In the present review we have discussed the occurrence of β-N-methylamino-L-alanine (BMAA) and its natural isomers, and the organisms and sample types in which the toxin(s) have been detected. Further, the review discusses general pathogenic mechanisms of neurodegenerative diseases, and how modes of action of BMAA fit in those mechanisms. The biogeography of BMAA occurrence presented here contributes to the planning of epidemiological research based on the geographical distribution of BMAA and human exposure. Analysis of BMAA mechanisms in relation to pathogenic processes of neurodegeneration is used to critically assess the potential significance of the amino acid as well as to identify gaps in our understanding. Taken together, these two approaches provide the basis for the discussion on the potential role of BMAA as a secondary factor in neurodegenerative diseases, the rationale for further research and possible directions the research can take, which are outlined in the conclusions.

Background and objectives: Non-motor symptoms in the form of increased sensitivity are often associated with the onset of idiopathic Bell’s palsy (IBP). The aims were to determine whether the pain threshold in the retroauricular regions (RAR) in IBP patients and the time of its occurrence is related to IBP severity. Materials and Methods: The study was conducted among 220 respondents (142 IBP patients, 78 healthy subjects (HS)). The degree of IBP was graded using the House–Brackmann and Sunnybrook Grading Scales (II—mild dysfunction, VI—total paralysis), whereas the pain thresholds were measured using the digital pressure algometer. Results: We found no difference in the degree of the pain threshold between the right and left RAR in the HS group. IBP patients belonging to groups II, III, IV, and V had lower pain thresholds in both RARs than HS and IBP patients belonging to group VI. There was no difference in the degree of pain threshold in RAR between the affected and unaffected side in IBP patients. The incidence of retroauricular pain that precedes paralysis and ceases after its occurrence in groups II and III of IBP patients is noticeably lower and the incidence of retroauricular pain that occurred only after the onset of paralysis is more frequent. Also, we found that the incidence of retroauricular pain that precedes paralysis and ceases after its occurrence in groups V and VI of IBP patients was more frequent. Conclusions: The degree of pain threshold lowering in RAR (bilaterally) is inversely related to the severity of IBP. We suggest that the occurrence of retroauricular pain before the onset of facial weakness is associated with higher severity of IBP while the occurrence after the onset is associated with lower severity of IBP.

Background and objectives: Spontaneous carotid-cavernous fistulas (CCFs) are rare, and they may be caused by an aneurysm rupture. Materials and Methods: A case of a man hospitalized for high-intensity hemicranial headache with sudden cough onset as part of an upper respiratory tract infection is presented. The pain was of a pulsating character, localized on the right, behind the eye, followed by nausea and vomiting. Neurological finding registered a wider rima oculi to the right and slight neck rigidity. Laboratory findings detected a mild leukocytosis with neutrophil predominance, while cytobiochemical findings of CSF and a computerized tomography (CT) scan of the endocranium were normal. Results: Magnetic resonance imaging (MRI) angiography indicated the presence of a carotid cavernous fistula with a pseudoaneurysm to the right. Digital subtraction angiography (DSA) was performed to confirm the existence of the fistula. The planned artificial embolization was not performed because a complete occlusion of the fistula occurred during angiographic examination. Patient was discharged without subjective complaints and with normal neurological findings. Conclusions: Hemicranial cough-induced headache may be the first sign of carotid cavernous fistula, which was resolved by a spontaneous thrombosis in preparation for artificial embolization.

Background and Objectives: Bell’s palsy (BP) is the most common cause of acute unilateral peripheral facial nerve paralysis. The aim of this study was to evaluate the time to complete clinical recovery in patients with BP treated with acupuncture and to identify baseline clinical and electrophysiological predictors of recovery outcomes. In addition, electrophysiological characteristics at the time of complete clinical recovery were examined. Materials and Methods: This prospective, observational, uncontrolled cohort study included 1050 patients with clinically confirmed BP who received acupuncture as the only therapeutic intervention between January 2017 and August 2025. Clinical severity was assessed using the House–Brackmann (HB) and Sunnybrook (SB) grading systems. Electrophysiological evaluation included compound muscle action potential (CMAP) analysis and needle electromyography (EMG). Time-to-event analysis was performed using the Kaplan–Meier method and Cox proportional hazards regression analysis. Results: Complete clinical recovery was achieved in 843 patients (80.3%). The median time to recovery was 40 days (IQR 30–60). Patients with milder baseline deficits (HB II–IV) demonstrated significantly faster recovery than those with severe paralysis (HB V–VI) (log-rank p < 0.001). In multivariable Cox regression analysis, higher baseline HB grade, older age, and more severe EMG denervation were independently associated with slower recovery. Residual electrophysiological abnormalities persisted in most patients despite complete clinical recovery. Conclusions: Recovery from BP is a dynamic and heterogeneous process, significantly influenced by initial clinical severity and the degree of electrophysiological impairment. Combined clinical and electrophysiological assessment may contribute to more precise prognostic stratification and follow-up of patients with BP. Persistent electrophysiological abnormalities despite complete clinical recovery suggest that complete clinical recovery may precede complete neurophysiological regeneration of the facial nerve.

Background/Objectives: Tension-type headache (TTH) and low back pain (LBP) are common chronic pain disorders associated with altered mechanical pain sensitivity, but direct comparison of regional pressure pain threshold (PPT) patterns remains limited. Methods: This cross-sectional comparative study included 600 participants: 200 patients with TTH, 200 patients with LBP, and 200 healthy controls. PPT was assessed using digital pressure algometry in cranial, lumbar, and lower-extremity regions. Each point was tested three times, and mean regional values were calculated. Between-group differences were analyzed using one-way ANOVA. ANCOVA models were additionally adjusted for age, sex, and BMI, and patient-only multivariable regression models were adjusted for age, sex, BMI, pain intensity, and symptom duration. Results: Significant differences were observed in all examined regions (all p < 0.001). Patients with TTH had the lowest cranial PPT values, whereas patients with LBP showed the lowest lumbar PPT values. Both pain groups also demonstrated significantly reduced PPT values in anatomically distant regions compared with healthy controls. These regional differences remained significant after adjustment for relevant demographic, anthropometric, and clinical variables. Conclusions: TTH and LBP demonstrate distinct regional PPT profiles while sharing a pattern of extraregional mechanical hypersensitivity. These findings may be compatible with broader alterations in nociceptive processing, although central sensitization was not directly assessed.