upper extremities and 45% of schwannoma occur in the head and neck and 13.5% in the lower limbs. Volar surface is affected more than the dorsal aspect and they may occur as multiple lesions or they may affect different nerves in the same extremity. Despite the classical description that schwannomas are well encapsulated and can be completely enucleated during excision, a portion of them have fascicular involvement and could not be completely shelled out. 75% of schwannoma of the upper extremity occur at elbow or distal to it. It occurs more in the mixed nerve instead of pure sensory or motor nerve. 50 %of patients have mixed nerve involvement. An important variant of schwannoma with degenerative changes are termed as Ancient schwannoma. This assumes significance since this may be confused with malignancy in both imaging and in histological studies. A clear understanding is crucial to the treatment plan for nerve tumors. We report a rare case of ancient schwannoma of the median nerve and take a review of the peripheral nerve tumors. pguygv neural sheath, arising from the Schwann cells derived from the neural crest (1) They are present as a painless swelling along the course of the nerves for a long time. They are the commonest tumor of the peripheral nerves, 5% of which occur in the adults (2). 19% of the tumors occur in upper extremities.(3) and 45% of schwannoma occur in the head and neck and 13.5% in the lower limbs. Discomfort may be the only complaint of the patient. Paraesthesia may be elicited on tapping of the swelling. The swelling may be misdiagnosed as ganglion, lipoma or lymph node. The tumors are round or ovoid, eccentric and well encapsulated. They are usually 2.5cm in size but they may grow up to 4­5 cm. The tumor is grayish, pink, yellow, brown or white in color. They are solitary and found along the anterior aspect of the extremities by the side of the nerves. Ancient schwannomas are a variant of schwannomas of long duration with degenerative changes. In long standing tumors the cut section may show variegated appearance and degenerative changes. The histological and radiological picture resembles that of malignancy but they are benign lesions. This case is reported for the rare nature of the ancient schwannoma of the median nerve and to analyze the surgical options available. II. Material and methods 2.1 case report A 75 years old lady presented with a painless swelling in the right cubital fossa of 10 years duration with complaints of increase in size of the swelling associated with pain for the past one year. She complained of pain and Paraesthesia in the median nerve distribution area of the right hand. She has numbness of the right hand with weakness in performing her day to day activities. There was atrophy of the Thenar muscles. The swelling measured 3.5 cm in length. The swelling was mobile on the transverse axis and not on the longitudinal c{kv .Tjgug zcv oqwqu zgcmpgvv cnvq. Pguexvvkqp qygu wjg pguyg ruqfxegf rqvkwkyg Tkpgnv vkip. Tjgug zcv nqvv of sensation in the distribution of the median nerve in the hand. The patient refused to undergo MRI examination due to economy reasons. A surgical workup and a pre­operative anesthetist assessment were obtained. With a clinical diagnosis of median nerve tumor the patient was planned for excision of the tumor. It was explained to the patient regarding the neurological deficit following the surgery and she may need a sural pguyg iuchw. Skpeg wjg rcwkgpwv

Schwannoma in the Upper Limbs

Schwannomas are the commonest tumours of peripheral nerves. Despite the classical description that schwannomas are well encapsulated and can be completely enucleated during excision, a portion of them have fascicular involvement and could not be completely shelled out. A retrospective review for 8 patients was carried out over 10 years. 75% of schwannoma occurred over the distal region of upper limb (at elbow or distal to it). It occurs more in the mixed nerve instead of pure sensory or motor nerve. 50% of patients had mixed nerve involvement. Fascicular involvement was very common in schwannoma (75% of patients). Removal of the tumour with fascicles can cause functional deficit. At present, there is no method (including preoperative MRI) which can predict the occurrence of fascicular involvement; the authors therefore proposed a new system to stratify patients who may benefit from interfascicular nerve grafts. In this group of patients, the authors strongly recommend that the possibility and option of nerve graft should be discussed with patients prior to schwannoma excision, so that nerve grafting could be directly proceeded with patient consent in case there is fascicular involvement of tumour found intraoperatively.

Atypical Presentations of Common Peroneal Neuropathy

Common peroneal neuropathy (CPN) can mimic lumbar radiculopathy both clinically and electrodiagnostically [1]. CPN caused by entrapment at the fibular head is the most frequent mononeuropathy of the lower limb [1]. The superficial peroneal sensory (SPS) nerve conduction study (NCS) is performed frequently in persons with suspected CPN. A normal SPS response often is used to differentiate radiculopathy from CPN. However, CPN at the fibular head can preferentially affect superficial peroneal motor fibers while sparing the SPS branches, making it difficult to differentiate it from L5 radiculopathy [1]. This finding is consistent with the concept of selective fascicular involvement in peripheral nerve lesions [1-3]. The 2 cases presented involve patients who had CPN with spared SPS fibers on electrodiagnostic testing (EDX), an uncharacteristic and atypical presentation. It is important to perform EDX to accurately diagnose such atypical CPN lesions, and especially to differentiate them from their common mimicker, L5 radiculopathy.

Intraneural Lipoma of the Ulnar Nerve

Sir: A 9-year-old girl presented with exertional discomfort of the right hand due to two slowly enlarging masses. There was no history of trauma, paresthesias, numbness, or weakness. Clinical examination revealed two discrete masses, one proximal to the flexor wrist crease measuring 5 × 1.5 × 0.5 cm and a second measuring 7 × 4 × 2 cm in the hypothenar eminence (Fig. 1). The masses were soft and mobile, with well-defined borders and no overlying skin changes. The Tinel sign was absent. An Allen's test demonstrated the ulnar artery of the hand to be patent, but with delayed filling.Fig. 1.: Gross appearance of the right wrist and hypothenar eminence masses of the right hand, measuring 5 × 1.5 × 0.5 cm and 7 × 4 × 2 cm, respectively. Intraoperative markings demonstrate the location and extent of the lesion. A single incision was made directly over the lesion and crossing the flexor wrist crease, as shown.Magnetic resonance imaging was consistent with a lipoma in the volar aspect of the right wrist and hand with displacement of the flexor digitorum superficialis tendons. Magnetic resonance angiography revealed radial displacement of the ulnar artery. At exploration, the mass appeared to be a large, multilobulated lipoma originating from within the ulnar nerve, with splaying of fascicles and attenuation of the hypothenar musculature. The ulnar artery was displaced radially. Resection yielded a 14-cm multilobulated mass with no residual lesion (Fig. 2). All nerve and fascicle groups, the ulnar artery, and the palmar arch were left intact.Fig. 2.: With the mass completely removed, the splayed, intact fascicles of the ulnar nerve are visible. The incision was closed directly without removing excess skin.Gross pathologic examination revealed an encapsulated, lobulated mass of homogeneous adipose tissue. Microscopic findings showed mature fibroadipose tissue consistent with the diagnosis of a benign intraneural lipoma. Postoperative evaluation at 2 weeks showed normal median and ulnar nerve function, with only mild weakness of the abductor digiti minimi. Follow-up at 1 month showed increased range of motion, improved ulnar sensation, and persistent, mild, residual small-finger weakness on abduction. Masses originating in the median and ulnar nerves are exceedingly rare.1,2 The nomenclature for such masses has been based primarily on pathologic descriptions, such as lipoma, intraneural lipoma, lipofibromatous hamartoma, fibrofatty proliferation, and fatty infiltration.1,3,4 Intraneural lipofibromas have been divided into three major entities based on pathologic descriptions and clinical/anatomical behavior: true intraneural lipomas, lipofibromas, and peripheral nerve hamartomas with marcrodactyly.3 True lipomas are soft, noninvasive, encapsulated tumors that displace adjacent structures. These lesions can be readily dissected from surrounding tissues and histologically contain fibrous and fatty tissue, but lack neural elements. Distinct from true lipomas, lipofibromas contain fibrous, fatty, and neural elements. Confined within the nerve sheath, lipofibromas are often impossible to separate from nerves without extensive interfascicular dissection or complete nerve resection. Nomenclature varies and includes the pseudonyms fibrofatty proliferation, intraneural lipoma, and lipomatous hamartoma. Hamartomas represent a third entity of benign tumors, similar to lipofibromas histologically in that they both contain fibrous, fatty, and neural elements. Some authors propose nomenclature that combines associations with macrodactyly: lipofibromatous hamartoma with or without macrodactyly.1,2 Patients present in childhood with swelling of the wrist or hand and varying degrees of compressive symptomatology. Magnetic resonance imaging is typically diagnostic but cannot delineate the degree of fascicular involvement.5 Operative exploration is indicated for progressive mass enlargement, overt compressive symptoms, and histopathologic confirmation. Depending on the anatomical relationship of the lesion, surgical treatment may involve biopsy and ligamentous decompression, limited interfascicular dissection, complete resection with nerve grafting, complete resection, and, occasionally, compensatory tendon transfer. In summary, benign, fibrofatty tumors of the hand and wrist are indeed rare. Associated symptoms are directly related to tumor size and anatomic location. The natural history is continued growth and potential exacerbation of symptoms without spontaneous regression.4 Surgical intervention should be considered in patients with large or indeterminate masses. Treatment by excision should be considered early in the disease process. Laura A. Bonneau, Stephen J. Delatte, M.D. Michael L. Bentz, M.D. Division of Plastic Surgery Department of Surgery University of Wisconsin-Madison Madison, Wis.

Blepharoptosis in association with ipsilateral adduction and elevation palsy A form of fascicular oculomotor palsy

A 16-year-old girl hospitalized with a sudden onset of blepharoptosis and diplopia revealed a combined paresis of the elevator palpebrae, the superior rectus, and the medial rectus muscles of the left eye as quantitatively demonstrated by the Hess chart and levator action test. A small midbrain lesion confined to the left cerebral peduncle and tegmentum, presumably by an ischemic or demyelinative process, was identified on magnetic resonance imaging. Despite uncertainty in its pathology, the incomplete oculomotor palsy of this case is certainly a consequence of oculomotor fascicular involvement in the intra-axial nerve root which initially fans out and then converges into the peripheral compact bundle. We speculate on the revised version of the oculomotor fascicular arrangements by which the neurophthalmologic features of the current case are better explained.

One-and-a-half syndrome. Type II: a case with rostral brain stem infarction

This article is about a patient who suddenly developed a right hemiparesis and stupor. Her neuro-ophthalmological examination revealed a left-sided ptosis and a combined vertical gaze palsy in addition to right esotropia, right conjugate gaze palsy, and abduction paralysis of the left eye on attempted gaze to the left with adduction nystagmus of the right eye. The horizontal eye movement disorder was similar to that in one-and-a-half syndrome, except for an abduction paralysis and an adduction nystagmus. MRI showed a rostral brain stem infarction on the left side. Left-sided ptosis and adduction paralysis were attributed to a left oculomotor fascicular involvement in the presence of a right hemiparesis. Right-sided esotropia and abduction paresis were consistent with a ‘pseudo-abducens palsy’, which has been reported in thalamo-mesencephalic lesions. Combined vertical gaze palsy is a classical finding of rostral brain stem infarction. Left-sided abduction paralysis with adduction nystagmus on the right si...