Vitamin B12 deficiency can present with a variety of neurological and cognitive symptoms. Especially in elderly patients, vitamin B12 deficiency can be easily overlooked because symptoms may be attributed to comorbid conditions or solely to the aging process. In this case study, we present two patients, a 71-year-old man and a 74-year-old female, with vitamin B12 deficiency. The male patient had a history of (partial) resection of the ileum/jejunum/colon because of intestinal ischemia. The female patient had a history of hypothyroidism, type 2 diabetes with complications (including peripheral neuropathy), mitochondrial myopathy, and chronic lymphocytic leukemia. Both patients presented with severe fatigue, cognitive impairment, and impaired walking. Next to this, the male patient suffered from depressive symptoms and mild disorientation, and the female patient experienced neuropathic pain. She also mentioned a positive family history for B12 deficiency. The first patient had normal to high B12 levels because he was already on B12 injections (once every three weeks) because of an earlier diagnosed B12 deficiency. The female patient had B12 levels within normal range (holotranscobalamin 54 pmol/L) and her diagnosis was confirmed by elevated homocysteine and methylmalonic acid levels. Treatment with frequent hydroxocobalamin injections and other supplements significantly improved their cognitive, emotional, and motor functions. These cases underscore the need for a high level of clinical suspicion in elderly patients, also in cases of normal B12 levels but with clinical signs of deficiency and a positive risk factor, such as stomach or small bowel surgery or positive family history.
Plain language titleA case study of two elderly patients with vitamin B12 deficiency and neurological and cognitive complaintsPlain language summaryVitamin B12 deficiency in elderly patients can be easily overlooked as symptoms can also be caused by other age-related diseases or the aging process. In our article we present two elderly patients, a 71-year-old male and a 74-year-old female, with neurological complaints, such as severe fatigue, cognitive decline, and walking impairment. The male patient had a history of small bowel surgery, and the female patient mentioned that she had several siblings with B12 deficiency. Additionally, the male patient suffered from depressive symptoms and mild disorientation, and the female had severe pain in her legs. The male patient already received B12 injections because of an earlier B12 diagnosis, but with a relatively low frequency. The B12 levels of the female patients were within the normal range. However, her diagnoses could be confirmed with additional laboratory measurements, such as homocysteine and methylmalonic acid. Treatment with frequent B12 injections and other supplements significantly improved their cognitive, emotional, and motor functions. Our study shows that clinicians should carefully consider the possibility of B12 deficiency in elderly patients with cognitive and neurological complaints, also in patients with B12 levels within the normal range, but with risk factors such as family members with B12 deficiency or conditions that may impair the vitamin B12 uptake, such as previous stomach or small bowel surgery.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a rare genetic disorder caused by mutations in the NOTCH3 gene, resulting in subcortical infarctions and leukoencephalopathy. It predominantly affects the brain\'s small blood arteries, resulting in repeated ischemic episodes including transient ischemic attacks and strokes leading to cognitive impairment and mental symptoms. We provide a case study of a 25-year-old patient suspected of having meningoencephalitis. CADASIL was diagnosed based on clinical examination, imaging investigations, and genetic analysis. Optimal patient care for this complicated illness requires early detection and proper management.

Transient global amnesia (TGA) is a rare condition characterized by a temporary loss of the ability to form new memories. Retrograde episodic memory loss may also occur but to a lesser extent. Although TGA is generally benign, its sudden onset and similarity to more dangerous conditions like transient ischemic attack (TIA) or cerebral vascular accident (CVA) can be concerning. We present the case of a 70-year-old female who experienced confusion and general memory loss after a vigorous workout on her stationary exercise bike. After displaying considerable amnestic symptoms, she was admitted to the hospital for further medical attention and underwent a magnetic resonance imaging (MRI) that concluded a TGA diagnosis. This case report aims to investigate the prognosis associated with risk factors and refine the diagnostic criteria of TGA. We explore whether TGA caused by exercise, leading to unilateral or bilateral hippocampal lesions, is linked to cognitive decline. It is not yet clear if the development of TGA with unilateral infarct or bilateral hippocampal lesions results in different clinical presentations or varying prognoses. Further research is needed to determine the long-term risks of cognitive decline associated with resulting infarcts and clinical presentations.

Burning mouth syndrome (BMS) is characterized by persistent oral burning sensations without corresponding organic findings. Dementia with Lewy bodies (DLB) is a common type of dementia and generally presents visual hallucination and parkinsonism as motor dysfunction besides cognitive decline. In this case report, we present a case in which DLB emerged during the treatment for BMS, with a relatively positive outcome for BMS. A 74 years-old female complained of burning pain in her mouth and a subsequent decrease in food intake. Following a diagnosis of BMS, pharmacotherapy was initiated. BMS was much improved with mirtazapine 15 mg and aripiprazole 1.0 mg, leading to the restoration of her food intake by day 180. However, BMS flared up again triggered by deteriorating physical condition of herself and that of her husband. With aripiprazole 1.5 mg and amitriptyline 25 mg, her BMS gradually improved by day 482. However, by day 510, an increase in anxiety was noted, accompanied by the occasionally misidentification of her husband on day 566. Her cognitive impairment and disorientation were also reported by her husband on the day 572, she was then immediately referred to a neurologist specialized dementia and diagnosed with DLB on the day 583. Her treatment was adjusted to include the prescription of rivastigmine which was titrated up to 9.0 mg. Considering the potential impact of amitriptyline on cognitive function, it was reduced and switched to mirtazapine; however, her oral sensations slightly got worse. Following the consultation with her neurologist, amitriptyline 10 mg was reintroduced and aripiprazole was discontinued on day 755. Remarkably, BMS gradually improved without deteriorating DLB. This case indicated the reaffirmed necessity of careful interviews for changes in daily life not only with the patients but also with their families through the medical assessments. It highlights the vigilance regarding potential cognitive decline underlying or induced as an adverse event especially when treating elderly patients with BMS. While the interaction between BMS and DLB remains unclear, this case underscores the importance of prudent diagnosis and constructing collaboration with specialists in managing BMS with the early phase of DLB.

Prion diseases are rare neurodegenerative diseases that have a rapid evolution. Creutzfeldt-Jakob disease (CJD) is the most common and its sporadic form the most frequent. Definitive diagnosis is only obtained through autopsy, and there are currently no available treatments. Here, we present a case of an 84-year-old woman presenting with resting tremor, abnormal gait, frequent falls, apraxia, visual hallucinations, and delirium. There were no signs of relevant metabolic, infectious, or nutritional alterations, and brain computed tomography (CT) scan and magnetic resonance imaging (MRI) had no significant findings. Two months later, the patient was completely immobile with mutism, seizures, and myoclonus. In the presence of a rapidly progressive dementia associated with myoclonus, it was hypothesized that the patient had CJD. The patient\'s clinical state deteriorated, she died, and autopsy confirmed sporadic CJD. The purpose of this case is to highlight a rare disease that can go undiagnosed because of low awareness and clinical suspicion and the importance of the differential diagnosis of dementia, a common disease at this age.

UNASSIGNED: Kelch-like protein 11antibody is a recently identified biomarker for paraneoplastic neurological syndromes associated with germ-cell tumors that was first described as an onconeural antibody causing autoimmune encephalitis associated with seminoma in 2019. Ataxia is the most prevalent presenting symptom, with other neurological symptoms including vertigo, double vision, hearing loss, tinnitus and dysarthria. Magnetic resonance imaging scans reveal that the lesions are mostly located in the cerebellum and brainstem, particularly in the pontine region, and may also exhibit cerebellar atrophy.
UNASSIGNED: In this study, we report the clinical features of Kelch-like protein 11 antibody-associated paraneoplastic neurological syndrome.
UNASSIGNED: We present a middle-aged female patient who presented with vertigo, cognitive decline, ataxia and limb weakness. A cell-based assay (CBA) showed positive IgG Kelch-like protein 11 in both her serum and CSF, as well as positive oligoclonal bands in her CSF. She was diagnosed with KLHL11 antibody-associated autoimmune encephalomyelitis and received high-dose intravenous methylprednisolone pulse therapy.
UNASSIGNED: Clinical outcomes suggest that patients with Kelch-like protein 11 antibody mostly have poor prognoses, excepting our case. We propose that early and appropriate treatments are critical for timely diagnosis and rapid improvement.

We describe the case of a young woman affected by debilitating chorea and rapidly progressive cognitive decline. While her original diagnosis was multiple sclerosis, we performed a full instrumental and genetic assessement, though which we identified multiple genetic variants, including a novel variant of the APP gene. We propose some possible mechanisms by which such variants may contribute to neuroinflammation and ultimately lead to this devastating clinical course.

UNASSIGNED: Nitrous oxide (N2O) is an increasingly popular recreational drug. N2O irreversibly disturbs the metabolism of vitamin B12, resulting in a functional deficiency. Vitamin B12 is vital for myelin synthesis and its deficiency primarily produces neurological complications. Inhaling N2O is more common and neurological complications are more evident than before.
UNASSIGNED: We report a young man who developed progressive limb numbness and unsteady walking after N2O abuse. The dominant diagnosis was subacute combined degeneration of the spinal cord (SCD). The patient was admitted to the hospital and given adenosylcobalamin treatment, but his symptoms progressed significantly from before and he developed acute cognitive impairment. After methylprednisolone combined with vitamin B12 treatment, symptoms significantly improved.
UNASSIGNED: Clinicians need to understand the presentation and treatment of SCD caused by N2O abuse. When symptoms progress despite conventional vitamin B12 therapy, the combination of methylprednisolone and vitamin B12 may be considered.

Care for geriatric patients can be difficult due to the complex nature of age-related comorbidities, multiple medications, and cognitive decline; this hardship multiplies when psychiatric illness or dementia are present and often exacerbates existing issues. Millions of lives have been lost in the COVID pandemic, and it has also severely harmed our collective mental health and cognition. The elderly population has felt that this impact the greatest as they are at the highest risk of isolation, cognitive inactivity, loneliness, and depression, all of which are risk factors for dementia. Studies associate loneliness with a 40% increase in the risk of dementia; thus, this pandemic and resulting isolation have likely caused an increase in cognition loss of the elderly. Furthermore, there is a documented bidirectional relationship between COVID-19 and psychiatric illness, both of which increase the likelihood of the other and are associated with worsening mental cognition. We present a case series of two patients with pre-existing psychiatric illness and cognitive decline, both exacerbated by COVID-19 infection, causing further decline in cognition.

BACKGROUND: Story recall is a simple and sensitive cognitive test that is commonly used to measure changes in episodic memory function in early Alzheimer disease (AD). Recent advances in digital technology and natural language processing methods make this test a candidate for automated administration and scoring. Multiple parallel test stimuli are required for higher-frequency disease monitoring.
OBJECTIVE: This study aims to develop and validate a remote and fully automated story recall task, suitable for longitudinal assessment, in a population of older adults with and without mild cognitive impairment (MCI) or mild AD.
METHODS: The \"Amyloid Prediction in Early Stage Alzheimer\'s disease\" (AMYPRED) studies recruited participants in the United Kingdom (AMYPRED-UK: NCT04828122) and the United States (AMYPRED-US: NCT04928976). Participants were asked to complete optional daily self-administered assessments remotely on their smart devices over 7 to 8 days. Assessments included immediate and delayed recall of 3 stories from the Automatic Story Recall Task (ASRT), a test with multiple parallel stimuli (18 short stories and 18 long stories) balanced for key linguistic and discourse metrics. Verbal responses were recorded and securely transferred from participants\' personal devices and automatically transcribed and scored using text similarity metrics between the source text and retelling to derive a generalized match score. Group differences in adherence and task performance were examined using logistic and linear mixed models, respectively. Correlational analysis examined parallel-forms reliability of ASRTs and convergent validity with cognitive tests (Logical Memory Test and Preclinical Alzheimer\'s Cognitive Composite with semantic processing). Acceptability and usability data were obtained using a remotely administered questionnaire.
RESULTS: Of the 200 participants recruited in the AMYPRED studies, 151 (75.5%)-78 cognitively unimpaired (CU) and 73 MCI or mild AD-engaged in optional remote assessments. Adherence to daily assessment was moderate and did not decline over time but was higher in CU participants (ASRTs were completed each day by 73/106, 68.9% participants with MCI or mild AD and 78/94, 83% CU participants). Participants reported favorable task usability: infrequent technical problems, easy use of the app, and a broad interest in the tasks. Task performance improved modestly across the week and was better for immediate recall. The generalized match scores were lower in participants with MCI or mild AD (Cohen d=1.54). Parallel-forms reliability of ASRT stories was moderate to strong for immediate recall (mean rho 0.73, range 0.56-0.88) and delayed recall (mean rho=0.73, range=0.54-0.86). The ASRTs showed moderate convergent validity with established cognitive tests.
CONCLUSIONS: The unsupervised, self-administered ASRT task is sensitive to cognitive impairments in MCI and mild AD. The task showed good usability, high parallel-forms reliability, and high convergent validity with established cognitive tests. Remote, low-cost, low-burden, and automatically scored speech assessments could support diagnostic screening, health care, and treatment monitoring.