Neurosyphilis remains a severe manifestation of syphilis, particularly in individuals living with HIV, where atypical presentations and treatment challenges are more common. Although ceftriaxone is considered an alternative to penicillin G, emerging reports suggest possible therapeutic failure in immunocompromised hosts. We describe a 63-year-old man with well-controlled HIV infection who developed seizures and altered mental status. Cerebrospinal fluid analysis confirmed neurosyphilis, and he was treated with high-dose intravenous ceftriaxone (2 g twice daily) for ten days. Despite therapy, neurological symptoms persisted, and repeat investigations showed ongoing inflammation. Ceftriaxone was replaced with intravenous doxycycline (100 mg twice daily), resulting in rapid clinical improvement within 72 hours. Follow-up cerebrospinal fluid studies and imaging demonstrated complete resolution of inflammatory changes. The patient completed a 28-day doxycycline course with sustained recovery. This case underscores the potential for ceftriaxone failure in HIV-associated neurosyphilis and supports considering doxycycline as an effective alternative in refractory cases.

Dysembryoplastic neuroepithelial tumor (DNET) is a benign central nervous system neoplasm, usually diagnosed in pediatric patients with epilepsy. We describe a case of a 57-year-old man presenting with a first episode of generalized tonic-clonic seizure and subacute cognitive decline, in whom a multicystic right temporal lobe lesion was detected. Further workup led to a new diagnosis of human immunodeficiency virus (HIV) infection. Comprehensive investigations excluded infectious and malignant etiologies. Review of prior imaging, combined with multidisciplinary input, led to a diagnosis of DNET. Two-year follow-up confirmed radiological stability, and the patient remained seizure-free under antiepileptic treatment. This case highlights the importance of expanding the differential diagnosis of cerebral lesions in HIV-positive adults and utilizing prior imaging to guide clinical decision-making.

Toxoplasma gondii encephalitis is a common but serious opportunistic infection in people living with human immunodeficiency virus (PLHIV), particularly those with advanced disease and low CD4 counts. Its classical manifestations include fever, altered mental status, seizures and focal neurological signs. Movement disorders are a less common consequence, with hemichorea-hemiballismus (HCHB) representing a rare but striking manifestation. We describe a 36-year-old man with advanced HIV disease who had defaulted on treatment. He presented with bizarre, involuntary movements of his left upper and lower limbs. His serum Toxoplasma IgG was positive, and brain imaging revealed a basal ganglia lesion leading to the presumptive diagnosis of cerebral toxoplasmosis. He was treated with anti-toxoplasmosis and anti-dyskinetic medications, achieving both clinical and radiological resolution after one month of therapy. A high clinical suspicion for Toxoplasma gondii encephalitis should be maintained in patients with advanced HIV disease who present with rare manifestations such as movement disorders. Timely management, guided by serology and brain imaging, is essential to improve treatment outcomes.

Epstein-Barr virus (EBV)-associated smooth muscle tumor (EBV-SMT) is a rare spindle cell tumor found in immunocompromised patients with HIV. This case report presents a patient with HIV-positive Epstein-Barr virus (EBV)-associated smooth muscle tumor (EBV-SMT) involving the brain and spine-a 39-year-old Hispanic female with HIV presented with severe headache, neck pain, and seizure-like activity. Magnetic resonance imaging (MRI) revealed multiple brain masses, prompting a diagnostic cerebral angiogram and subsequent surgery to remove them. Despite initial improvement, the patient later succumbed to aspiration pneumonia and cardiac arrest. Epstein-Barr virus (EBV)-associated smooth muscle rare tumors (EBV-SMTs) in HIV patients with low CD4 counts require clinical suspicion and Epstein-Barr virus (EBV) involvement in brain tumor diagnosis. Early HIV detection, CD4 monitoring, and antiretroviral therapy (ART) management can decrease the risk of these malignancies.

Oxcarbazepine (OXC) is a second-generation antiseizure medication, effective through its active metabolite, 10-mono-hydroxy derivative (MHD). OXC is used as adjunctive therapy for focal-onset and primary generalized tonic-clonic seizures, with recommended dosing based on age and body weight. This study uses physiologically based pharmacokinetic (PBPK) modeling and leverages pharmacokinetic (PK) data acquired from children enrolled in pragmatic trials to understand dosing and subsequent exposure requirements in children with obesity. Drug concentrations of OXC and MHD (n = 148 each) from children with (n = 31) and without (n = 10) obesity, aged 2-20 years, were collected from two clinical trials (NCT01431326 and NCT02993861) and used for external evaluation of a previously developed PBPK model of OXC using PK-Sim. We used a previously published virtual population that accounts for the obesity-related changes in physiology (e.g., liver size and glomerular filtration rate) in children for PK simulations in children with obesity. Model evaluation showed that ≥80% of MHD concentrations contributed by about two thirds of study subjects (26 out of 41) fell within the 90% prediction interval. The PBPK model showed that children with obesity had lower median (interquartile range) simulated weight-normalized clearance (0.060 L/h/kg [0.048-0.076 L/h/kg]) than children without obesity (0.067 L/h/kg [0.060-0.077 L/h/kg]). Simulations revealed that the recommended pediatric dosing regimen produced comparable MHD exposure between children with and without obesity at steady state, supporting its applicability regardless of obesity status. This PBPK-based dosing aligns with product label recommendations and demonstrates the potential of PBPK modeling for dosing other drugs in children with obesity.

We report an extremely rare case of CNS vasculitis caused by dual infection with varicella-zoster virus (VZV) and Epstein-Barr virus (EBV) in a man in his early 40s with newly diagnosed AIDS. He presented with seizures and encephalopathy, followed by recurrent multifocal strokes and MRI findings consistent with diffuse cerebral vasculitis. CSF analysis showed lymphocytic pleocytosis and tested positive for both VZV and EBV. Despite antiviral therapy and a brief course of corticosteroids, the patient experienced relapse and required retreatment. Clinical improvement was achieved with prolonged corticosteroid therapy combined with immune reconstitution via antiretroviral therapy. This case highlights the diagnostic challenges and potential for compounded vascular injury in dual herpesvirus CNS infection, emphasizing the importance of early recognition and the consideration of extended corticosteroid therapy in immunocompromised patients.

The international popularity of cannabis and the shifting legal landscape have propelled conversations around its medical and recreational use to the forefront of public discussion. Clinicians face increased questions from patients, though there is a lack of clear medical consensus on several conditions for which cannabis is commonly used. As of 2025, key indications for cannabis and cannabinoid use are nausea and vomiting induced by chemotherapy, loss of appetite due to HIV/AIDS, Dravet syndrome, Lennox-Gastaut syndrome, seizures associated with tuberous sclerosis, and multiple sclerosis spasticity. We reviewed current evidence for cannabis and cannabinoid treatment of chronic noncancer pain, insomnia, and psychiatric and neurologic disorders. We also considered current inconclusive evidence for cannabis to treat opioid use disorder and neurological disorders. Risks associated with cannabis and cannabinoid use include addiction, decreased neurocognitive function (particularly in adolescents) cannabinoid hyperemesis syndrome, psychosis, perinatal complications, cardiovascular and pulmonary disorders, as well as physical injury risks, such as falls and motor vehicle accidents. As public and clinical interest in cannabis grows, clinicians must evaluate potential harms alongside benefits relevant to the medical condition for which cannabis is being considered. Anecdotal experiences and commercial claims, whether positive or negative, and however compelling, must be eschewed in favor of research findings and facts to guide clinical decision‑making.

Extrapulmonary tuberculosis (TB), particularly when it involves the central nervous system (CNS), remains a significant clinical challenge. Cerebral tuberculoma, though rare, can present with complex symptoms that overlap with other neurological conditions, making timely diagnosis difficult. The condition demands a multidisciplinary approach for accurate diagnosis and effective management, especially in patients with multiple comorbidities. This report describes a complex case of pre-extensively drug-resistant TB affecting both the lungs and CNS in a 54-year-old immunocompromised male with AIDS, chronic hepatitis B and C, COVID-19, and reactivated varicella. The patient presented with systemic symptoms and new-onset neurological deficits, including seizures and right-sided paresis. Brain MRI revealed a cerebral tuberculoma with surrounding edema. Sputum testing confirmed Mycobacterium tuberculosis resistant to multiple first- and second-line agents. Treatment included a five-drug anti-tuberculosis regimen followed by initiation of antiretroviral therapy. The clinical course was complicated by immune reconstitution inflammatory syndrome, hepatic decompensation, and varicella reactivation. Despite profound immunosuppression and multisystem involvement, the patient achieved a favorable outcome through aggressive, multidisciplinary management. This case underscores the diagnostic complexity of CNS TB in patients with advanced HIV infection and multiple viral coinfections and highlights the critical role of early neuroimaging and coordinated care.

Cryptococcal meningoencephalitis is a grave and lethal form of an opportunistic infection usually occurring in immunocompromised patients (i.e., those with AIDS, organ transplant recipients, or those on immunosuppressive therapy) caused by Cryptococcus species, namely Cryptococcus neoformans, which has a worldwide distribution, or Cryptococcus gattii, which is predominantly found in tropical, subtropical, and temperate regions. Cryptococcus species are usually found in soil contaminated with bird or animal droppings in the form of cryptococcal spores. The former occurs predominantly in immunocompromised patients, affecting the central nervous system (CNS), while the latter occurs in immunocompetent patients, affecting the pulmonary system predominantly. Transmission occurs through these spores, which subsequently disseminate to the CNS through the hematogenous route. Manifestations include fever, headache, nausea, altered mental status, and meningismus in certain cases, potentially advancing to neurological problems such as elevated intracranial pressure, blindness, and seizures. Presentation in immunocompetent individuals is indolent, so diagnosis and treatment are delayed. Timely diagnosis and immediate treatment are essential to avert complications and mortality. Over the past few years, cryptococcal infection has seen an upward trend globally. Despite the availability of antifungal therapy, it has emerged as a significant public health concern, rendering it a therapeutically challenging case. Moreover, infrequent coinfections with bacteria or viruses might complicate therapy and prognosis. We hereby report a rare case of cryptococcal meningoencephalitis with herpes zoster coinfection occurring in an HIV patient with a normal CD4 count.

Dural venous sinus thrombosis (DVST) is characterized by thrombosis in the cerebral veins, the dural venous sinus, or both. Headache is the most common initial symptom. Patients can present with seizures, papilledema, focal neurological deficits, and mental status alteration. We describe a case of a young HIV-positive patient with a seizure disorder who presented with unrelenting headaches and breakthrough seizures and was diagnosed with thrombosis in the superior sagittal sinus extending to the left transverse and sigmoid sinuses with venous thrombosis in the left vein of Trolard. This case is highly relevant, reminding clinicians to keep a high index of suspicion for DVST in any patient with headache and neurological manifestations.