CSF1R-related disorder, a catastrophic neurodegenerative disease, arises from genetic mutations in the colony-stimulating CSF1R. Initial misdiagnosis is common, as demonstrated by this case involving a 52-year-old female who presented with symptoms of limb numbness and weakness. Differential diagnosis first indicated Parkinsonism, lacunar infarction, and cervical spondylosis. Subsequently, however, this patient's clinical presentation evolved to include bradykinesia, cognitive decline, and a spectrum of neurological manifestations. A Pan-V2 assay revealed a heterozygous mutation in the CSF1R gene. Craniocerebral MRI showed cerebral infarctions, lacunar infarctions, and leukoaraiosis. Despite symptomatic treatments, our patient's clinical status continued to decline until her family chose to discontinue further medical interventions. This case underscores the diagnostic complexities of early detection of CSF1R-related disorders. It emphasizes the importance of including leukodystrophy in such differential diagnoses and the need for prompt genetic screening in patients who present with progressive leukoencephalopathy, especially when cerebrospinal fluid analysis is unremarkable.

Here we report the case of an individual who developed proper- and common-name anomia with no category specificity, alexia with agraphia for kanji (Japanese morphograms), and mild verbal and semantic memory impairment after unilateral herpes simplex encephalitis. Although their common-name anomia, alexia with agraphia, and semantic memory impairment resolved within 2 years, this individual continued to experience proper-name anomia and verbal memory impairment. Encephalitic damage was limited to the left anterior temporal lobe (ATL), amygdala, hippocampus, and parahippocampal gyrus, sparing the mid-fusiform and posterior inferior temporal gyri. Although ATL lesions are not typically associated with semantic memory impairment, we suggest that damage to the left ATL can result in both proper- and common-name anomia, as was evident in the current case. In these cases, proper-name anomia may be more severe and persistent than common-name anomia, which may be mild and significantly improved within several years. In cases of semantic memory deficits, persistent common-name anomia, and severe alexia with agraphia, there is typically more extensive involvement of the temporal lobe than seen in the current case, including the mid-fusiform and posterior inferior temporal gyri.

Although episodic memory is the primary concern in individuals with mild cognitive impairment (MCI), other cognitive functions may also be affected, including language. Language impairment in individuals with MCI has been attributed primarily to the breakdown of semantic representations, difficulties in accessing semantic information, and the weakening of executive functions. However, in most prior studies of word processing in individuals with MCI, researchers have used measures focused on noun production.

Psychotropic polypharmacy presents a diagnostic challenge that may be further complicated by inadequate medication history and underappreciation of the cognitive effects of such polypharmacy. Here we present the case of a 57-year-old man who presented to our memory clinic with progressive cognitive decline and a prior neuropsychological evaluation supporting the diagnosis of a neurodegenerative disorder. He was taking multiple psychotropic medications at the time, but the exact dosages were unclear due to a lack of collateral history. He was also taking prescribed opioids and a combination of buprenorphine and naloxone for pain relief, again with unclear dosages at the time of presentation. Brain imaging and cerebrospinal spinal fluid biomarker testing were negative for Alzheimer pathophysiologic processes. Months later, the patient was taken to the emergency room after an overdose caused by overuse of opioid medications. Once he was taken off all psychoactive medications, the patient's cognitive impairment completely reversed, and he became independent in activities of daily living. Psychotropic polypharmacy can have a myriad of cognitive manifestations which need to be better recognized by clinicians. Deprescription of such medications should be attempted whenever clinically appropriate.

Impulsivity resulting in unrestrained eating has been implicated as a contributing factor for obesity. Delay discounting (DD) tasks where individuals choose between a smaller immediate reward and a larger delayed reward provide useful data to describe impulsive decision-making and to determine the extent to which delayed rewards are discounted.

Antisocial behaviors occur in up to 91% of individuals with behavioral variant frontotemporal dementia (bvFTD). Prior work has shown that antisocial behaviors can be differentiated into aggressive and nonaggressive rule-breaking behavioral subtypes. Socioemotional dysfunction is common in bvFTD and unique compared to other types of dementia.

The emergence of new-onset neuropsychiatric symptoms in middle age presents a diagnostic challenge, particularly when differentiating between a primary psychiatric disorder and an early neurodegenerative disease. The discrepancy between bedside clinical diagnosis and subsequent neuropathological findings in such cases further highlights the difficulty of accurately predicting pathology, especially when there are no evident focal lesions or changes in brain volume. Here we present the case of a 59-year-old woman with inconclusive neuroimaging who exhibited pronounced neuropsychiatric and behavioral symptoms initially suggestive of a mood disorder, then of behavioral variant frontotemporal dementia. However, upon autopsy, we identified coexisting Lewy body disease pathology and tau-related changes, including argyrophilic grain disease and primary age-related tauopathy. This case illustrates the challenges encountered when diagnosing late-onset neuropsychiatric symptoms, emphasizes the link between such symptoms and early-onset dementia and argyrophilic grain disease, and contributes to our understanding of the impact of mixed neuropathology in this population. Accurate diagnosis is essential for the development of molecular-specific therapies and, as well as for accurate prognosis and enrollment in clinical trials.

Evaluation of sensory functions in chronic stroke survivors is essential to plan and implement effective treatment and rehabilitation.

The dorsomedial prefrontal cortex plays a critical role in movement initiation, and damage to this area can impair this function. Here we present the case of an individual who had difficulty with voluntary initiation of liquid swallowing after surgical removal of a glioblastoma from the right dorsomedial prefrontal cortex. This individual had no difficulty swallowing solids, perhaps because of the additional external movement triggers (eg, chewing) involved. Liquid swallowing involves fewer movement triggers and requires a quicker application of force during the oral propulsive phase when liquids are transferred from the oral cavity to the oropharynx. This individual did not have buccofacial apraxia or apraxia of speech, which are often associated with swallowing apraxia linked to damage in the precentral, premotor, and inferior frontal gyri. To our knowledge, few studies have focused on movement initiation impairments affecting the upper extremities and speech, and cases involving swallowing are notably rare.

The rubber hand illusion (RHI) is a well-established method for studying body ownership: Given adequate concordance of visual, sensory, and proprioceptive stimuli, the individual experiences a rubber hand as his or her own.

While the cognitive hallmark of typical Alzheimer disease (AD) is impaired memory consolidation, increasing evidence suggests that the frontal lobes and associated executive functions are also impacted.

The clinical features of neuropsychiatric systemic lupus erythematosus (NPSLE) are heterogeneous. Furthermore, therapeutic decision-making for NPSLE depends on the recognition of clinical syndromes that have not been sufficiently studied. This report describes the case of a 36-year-old woman with NPSLE who exhibited severe cognitive dysfunction and affective psychosis with persistent nihilistic delusions such as those described in the Cotard delusion. The patient insisted for several months that she was already dead. CSF analysis showed elevated levels of anti-ribosomal P antibodies and a positive determination of oligoclonal bands. Additionally, 18F -FDG PET/CT imaging revealed severe bilateral frontal hypermetabolism suggestive of brain inflammation and occipital hypometabolism. Results from the Systematic Lupus Erythematosus Disease Activity Index 2000 and the Systemic Lupus Erythematosus Disease Activity Score were consistent with an active state of the immunological disease. We then determined by an algorithm that this neuropsychiatric event could be attributed to the activity of the underlying immunological disease. Despite immunosuppressive and symptomatic treatment, only a partial improvement in cognition was achieved. The psychopathological features of the Cotard delusion remained unchanged 4 months after onset. However, we observed rapid remission of affective psychosis and significant improvement in cognition following electroconvulsive therapy. Subsequent follow-up examinations showed a sustained remission. This case describes a protracted form of the Cotard delusion, the diagnostic challenges that arise in the context of SLE, and treatment dilemmas that necessitate collaboration between neurology, psychiatry, and rheumatology.

Phonemic paraphasia, a common characteristic of conduction aphasia, has traditionally been attributed to phonological representation dysfunction. An alternative hypothesis posits that phonemic paraphasia arises from difficulty converting phonemes into their corresponding articulatory maneuvers. However, detailed case studies supporting this theory have been lacking. In this report, we present the case of a 61-year-old right-handed man with right temporo-parietal infarction who exhibited crossed aphasia characterized by typical conduction aphasia symptoms (eg, relatively fluent speech with intact comprehension, frequent phonemic paraphasia, and pronounced difficulties in oral repetition) in the absence of distorted articulation, syllable segmentation, and prosody impairment. Despite the frequent occurrence of phonemic paraphasia and articulatory challenges, our patient's phonological representations remained relatively intact. His phonemic paraphasia was often self-corrected to produce correct responses, a feature known as conduit d'approche. During the oral repetition of individual mora (ie, the smallest unit of speech in Japanese), we observed that the patient consistently traced the corresponding Hiragana phonetic symbol accurately, despite his difficulties in articulation. We substantiated this phenomenon through objective assessment and posit that it resulted from an unusual separation of language functions in crossed aphasia-specifically, a disconnection between phonological representations in the right temporo-parietal cortex and speech articulation engrams in the left hemisphere. In this case of conduction aphasia, articulatory-based phonemic paraphasia may be viewed as an inability to convert phonemes into the appropriate articulatory maneuvers rather than as phonological representation dysfunction or apraxia of speech.

Impairment in semantic knowledge contributes to Alzheimer disease (AD)-related decline. However, the particulars of the impact AD has on specific domains of knowledge remain debatable.

Individuals with idiopathic adult-onset isolated cervical dystonia (CD) may have cognitive difficulties and increased mood challenges. Social cognition and executive functioning may be particularly affected.

Individuals with acquired brain injury have reported subjective complaints of depth perception deficits, but few have undergone objective assessments to confirm these deficits. As a result, the literature currently lacks reports detailing the correlation between subjective depth perception deficits and objective stereoscopic vision deficits in individuals with acquired brain injury, particularly those cases that are characterized by a clearly defined lesion. To investigate this relationship, we recruited three individuals with acquired brain injury who experienced depth perception deficits and related difficulties in their daily lives. We had them take neurologic, ophthalmological, and neuropsychological examinations. We also had them take two types of stereoscopic vision tests: a Howard-Dolman-type stereoscopic vision test and the Topcon New Objective Stereo Test. Then, we compared the results with those of two control groups: a group with damage to the right hemisphere of the brain and a group of healthy controls. Performance on the two stereoscopic vision tests was severely impaired in the three patients. One of the patients also presented with cerebral diplopia. We identified the potential neural basis of these deficits in the cuneus and the posterior section of the superior parietal lobule, which play a role in vergence fusion and are located in the caudal region of the dorso-dorsal visual pathway, which is known to be crucial not only for visual spatial perception, but also for reaching, grasping, and making hand postures in the further course of that pathway.

Behavioral neurology & neuropsychiatry (BNNP) is a field that seeks to understand brain-behavior relationships, including fundamental brain organization principles and the many ways that brain structures and connectivity can be disrupted, leading to abnormalities of behavior, cognition, emotion, perception, and social cognition. In North America, BNNP has existed as an integrated subspecialty through the United Council for Neurologic Subspecialties since 2006. Nonetheless, the number of behavioral neurologists across academic medical centers and community settings is not keeping pace with increasing clinical and research demand. In this commentary, we provide a brief history of BNNP followed by an outline of the current challenges and opportunities for BNNP from the behavioral neurologist's perspective across clinical, research, and educational spheres. We provide a practical guide for promoting BNNP and addressing the shortage of behavioral neurologists to facilitate the continued growth and development of the subspecialty. We also urge a greater commitment to recruit trainees from diverse backgrounds so as to dismantle persistent obstacles that hinder inclusivity in BNNP-efforts that will further enhance the growth and impact of the subspecialty. With rapidly expanding diagnostic and therapeutic approaches across a range of conditions at the intersection of neurology and psychiatry, BNNP is well positioned to attract new trainees and expand its reach across clinical, research, and educational activities.

We present a review of the definition, classification, and epidemiology of primary progressive aphasia (PPA); an update of the taxonomy of the clinical syndrome of PPA; and recent advances in the neuroanatomy, pathology, and genetics of PPA, as well as the search for biomarkers and treatment. PPA studies that have contributed to concepts of language organization and disease propagation in neurodegeneration are also reviewed. In addition, the issues of heterogeneity versus the relationships of the clinical phenotypes and their relationship to biological, pathological, and genetic advances are discussed, as is PPA's relationship to other conditions such as frontotemporal dementia, corticobasal degeneration, progressive supranuclear palsy, Pick disease, and amyotrophic lateral sclerosis. Arguments are presented in favor of considering these conditions as one entity versus many.