A Rare Pediatric Encounter: Transverse Myelitis With Subacute Bilateral Lower Extremity Weakness

This case report provides a comprehensive overview of a rare instance of transverse myelitis (TM) in an 11-year-old male who presented with subacute bilateral lower extremity weakness, sensory loss, and bowel/bladder dysfunction. Diagnostic evaluations, including MRI and cerebrospinal fluid (CSF) analysis, confirmed TM. Management with high-dose intravenous corticosteroids and rehabilitative therapies led to symptom stabilization and modest recovery, although some permanent deficits are anticipated. The report highlights the importance of prompt diagnosis and intervention in pediatric patients with acute neurologic symptoms localized to the spinal cord. It contributes to the existing literature by detailing the clinical and diagnostic features of pediatric TM, aiding in early recognition and management to minimize permanent disability. Future research should focus on understanding the underlying pathophysiology with a view to developing targeted therapies.

Intramedullary Thoracic Spinal Cord Abscess Mimicking an Intramedullary Tumor: A Case Report

An intramedullary abscess is an extremely rare form of infection of the spinal cord, with only about 100 cases reported in the literature. It typically presents with back pain, neurological deficits, and, occasionally, fever. The purpose of this article is to report a case of an intramedullary thoracic spinal cord abscess that was initially misdiagnosed as an intramedullary tumor. A 48-year-old female presented with chronic inter-scapular pain and lower limb weakness. The patient was initially misdiagnosed as a case of intramedullary spinal cord tumor, primarily due to the rarity of intramedullary spinal cord abscess (ISCA) as well as the absence of ring enhancement in the lesion on MRI. However, during a surgical procedure for the excision of the lesion, it was found to be a case of ISCA. The purulent contents of the lesion were evacuated, and the patient was treated with IV antibiotics, leaving the patient with a slight residual lower limb weakness on the follow-up examination. This case highlights the importance of considering intramedullary abscess as a possible diagnosis in patients with back pain and neurological deficits, even in the absence of ring enhancement on imaging. Prompt surgical intervention should be considered in probable cases of intramedullary spinal cord tumors.

Thoracic Spinal Cord Neuroinflammation as a Novel Therapeutic Target in Pulmonary Hypertension

BACKGROUND

Pulmonary hypertension (PH) is associated with aberrant sympathoexcitation leading to right ventricular failure (RVF), arrhythmias, and death. Microglial activation and neuroinflammation have been implicated in sympathoexcitation in experimental PH. We recently reported the first evidence of thoracic spinal cord (TSC) neuroinflammation in PH rats. Here, we hypothesize that PH is associated with increased cardiopulmonary afferent signaling leading to TSC-specific neuroinflammation and sympathoexcitation. Furthermore, inhibition of TSC neuroinflammation rescues experimental PH and RVF.

METHODS

We performed transcriptomic analysis and its validation on the TSC of monocrotaline (n=8) and Sugen hypoxia (n=8) rat models of severe PH-RVF. A group of monocrotaline rats received either daily intrathecal microglial activation inhibitor minocycline (200 μg/kg per day, n=5) or PBS (n=5) from day 14 through 28. Echocardiography and right ventricle-catheterization were performed terminally. Real-time quantitative reverse transcription PCR, immunolocalization, microglia+astrocyte quantification, and terminal deoxynucleotidyl transferase dUTP nick end labeling were assessed. Plasma catecholamines were measured by ELISA. Human spinal cord autopsy samples (Control n=3; PAH n=3) were assessed to validate preclinical findings.

RESULTS

Increased cardiopulmonary afferent signaling was demonstrated in preclinical and clinical PH. Our findings delineated common dysregulated genes and pathways highlighting neuroinflammation and apoptosis in the remodeled TSC and highlighted increased sympathoexcitation in both rat models. Moreover, we validated significantly increased microglial and astrocytic activation and CX3CL1 expression in TSC of human PAH. Finally, amelioration of TSC neuroinflammation by minocycline in monocrotaline rats inhibited microglial activation, decreased proinflammatory cytokines, sympathetic nervous system activation and significantly attenuated PH and RVF.

CONCLUSIONS

Targeting neuroinflammation and associated molecular pathways and genes in the TSC may yield novel therapeutic strategies for PH and RVF.

Whole CNS 3D Cryo-Fluorescence Tomography Shows CSF Clearance along Nasal Lymphatics, Spinal Nerves, and Lumbar/Sacral Lymph Nodes

Unwanted proteins and metabolic waste in cerebral spinal fluid are cleared from the brain by meningeal and nasal lymphatics and the perineural sheath of cranial nerves; however, the distribution and clearance of cerebral spinal fluid (CSF) along the subarachnoid space of the entire spinal cord is not fully understood. Cryo-fluorescence tomography (CFT) was used to follow the movement of tracers from the ventricular system of the brain down through the meningeal lining of the spinal cord and out to the spinal lymphatic nodes. Isoflurane-anesthetized mice were infused into the lateral cerebroventricle with 5.0 µL of quantum dots [QdotR 605 ITKTM amino (PEG)] over two mins. Mice were allowed to recover (ca 2-3 min) and remained awake and ambulatory for 5, 15, 30, 60, and 120 min after which they were euthanized, and the entire intact body was frozen at -80^°. The entire mouse was sectioned, and white light and fluorescent images were captured after each slice to produce high resolution three-dimensional volumes. Tracer appeared throughout the ventricular system and central canal of the spinal cord and the entire subarachnoid space of the CNS. A signal could be visualized in the nasal cavity, deep cervical lymph nodes, thoracic lymph nodes, and more superficial submandibular lymph nodes as early as 15 min post infusion. A fluorescent signal could be visualized along the dorsal root ganglia and down the proximal extension of the spinal nerves of the thoracic and lumbar segments at 30 min. There was a significant accumulation of tracer in the lumbar and sacral lymph nodes between 15-60 min. The dense fluorescent signal in the thoracic vertebrae noted at 5- and 15-min post infusion was significantly reduced by 30 min. Indeed, all signals in the spinal cord were ostensibly absent by 120 min, except for trace amounts in the coccyx. The brain still had some residual signal at 120 min. These data show that Qdots with a hydrodynamic diameter of 16-20 nm rapidly clear from the brain of awake mice. These data also clearly demonstrate the rapid distribution and efflux of traces along a major length of the vertebral column and the potential contribution of the spinal cord in the clearance of brain waste.

Intradural Extramedullary Solitary Fibrous Tumor of the Thoracic Spinal Cord

Solitary fibrous tumors (SFTs) are rare soft tissue neoplasms that can impact the central nervous system (CNS). SFTs comprise <1% of all primary CNS tumors. Here, we describe a rare case of intradural, extramedullary SFT arising within the thoracic spine that was treated with surgical resection. Histological features were evaluated and revealed a highly cellular tumor with positive expression of BCL2, CD34, CD99, and STAT6 proteins that are consistent with a diagnosis of SFT. We discuss the use of surgical intervention for long-term disease control of spinal SFT and evaluate the role of postoperative radiation therapy in management strategies. Lastly, we review the literature reports of intradural, extramedullary SFTs in the thoracic spine. The importance of molecular characterization by histopathology to properly determine diagnosis and prognosis is emphasized.

Pilomyxoid astrocytoma of the thoracic spinal cord: Extremely rare case report of over 70-year-old patient

The Pilomyxoid is rare tumor in elderly population, in addition to the occurrence of an isolated lesion in spinal cord is extremely rare in non-pediatric population. Taking biopsy and subtotal resection is the starting point in essential approach for the treatment. After defining the histopathological nature of the tumor and specified that is Pilomyxoid, the next step is the combination of reoperation and adjuvant therapy.

Surgical management and outcome of adult posterior cranial fossa and spinal hemangioblastoma: a 6-case series and literature review

OBJECTIVE

Hemangioblastomas of the posterior cranial fossa and spinal cord in adults are excessively vascularized, well-differentiated, and scarce tumors with no metastatic potential. This paper discusses its surgical management and outcome, pointing out their morphological, radiological, and histopathological aspects. This report based on a personal series of six patients and on a literature review.

METHODS

A single-institution personal 6-case series of adult patients diagnosed and operated on by a senior neurosurgeon (KIA) due to posterior cranial fossa or spinal cord hemangioblastoma was analyzed. For easier understanding of hemangioblastoma, we have classified them into four different types.

RESULTS

The tumors, which were all surgically treated, were located in the posterior cranial fossa in five patients (4 cerebellar, 1 brain stem) and intramedullary in the thoracic spinal cord in one patient. All patients successfully recovered neurologically after a complete tumor resection, having no post-operative neurological deficit or other complications.

CONCLUSION

Surgical management of cerebellar and spinal cord hemangioblastoma in adults is highly dependent on its morphological features, as well as on microsurgical technique applied. Since huge differences exist between the cystic/nodular tumor type (Type 1) and the solid type and its two additional variants (Types 2-4), morphology is the most important consideration when deciding surgical approach. Despite significant morphological differences among different subtypes of hemangioblastomas, their histology appears to be relatively similar. Nonetheless, a meticulous and refined surgical technique has to be utilized to achieve a successful outcome.

Recurrent thoracic intramedullary schwannoma: report of two cases with long term follow up

Occurrence of intramedullary schwannomas is rare as Schwann cells are generally present in the nerve root and not in the spinal cord. To date, approximately around 60 cases of intramedullary schwannoma in patients without neurofibromatosis have been reported in the English literature, of which only eight were children. We describe two cases of thoracic intramedullary schwannomas that recurred after primary excision. A 10 years old boy presented with weakness of both lower limbs. Magnetic resonance imaging showed a D10 to D12 intramedullary lesion, which was excised near totally and confirmed to be a schwannoma on histopathological examination. The tumour recurred twice after that and was re operated both times. Another 57 years old lady presented with weakness of both lower limbs and a history of being operated in the past for D9-D10 intramedullary lesion. She was re-operated with total removal of the lesion confirmed to be schwannoma on histopathological examination. Intramedullary schwannoma may recur after resection.

Sympathetic Discharges in intercostal and abdominal nerves

There are hardly any published data on the characteristics of muscle nerve sympathetic discharges occurring in parallel with the somatic motoneurone discharges in the same nerves. Here, we take advantage of the naturally occurring respiratory activity in recordings of efferent discharges from branches of the intercostal and abdominal nerves in anesthetized cats to make this comparison. The occurrence of efferent spikes with amplitudes below that for alpha motoneurones were analyzed for cardiac modulation, using cross-correlation between the times of the R-wave of the ECG and the efferent spikes. The modulation was observed in nearly all recordings, and for all categories of nerves. It was strongest for the smallest amplitude spikes or spike-like waveforms, which were deduced to comprise postsynaptic sympathetic discharges. New observations were: (1) that the cardiac modulation of these discharges was modest compared to most previous reports for muscle nerves; (2) that the amplitudes of the sympathetic discharges compared to those of the somatic spikes were strongly positively correlated to nerve diameter, such that, for the larger nerves, their amplitudes overlapped considerably with those of gamma motoneurone spikes. This could be explained by random summation of high rates of unit sympathetic spikes. We suggest that under some experimental circumstances this overlap could lead to considerable ambiguity in the identity of the discharges in efferent neurograms.

Cardiac modulation of alpha motoneuron discharges

Recordings of alpha motoneuron discharges from branches of the intercostal and abdominal nerves in anesthetized cats were analyzed for modulation during the cardiac cycle. Cardiac modulation was assessed by the construction of cross-correlation histograms between the R-wave of the ECG and the largest amplitude efferent spikes. In all but two recordings (which were believed to have either no or few alpha spikes), the histograms showed relatively short duration peaks and/or troughs (widths at half amplitude 4-50 ms) at lags of 10-150 ms. These observations were deduced to result from activity in oligosynaptic pathways, probably from muscle spindle afferents, whose discharges are known to be synchronized to the cardiac pulse. The results suggest that onward transmission of the cardiac signal from thoracic muscle afferents (and possibly from other dynamically sensitive afferents) to other parts of the central nervous system is highly likely and that therefore these afferents could contribute to cardiac interoception. NEW & NOTEWORTHY It has been recognized since 1933 that muscle spindles respond to the cardiac pulse, but it is unknown whether this cardiac signal is transmitted to other levels in the nervous system. Here we show that a cardiac signal, likely arising from muscle spindles, is present in the efferent activities of thoracic and abdominal muscle nerves, suggesting probable onward transmission of this signal to higher levels and therefore that muscle spindles could contribute to cardiac interoception.

Ossification of ligamentum flavum, a rare cause of myelopathy: First case report of a Lebanese patient

Ossification of ligamentum flavum (OLF) is a well-known pathology causing myelopathy, although it is a rare disease. The most commonly affected population is from the Far East and mainly Japanese. However, few reports and studies have shown the prevalence of the disease all over the world. We report the case of a 33-year-old man presenting with signs of progressive myelopathy. Magnetic resonance imaging (MRI) showed Th2-Th11 OLF with severe narrowing and intramedullary hypersignal at the level Th2-Th3. This is the first Lebanese case reported in the literature. A decompressive laminectomy with flavectomy was done. This case adds to the previous reported cases on the occurrence of the disease in different populations.

A neural correlate of visceral emotional responses: evidence from fMRI of the thoracic spinal cord

Functional magnetic resonance imaging (fMRI) of thoracic spinal cord neurons was used to examine the neural correlates of visceral emotional responses. Participants completed four spinal fMRI runs involving passive viewing (i.e. no movement) and motoric responses to negative or neutral images. Negative images, particularly in the movement condition, elicited robust activity in motoric nuclei, indicating 'action preparedness'. These images also enhanced activity in autonomic and sensory nuclei, thus providing a clear neural representation of visceral responses to emotional stimuli.

Absence of synergy for monosynaptic Group I inputs between abdominal and internal intercostal motoneurons

Internal intercostal and abdominal motoneurons are strongly coactivated during expiration. We investigated whether that synergy was paralleled by synergistic Group I reflex excitation. Intracellular recordings were made from motoneurons of the internal intercostal nerve of T8 in anesthetized cats, and the specificity of the monosynaptic connections from afferents in each of the two main branches of this nerve was investigated. Motoneurons were shown by antidromic excitation to innervate three muscle groups: external abdominal oblique [EO; innervated by the lateral branch (Lat)], the region of the internal intercostal muscle proximal to the branch point (IIm), and muscles innervated from the distal remainder (Dist). Strong specificity was observed, only 2 of 54 motoneurons showing excitatory postsynaptic potentials (EPSPs) from both Lat and Dist. No EO motoneurons showed an EPSP from Dist, and no IIm motoneurons showed one from Lat. Expiratory Dist motoneurons fell into two groups. Those with Dist EPSPs and none from Lat (group A) were assumed to innervate distal internal intercostal muscle. Those with Lat EPSPs (group B) were assumed to innervate abdominal muscle (transversus abdominis or rectus abdominis). Inspiratory Dist motoneurons (assumed to innervate interchondral muscle) showed Dist EPSPs. Stimulation of dorsal ramus nerves gave EPSPs in 12 instances, 9 being in group B Dist motoneurons. The complete absence of heteronymous monosynaptic Group I reflex excitation between muscles that are synergistically activated in expiration leads us to conclude that such connections from muscle spindle afferents of the thoracic nerves have little role in controlling expiratory movements but, where present, support other motor acts.

Axonal projections of Renshaw cells in the thoracic spinal cord

Renshaw cells are widely distributed in all segments of the spinal cord, but detailed morphological studies of these cells and their axonal branching patterns have only been made for lumbosacral segments. For these, a characteristic distribution of terminals was reported, including extensive collateralization within 1-2 mm of the soma, but then more restricted collaterals given off at intervals from the funicular axon. Previous authors have suggested that the projections close to the soma serve inhibition of motoneurons (known to be greatest for the motor nuclei providing the Renshaw cell excitation) but that the distant projections serve mainly the inhibition of other neurons. However, in thoracic segments, inhibition of motoneurons is known to occur over two to three segments (20-40 mm) from the presumed somatic locations of the Renshaw cells. Here, we report the first detailed morphological study of Renshaw cell axons outside the lumbosacral segments, which investigated whether this different distribution of motoneuron inhibition is reflected in a different pattern of Renshaw cell terminations. Four Renshaw cells in T7 or T8 segments were intracellularly labeled with neurobiotin in anesthetized cats and their axons traced for distances ≥6 mm from the somata. The only morphological difference detected within this distance in comparison with Renshaw cells in the lumbosacral cord was a minimal taper in the funicular axons, where in the lumbosacral cord this is pronounced. Patterns of termination were virtually identical to those in the lumbosacral segments, so we conclude that these patterns are unrelated to the pattern of motoneuronal inhibition.

Biomechanical study of the spinal cord in thoracic ossification of the posterior longitudinal ligament

BACKGROUND

Ossification of the posterior longitudinal ligament (OPLL) in the thoracic spine produces myelopathy. This is often progressive and is not affected by conservative treatment. Therefore, decompressive surgery is usually chosen.

OBJECTIVE

To conduct a stress analysis of the thoracic OPLL.

METHODS

The three-dimensional finite element spinal cord model was established. We used local ossification angle (LOA) for the degree of compression of spinal cord. LOA was the medial angle at the intersection between a line from the superior posterior margin at the cranial vertebral body of maximum OPLL to the top of OPLL with beak type, and a line from the lower posterior margin at the caudal vertebral body of the maximum OPLL to the top of OPLL with beak type. LOA 20°, LOA 25°, and LOA 30° compression was applied to the spinal cord in a preoperative model, the posterior decompressive model, and a model for the development of kyphosis.

RESULTS

In a preoperative model, at more than LOA 20° compression, high stress distributions in the spinal cord were observed. In a posterior decompressive model, the stresses were lower than in the preoperative model. In the model for development of kyphosis, high-stress distributions were observed in the spinal cord at more than LOA 20° compression.

CONCLUSIONS

Posterior decompression was an effective operative method. However, when the preoperative LOA is more than 20°, it is very likely that symptoms will worsen. If operation is performed at greater than LOA 20°, then correction of kyphosis by fixation of instruments or by forward decompression should be considered.