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1.
Cereb Cortex ; 34(5)2024 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-38715405

RESUMO

OBJECTIVES: This retrospective study aimed to identify quantitative magnetic resonance imaging markers in the brainstem of preterm neonates with intraventricular hemorrhages. It delves into the intricate associations between quantitative brainstem magnetic resonance imaging metrics and neurodevelopmental outcomes in preterm infants with intraventricular hemorrhage, aiming to elucidate potential relationships and their clinical implications. MATERIALS AND METHODS: Neuroimaging was performed on preterm neonates with intraventricular hemorrhage using a multi-dynamic multi-echo sequence to determine T1 relaxation time, T2 relaxation time, and proton density in specific brainstem regions. Neonatal outcome scores were collected using the Bayley Scales of Infant and Toddler Development. Statistical analysis aimed to explore potential correlations between magnetic resonance imaging metrics and neurodevelopmental outcomes. RESULTS: Sixty preterm neonates (mean gestational age at birth 26.26 ± 2.69 wk; n = 24 [40%] females) were included. The T2 relaxation time of the midbrain exhibited significant positive correlations with cognitive (r = 0.538, P < 0.0001, Pearson's correlation), motor (r = 0.530, P < 0.0001), and language (r = 0.449, P = 0.0008) composite scores at 1 yr of age. CONCLUSION: Quantitative magnetic resonance imaging can provide valuable insights into neurodevelopmental outcomes after intraventricular hemorrhage, potentially aiding in identifying at-risk neonates. Multi-dynamic multi-echo sequence sequences hold promise as an adjunct to conventional sequences, enhancing the sensitivity of neonatal magnetic resonance neuroimaging and supporting clinical decision-making for these vulnerable patients.


Assuntos
Tronco Encefálico , Recém-Nascido Prematuro , Imageamento por Ressonância Magnética , Humanos , Masculino , Feminino , Imageamento por Ressonância Magnética/métodos , Recém-Nascido , Estudos Retrospectivos , Tronco Encefálico/diagnóstico por imagem , Tronco Encefálico/crescimento & desenvolvimento , Lactente , Hemorragia Cerebral Intraventricular/diagnóstico por imagem , Hemorragia Cerebral/diagnóstico por imagem , Transtornos do Neurodesenvolvimento/diagnóstico por imagem , Transtornos do Neurodesenvolvimento/etiologia , Idade Gestacional
3.
Sci Transl Med ; 16(745): eadj4303, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38691619

RESUMO

Consciousness is composed of arousal (i.e., wakefulness) and awareness. Substantial progress has been made in mapping the cortical networks that underlie awareness in the human brain, but knowledge about the subcortical networks that sustain arousal in humans is incomplete. Here, we aimed to map the connectivity of a proposed subcortical arousal network that sustains wakefulness in the human brain, analogous to the cortical default mode network (DMN) that has been shown to contribute to awareness. We integrated data from ex vivo diffusion magnetic resonance imaging (MRI) of three human brains, obtained at autopsy from neurologically normal individuals, with immunohistochemical staining of subcortical brain sections. We identified nodes of the proposed default ascending arousal network (dAAN) in the brainstem, hypothalamus, thalamus, and basal forebrain. Deterministic and probabilistic tractography analyses of the ex vivo diffusion MRI data revealed projection, association, and commissural pathways linking dAAN nodes with one another and with DMN nodes. Complementary analyses of in vivo 7-tesla resting-state functional MRI data from the Human Connectome Project identified the dopaminergic ventral tegmental area in the midbrain as a widely connected hub node at the nexus of the subcortical arousal and cortical awareness networks. Our network-based autopsy methods and connectivity data provide a putative neuroanatomic architecture for the integration of arousal and awareness in human consciousness.


Assuntos
Tronco Encefálico , Estado de Consciência , Imageamento por Ressonância Magnética , Vigília , Humanos , Tronco Encefálico/diagnóstico por imagem , Tronco Encefálico/fisiologia , Vigília/fisiologia , Estado de Consciência/fisiologia , Imageamento por Ressonância Magnética/métodos , Imagem Multimodal/métodos , Conectoma , Vias Neurais/fisiologia , Masculino , Feminino , Imagem de Difusão por Ressonância Magnética , Adulto , Nível de Alerta/fisiologia
4.
Neurology ; 102(10): e209421, 2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38701401

RESUMO

Pupillary assessment is a quintessential part of the clinical examination in neuro-intensive care patients because it provides insight into the integrity of midbrain reflex arcs. Abnormal pupils, particularly anisocoria and later bilateral fixed mydriasis, are classically used to assess expansive intracranial processes because they are frequently considered early indicators of transtentorial midbrain compression due to elevated intracranial pressure. Complex ocular motor deficits mapping to the midbrain are rarely described in the setting of high transtentorial pressure. This is likely because ocular motor deficits typically occur in conjunction with decreased consciousness and corticospinal tract dysfunction reflecting advanced midbrain compromise. We present a case of left midbrain compression due to downward herniation in a patient with acute-on-chronic bilateral subdural hematoma. Ocular motor assessment demonstrated left internuclear ophthalmoplegia (INO) and an ocular tilt reaction, termed INO plus. However, pupillary, mental status, and sensorimotor examinations were unremarkable. Head magnetic resonance imaging revealed acute perforator ischemia in the left pontomesencephalic tegmentum, localizing to the ipsilateral medial longitudinal fasciculus and graviceptive oculocephalic circuits. Microvascular compromise secondary to mechanical pressure is discussed as a causative mechanism. We caution against overreliance on "telltale pupils" in suspected brainstem compression and recommend checking for other oculomotor signs.


Assuntos
Transtornos da Motilidade Ocular , Humanos , Transtornos da Motilidade Ocular/etiologia , Tronco Encefálico/diagnóstico por imagem , Masculino , Imageamento por Ressonância Magnética , Feminino , Idoso
6.
Cephalalgia ; 44(4): 3331024241245658, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38613233

RESUMO

BACKGROUND: Many risk factors have been associated with migraine progression, including insufficient and ineffective utilization of migraine medications; however, they have been inadequately explored. This has resulted in suboptimal usage of medications without effective altering of prescribing recommendations for patients, posing a risk for migraine chronification. METHODS: Our aim is to conduct a comprehensive review of the available evidence regarding the underuse of migraine medications, both acute and preventive. The term "underuse" includes, but is not limited to: (1) ineffective use of appropriate and inappropriate medication; (2) underutilization; (3) inappropriate timing of usage; and (4) patient dissatisfaction with medication. RESULTS: The underuse of both acute and preventive medications has been shown to contribute to the progression of migraine. In terms of acute medication, chronification occurs as a result of insufficient drug use, including failure of the prescriber to select the appropriate type based on pain intensity and disability, patients taking medication too late (more than 60 minutes after the onset or after central sensitization has occurred as evidenced by allodynia), and discontinuation because of lack of effect or intolerable side effects. The underlying cause of inadequate effectiveness of acute medication lies in its inability to halt the propagation of peripheral activation to central sensitization in a timely manner. For oral and injectable preventive migraine medications, insufficient efficacy and intolerable side effects have led to poor adherence and discontinuation with subsequent progression of migraine. The underlying pathophysiology here is rooted in the repetitive stimulation of afferent sensory pain fibers, followed by ascending brainstem pain pathways plus dysfunction of the endogenous descending brainstem pain inhibitory pathway. Although anti-calcitonin gene-related peptide (CGRP) medications partially address pain caused by the above factors, including decreased efficacy and tolerability from conventional therapy, some patients do not respond well to this treatment. Research suggests that initiating preventive anti-CGRP treatment at an early stage (during low frequency episodic migraine attacks) is more beneficial than commencing it during high frequency episodic attacks or when chronic migraine has begun. CONCLUSIONS: The term "medication underuse" is underrecognized, but it holds significant importance. Optimal usage of acute care and preventive migraine medications could potentially prevent migraine chronification and improve the treatment of migraine attacks.


Assuntos
Cefaleia , Transtornos de Enxaqueca , Humanos , Transtornos de Enxaqueca/tratamento farmacológico , Transtornos de Enxaqueca/prevenção & controle , Dor , Fatores de Risco , Tronco Encefálico , Peptídeo Relacionado com Gene de Calcitonina
7.
J Neuroimmune Pharmacol ; 19(1): 13, 2024 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-38613591

RESUMO

The occurrence of major asthma symptoms is largely attributed to airway vagal hypertonia, of which the central mechanisms remain unclear. This study tests the hypotheses that endothelin-1-mediated brainstem glial activation produces asthmatic airway vagal hypertonia via enhanced action of adenosine 5'-triphosphate on neuronal purinergic P2X4 receptors. A rat model of asthma was prepared using ovalbumin. Airway vagal tone was evaluated by the recurrent laryngeal discharge and plethysmographic measurement of pulmonary function. The changes in the brainstem were examined using ELISA, Western blot, luciferin-luciferase, quantitative reverse transcription-polymerase chain reaction, enzyme activity assay and immunofluorescent staining, respectively. The results showed that in the medulla of rats, endothelin receptor type B and P2X4 receptors were primarily expressed in astrocytes and neurons, respectively, and both of which, along with endothelin-1 content, were significantly increased after ovalbumin sensitization. Ovalbumin sensitization significantly increased recurrent laryngeal discharge, which was blocked by acute intracisternal injection of P2X4 receptor antagonist 5-BDBD, knockdown of brainstem P2X4 receptors, and chronic intraperitoneal injection of endothelin receptor type B antagonist BQ788, respectively. Ovalbumin sensitization activated microglia and astrocytes and significantly decreased ecto-5'-nucleotidase activity in the medulla, and all of which, together with the increase of medullary P2X4 receptor expression and decrease of pulmonary function, were reversed by chronic BQ788 treatment. These results demonstrated that in rats, allergic airway challenge activates both microglia and astrocytes in the medulla via enhanced endothelin-1/endothelin receptor type B signaling, which subsequently causes airway vagal hypertonia via augmented adenosine 5'-triphosphate/P2X4 receptor signaling in central neurons of airway vagal reflex.


Assuntos
Asma , Polifosfatos , Receptores Purinérgicos P2X4 , Ratos , Animais , Ratos Sprague-Dawley , Endotelina-1 , Ovalbumina/toxicidade , Asma/induzido quimicamente , Tronco Encefálico , Hipertonia Muscular , Trifosfato de Adenosina , Receptores de Endotelina , Adenosina
9.
J Neurosurg ; 140(4): 1160-1168, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38564813

RESUMO

OBJECTIVE: The lateral aspect of the cerebellomesencephalic fissure frequently harbors vascular pathology and is a common surgical corridor used to access the pons tegmentum, as well as the cerebellum and its superior and middle peduncles. The quadrangular lobule of the cerebellum (QLC) represents an obstacle to reach these structures. The authors sought to analyze and compare exposure of the cerebellar interpeduncular region (CIPR) before and after QLC resection and provide a case series to evaluate its clinical applicability. METHODS: Forty-two sides of human brainstems were prepared with Klingler's method and dissected. The exposure area before and after resection of the QLC was measured and statistically studied. A case series of 59 patients who underwent QLC resection for the treatment of CIPR lesions was presented and clinical outcomes were evaluated at 1-year follow-up. RESULTS: The anteroposterior surgical corridor of the CIPR increased by 10.3 mm after resection of the QLC. The mean exposure areas were 42 mm2 before resection of the QLC and 159.6 mm2 after resection. In this series, ataxia, extrapyramidal syndrome, and akinetic mutism were found after surgery. However, all these cases resolved within 1 year of follow-up. Modified Rankin Scale score improved by 1 grade, on average. CONCLUSIONS: QLC resection significantly increased the exposure area, mainly in the anteroposterior axis. This surgical strategy appears to be safe and may help the neurosurgeon when operating on the lateral aspect of the cerebellomesencephalic fissure.


Assuntos
Cerebelo , Procedimentos Neurocirúrgicos , Humanos , Cerebelo/cirurgia , Procedimentos Neurocirúrgicos/métodos , Tronco Encefálico/cirurgia , Microcirurgia/métodos , Craniotomia/métodos
10.
Neurosurg Rev ; 47(1): 137, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38564039

RESUMO

Despite 2-staged stereotactic radiosurgery (2-SSRS) has been reported to provide patients with improved survival and limited toxicity, 2-SSRS for brainstem metastases (BSM) larger than 2 cm3 remains challenging. We tried to find out the effectiveness and safety of 2-SSRS plus bevacizumab therapy for BSMs over 2 cm3 and prognostic factors that related to the tumor local control. Patients that received 2-SSRS plus bevacizumab therapy from four gamma knife center were retrospectively studied from Jan 2014 to December 2023. Patients' domestic characteristics and the tumor features were evaluated before and after the treatment. Cox regression model was used to find out prognostic factors for tumor local control. 53 patients with 63 lesions received the therapy. The median peri-tumor edema volume greatly reduced at the end of therapy (P < 0.01), the median tumor volume dramatically reduced (P < 0.01) and patients' KPS score improved significantly (P < 0.05) 3 months after the therapy. Patients' median OS was 12.8 months. The tumor local control rate at 3, 6, and 12 months was 98.4%, 93.4%, and 85.2%. The incidence side effects were mainly oral and nasal hemorrhage (5.7%, 3/53), and radiation necrosis (13.2%, 7/53). Patients with primary lung adenocarcinoma, therapeutic dose over 12 Gy at second-stage SRS, primary peri-tumor edema volume less than 2.3 cm³, primary tumor volume less than 3.7 cm³ would enjoy longer tumor local control. These results suggested that 2-SSRS plus bevacizumab therapy was effective and safe for BSMs over 2 cm3. However, it is important for patients with BSM to receive early diagnosis and treatment to achieve good tumor local control.


Assuntos
Tronco Encefálico , Neoplasias , Humanos , Bevacizumab/uso terapêutico , Estudos Retrospectivos , Edema
11.
BMC Neurol ; 24(1): 121, 2024 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-38609854

RESUMO

BACKGROUND: Uraemia causes a generalised encephalopathy as its most common neurological complication. Isolated brainstem uraemic encephalopathy is rare. We report a case of fatigable ptosis and complex ophthalmoplegia in brainstem uraemic encephalopathy. CASE PRESENTATION: A 22-year-old Sri Lankan man with end stage renal failure presented with acute onset diplopia and drooping of eyelids progressively worsening over one week. The patient had not complied with the prescribed renal replacement therapy which was planned to be initiated 5 months previously. On examination, his Glasgow coma scale score was 15/15, He had a fatigable asymmetrical bilateral ptosis. The ice-pack test was negative. There was a complex ophthalmoplegia with bilateral abduction failure and elevation failure of the right eye. The diplopia did not worsen with prolonged stare. The rest of the neurological examination was normal. Serum creatinine on admission was 21.81 mg/dl. The repetitive nerve stimulation did not show a decremental pattern. Magnetic resonance imaging (MRI) of the brain demonstrated diffuse midbrain and pontine oedema with T2 weighted/FLAIR hyperintensities. The patient was haemodialyzed on alternate days and his neurological deficits completely resolved by the end of the second week of dialysis. The follow up brain MRI done two weeks later demonstrated marked improvement of the brainstem oedema with residual T2 weighted/FLAIR hyperintensities in the midbrain. CONCLUSIONS: Uraemia may rarely cause an isolated brainstem encephalopathy mimicking ocular myasthenia, which resolves with correction of the uraemia.


Assuntos
Encefalopatias Metabólicas , Encefalopatias , Miastenia Gravis , Oftalmoplegia , Uremia , Masculino , Humanos , Adulto Jovem , Adulto , Diplopia , Tronco Encefálico/diagnóstico por imagem , Miastenia Gravis/complicações , Miastenia Gravis/diagnóstico , Uremia/complicações , Uremia/diagnóstico , Uremia/terapia , Encefalopatias/diagnóstico , Edema , Oftalmoplegia/diagnóstico , Oftalmoplegia/etiologia
12.
Front Immunol ; 15: 1358886, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38660303

RESUMO

Background: Bickerstaff brainstem encephalitis (BBE) is a rare disease considered caused by acute demyelination of the brainstem, most often resulting from secondary autoimmune responses. To our knowledge, this is the first probable case report of shingles-associated BBE with anti-sulfatide IgM positivity. Case presentation: We report the case of an 83-year-old woman with symptoms of progressive limb weakness, difficulty swallowing food, and disturbed consciousness that occurred 4 weeks following herpes zoster infection. Autoimmune anti-sulfatide antibodies were positive and fluid-attenuated inversion recovery (FLAIR) sequences revealed clear high signal intensity in pons and bilateral thalamus. Our patient's condition improved markedly with glucocorticoid treatment. After 2 months of treatment, our patient was fully recovered. We considered that for her case, BBE is the most appropriate diagnosis. Conclusions: We emphasize the importance of a careful medical history and assessment of clinical symptoms, performing MRI, testing autoimmune antibodies for rapid diagnosis, and ruling out differential diagnoses. Further studies involving more patients with BBE with IgM anti-sulfatide autoantibodies will increase the understanding of the clinical characteristics and advance the diagnosis and treatment of this syndrome. Meanwhile, it is crucial for dermatologists to know about this severe neurological complication following shingles.


Assuntos
Autoanticorpos , Tronco Encefálico , Encefalite , Imunoglobulina M , Sulfoglicoesfingolipídeos , Humanos , Feminino , Tronco Encefálico/imunologia , Idoso de 80 Anos ou mais , Imunoglobulina M/imunologia , Imunoglobulina M/sangue , Autoanticorpos/imunologia , Autoanticorpos/sangue , Encefalite/diagnóstico , Encefalite/imunologia , Encefalite/tratamento farmacológico , Sulfoglicoesfingolipídeos/imunologia , Imageamento por Ressonância Magnética , Glucocorticoides/uso terapêutico
13.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 55(2): 290-296, 2024 Mar 20.
Artigo em Chinês | MEDLINE | ID: mdl-38645855

RESUMO

Objective: To study the microanatomic structure of the subtemporal transtentorial approach to the lateral side of the brainstem, and to provide anatomical information that will assist clinicians to perform surgeries on the lateral, circumferential, and petroclival regions of the brainstem. Methods: Anatomical investigations were conducted on 8 cadaveric head specimens (16 sides) using the infratemporal transtentorial approach. The heads were tilted to one side, with the zygomatic arch at its highest point. Then, a horseshoe incision was made above the auricle. The incision extended from the midpoint of the zygomatic arch to one third of the mesolateral length of the transverse sinus, with the flap turned towards the temporal part. After removing the bone, the arachnoid and the soft meninges were carefully stripped under the microscope. The exposure range of the surgical approach was observed and the positional relationships of relevant nerves and blood vessels in the approach were clarified. Important structures were photographed and the relevant parameters were measured. Results: The upper edge of the zygomatic arch root could be used to accurately locate the base of the middle cranial fossa. The average distances of the star point to the apex of mastoid, the star point to the superior ridge of external auditory canal, the anterior angle of parietomastoid suture to the superior ridge of external auditory canal, and the anterior angle of parietomastoid suture to the star point of the 10 adult skull specimens were 47.23 mm, 45.27 mm, 26.16 mm, and 23.08 mm, respectively. The subtemporal approach could fully expose the area from as high as the posterior clinoid process to as low as the petrous ridge and the arcuate protuberance after cutting through the cerebellar tentorium. The approach makes it possible to handle lesions on the ventral or lateral sides of the middle clivus, the cistern ambiens, the midbrain, midbrain, and pons. In addition, the approach can significantly expand the exposure area of the upper part of the tentorium cerebelli through cheekbone excision and expand the exposure range of the lower part of the tentorium cerebelli through rock bone grinding technology. The total length of the trochlear nerve, distance of the trochlear nerve to the tentorial edge of cerebellum, length of its shape in the tentorial mezzanine, and its lower part of entering into the tentorium cerebelli to the petrosal ridge were (16.95±4.74) mm, (1.27±0.73) mm, (5.72±1.37) mm, and (4.51±0.39) mm, respectively. The cerebellar tentorium could be safely opened through the posterior clinoid process or arcuate protrusion for localization. The oculomotor nerve could serve as an anatomical landmark to locate the posterior cerebral artery and superior cerebellar artery. Conclusion: Through microanatomic investigation, the exposure range and intraoperative difficulties of the infratemporal transtentorial approach can be clarified, which facilitates clinicians to accurately and safely plan surgical methods and reduce surgical complications.


Assuntos
Cadáver , Humanos , Tronco Encefálico/anatomia & histologia , Tronco Encefálico/cirurgia , Osso Temporal/anatomia & histologia , Osso Temporal/cirurgia , Fossa Craniana Média/anatomia & histologia , Fossa Craniana Média/cirurgia , Craniotomia/métodos
14.
Int J Surg ; 110(4): 2217-2225, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38668661

RESUMO

BACKGROUND: Brainstem cavernous malformations (BSCMs) often present with haemorrhage, but the optimal timing for microsurgical intervention remains unclear. This study aims to explore how intervention timing relates to neurological outcomes in haemorrhagic BSCM patients undergoing microsurgery, offering insights for clinical decisions. METHODS: A total of 293 consecutive patients diagnosed with BSCMs, who underwent microsurgery were identified between March 2011 and January 2023 at two comprehensive centres in China, with a postoperative follow-up duration exceeding 6 months. Utilizing logistic regression models with restricted cubic splines, distinct time groups were identified. Subsequently, matching weight analysis compared these groups in terms of outcomes, new haemorrhage rates, cranial nerve deficits, and perioperative complications. The primary outcome was an unfavourable outcome, which was defined as a mRS score greater than 2 at the latest follow-up. RESULTS: Among the 293 patients, 48.5% were female, median age was (39.9±14.3) years, and median haemorrhage-to-treatment time was 42 days. Patients were categorized into acute (≤21 days), subacute (22-42 days), and delay (>42 days) intervention groups. After matching, 186 patients were analyzed. Adjusted analysis showed lower unfavourable outcome rates for acute [adjusted odds ratio (OR), 0.73; 95% CI, 0.65-0.82; P<0.001] and subacute (adjusted OR, 0.83; 95% CI, 0.72-0.95; P=0.007) groups compared to the delay group. Subacute intervention led to fewer cranial nerve deficits (adjusted OR, 0.76; 95% CI, 0.66-0.88, P<0.001). New haemorrhage incidence didn't significantly differ among groups. CONCLUSIONS: For haemorrhagic BSCMs patients, delayed microsurgical intervention that exceeded 42 days after a prior haemorrhage were associated with an increased risk of unfavourable neurological outcomes.


Assuntos
Hemangioma Cavernoso do Sistema Nervoso Central , Microcirurgia , Tempo para o Tratamento , Humanos , Feminino , Masculino , Adulto , Pessoa de Meia-Idade , Hemangioma Cavernoso do Sistema Nervoso Central/cirurgia , Hemangioma Cavernoso do Sistema Nervoso Central/complicações , Tempo para o Tratamento/estatística & dados numéricos , China/epidemiologia , Estudos de Coortes , Resultado do Tratamento , Tronco Encefálico/cirurgia , Estudos Retrospectivos
15.
Neuropathol Appl Neurobiol ; 50(3): e12977, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38680020

RESUMO

AIM: Leigh syndrome (LS), the most common paediatric presentation of genetic mitochondrial dysfunction, is a multi-system disorder characterised by severe neurologic and metabolic abnormalities. Symmetric, bilateral, progressive necrotizing lesions in the brainstem are defining features of the disease. Patients are often symptom free in early life but typically develop symptoms by about 2 years of age. The mechanisms underlying disease onset and progression in LS remain obscure. Recent studies have shown that the immune system causally drives disease in the Ndufs4(-/-) mouse model of LS: treatment of Ndufs4(-/-) mice with the macrophage-depleting Csf1r inhibitor pexidartinib prevents disease. While the precise mechanisms leading to immune activation and immune factors involved in disease progression have not yet been determined, interferon-gamma (IFNγ) and interferon gamma-induced protein 10 (IP10) were found to be significantly elevated in Ndufs4(-/-) brainstem, implicating these factors in disease. Here, we aimed to explore the role of IFNγ and IP10 in LS. METHODS: To establish the role of IFNγ and IP10 in LS, we generated IFNγ and IP10 deficient Ndufs4(-/-)/Ifng(-/-) and Ndufs4(-/-)/IP10(-/-) double knockout animals, as well as IFNγ and IP10 heterozygous, Ndufs4(-/-)/Ifng(+/-) and Ndufs4(-/-)/IP10(+/-), animals. We monitored disease onset and progression to define the impact of heterozygous or homozygous loss of IFNγ and IP10 in LS. RESULTS: Loss of IP10 does not significantly impact the onset or progression of disease in the Ndufs4(-/-) model. IFNγ loss significantly extends survival and delays disease progression in a gene dosage-dependent manner, though the benefits are modest compared to Csf1r inhibition. CONCLUSIONS: IFNγ contributes to disease onset and progression in LS. Our findings suggest that IFNγ targeting therapies may provide some benefits in genetic mitochondrial disease, but targeting IFNγ alone would likely yield only modest benefits in LS.


Assuntos
Modelos Animais de Doenças , Progressão da Doença , Complexo I de Transporte de Elétrons , Interferon gama , Doença de Leigh , Camundongos Knockout , Animais , Doença de Leigh/patologia , Doença de Leigh/genética , Interferon gama/metabolismo , Camundongos , Complexo I de Transporte de Elétrons/genética , Complexo I de Transporte de Elétrons/deficiência , Camundongos Endogâmicos C57BL , Tronco Encefálico/patologia , Tronco Encefálico/metabolismo
16.
J Alzheimers Dis ; 99(1): 307-319, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38669537

RESUMO

Background: Alzheimer's disease (AD) pathology is considered to begin in the brainstem, and cerebral microglia are known to play a critical role in AD pathogenesis, yet little is known about brainstem microglia in AD. Translocator protein (TSPO) PET, sensitive to activated microglia, shows high signal in dorsal brainstem in humans, but the precise location and clinical correlates of this signal are unknown. Objective: To define age and AD associations of brainstem TSPO PET signal in humans. Methods: We applied new probabilistic maps of brainstem nuclei to quantify PET-measured TSPO expression over the whole brain including brainstem in 71 subjects (43 controls scanned using 11C-PK11195; 20 controls and 8 AD subjects scanned using 11C-PBR28). We focused on inferior colliculi (IC) because of visually-obvious high signal in this region, and potential relevance to auditory dysfunction in AD. We also assessed bilateral cortex. Results: TSPO expression was normally high in IC and other brainstem regions. IC TSPO was decreased with aging (p = 0.001) and in AD subjects versus controls (p = 0.004). In cortex, TSPO expression was increased with aging (p = 0.030) and AD (p = 0.033). Conclusions: Decreased IC TSPO expression with aging and AD-an opposite pattern than in cortex-highlights underappreciated regional heterogeneity in microglia phenotype, and implicates IC in a biological explanation for strong links between hearing loss and AD. Unlike in cerebrum, where TSPO expression is considered pathological, activated microglia in IC and other brainstem nuclei may play a beneficial, homeostatic role. Additional study of brainstem microglia in aging and AD is needed.


Assuntos
Envelhecimento , Doença de Alzheimer , Tronco Encefálico , Microglia , Tomografia por Emissão de Pósitrons , Receptores de GABA , Humanos , Doença de Alzheimer/patologia , Doença de Alzheimer/metabolismo , Microglia/metabolismo , Microglia/patologia , Masculino , Idoso , Feminino , Envelhecimento/patologia , Tronco Encefálico/metabolismo , Tronco Encefálico/patologia , Receptores de GABA/metabolismo , Idoso de 80 Anos ou mais , Pessoa de Meia-Idade , Isoquinolinas , Adulto
17.
Brain Res ; 1835: 148908, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-38582416

RESUMO

BDNF, a neurotrophic factor, and its receptors have been implicated in the pathophysiology of mild traumatic brain injury (mTBI). The brainstem houses many vital functions, that are also associated with signs and symptoms of mTBI, but has been understudied in mTBI animal models. We determined the extent to which neurotrophic protein and associated receptor expression is affected within the brainstem of adult rats following mTBI. Their behavioral function was assessed and temporal expression of the 'negative' regulators of neuronal function (p75, t-TrkB, and pro-BDNF) and 'positive' neuroprotective (FL-TrkB and m-BDNF) protein isoforms were determined via western blot and immunohistochemistry at 1, 3, 7, and 14 post-injury days (PID) following mTBI or sham (control) procedure. Within the brainstem, p75 expression increased at PID 1 vs. sham animals. t-TrkB and pro-BDNF expression increased at PID 7 and 14. The 'positive' protein isoforms of FL-TrkB and m-BDNF expression were increased only at PID 7. The ratio of t-TrkB:FL-TrkB (negative:positive) was substantial across groups and time points, suggesting a negative impact of neurotrophic signaling on neuronal function. Additional NeuN experiments revealed cell death occurring within a subset of neurons within the medulla. While behavioral measures improved by PID 7-14, negative neurotrophic biochemical responses persisted. Despite the assertion that mTBI produces "mild" injury, evidence of cell death was observed in the medulla. Ratios of TrkB and BDNF isoforms with conflicting functions suggest that future work should specifically measure each subtype since they induce opposing downstream effects on neuronal function.


Assuntos
Tronco Encefálico , Fator Neurotrófico Derivado do Encéfalo , Ratos Sprague-Dawley , Receptor trkB , Animais , Masculino , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Receptor trkB/metabolismo , Tronco Encefálico/metabolismo , Ratos , Concussão Encefálica/metabolismo , Modelos Animais de Doenças , Neurônios/metabolismo , Isoformas de Proteínas/metabolismo , Fatores de Tempo , Proteínas do Tecido Nervoso/metabolismo , Lesões Encefálicas Traumáticas/metabolismo
18.
J Neurol Sci ; 460: 123013, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38653116

RESUMO

BACKGROUND: Lesion occurring in the brainstem may cause a postural tilt and balance disorders, which could be due to an inaccurate perception of the body orientation. The objective of this study was to determine the effects of a brainstem stroke on body representation in horizontal and frontal plane, and links with impaired posture and neuroanatomy. METHODS: Forty patients with stroke in left brainstem (L-BS) or right (R-BS) were compared with 15 matched control subjects (C). The subjective straight-ahead (SSA) was investigated using a method disentangling lateral deviation and tilt components of error. RESULTS: The L-BS patients had contralesional lateral deviation of SSA. In addition, they showed an ipsilesional tilt, more severe for the trunk than for the head. By contrast, in R-BS patients, the representation of the body midline was fairly accurate in both the horizontal and frontal planes and did not differ from that of control subjects. CONCLUSION: This work highlights an asymmetry of representation of body associated with left brainstem lesions extending to the right cerebral hemisphere. This deviation appears only after a left lesion, which may point to a vestibular dominance. These results open a new perspective of neuro-rehabilitation of postural disorders after a stroke, with the correction of the representation of body orientation.


Assuntos
Tronco Encefálico , Lateralidade Funcional , Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Tronco Encefálico/fisiopatologia , Tronco Encefálico/diagnóstico por imagem , Lateralidade Funcional/fisiologia , Adulto , Acidente Vascular Cerebral/fisiopatologia , Acidente Vascular Cerebral/complicações , Postura/fisiologia , Infartos do Tronco Encefálico/diagnóstico por imagem , Infartos do Tronco Encefálico/fisiopatologia , Infartos do Tronco Encefálico/complicações , Imagem Corporal/psicologia
19.
BMJ Case Rep ; 17(4)2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38627057

RESUMO

Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) is a recently described chronic inflammatory central nervous system disease. This case report describes a young female patient presenting with weakness in bilateral upper and lower limbs and tinnitus for 2 months. A neurological examination revealed signs of brainstem and cerebellar involvement. MRI brain showed characteristic features of CLIPPERS, with punctate and nodular enhancement in the pons and cerebellum. Differential diagnoses were systematically considered and excluded. The patient showed significant clinical and radiological improvement with steroid therapy. No clinical or radiological red flags occurred during the follow-up. This case underscores the critical role of integrating clinical and radiological findings to effectively diagnose and manage CLIPPERS. It emphasises the importance of ruling out alternative diagnoses through a thorough evaluation.


Assuntos
Doenças do Sistema Nervoso Central , Inflamação , Humanos , Feminino , Inflamação/diagnóstico , Ponte/diagnóstico por imagem , Tronco Encefálico/diagnóstico por imagem , Doenças do Sistema Nervoso Central/diagnóstico , Doenças do Sistema Nervoso Central/diagnóstico por imagem , Esteroides/uso terapêutico , Imageamento por Ressonância Magnética
20.
Am J Physiol Lung Cell Mol Physiol ; 326(6): L698-L712, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38591125

RESUMO

Chronic intermittent hypoxia (CIH) is a prevalent condition characterized by recurrent episodes of oxygen deprivation, linked to respiratory and neurological disorders. Prolonged CIH is known to have adverse effects, including endothelial dysfunction, chronic inflammation, oxidative stress, and impaired neuronal function. These factors can contribute to serious comorbidities, including metabolic disorders and cardiovascular diseases. To investigate the molecular impact of CIH, we examined male C57BL/6J mice exposed to CIH for 21 days, comparing with normoxic controls. We used single-nucleus RNA sequencing to comprehensively examine the transcriptomic impact of CIH on key cell classes within the brainstem, specifically excitatory neurons, inhibitory neurons, and oligodendrocytes. These cell classes regulate essential physiological functions, including autonomic tone, cardiovascular control, and respiration. Through analysis of 10,995 nuclei isolated from pontine-medullary tissue, we identified seven major cell classes, further subdivided into 24 clusters. Our findings among these cell classes, revealed significant differential gene expression, underscoring their distinct responses to CIH. Notably, neurons exhibited transcriptional dysregulation of genes associated with synaptic transmission, and structural remodeling. In addition, we found dysregulated genes encoding ion channels and inflammatory response. Concurrently, oligodendrocytes exhibited dysregulated genes associated with oxidative phosphorylation and oxidative stress. Utilizing CellChat network analysis, we uncovered CIH-dependent altered patterns of diffusible intercellular signaling. These insights offer a comprehensive transcriptomic cellular atlas of the pons-medulla and provide a fundamental resource for the analysis of molecular adaptations triggered by CIH.NEW & NOTEWORTHY This study on chronic intermittent hypoxia (CIH) from pons-medulla provides initial insights into the molecular effects on excitatory neurons, inhibitory neurons, and oligodendrocytes, highlighting our unbiased approach, in comparison with earlier studies focusing on single target genes. Our findings reveal that CIH affects cell classes distinctly, and the dysregulated genes in distinct cell classes are associated with synaptic transmission, ion channels, inflammation, oxidative stress, and intercellular signaling, advancing our understanding of CIH-induced molecular responses.


Assuntos
Hipóxia , Camundongos Endogâmicos C57BL , Neurônios , Oligodendroglia , Transcriptoma , Animais , Oligodendroglia/metabolismo , Camundongos , Masculino , Hipóxia/metabolismo , Hipóxia/genética , Neurônios/metabolismo , Neurônios/patologia , Tronco Encefálico/metabolismo
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