Analysis of risk factors for long-term mortality in patients with stage II and III tuberculous meningitis.

OBJECTIVE: To investigate risk factors associated with long-term mortality in patients with stage II and III tuberculous meningitis (TBM). METHODS: This retrospective analysis examined patients who were first diagnosed with stage II and III TBM at West China Hospital of Sichuan University between January 1, 2018 and October 1, 2019. Patients were followed via telephone and categorized into survival and mortality groups based on 4-year outcomes. Multivariate logistic regression identified independent risk factors for long-term mortality in stage II and III TBM. RESULTS: In total, 178 patients were included, comprising 108 (60.7%) males and 36 (20.2%) non-survivors. Mean age was 36 ± 17 years. Compared to survivors, non-survivors demonstrated significantly higher age, heart rate, diastolic blood pressure, blood glucose, rates of headache, neurological deficits, cognitive dysfunction, impaired consciousness, hydrocephalus, and basal meningeal inflammation. This group also exhibited significantly lower Glasgow Coma Scale (GCS) scores, blood potassium, albumin, and cerebrospinal fluid chloride. Multivariate analysis revealed age (OR 1.042; 95% CI 1.015-1.070; P = 0.002), GCS score (OR 0.693; 95% CI 0.589-0.814; P < 0.001), neurological deficits (OR 5.204; 95% CI 2.056-13.174; P < 0.001), and hydrocephalus (OR 2.680; 95% CI 1.081-6.643; P = 0.033) as independent mortality risk factors. The ROC curve area under age was 0.613 (95% CI 0.506-0.720; P = 0.036) and 0.721 (95% CI 0.615-0.826; P < 0.001) under GCS score. CONCLUSION: Advanced age, reduced GCS scores, neurological deficits, and hydrocephalus were identified as independent risk factors for mortality in stage II and III TBM patients.

Sensory Neurotization of the Ulnar Nerve, Surgical Techniques and Functional Outcomes: A Review.

When ulnar nerve lesions happen above the wrist level, sensation recovery after acute repair or nerve grafting is often challenging. Distal sensory nerve transfers may be an option for overcoming these sequelae. However, little data has been published on this topic. This study aims to review the surgical procedures currently proposed, along with their functional results. Six donor nerves have been described at the wrist level: the palmar branch of the median nerve, the cutaneous branch of the median nerve to the palm with or without fascicles of the ulnar digital nerve of the index finger, the posterior interosseous nerve, the third palmar digital nerve, the radial branch of the superficial radial nerve, the median nerve, and the fascicule for the third web space. Three donor nerves have been reported at the hand level: the ulnar digital nerves of the index, and the radial or ulnar digital nerves of the long finger. Three target sites were used: the superficial branch of the ulnar nerve, the dorsal branch of the ulnar nerve, and the ulnar digital branch of the fifth digit. All the technical points have been illustrated with anatomical dissection pictures. After assessing sensory recovery using the British Medical Research Council scale, a majority of excellent recoveries scaled S3+ or S4 have been reported in the targeted territory for each technique.

Intracerebral mucormycosis after COVID-19: illustrative cases.

BACKGROUND: In this case report the authors present two female patients with intracranial mucormycosis after coronavirus disease 2019 (COVID-19). OBSERVATIONS: The first patient was a 30-year-old woman with no past medical history or allergies who presented with headaches and vomiting. Magnetic resonance imaging (MRI) and computed tomography of the skull showed an endonasal infection, which had already destroyed the frontal skull base and caused a large frontal intracranial abscess. The second patient was a 29-year-old woman with multiple pre-existing conditions, who was initially admitted to the hospital due to a COVID-19 infection and later developed a hemiparesis of the right side. Here, the MRI scan showed an abscess configuration in the left motor cortex. In both cases, rapid therapy was performed by surgical clearance and abscess evacuation followed by antifungal, antidiabetic, and further supportive treatment for several weeks. LESSONS: Both cases are indicative of a possible correlation of mucormycosis in the setting of severe immunosuppression involved with COVID-19, both iatrogenic with the use of steroids and previous medical history. Furthermore, young and supposedly healthy patients can also be affected by this rare disease.

Distal pronator teres motor branch transfer for wrist extension restoration in radial nerve paralysis.

OBJECTIVE: The authors describe the anatomy of the motor branches of the pronator teres (PT) as it relates to transferring the nerve of the extensor carpi radialis brevis (ECRB) to restore wrist extension in patients with radial nerve paralysis. They describe their anatomical cadaveric findings and report the results of their nerve transfer technique in several patients followed for at least 24 months postoperatively. METHODS: The authors dissected both upper limbs of 16 fresh cadavers. In 6 patients undergoing nerve surgery on the elbow, they dissected the branches of the median nerve and confirmed their identity by electrical stimulation. Of these 6 patients, 5 had had a radial nerve injury lasting 7-12 months, underwent transfer of the distal PT motor branch to the ECRB, and were followed for at least 24 months. RESULTS: The PT was innervated by two branches: a proximal branch, arising at a distance between 0 and 40 mm distal to the medial epicondyle, responsible for PT superficial head innervation, and a distal motor branch, emerging from the anterior side of the median nerve at a distance between 25 and 60 mm distal to the medial epicondyle. The distal motor branch of the PT traveled approximately 30 mm along the anterior side of the median nerve; just before the median nerve passed between the PT heads, it bifurcated to innervate the deep head and distal part of the superficial head of the PT. In 30% of the cadaver limbs, the proximal and distal PT branches converged into a single trunk distal to the medial epicondyle, while they converged into a single branch proximal to it in 70% of the limbs. The proximal and distal motor branches of the PT and the nerve to the ECRB had an average of 646, 599, and 457 myelinated fibers, respectively.All patients recovered full range of wrist flexion-extension, grade M4 strength on the British Medical Research Council scale. Grasp strength recovery achieved almost 50% of the strength of the contralateral side. All patients could maintain their wrist in extension while performing grasp measurements. CONCLUSIONS: The distal PT motor branch is suitable for reinnervation of the ECRB in radial nerve paralysis, for as long as 7-12 months postinjury.

Reconstruction of the spinal accessory nerve with selective fascicular nerve transfer of the upper trunk.

OBJECTIVE: Spinal accessory nerve palsy is frequently caused by iatrogenic damage during neck surgery in the posterior triangle of the neck. Due to late presentation, treatment regularly necessitates nerve grafts, which often results in a poor outcome of trapezius function due to long regeneration distances. Here, the authors report a distal nerve transfer using fascicles of the upper trunk related to axillary nerve function for reinnervation of the trapezius muscle. METHODS: Five cases are presented in which accessory nerve lesions were reconstructed using selective fascicular nerve transfers from the upper trunk of the brachial plexus. Outcomes were assessed at 20 ± 6 months (mean ± SD) after surgery, and active range of motion and pain levels using the visual analog scale were documented. RESULTS: All 5 patients regained good to excellent trapezius function (3 patients had grade M5, 2 patients had grade M4). The mean active range of motion in shoulder abduction improved from 55° ± 18° before to 151° ± 37° after nerve reconstruction. In all patients, unrestricted shoulder arm movement was restored with loss of scapular winging when abducting the arm. Average pain levels decreased from 6.8 to 0.8 on the visual analog scale and subsided in 4 of 5 patients. CONCLUSIONS: Restoration of spinal accessory nerve function with selective fascicle transfers related to axillary nerve function from the upper trunk of the brachial plexus is a good and intuitive option for patients who do not qualify for primary nerve repair or present with a spontaneous idiopathic palsy. This concept circumvents the problem of long regeneration distances with direct nerve repair and has the advantage of cognitive synergy to the target function of shoulder movement.

T2 mapping of lumbosacral nerves in patients suffering from unilateral radicular pain due to degenerative disc disease.

OBJECTIVELumbosacral radicular syndrome (LRS) is a very common condition, often requiring diagnostic imaging with the aim of elucidating a structural cause when symptoms are longer lasting. However, findings on conventional anatomical MRI do not necessarily correlate with clinical symptoms, and it is primarily performed for the qualitative evaluation of surrounding compressive structures, such as herniated discs, instead of to evaluate the nerves directly. The present study investigated the performance of quantitative imaging by using magnetic resonance neurography (MRN) in patients with LRS.METHODSEighteen patients (55.6% males, mean age 64.4 ± 10.2 years), with strict unilateral LRS matching at least one dermatome and suspected disc herniation, underwent high-resolution 3-T MRN using T2 mapping. On T2 maps, the presumably affected and contralateral unaffected nerves were identified; subsequent regions of interest (ROIs) were placed at preganglionic, ganglionic, and postganglionic sites; and T2 values were extracted. Patients then underwent an epidural steroid injection (ESI) with local anesthetic agents at the site of suspected nerve affection. T2 values of the affected nerves were compared against the contralateral nerves. Furthermore, receiver operating characteristics were calculated based on the measured T2 values and the responsiveness to ESI.RESULTSThe mean T2 value was 77.3 ± 1.9 msec for affected nerves and 74.8 ± 1.4 msec for contralateral nerves (p < 0.0001). In relation to ESI performed at the site of suspected nerve affection, MRN with T2 mapping had a sensitivity/specificity of 76.9%/60.0% and a positive/negative predictive value of 83.3%/50.0%. Signal alterations in affected nerves according to qualitative visual inspection were present in only 22.2% of patients.CONCLUSIONSAs one of the first of its kind, this study revealed elevated T2 values in patients suffering from LRS. T2 values of lumbosacral nerves might be used as more objective parameters to directly detect nerve affection in such patients.

Phrenic to musculocutaneous nerve transfer for traumatic brachial plexus injuries: analyzing respiratory effects on elbow flexion control.

OBJECTIVE: In this study, the authors sought to identify the relationship between breathing and elbow flexion in patients with a traumatic brachial plexus injury (TBPI) who undergo a phrenic nerve (PN) transfer to restore biceps flexion. More specifically, the authors studied whether biceps strength and the maximal range of active elbow flexion differ between full inspiration and expiration, and whether electromyography (EMG) activity in the biceps differs between forced maximum breathing during muscular rest, normal breathing during rest, and at maximal biceps contraction. All these variables were studied in a cohort with different intervals of follow-up, as the authors sought to determine if the relationship between breathing movements and elbow flexion changes over time. METHODS: The British Medical Research Council muscle-strength grading system and a dynamometer were used to measure biceps strength, which was measured 1) during a maximal inspiratory effort, 2) during respiratory repose, and 3) after a maximal expiratory effort. The maximum range of elbow flexion was measured 1) after maximal inspiration, 2) during normal breathing, and 3) after maximal expiration. Postoperative EMG testing was performed 1) during normal breathing with the arm at rest, 2) during sustained maximal inspiration with the arm at rest, and 3) during maximal voluntary biceps contraction. Within-group (paired) comparisons, and both correlation and regression analyses were performed. RESULTS: Twenty-one patients fit the study inclusion criteria. The mean interval from trauma to surgery was 5.5 months, and the mean duration of follow-up 2.6 years (range 10 months to 9.6 years). Mean biceps strength was 0.21 after maximal expiration versus 0.29 after maximal inspiration, a difference of 0.08 (t = 4.97, p < 0.001). Similarly, there was almost a 21° difference in maximum elbow flexion, from 88.8° after expiration to 109.5° during maximal inspiration (t = 5.05, p < 0.001). Involuntary elbow flexion movement during breathing was present in 18/21 patients (86%) and averaged almost 20°. Measuring involuntary EMG activity in the biceps during rest and contraction, there were statistically significant direct correlations between readings taken during normal and deep breathing, which were moderate (r = 0.66, p < 0.001) and extremely strong (r = 0.94, p < 0.001), respectively. Involuntary activity also differed significantly between normal and deep breathing (2.14 vs 3.14, t = 4.58, p < 0.001). The degrees of involuntary flexion were significantly greater within the first 2.6 years of follow-up than later. CONCLUSIONS: These results suggest that the impact of breathing on elbow function is considerable after PN transfer for elbow function reconstruction following a TBPI, both clinically and electromyographically, but also that there may be some waning of this influence over time, perhaps secondary to brain plasticity. In the study cohort, this waning impacted elbow range of motion more than biceps muscle strength and EMG recordings.

Contralateral C7 to C7 nerve root transfer in reconstruction for treatment of total brachial plexus palsy: anatomical basis and preliminary clinical results.

OBJECTIVEContralateral C7 (CC7) nerve root has been used as a donor nerve for targeted neurotization in the treatment of total brachial plexus palsy (TBPP). The authors aimed to study the contribution of C7 to the innervation of specific upper-limb muscles and to explore the utility of C7 nerve root as a recipient nerve in the management of TBPP.METHODSThis was a 2-part investigation. 1) Anatomical study: the C7 nerve root was dissected and its individual branches were traced to the muscles in 5 embalmed adult cadavers bilaterally. 2) Clinical series: 6 patients with TBPP underwent CC7 nerve transfer to the middle trunk of the injured side. Outcomes were evaluated with the modified Medical Research Council scale and electromyography studies.RESULTSIn the anatomical study there were consistent and predominantly C7-derived nerve fibers in the lateral pectoral, thoracodorsal, and radial nerves. There was a minor contribution from C7 to the long thoracic nerve. The average distance from the C7 nerve root to the lateral pectoral nerve entry point of the pectoralis major was the shortest, at 10.3 ± 1.4 cm. In the clinical series the patients had been followed for a mean time of 30.8 ± 5.3 months postoperatively. At the latest follow-up, 5 of 6 patients regained M3 or higher power for shoulder adduction and elbow extension. Two patients regained M3 wrist extension. All regained some wrist and finger extension, but muscle strength was poor. Compound muscle action potentials were recorded from the pectoralis major at a mean follow-up of 6.7 ± 0.8 months; from the latissimus dorsi at 9.3 ± 1.4 months; from the triceps at 11.5 ± 1.4 months; from the wrist extensors at 17.2 ± 1.5 months; from the flexor carpi radialis at 17.0 ± 1.1 months; and from the digital extensors at 22.8 ± 2.0 months. The average sensory recovery of the index finger was S2. Transient paresthesia in the hand on the donor side, which resolved within 6 months postoperatively, was reported by all patients.CONCLUSIONSThe C7 nerve root contributes consistently to the lateral pectoral nerve, the thoracodorsal nerve, and long head of the triceps branch of the radial nerve. CC7 to C7 nerve transfer is a reconstructive option in the overall management plan for TBPP. It was safe and effective in restoring shoulder adduction and elbow extension in this patient series. However, recoveries of wrist and finger extensions are poor.

Associations between clinical outcome and navigated transcranial magnetic stimulation characteristics in patients with motor-eloquent brain lesions: a combined navigated transcranial magnetic stimulation-diffusion tensor imaging fiber tracking approach.

OBJECTIVE Navigated transcranial magnetic stimulation (nTMS) and diffusion tensor imaging fiber tracking (DTI FT) based on nTMS data are increasingly used for preoperative planning and resection guidance in patients suffering from motor-eloquent brain tumors. The present study explores whether nTMS-based DTI FT can also be used for individual preoperative risk assessment regarding surgery-related motor impairment. METHODS Data derived from preoperative nTMS motor mapping and subsequent nTMS-based tractography in 86 patients were analyzed. All patients suffered from high-grade glioma (HGG), low-grade glioma (LGG), or intracranial metastasis (MET). In this context, nTMS-based DTI FT of the corticospinal tract (CST) was performed at a range of fractional anisotropy (FA) levels based on an individualized FA threshold ([FAT]; tracking with 50%, 75%, and 100% FAT), which was defined as the highest FA value allowing for visualization of fibers (100% FAT). Minimum lesion-to-CST distances were measured, and fiber numbers of the reconstructed CST were assessed. These data were then correlated with the preoperative, postoperative, and follow-up status of motor function and the resting motor threshold (rMT). RESULTS At certain FA levels, a statistically significant difference in lesion-to-CST distances was observed between patients with HGG who had no impairment and those who developed surgery-related transient or permanent motor deficits (75% FAT: p = 0.0149; 100% FAT: p = 0.0233). In this context, no patient with a lesion-to-CST distance ≥ 12 mm suffered from any new surgery-related permanent paresis (50% FAT and 75% FAT). Furthermore, comparatively strong negative correlations were observed between the rMT and lesion-to-CST distances of patients with surgery-related transient paresis (Spearman correlation coefficient [rs]; 50% FAT: rs = -0.8660; 75% FAT: rs = -0.8660) or surgery-related permanent paresis (50% FAT: rs = -0.7656; 75% FAT: rs = -0.6763). CONCLUSIONS This is one of the first studies to show a direct correlation between imaging, clinical status, and neurophysiological markers for the integrity of the motor system in patients with brain tumors. The findings suggest that nTMS-based DTI FT might be suitable for individual risk assessment in patients with HGG, in addition to being a surgery-planning tool. Importantly, necessary data for risk assessment were obtained without significant additional efforts, making this approach potentially valuable for direct clinical use.

Results of nerve grafting in radial nerve injuries occurring proximal to the humerus, including those within the posterior cord.

OBJECTIVE Results of radial nerve grafting are largely unknown for lesions of the radial nerve that occur proximal to the humerus, including those within the posterior cord. METHODS The authors describe 13 patients with proximal radial nerve injuries who were surgically treated and then followed for at least 24 months. The patients' average age was 26 years and the average time between accident and surgery was 6 months. Sural nerve graft length averaged 12 cm. Recovery was scored according to the British Medical Research Council (BMRC) scale, which ranges from M0 to M5 (normal muscle strength). RESULTS After grafting, all 7 patients with an elbow extension palsy recovered elbow extension, scoring M4. Six of the 13 recovered M4 wrist extension, 6 had M3, and 1 had M2. Thumb and finger extension was scored M4 in 3 patients, M3 in 2, M2 in 2, and M0 in 6. CONCLUSIONS The authors consider levels of strength of M4 for elbow and wrist extension and M3 for thumb and finger extension to be good results. Based on these criteria, overall good results were obtained in only 5 of the 13 patients. In proximal radial nerve lesions, the authors now advocate combining nerve grafts with nerve or tendon transfers to reconstruct wrist, thumb, and finger extension.

Results of nerve grafting in radial nerve injuries occurring proximal to the humerus, including those within the posterior cord.

OBJECT Results of radial nerve grafting are largely unknown for lesions of the radial nerve that occur proximal to the humerus, including those within the posterior cord. METHODS The authors describe 13 patients with proximal radial nerve injuries who were surgically treated and then followed for at least 24 months. The patients' average age was 26 years and the average time between accident and surgery was 6 months. Sural nerve graft length averaged 12 cm. Recovery was scored according to the British Medical Research Council (BMRC) scale, which ranges from M0 to M5 (normal muscle strength). RESULTS After grafting, all 7 patients with an elbow extension palsy recovered elbow extension, scoring M4. Six of the 13 recovered M4 wrist extension, 6 had M3, and 1 had M2. Thumb and finger extension was scored M4 in 3 patients, M3 in 2, M2 in 2, and M0 in 6. CONCLUSIONS The authors consider levels of strength of M4 for elbow and wrist extension and M3 for thumb and finger extension to be good results. Based on these criteria, overall good results were obtained in only 5 of the 13 patients. In proximal radial nerve lesions, the authors now advocate combining nerve grafts with nerve or tendon transfers to reconstruct wrist, thumb, and finger extension.

Nerve transfers for elbow and finger extension reconstruction in midcervical spinal cord injuries.

OBJECT: The objective of this study was to report the results of elbow, thumb, and finger extension reconstruction via nerve transfer in midcervical spinal cord injuries. METHODS: Thirteen upper limbs from 7 patients with tetraplegia, with an average age of 26 years, were operated on an average of 7 months after a spinal cord injury. The posterior division of the axillary nerve was used to reinnervate the triceps long and upper medial head motor branches in 9 upper limbs. Both the posterior division and the branch to the middle deltoid were used in 2 upper limbs, and the anterior division of the axillary nerve in the final 2 limbs. For thumb and finger extension reconstruction, the nerve to the supinator was transferred to the posterior interosseous nerve. RESULTS: In 22 of the 27 recipient nerves, a peripheral type of palsy with muscle denervation was identified. At an average of 19 months follow-up, elbow strength scored M4 in 11 upper limbs and M3 in 2, according to the British Medical Research Council scale. Thumb extension scored M4 in 8 upper limbs and scored M3 in 4. Finger extension scored M4 in 12 hands. No donor-site deficits were reported or observed. CONCLUSIONS: Nerve transfers are effective at restoring elbow, thumb, and finger extension in patients with a midcervical spinal cord injury, which occurs in the majority of patients with a peripheral type of palsy with muscle denervation in their upper limbs. Efforts should be made to perform operations in these patients within 12 months of injury.

A new neurophysiological approach to assess central motor conduction damage to proximal and distal muscles of lower limbs.

OBJECTIVE: To develop a neurophysiological method to explore central motor pathways to proximal and distal muscles of lower limbs. METHODS: MEPs to transcranial magnetic stimulation using the double cone coil were bilaterally and simultaneously recorded from vastus medialis, tibialis anterior and flexor hallucis brevis. Voluntary facilitation was controlled using a predefined sequence of movements of constant amplitude. Compound motor action potentials elicited by maximal high voltage electrical stimulation of lumbosacral roots (root-CMAPs) were recorded from the same muscles to obtain the corresponding peripheral conduction times. We studied 28 healthy subjects and 28 multiple sclerosis (MS) patients with no or mild motor impairment. RESULTS: The described facilitation procedure and the averaging of 5 MEPs reduced area variability to about 10%. In MS patients conduction slowing and/or MEP area reduction in at least one muscle was found in 91.7% of cases, with significant correlation with individual motor impairment. CONCLUSIONS: Combined use of stable MEPs and maximal root-CMAPs was able to detect both conduction slowing and conduction failure in central motor pathways to proximal and distal districts of lower limbs in MS patients. SIGNIFICANCE: The proposed method provides an extensive electrophysiological mapping of central motor impairment of lower limbs in clinical application.

Prognostic value of computed tomography-evident cerebral infarcts in adult patients with tuberculous meningitis and hydrocephalus treated with an external ventricular drain.

OBJECTIVE: Tuberculous meningitis (TBM) frequently is complicated by hydrocephalus and cerebral infarction. Previous studies have shown radiologic evidence of cerebral infarction in TBM to be an indicator of poor outcome in both adults and children. Our objective was to assess short-term mortality in adult patients with TBM and hydrocephalus treated with an external ventricular drain and to assess the prognostic value of cerebral infarction on admission computed tomography imaging within this cohort. METHODS: This was a retrospective case series based on an adult intensive care unit admissions database, analyzing demographic, clinical, diagnostic, and radiologic data against short-term mortality. RESULTS: A total of 25 patients managed from 2005 to 2011 were identified. Three patients were excluded. Mean age was 31 years. British Medical Research Council clinical severity grading was grade I in 9.1%, grade II in 31.8%, and grade III in 59.1%. Short-term mortality was 68.2% overall. Cerebral infarction on admission scanning was seen in 10 patients (45.5%). Prevalence of infarcts was not significantly higher in HIV-positive patients (50.0% vs. 42.9%). Mortality in the group with infarcts was 100%, compared with 41.7% in the group without infarcts. Mortality in patients with an admission Glasgow Coma Scale of 8 or less was 91.7%. Mortality in the HIV-positive group was slightly greater, but this increase did not reach statistical significance (71.4% vs. 57.1% P = 0.6). Univariate analysis showed presence of infarcts at admission, Glasgow Coma Scale ≤8 at admission and age of 30 years or more to be significantly related to mortality. There was also a statistically significantly increased mortality according to British Medical Research Council grade. CONCLUSION: TBM with hydrocephalus requiring cerebrospinal diversion carries a significant short-term mortality. Within this cohort, the group of patients who have computed tomography-evident cerebral infarcts at admission has an even worse outcome, with a significantly greater short-term mortality prevalence.