Differential Cognitive Effects of Unilateral Subthalamic Nucleus Deep Brain Stimulation for Parkinson's Disease.

OBJECTIVE: The aim of this study was to investigate the cognitive effects of unilateral directional versus ring subthalamic nucleus deep brain stimulation (STN DBS) in patients with advanced Parkinson's disease. METHODS: We examined 31 participants who underwent unilateral STN DBS (left n = 17; right n = 14) as part of an National Institutes of Health (NIH)-sponsored randomized, double-blind, crossover study contrasting directional versus ring stimulation. All participants received unilateral DBS implants in the hemisphere more severely affected by motor parkinsonism. Measures of cognition included verbal fluency, auditory-verbal memory, and response inhibition. We used mixed linear models to contrast the effects of directional versus ring stimulation and implant hemisphere on longitudinal cognitive function. RESULTS: Crossover analyses showed no evidence for group-level changes in cognitive performance related to directional versus ring stimulation. Implant hemisphere, however, impacted cognition in several ways. Left STN participants had lower baseline verbal fluency than patients with right implants (t [20.66 = -2.50, p = 0.02]). Verbal fluency declined after left (p = 0.013) but increased after right STN DBS (p < 0.001), and response inhibition was faster following right STN DBS (p = 0.031). Regardless of hemisphere, delayed recall declined modestly over time versus baseline (p = 0.001), and immediate recall was unchanged. INTERPRETATION: Directional versus ring STN DBS did not differentially affect cognition. Similar to prior bilateral DBS studies, unilateral left stimulation worsened verbal fluency performance. In contrast, unilateral right STN surgery increased performance on verbal fluency and response inhibition tasks. Our findings raise the hypothesis that unilateral right STN DBS in selected patients with predominant right brain motor parkinsonism could mitigate declines in verbal fluency associated with the bilateral intervention. ANN NEUROL 2024;95:1205-1219.

Differential cognitive effects of unilateral left and right subthalamic nucleus deep brain stimulation for Parkinson disease.

Objective: To investigate hemispheric effects of directional versus ring subthalamic nucleus (STN) deep brain stimulation (DBS) surgery on cognitive function in patients with advanced Parkinson's disease (PD). Methods: We examined 31 PD patients (Left STN n = 17; Right STN n = 14) who underwent unilateral subthalamic nucleus (STN) DBS as part of a NIH-sponsored randomized, cross-over, double-blind (ring vs directional) clinical trial. Outcome measures were tests of verbal fluency, auditory-verbal memory, and response inhibition. First, all participants were pooled together to study the effects of directional versus ring stimulation. Then, we stratified the groups by surgery hemisphere and studied the longitudinal changes in cognition post-unilateral STN DBS. Results: Relative to pre-DBS cognitive baseline performances, there were no group changes in cognition following unilateral DBS for either directional or ring stimulation. However, assessment of unilateral DBS by hemisphere revealed a different pattern. The left STN DBS group had lower verbal fluency than the right STN group (t(20.66 = -2.50, p = 0.02). Over a period of eight months post-DBS, verbal fluency declined in the left STN DBS group (p = 0.013) and improved in the right STN DBS group over time (p < .001). Similarly, response inhibition improved following right STN DBS (p = 0.031). Immediate recall did not significantly differ over time, nor was it affected by implant hemisphere, but delayed recall equivalently declined over time for both left and right STN DBS groups (left STN DBS p = 0.001, right STN DBS differ from left STN DBS p = 0.794). Conclusions: Directional and ring DBS did not differentially or adversely affect cognition over time. Regarding hemisphere effects, verbal fluency decline was observed in those who received left STN DBS, along with the left and right STN DBS declines in delayed memory. The left STN DBS verbal fluency decrement is consistent with prior bilateral DBS research, likely reflecting disruption of the basal-ganglia-thalamocortical network connecting STN and inferior frontal gyrus. Interestingly, we found an improvement in verbal fluency and response inhibition following right STN DBS. It is possible that unilateral STN DBS, particularly in the right hemisphere, may mitigate cognitive decline.

Resection of Brainstem Arteriovenous Malformations: Pearls and Pitfalls for Minimizing Complications.

BACKGROUND: The decision-making process surrounding resection of arteriovenous malformations (AVMs) in proximity to vital brainstem structures is a complex topic. Intricate vasculature in the setting of exquisite brainstem eloquence creates a high-risk operative landscape with the potential for devastating complications. Effective resections are driven by mastery of the relevant operative anatomy, preservation of pertinent vasculature, and technical experience and acumen. METHODS: This article provides a narrative literature review on the resection of brainstem AVMs. RESULTS: Operative anatomy and approaches to AVMs of the midbrain (anterior/posterior), pons (anterior/lateral), and medulla (anterior/lateral) are discussed herein, with a focus on pearls and pitfalls for minimizing complications during resection. CONCLUSIONS: Careful consideration of the patient's clinical background, the natural history of the lesion, and expertise of the treating surgeon are paramount for improving the natural course of brainstem AVMs.

Resection of Brainstem Cavernous Malformations: Pearls and Pitfalls for Minimizing Complications.

BACKGROUND: Surgical management of brainstem cavernous malformations (CMs) is a controversial topic in the field of neurosurgery. These lesions have a propensity to hemorrhage, thereby disrupting surrounding brainstem eloquence. METHODS: This article provides the personal reflections of the senior author and a narrative literature review on resection of brainstem CMs. RESULTS: Here we discuss the indications for microsurgery, microsurgical techniques and nuances, and perioperative management considerations necessary to minimize complications during resection of brainstem CMs, which are lesions of venous origin. CONCLUSIONS: The natural history of the lesion, risk of future hemorrhage, and potential for symptom resolution should be carefully considered when planning to resect brainstem CMs. Nuanced microsurgical techniques with minimal disruption of normal tissues provide the best chance of satisfactory outcomes.

Correction: Predictive Value of Credit Score on Surgery Resident and Fellow Academic and Professional Performance.

[This corrects the article DOI: 10.7759/cureus.15946.].

Malignant lymphomatous invasion of Meckel's cave: pathoanatomical considerations of the petrous apex.

Secondary central nervous system lymphoma is rare, occurring in up to 10% of non-Hodgkin's lymphoma patients and in 5% of diffuse large B-cell lymphoma patients. The prognosis is poor, even rarer is metastasis of large B-cell lymphomas into Meckel's cave and the trigeminal nerve roots. We describe a relapsing case of a large B-cell lymphoma that migrated into Meckel's cave, the mandibular branch of the trigeminal nerve and the adjacent cavernous sinus. We review petrous apex anatomy, review the literature of metastatic spread into Meckel's cave and analyse existing pathoanatomical studies that explain the conduits and barriers of tumour spread. Understanding this pathoanatomical relationship is critical for neurologists and neurosurgeons alike to effectively correlate patient signs and symptoms to intracranial pathology and identify origins and sites of metastatic dispersion in similar rare clinical scenarios.

Reliability of self-report versus the capacity to consent to treatment instrument to make medical decisions in brain metastasis and other metastatic cancers.

OBJECTIVE: To evaluate the ability of persons with metastatic cancer to self-assess their medical decision-making capacity (MDC). To investigate this, we compared an objective measure of MDC with self-ratings and evaluated predictors of agreement. METHODS: Data were obtained from a cross-sectional study of metastatic cancer patients at a large academic medical center. Across all standards of MDC, sensitivity, specificity, and reliability using Gwet's AC1 statistic were calculated using the objective measure as the gold standard. Logistic regression was used to evaluate predictors of agreement between the measures across all MDC standards. RESULTS: In those with brain metastases, high sensitivity (greater than 0.7), but low specificity was observed for all standards. Poor reliability was observed across all standards. Higher age resulted in higher odds of disagreement for Standard 3 (appreciation) (OR: 1.07, 95% CI: 1.00, 1.15) and Standard 4 (reasoning) (OR: 1.05, 95% CI: 1.00, 1.10). For Standard 3, chemotherapy use and brain metastases compared to other metastases resulted in higher odds of disagreement (Chemotherapy: OR: 5.62, 95% CI: 1.37, 23.09, Brain Metastases: OR: 5.93, 95% CI: 1.28, 27.55). For Standard 5 (understanding), no predictors were associated with disagreement. CONCLUSIONS: For less cognitively complex standards (e.g., appreciation), self-report may be more valid and reliable than more cognitively complex standards (e.g., reasoning or understanding). However, overall, MDC self-report in the current sample is suboptimal. Thus, the need for detailed assessment of MDC, especially when patients are older or used chemotherapy, is indicated. Other studies should be conducted to assess MDC agreement longitudinally.

Predictive Value of Credit Score on Surgery Resident and Fellow Academic and Professional Performance.

Introduction Surgical specialties consistently remain among the most competitive residency and fellowship programs with some of the highest rates of unmatched applicants. Attrition in surgical specialties is as high as 30% and particularly problematic given the extended duration of training and limited number of positions. Applicants are traditionally evaluated using a streamlined set of objective metrics, such as board scores, class rank, leadership, letters of recommendation, research productivity, and volunteerism. Consumer credit scores have been shown to be predictors of personality and work performance, however, the literature has yet to explore consumer credit histories in the context of surgical resident and fellow performance. This study aims to determine whether consumer credit scores of surgery residents and fellows are predictive of academic and professional performance. Methods This is a multi-institutional observational survey study across all American Council of Graduate Medical Education and Royal College of Physicians and Surgeons accredited surgical residency and fellowship programs in the United States and Canada. Ninety-nine surgical residents and fellows with educational status of post-graduate year two or higher participated in this study. Dichotomous (yes or no) survey items were formulated to assess performance indicators in the domains of notable achievements and awards, research output, written examination performance, professionalism, and surgical/technical skills. Three-digit Fair Isaac Corporation (FICO) credit scores, a widely accepted consumer reporting score, were collected to avoid calculation variability between algorithms.  Results Surgical residents and fellows reported credit scores between 611( fair) and 853 (exceptional) with a median (interquartile range) of 774 (715-833). The majority of participants 51.5%(51) reported very good credit scores. Those with higher credit scores (very good/exceptional) were 377% more likely to have one or more positive performance indicators OR (95% CI) = 3.77 (1.43-9.97). Similarly, residents with lower credit scores (fair/good) were only 40% more likely to have one or more negative performance indicators. The credit score has a moderate ability to distinguish between the presence and absence of positive performance indicators (area under the curve {AUC} = 0.70, p = 0.001). The use of 753 as a credit score cutoff is 78.9% sensitive and 52.4% specific for discerning surgery residents and fellows with one or more positive performance indicators. The credit score did not significantly discern those with negative performance indicators. Conclusions While credit score was significantly functional in discerning those with and without positive performance indicators, sensitivity and specificity rates leave much to be desired. This study suggests credit score may have a utility as a companion to traditional metrics used in identifying candidates for surgery residencies and fellowships who will have positive performance in the domains of research productivity, written examination performance, and professional awards and recognition. Additional studies are needed to assess this utility on a larger scale.

Myeloneuropathy in the Setting of Hypocupremia: An Overview of Copper-Related Pathophysiology.

A posterior cord or dorsal column myelopathy due to neurosyphilis presenting as a tabetic gait is a classic neurological vignette and is taught to all medical students. Its clinical presentation is so graphic that its simulacrum with diseases other than neurosyphilis is labeled as pseudotabes. The latter can be seen with vitamin B12 deficiency as a subacute combined degeneration (SCD) of the spinal cord, another neurology classic. However, not all cases of pseudotabes are due to posterior cord myelopathy as some can arise with other deafferentation syndromes such as polyganglioneuropathies as seen with paraneoplastic syndromes, Sjogren's syndrome, idiopathic autoimmune diseases, and post-viral neuronopathies. A unique and interesting cause of pseudotabes is due to copper deficiency; copper being a metallic trace element that is fundamental to cellular life. Herein, we present a case of copper deficiency manifesting as pseudotabes and review the biochemical properties of copper and its effects on the nervous system.

Correlates of deep brain stimulation consensus conference decision to treat primary dystonia.

BACKGROUND: Deep brain stimulation (DBS) is an effective treatment for motor disturbance in people with primary dystonia (PWD). Numerous factors are considered by an interdisciplinary consensus conference before deciding candidacy for DBS surgery (e.g., demographic, medical, cognitive, and behavioral factors). However, little is known about which of these factors are associated with PWD DBS surgery consensus conference decisions. OBJECTIVE: Our goal was to examine whether pre-operative demographic, medical, and cognitive/behavioral variables are associated DBS consensus conference decisions in patients with dystonia. METHODS: Thirty-two PWD completed comprehensive presurgery workup included neurological and neuropsychological exams, and neuroimaging in consideration for DBS surgery. An interdisciplinary conference committee either recommended or did not recommend DBS surgery based upon these data. Demographic and medical data (e.g., dystonia disease characteristics, medical comorbidities, medications) were also collected. We also examined impact from cardiovascular disease factors, using a Revised Cardiac Risk Index. PWD were grouped based on DBS conference decision (eligible: n = 21, ineligible: n = 11) and compared across demographic, medical, and cognitive/behavioral variables. RESULTS: Across clinical variables, PWD who were deemed ineligible for DBS surgery had a higher Revised Cardiac Risk Index. PWD who were classified as ineligible displayed lower global cognitive functioning, working memory, phonemic fluency, memory retrieval, and cognitive flexibility. CONCLUSIONS: Consensus decision making regarding DBS surgery eligibility involves a multifactorial process. We found that deficits in executive functioning were associated with the DBS consensus committee decision. We also observed elevated cardiac risk among these individuals, likely reflecting the relation between vascular health and cognition. Implications, and clinical and scientific applications of these findings are discussed.

Branchial Cleft Cyst Harbors Metastatic Papillary Thyroid Carcinoma.

Branchial cleft cysts are congenital anomalies which develop in utero, most commonly arising from the second branchial cleft. They are often asymptomatic lateral neck masses but can enlarge and become symptomatic in the setting of infection. The cystic cavity can form a potential space which can harbor infection and, in rare cases, malignant spread of primary tumors. Herein, we present a rare case of a 28-year-old male with an enlarging branchial cleft cyst of six months duration following an upper respiratory infection. Routine post-surgical histopathological examination of the excised mass revealed metastatic papillary thyroid carcinoma. To our knowledge, this case is one of five cases reported within the primary literature. This case draws attention to the occult nature of papillary thyroid carcinoma and the importance of routine histopathological examination of seemingly benign surgically excised lesions.

Atypical Neuroleptic Malignant Syndrome in the Setting of Quetiapine Overdose: A Case Report and Review of the Literature.

Neuroleptic malignant syndrome (NMS) is a rare and life-threatening emergency. The condition is largely iatrogenic and is often precipitated by medications such as antipsychotics. First-generation antipsychotics are more likely to cause NMS than second-generation antipsychotics. The literature lacks an objective measure for NMS diagnosis. Instead, the diagnosis relies largely on the recognition of characteristic symptoms in the presence of an inciting medication. Additional challenges exist with concomitant disease processes and toxicities that may distort the clinical picture. Here, we report a case of a 44-year-old Caucasian man who presented with atypical NMS in the setting of quetiapine overdose. The patient remained uncharacteristically afebrile throughout his admission. Although the patient recovered, extended delays in identification and management can contribute to an increased risk of morbidity and mortality.

The Impact of the COVID-19 Pandemic on Resident Physicians Well-Being in the Surgical and Primary Care Specialties in the United States and Canada.

PURPOSE:  The COVID-19 pandemic disrupted the professional, social, and spiritual activities of resident physicians around the world, impacting wellness and personal relationships. Moreover, social distancing caused significant limitations or shutdown of places of worship, including churches, synagogues, mosques, etc. Our goal was to survey resident physicians in primary care and surgical subspecialties in the United States (U.S.) and Canada and to examine the effect of the COVID-19 pandemic on their well-being. METHODS:  An international cross-sectional study was performed in November 2020, using an anonymous survey of programs in the U.S. and Canada, containing 20 questions to assess the impact of the pandemic on resident participation in social and spiritual activities and the effects on their wellness, and personal relationships. The emails with survey links attached were sent to individual program coordinators from accredited residency training programs in the United States and Canada. This consisted of programs accredited by the American Osteopathic Association (AOA), The Royal College of Physicians and Surgeons of Canada (RCPSC), and the Accreditation Council of Graduate Medical Education (ACGME). The survey was evenly divided among surgical programs (General Surgery, Neurological Surgery, Orthopedic Surgery, Urological Surgery, and Integrated Surgical Residency Programs such as Plastic Surgery, Cardiothoracic Surgery, Pediatric Surgery, and Vascular Surgery) as well as primary care programs (Internal Medicine and Family Medicine). RESULTS:  A total of 196 residents, 60 primary care residents, and 136 surgery residents participated in the study. Ninety-six participants (49%) were female, and 98 of the participants (50%) were male, with the remainder two residents identifying as "Other." Of the primary care residents, the majority (39, 65%) were female. Conversely, the majority (77, 57%) of surgery residents were male. CONCLUSION:  The COVID-19 pandemic has affected the social lives, relationships, and spiritual well-being of both surgical and primary care resident physicians. However, primary care residents reported significantly greater engagement in personal relationships and were more likely to express feelings of mental and physical exhaustion, prohibiting social attendance.

Transtentorial Approach to Parahippocampal Lesions: A Technically Challenging Approach for Preserving Temporal Lobe Structures.

In this installment of the Neurosurgical Atlas Series for WORLD NEUROSURGERY, the authors examine the paramedian supracerebellar transtentorial (SCTT) approach as a means of accessing the basal posteromedial temporal lobe for both intradural and extradural lesions. While other approaches, such as the subtemporal, transtemporal, and transsylvian routes, are often used to reach this otherwise impervious region, all of them do so at the expense of supratentorial structural integrity. Despite the long and narrow working distance provided by the SCTT approach, the access it provides to critical, deep-seated regions with little to no associated morbidity makes it our preferred approach in these patients. In this work, we highlight the perioperative considerations for this procedure, discuss the technical nuances of all aspects of the operation, and provide discussion on the approach in the context of its evolution and alternatives.

Capacity to consent to research participation in adults with metastatic cancer: comparisons of brain metastasis, non-CNS metastasis, and healthy controls.

BACKGROUND: To evaluate the ability of individuals with metastatic cancer to provide informed consent to research participation, we used a structured vignette-based interview to measure 4 consenting standards across 3 participant groups. METHODS: Participants included 61 individuals diagnosed with brain metastasis, 41 individuals diagnosed with non-CNS metastasis, and 17 cognitively intact healthy controls. All groups were evaluated using the Capacity to Consent to Research Instrument (CCRI), a performance-based measure of research consent capacity. The ability to provide informed consent to participate in research was evaluated across 4 consent standards: expressing choice, appreciation, reasoning, and understanding. Capacity performance ratings (intact, mild/moderate impairment, severe impairment) were identified based on control group performance. RESULTS: Results revealed that the brain metastasis group performed significantly lower than healthy controls on the consent standard of understanding, while both metastatic cancer groups performed below controls on the consent standard of reasoning. Both metastatic cancer groups performed similar to controls on the standards of appreciation and expressing choice. Approximately 60% of the brain metastasis group, 54% of the non-CNS metastasis group, and 18% of healthy controls showed impaired research consent capacity. CONCLUSIONS: Our findings, using a performance-based assessment, are consistent with other research indicating that the research consent process may be overly cumbersome and confusing. This, in turn, may lead to research consent impairment not only in patient groups but also in some healthy adults with intact cognitive ability.

Bilateral Orbital Metastases Masquerading as Ocular Myasthenia Gravis: A Case Report and Review of the Literature.

Ocular myasthenia gravis and orbital metastases have overlapping symptoms but divergent diagnostic and treatment strategies. Here, we present a 58-year-old female, with a 20-year history of advanced metastatic breast cancer, who presented to the neurology clinic with fatigue, muscle weakness, bilateral ptosis, and diplopia that worsened throughout the day. While the initial presentation was consistent with ocular myasthenia gravis, a subsequent evaluation revealed bilateral metastatic lesions of breast origin within the orbits. This case highlights the variable nature of metastatic disease and underscores the importance of a comprehensive neoplastic workup in patients with new-onset symptomatology and a prior history of advanced cancer despite purported remission status.

Relationship between cognitive functioning, mood, and other patient factors on quality of life in metastatic brain cancer.

OBJECTIVE: Neurocognitive functioning (NCF), mood disturbances, physical functioning, and social support all share a relationship with health-related quality of life (HRQOL). However, investigations into these relationships have not been conducted in persons with brain metastases (BM). PATIENTS AND METHODS: Ninety-three newly diagnosed persons with BM were administered various cognitive batteries. Data were collected across a wide range of categories (ie, cognitive, demographic, disease/treatment, mood, social support, physical functioning). The Functional Assessment of Cancer Treatment (FACT) scale was used to measure HRQOL. RESULTS: Mood and physical function correlated with lower HRQOL in every measured domain. Verbal learning and memory correlated with every FACT subscale except emotional quality of life. Social support also correlated with several HRQOL domains. Stepwise linear regression revealed that mood predicted general well-being and several FACT subscales, including physical, emotional and cognitive well-being. Social support and physical health were predictive of general well-being. Verbal learning and memory predicted cognitive well-being. CONCLUSION: HRQOL is a complex construct affected by numerous variables. In particular, mood, physical functioning, and learning and memory were important predictors of HRQOL, and clinicians are encouraged to obtain information in these areas during baseline assessments in persons with BM.

Spontaneous Migration of a Ventriculoperitoneal Shunt into the Venous System: A Multidisciplinary Approach.

Ventriculoperitoneal shunt catheter migration is a rare but documented complication. The exact mechanism of this occurrence is not well understood. We report the case of an 81-year-old male who initially presented with symptoms consistent with normal pressure hydrocephalus. A ventriculoperitoneal shunt was placed uneventfully. Four months later, the patient presented complaining of a persistent headache despite multiple adjustments in the shunt setting. Shunt series radiographs demonstrated the distal catheter passing through the superior vena cava and looping into the right cardiac atrium and ventricle. Catheter retrieval was attempted from a proximal retroauricular incision but required a combination of snare technique by interventional radiology and, ultimately, surgical venotomy by a cardiothoracic surgeon. The distal catheter was replaced in the abdomen, and the patient had no further complications. This case is the first of its kind reported in the literature that includes a treatment team comprising neurosurgery, interventional radiology, and cardiothoracic surgery. We highlight the importance of a multidisciplinary approach to best address the migrated catheter.

Autoantibody-Negative Immune-Mediated Necrotizing Myopathy Responds to Early and Aggressive Treatment: A Case Report.

Immune-mediated necrotizing myopathy (IMNM) is a rare idiopathic disease that is further classified by the presence of serum antibodies. A modicum of patients lack serum autoantibodies. Significantly elevated creatine kinase (CK) is highly characteristic of IMNM. The pathophysiology of IMNM is partially understood, and effective treatment options are limited, particularly in patients without serum autoantibodies. In this case, we report a 76-year-old male presenting with a four-month history of proximal muscle weakness. Muscle biopsy and serology confirmed the diagnosis of autoantibody-negative IMNM. Early and aggressive treatment with high-dose steroids and a course of intravenous immunoglobulin significantly reduced the patient's symptoms and CK within three months. This case serves as an example of an effective treatment outcome in a patient with this rare idiopathic necrotizing myopathy.