Clinical, Electrodiagnostic, and Ultrasound Findings in 87 Patients With Finger Drop.

BACKGROUND: The inability to extend the fingers at the metacarpophalangeal and interphalangeal joints leads to finger drop. While wrist drop and foot drop are well recognized, the causes of finger drop are poorly understood. AIMS: This study describes the clinical, electrodiagnostic (EDX), and ultrasound (US) features in patients with finger drop. MATERIALS AND METHODS: This is a retrospective study of 87 patients presenting with finger drop and referred for EDX studies during the past 10 years. We analyzed the clinical picture, EDX data, and US findings. The patients were categorized into global (all five digits) or partial (limited to 1-4 digits) finger drop. RESULTS: Fifty-six (64%) patients had global finger drop, while 31 (36%) had partial finger drop. The frequent cause of finger drop was Parsonage-Turner syndrome (PTS) (29 [33%]), followed by trauma (23 [26%]), cervical radiculopathy (16 [18%]), extensor tendon rupture (four [4%]), and compression/entrapment (two [2%]). In 13 (15%) patients, no cause was identified. A total of 13/16 (81%) patients with cervical radiculopathy and four of the patients with tendon rupture had partial finger drop, while 52/64 (81%) with posterior interosseous nerve (PIN) neuropathy had global finger drop. Of the 16 patients who experienced cervical radiculopathy as the cause of the finger drop, 15 patients had C7 and C8 radiculopathy and one patient had C7 radiculopathy. EDX studies of patients with PTS revealed partial axon loss in 18 (62%) patients, conduction block in eight (28%), and total axon loss in four (14%). Enlarged fascicles were observed by US in 40% of patients with PTS. EDX studies of patients who sustained iatrogenic nerve injury causing finger drop demonstrated total axon loss in six (46%) patients, partial axon loss in four (31%), demyelination in two (15%), and conduction block in two (15%). CONCLUSIONS: PIN neuropathy is the most common cause of finger drop, however, lesser-known causes such as cervical radiculopathy and extensor tendon rupture should also be considered. Global finger drop is suggestive of PIN neuropathy, while partial finger drop occurs more often in cervical radiculopathy and tendon rupture. EDX and US studies provide valuable information for localizing the lesion site and may reveal the cause of the finger drop.

Unilateral Calf Atrophy: A Case Series of Clinical and Electrodiagnostic Findings With a Review of the Literature.

Unilateral calf atrophy may result from several medical conditions, such as lumbar radiculopathy, asymmetric myopathy/dystrophy, a Baker's (popliteal) cyst leading to tibial nerve compression, and disuse atrophy. We present a case series of four patients with unilateral calf atrophy, including chronic neurogenic atrophy (benign focal amyotrophy, one patient), tibial nerve compression at the popliteal fossa by a Baker's cyst (one patient), and disuse atrophy (two patients). All four patients underwent electrodiagnostic (EDX) studies, and two of them had denervation changes of the gastrocnemius. One patient underwent an ultrasound (US), which revealed a large cyst in the popliteal fossa causing compression of the tibial nerve. The differential diagnosis of unilateral calf atrophy as well as diagnostic techniques to confirm the underlying pathology are described. EDX and US studies are useful in differentiating between the varied conditions that may cause asymmetric calf muscle wasting.

Anti-cancer therapeutic agents and carpal tunnel syndrome: Clinical, electrodiagnostic, and ultrasound findings in seven patients.

INTRODUCTION: Carpal tunnel syndrome (CTS) is the most common entrapment neuropathy and rarely develops after drug therapy. This study describes the clinical, electrodiagnostic (EDX), and ultrasound (US) findings in seven patients who experienced CTS due to anti-cancer therapeutic agents. METHODS: All patients underwent EDX testing, and four patients had an US study. RESULTS: CTS occurred in four patients with aromatase inhibitors, two with immune checkpoint inhibitors, and one with a selective estrogen receptor modulator. The mean duration between initiation of the anti-cancer therapeutic agents and symptom onset was 6 weeks (range: 2-12 weeks). Decreased digit sensation was noted in all patients; wasting and weakness of the abductor pollicis brevis (APB) was observed in three (42.8%) patients. The compound muscle action potentials (CMAP) of the APB and sensory nerve action potentials of the second or third digit could not be recorded in two (28.5%) and four (57.1%) patients, respectively. The needle EMG detected fibrillations and positive sharp waves in the APB in two patients. The motor unit potentials of the APB were decreased with large polyphasics in three (42.8%) patients. Of the four patients who underwent US testing, all had increased cross-sectional area of the median nerve at the carpal tunnel inlet, three (75%) had thenar muscle atrophy, and two (50%) had a loss of fascicular pattern. Three (42.8%) patients underwent a CTR. CONCLUSIONS: Physicians should be cognizant of the relationship between anti-cancer therapeutic agents and CTS. EDX studies and US play important roles in the diagnostic assessment of such patients.

Osteopontin is associated with dementia in the presence of cerebral small vessel disease.

BACKGROUND: Osteopontin (OPN) is a proinflammatory cytokine that has been recently implicated in neuroinflammation and neurodegeneration. We hypothesized that an increase in plasma osteopontin is a deleterious neuroinflammatory marker in people with dementia and cerebral small vessel disease (CSVD). METHODS: A pilot study was conducted on participants in the Northern Manhattan Study (NOMAS). Three groups were selected based on their dementia status and evidence of subclinical CSVD and chosen to be similar in age, sex, and education attainment: No dementia/No CSVD (n=19), Dementia/No CSVD (n=22), and Dementia+CSVD (n=21). Dementia (any type) was diagnosed by consensus adjudication following a series of comprehensive neuropsychological assessments and a review of the medical history. CSVD was indicated by silent brain infarcts, enlarged perivascular spaces, cerebral microbleeds, and white matter hyperintensity volumes (WMHV) on MRI. Multinomial logistic regression was used to examine the difference in OPN levels across groups, adjusting for key determinants of CSVD and neurodegeneration. RESULTS: Plasma osteopontin levels were elevated in the Dementia+CSVD group (mean=70.69±39.00 ng/ml) but not in the Dementia/No CSVD group (mean=45.46±19.11 ng/ml) compared to the No dementia/No CSVD group (mean=36.43±15.72 ng/ml). Osteopontin was associated with Dementia+CSVD (Odds Ratio (OR) per ng/ml=1.06, 95%CI 1.02-1.11) after adjusting for covariates, including brain volume. OPN was strongly correlated with WMHV (Spearman's rank correlation =0.46, p=0.0001), but not with other components of CSVD. CONCLUSION: In this pilot, greater levels of plasma osteopontin were associated with dementia with evidence of CSVD. This link was predominately driven by the contribution of OPN to dementia through the burden of white matter lesions.

Clinical Spectrum of Postsurgical Parsonage-Turner Syndrome: A Perspective From an Electrodiagnostic Laboratory.

BACKGROUND: Parsonage-Turner syndrome (PTS) is an underdiagnosed disorder characterized by the acute onset of severe pain in the shoulder/scapula/arm followed by muscle weakness/numbness in the distribution of nerves derived from the brachial plexus (BP). Surgical procedures are one of several antecedent events of PTS. This study describes the clinical spectrum of postsurgical Parsonage-Turner syndrome (PSPTS) in a large cohort of patients. MATERIALS AND METHODS: Charts of patients diagnosed with PTS during a 16-year (2006-2022) retrospective review were analyzed to identify cases of PSPTS. The clinical criteria for PSPTS included the new onset of severe pain two days to four weeks after a surgical procedure followed by weakness of muscles innervated by one or more nerves arising from the BP. EDX criteria consist of denervation localized to branches of the BP. PSPTS cases were subdivided into two categories: definite PSPTS (surgery at a remote site) and probable PSPTS (surgery of the ipsilateral upper extremity or the cervical spine). RESULTS: Of 202 patients (204 episodes) diagnosed with PTS, 111 (54%) were idiopathic and 61 (30%) were PSPTS. Of the 61 PSPTS episodes, 26 were definite and 35 were probable PSPTS. The anterior interosseous nerve (AIN) was most affected, followed by the posterior interosseous (PIN), and suprascapular nerve. CONCLUSION: In this series, surgery was the most commonly recognized antecedent event for PTS, and the AIN and PIN were the most frequent nerves affected. Surgeons should consider PTS in patients who develop postoperative severe shoulder pain and weakness of muscles innervated by the BP.

Clinical Features of a Newly Described Mutation of Myelin Protein Zero in a Family.

Charcot-Marie-Tooth (CMT) disease is the most common hereditary neuropathy. Duplication of the peripheral myelin protein-22 (PMP22) gene is the most frequent genetic abnormality in CMT disease. Although rare compared to PMP22 gene mutations, many different myelin protein zero (MPZ) gene mutations have been described in patients with CMT disease. MPZ gene mutations are known to cause hereditary neuropathies with heterogenous phenotypes ranging from early-onset severe demyelinating to adult-onset axonal forms. MPZ, the major protein component of peripheral nerve myelin, is important for myelin compaction. We report a family in which a mother and her son, both with adult-onset CMT disease, showed a newly described mutation p.Glu37Lys of the MPZ gene. The clinical features of the mother provided insight into the progression of the disease over decades, while features in the early stage of the disease could be studied in the son. Clinical, electrodiagnostic, and sonographic findings are described in the early and late stages of the disease. The MPZ gene mutation p.Glu37Lys is associated with clinical features of a progressive axonal type of adult-onset CMT disease.

Iatrogenic Ulnar Nerve Neuropathy Following Reverse Total Shoulder Arthroplasty: Electrodiagnostic Findings in 18 Patients.

Background A reverse total shoulder arthroplasty (RTSA) is often recommended for rotator cuff pathology and may be associated with a myriad of complications, including prosthetic instability, infection, humeral problems, and glenoid loosening. Neurological injuries following an RTSA are infrequent and are usually related to brachial plexus or proximal nerve injury in the affected arm. Iatrogenic ulnar nerve neuropathy is exceedingly rare. Aims This study describes the clinical and electrodiagnostic (EDX) features of 18 patients with ulnar nerve neuropathy complicating RTSA. Materials and methods All patients underwent EDX studies, and 14 had an ultrasound (US) study. Results All patients complained of numbness, tingling, hyperalgesia, and/or allodynia in the distribution of the ulnar nerve. Eight (44%) patients reported hand weakness, and one (6%) noted wasting of the intrinsic hand muscles. Decreased pinprick sensation in the ulnar nerve distribution was detected in all patients. Seventeen (94%) patients had weakness of the ulnar nerve-innervated intrinsic hand muscles. All patients had focal slowing of the motor conduction of the ulnar nerve across the elbow. Sensory potentials were either absent or of a low amplitude over the digital and/or dorsal cutaneous branch of the ulnar nerve in all patients. Twelve (86%) patients showed an increase in the cross-sectional area (CSA) of the ulnar nerve at the elbow; six (43%) had a hypoechoic ulnar nerve. Ulnar nerve neuropathy was confirmed at the elbow in all 18 patients. Of the 14 (78%) patients who underwent surgical intervention for ulnar nerve neuropathy following an RTSA, only four had complete symptom resolution. Conclusions Surgeons should be cognizant of ulnar nerve neuropathy as a potential complication of an RTSA and take precautions to avoid damage to the ulnar nerve intraoperatively. EDX and US studies should be performed to confirm and assess the site and severity of the injury.

Causes of Dorsal Cutaneous Branch of the Ulnar Nerve Neuropathy Among Patients Undergoing Electrodiagnostic Studies: A Series of 14 Patients.

BACKGROUND: Isolated neuropathy of the dorsal cutaneous branch of the ulnar nerve (DCBUN) is rare and most cases are secondary to trauma, often iatrogenic. The topography of sensory abnormalities and abnormal electrodiagnostic (EDX) findings are crucial in confirming DCBUN neuropathy.  Materials and methods: This is a retrospective study of patients with isolated involvement of the DCBUN from among patients referred for EDX studies for upper extremity symptoms. All patients underwent a focused neurological examination followed by EDX studies. Ultrasound (US) studies were performed in two patients.  Results: Of the 14 patients with DCBUN neuropathy, decreased pinprick sensation in the distribution of the DCBUN was noted in 11 (78%) patients. DCBUN sensory nerve action potential (SNAP) was not recordable in 13 (92%) patients. In one patient who had a recordable SNAP, the latency was prolonged, and the amplitude was decreased. Four (28%) patients had incidental EDX abnormalities suggestive of entrapment of the median nerve at the carpal tunnel. The most common cause of DCBUN neuropathy was trauma in 13 (92%) patients, of which eight were iatrogenic. No specific etiology was detected in one patient (7%). Of the two patients who underwent US studies, one had increased cross-sectional area (CSA) at the wrist with prominent fascicles and hyperechoic scar tissue, while the CSA was normal in the other patient. CONCLUSIONS: Although rare, DCBUN neuropathy can be readily confirmed by typical clinical features and EDX findings. Surgeons should be aware of the anatomy and clinical features of DCBUN neuropathy and avoid injuring the nerve during surgical procedures at the wrist and forearm.

Etiology of spastic foot drop among 16 patients undergoing electrodiagnostic studies: patient series.

BACKGROUND: Differentiating foot drop due to upper motor neuron (UMN) lesions from that due to lower motor neuron lesions is crucial to avoid unnecessary surgery or surgery at the wrong location. Electrodiagnostic (EDX) studies are useful in evaluating patients with spastic foot drop (SFD). OBSERVATIONS: Among 16 patients with SFD, the cause was cervical myelopathy in 5 patients (31%), cerebrovascular accident in 3 (18%), hereditary spastic paraplegia in 2 (12%), multiple sclerosis in 2 (12%), chronic cerebral small vessel disease in 2 (12%), intracranial meningioma in 1 (6%), and diffuse brain injury in 1 (6%). Twelve patients (75%) had weakness of a single leg, whereas 2 others (12%) had bilateral weakness. Eleven patients (69%) had difficulty walking. The deep tendon reflexes of the legs were hyperactive in 15 patients (94%), with an extensor plantar response in 9 patients (56%). Twelve patients (75%) had normal motor and sensory conduction, 11 of whom had no denervation changes of the legs. LESSONS: This study is intended to raise awareness among surgeons about the clinical features of SFD. EDX studies are valuable in ruling out peripheral causes of foot drop, which encourages diagnostic investigation into a UMN source for the foot drop.

Impact of Occupations and Hobbies on the Severity of Carpal Tunnel Syndrome: An Electrodiagnostic Perspective.

OBJECTIVE: This study describes the clinical and electrodiagnostic (EDX) findings as well as occupations and hobbies in 613 patients diagnosed with carpal tunnel syndrome (CTS). METHODS: Patients with moderate, moderately severe, or severe CTS based on EDX criteria were included. RESULTS: The most common occupations included workers in offices, construction/maintenance, and assembly lines. The occupation severity scores were greatest in garment workers, musicians, and landscapers. Regardless of occupation, patient age and occupation duration were significantly correlated ( P < 0.001). Gardeners had the highest average severity score of the hobbies, followed by painters, those who sew, and individuals who perform house chores. CONCLUSIONS: Physicians should be aware of particular occupations and hobbies associated with a greater risk of severe CTS and offer modifications to their patients' work duties and hobbies to minimize the likelihood of developing severe CTS.

Etiological study of superficial radial nerve neuropathy: series of 34 patients.

Objectives: Superficial radial nerve (SRN) neuropathy is a rare focal neuropathy leading to pain and paresthesia of the dorsolateral aspect of the hand. Reported causes include trauma, extrinsic compression, or it may be idiopathic. We describe the clinical and electrodiagnostic (EDX) features of 34 patients with SRN neuropathy of varied etiology. Methods: This is a retrospective study of patients with upper limb neuropathy referred for EDX studies who were found to have SRN neuropathy based on clinical and EDX findings. Twelve patients also had ultrasound (US) evaluations. Results: Decreased pinprick sensation was noted in the distribution of the SRN in 31 (91%) patients, and a positive Tinel's sign was observed in 9 (26%). Sensory nerve action potentials (SNAPs) were not recordable in 11 (32%) patients. Of the patients who had a recordable SNAP, the latency was delayed, and the amplitude was decreased in all cases. Of the 12 patients who underwent US studies, 6 (50%) had an increased cross-sectional area of the SRN at or immediately proximal to the site of injury/compression. A cyst was located adjacent to the SRN in 2 patients. The most common cause of SRN neuropathy was trauma in 19 (56%) patients, of which 15 were iatrogenic. A compressive etiology was identified in 6 patients (18%). No specific etiology was detected in 10 patients (29%). Conclusion: This study is aimed at raising the awareness among surgeons about the clinical features and varied causes of SRN neuropathy; such knowledge may potentially lessen iatrogenic causes of injury.

Iatrogenic median and ulnar nerve injuries during carpal tunnel release: clinical, electrodiagnostic, and ultrasound features in 12 patients. Patient series.

BACKGROUND: Nerve injuries during carpal tunnel release (CTR) are rare. Electrodiagnostic (EDX) and ultrasound (US) studies may be helpful in evaluating iatrogenic nerve injuries during CTR. OBSERVATIONS: Nine patients sustained a median nerve injury, and 3 patients experienced ulnar nerve damage. Decreased sensation occurred in 11 patients, and dysesthesia occurred in 1 patient. Abductor pollicis brevis (APB) weakness occurred in all patients with median nerve injury. Of the 9 patients with median nerve injury, the compound muscle action potentials (CMAPs) of the APB and sensory nerve action potentials (SNAPs) of the 2nd or 3rd digit were not recordable in 6 and 5 patients, respectively. Of the 3 patients sustaining ulnar nerve injuries, the CMAPs of the abductor digiti minimi (ADM) and SNAPs of the 5th digit were not recordable in 1 patient; 2 patients showed prolonged latency and decreased amplitude of CMAPs/SNAPs. US studies of 8 patients with a median nerve injury showed a neuroma within the carpal tunnel. One patient underwent surgical repair urgently, and 6 did so after variable intervals. LESSONS: Surgeons should be cognizant of nerve injuries during CTR. EDX and US studies are useful in evaluating iatrogenic nerve injuries during CTR.

Gunshot-related nerve injuries of the upper extremities: clinical, electromyographic, and ultrasound features in 22 patients.

Objectives: Gunshot wounds of the upper extremities may cause permanent neurovascular injuries, leading to significant morbidity, chronic pain, functional loss, and disability. While there are many reports on the incidence and intraoperative findings in gunshot-related nerve injuries (GSNI) sustained during wars, there is a paucity of details pertaining to GSNI of the upper extremities in civilians. The goal of this paper is to provide the clinical, electrodiagnostic (EDX), and ultrasound (US) findings in 22 patients with GSNI of the upper extremities. Methods: This is a retrospective study of patients referred for EDX studies to evaluate the presence of nerve injury after sustaining GSWs to the upper extremities. All patients underwent EDX studies, and 16 patients had US evaluations. Numerous metrics were documented including presenting symptoms, neurological abnormalities, EDX findings, and US features. Results: The forearm was the most frequent location of injury (8 [36%] patients). The ulnar nerve was the most common injured nerve (10 [45%] patients), followed by the brachial plexus (7 [32%] patients). All patients complained of muscle weakness; the most frequently affected muscles were the first dorsal interosseous (FDI) (14 [64%] patients) and abductor pollicis brevis (APB) (11 [50%] patients). Muscle atrophy was noted in 19 (86%) patients, 15 of whom had atrophy of the FDI. Axonotmesis was the type of nerve injury in all patients based on EDX studies. Of the 16 patients who underwent US studies, a neuroma in continuity was noted in 4 (25%) patients and neurotmesis in 1 (6.2%) patient. Eleven (69%) patients had enlarged and/or hypoechoic nerves. Conclusions: Axonotmesis of the ulnar nerve was the most common finding among patients sustaining gunshot injuries to the upper extremities. EDX and US studies provide valuable insight into the underlying pathophysiology and guidance for management of patients with GSNI of the upper extremities.

Role of electromyography and ultrasonography in the diagnosis of double crush lumbar radiculopathy and common fibular injury: illustrative cases.

BACKGROUND: Double crush syndrome consists of two compression sites along a peripheral nerve and is rare in the lower extremities. Electrodiagnostic and ultrasound (US) studies may be helpful in evaluating foot drop involving overlapping pathologies. OBSERVATIONS: Case 1 involved a man who presented with left dorsiflexor weakness and left foot numbness. Electromyography (EMG) revealed a left common fibular nerve entrapment neuropathy and left L5 radiculopathy. US and magnetic resonance imaging (MRI) revealed a large cystic lesion of the left common fibular nerve treated by cyst removal. The left foot drop persisted postoperatively. Lumbar computed tomography myelography revealed severe left foraminal stenosis at L5-S1. Multilevel lumbar laminectomies and facetectomies with an L5-S1 fusion were performed. Within 1 month postoperatively, the left foot drop had improved. Case 2 involved a man who developed a right foot drop caused by right lumbar foraminal stenosis at L4-5 and L5-S1. EMG and US of the right common fibular neuropathy showed large fascicles involving the right common fibular nerve. MRI revealed a hyperintense signal of the right common fibular nerve. Spontaneous improvement occurred within 6 months without surgery. LESSONS: Spine surgeons should recognize double crush in the lower extremities. EMG and US are valuable in detecting peripheral nerve abnormalities, especially in cases with overlapping lumbar pathology.

Early-Onset Dropped Head Syndrome and Person-in-the-Barrel Syndrome After Radiation Therapy: Clinical, Electromyographic, and MRI Findings.

Dropped head syndrome (DHS) involves severe weakness of the neck extensor muscles causing the mandible to drop to the chest wall. Isolated neck extensor weakness is a rare complication of radiotherapy. This condition may result within a few weeks or months following radiotherapy (early-onset) or several years after radiotherapy (late-onset), with the latter more commonly encountered. Person-in-the-barrel syndrome is marked by bilateral brachial diplegia, intact cranial nerves, and preserved lower extremity strength. We describe the unique clinical profile of a patient with a six-week history of significant neck and bilateral upper extremity weakness who was diagnosed three months prior to the onset of these symptoms with moderately differentiated squamous cell carcinoma within the base of the tongue (Stage III T2N1M0) and metastasis to the cervical lymph nodes. She underwent concurrent chemotherapy with three cycles of cisplatin (197 mg {100 mg/m2} x 197 m2) and hyperfractionated external beam radiation therapy (total dose cGy 7000 cGy in 35 fractions {200 cGy per fraction}). She reported the rapid onset of neck and bilateral upper extremity weakness six weeks following cisplatin termination and four weeks after radiation termination. A cervical MRI suggested myositis of the cervical paraspinal muscles, and electrodiagnostic studies indicated an inflammatory myopathic process involving the cervical paraspinal and shoulder girdle muscles. The patient attained a complete resolution of her symptoms eight months after onset. This case illustrates the rare phenomenon of early-onset DHS and person-in-the-barrel syndrome caused by radiation-induced myositis. Prompt recognition of the symptoms associated with DHS and timely treatment offer the best prognosis for recovery.

Multifocal intradural extramedullary ependymoma, MYCN amplified: illustrative case.

BACKGROUND: Ependymomas are the most frequent tumors of the adult spinal cord, representing 1.9% of all central nervous system tumors and 60% of spinal cord tumors. Spinal ependymomas are usually solitary, intramedullary lesions. While intradural extramedullary (IDEM) ependymomas are infrequent, multifocal IDEM ependymomas are exceptionally rare. OBSERVATIONS: The authors reported the first case in the literature of a patient diagnosed with multifocal IDEM ependymomas who was treated with tumor resection and brain and spinal radiotherapy. The patient presented with a 10-day history of bilateral leg numbness extending to the umbilicus and gait instability. Magnetic resonance imaging (MRI) studies revealed multiple enhancing nodular nodules throughout the entire spinal canal. Brain MRI revealed no abnormal lesions. A World Health Organization grade II ependymoma was confirmed histologically. At 31 months postoperatively, the patient remained clinically asymptomatic. Although cervical and thoracic MRI revealed stable intradural nodules and several areas of leptomeningeal enhancement, no malignant cells were seen in the cerebrospinal fluid (CSF). He underwent genetic testing to determine the appropriate chemotherapeutic agent if activation of the tumor should arise. LESSONS: Because complete resection of multifocal IDEM ependymomas is not feasible, continued monitoring with brain and spine MRI is warranted to detect potential tumor dissemination in the CSF.

Flaccid Brachial Monoplegia As Initial Presentation in a Patient With Progressive Multifocal Leukoencephalopathy.

Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease caused by activation of John Cunningham virus (JCV) replication in the setting of impaired cellular immunity. A positive polymerase chain reaction (PCR) assay for JCV DNA in the cerebrospinal fluid (CSF) in conjunction with clinical findings and neuroimaging are diagnostic of PML. A false negative JCV PCR in the CSF may occur, necessitating PML confirmation by brain biopsy. We describe the unique clinical profile of a patient with no prior history of immunocompromise, referred to us for electrodiagnostic evaluation, who initially presented with rapidly progressive weakness of the right upper extremity. The unusual pattern of motor weakness suggested a conduction block or disconnection at the subcortical level. The patient was later diagnosed with atypical small cell lymphocytic lymphoma although not treated with monoclonal antibodies or other forms of chemotherapy. The CSF was negative for JCV, and PML was subsequently confirmed by brain biopsy. This case illustrates an uncommon presentation of PML and highlights the need for a high index of suspicion to diagnose PML.

Transhemispheric cortex remodeling promotes forelimb recovery after spinal cord injury.

Understanding the reorganization of neural circuits spared after spinal cord injury in the motor cortex and spinal cord would provide insights for developing therapeutics. Using optogenetic mapping, we demonstrated a transhemispheric recruitment of neural circuits in the contralateral cortical M1/M2 area to improve the impaired forelimb function after a cervical 5 right-sided hemisection in mice, a model mimicking the human Brown-Séquard syndrome. This cortical reorganization can be elicited by a selective cortical optogenetic neuromodulation paradigm. Areas of whisker, jaw, and neck, together with the rostral forelimb area, on the motor cortex ipsilateral to the lesion were engaged to control the ipsilesional forelimb in both stimulation and nonstimulation groups 8 weeks following injury. However, significant functional benefits were only seen in the stimulation group. Using anterograde tracing, we further revealed a robust sprouting of the intact corticospinal tract in the spinal cord of those animals receiving optogenetic stimulation. The intraspinal corticospinal axonal sprouting correlated with the forelimb functional recovery. Thus, specific neuromodulation of the cortical neural circuits induced massive neural reorganization both in the motor cortex and spinal cord, constructing an alternative motor pathway in restoring impaired forelimb function.

Nerve Ultrasound Findings before and after Surgery in a Patient with Charcot-Marie-Tooth Disease Type 1A and Comorbid Carpal Tunnel Syndrome.

The diagnosis of comorbid carpal tunnel syndrome (CTS) in patients with Charcot-Marie-Tooth (CMT) disease is challenging due to the overlapping symptoms and inconclusive electrodiagnostic studies (EDX). This case report is aimed at illustrating the value of ultrasonography (US) in a patient with CMT1 disease and comorbid CTS. A 28-year-old woman presented with symptoms of painful paresthesia and weakness of both hands. EDX demonstrated a demyelinating sensory-motor polyneuropathy in the upper and lower extremities, consistent with CMT1 disease. US showed an increased cross-sectional area (CSA) of the median nerve at the carpal tunnel inlet (CTI) with a significant drop in the diameter within the carpal tunnel, confirming concurrent CTS. Genetic testing confirmed PMP22 duplication consistent with CMT1A. Bilateral carpal tunnel releases were performed with partial symptom resolution within 3 weeks. Postoperative EDX demonstrated improved motor conduction across the wrist, but the sensory potentials continued to be unrecordable. US showed a significant reversal of the diameter-drop of the median nerve within the carpal tunnel and decrease in CSA at the CTI. US imaging is a valuable technique for identifying comorbid CTS in patients with CMT and directing appropriate treatment.

Brachioradial Pruritus: Clinical, Electromyographic, and Cervical MRI Features in Nine Patients.

Background Brachioradial pruritus (BRP) is a neuropathic dysesthesia manifesting as pruritus over the dorsolateral forearm. While the etiology is unknown, intensive sun exposure and cervical spine disease have been proposed. This study describes the clinical, electrodiagnostic (EDX), and cervical MRI findings in nine patients diagnosed with BRP. Materials and methods All patients underwent EDX and cervical MRIs. Numerous metrics were documented including presenting symptoms, neurological examination, EDX findings, and cervical MRI features. Results All nine patients experienced pruritus of the arms/forearms, typical of BRP, which was unilateral in eight (89%) cases. Decreased pinprick sensation was noted in the arms/forearms (five [56%] patients) or of the thumbs, index, and/or middle fingers (four [44%] patients). Four (44%) patients had either decreased or absent biceps and brachioradialis deep tendon reflexes (DTRs), while one (11%) patient had decreased triceps and brachioradialis DTRs. The EDX revealed abnormalities in eight (89%) patients. Increased polyphasic units, decreased motor units, and/or denervation changes were recorded by needle electromyography (EMG) in eight (89%) patients: the biceps in seven (88%) and both the brachioradialis and triceps in four (50%) patients. The EMG abnormalities indicated chronic radiculopathy involving C6 in six patients and C5 and C6 in one patient. All nine patients had cervical spine disease, encompassing disc protrusions, spondylosis, spinal stenosis, and/or foraminal stenosis. Conclusions BRP in this series of patients was accompanied by chronic cervical radiculopathy involving predominantly C6 and C5. EDX and cervical spine MR imaging should be considered essential investigations in the evaluation of patients with BRP.