Functional neurological disorder (FND) has been increasingly reconsidered as a diagnostically and therapeutically tractable entity; however, significant ethical challenges remain in clinical practice. This review summarizes the recent literature and classifies the ethical issues regarding FND into four categories: (1) stigma, (2) misdiagnosis and iatrogenic harm, (3) discrepancies in pathophysiological understanding and neglect of patient experiences, and (4) gender-related and historical biases. Patients with FND are frequently stigmatized, which may compromise their dignity and quality of life. A misdiagnosis can result in unnecessary and potentially harmful interventions. Moreover, persistent gaps between patients’ and clinicians’ perceptions regarding symptom voluntariness and meaning often lead to inadequate communication and care. Historically, FND has been disproportionately attributed to women, reflecting deep-seated gender biases that continue to influence diagnosis and treatment. Addressing these issues requires careful application of the four principles of biomedical ethics—autonomy, beneficence, non-maleficence, and justice—in clinical decision-making and patient care.

We report a case of a 75-year-old woman who has had poor physical performance since childhood and developed bilateral lower limb muscle weakness at age 54. At 64, she was diagnosed with Charcot–Marie–Tooth disease type 4C (CMT4C) due to a homozygous p.Arg77Trp variant in the SH3TC2 gene. At 74, she developed memory impairment. At 75, brain MRI revealed extensive cerebral white matter lesions with T₂-weighted hyperintensity and linear high intensity signal along the corticomedullary junction on diffusion-weighted imaging. Suspecting neuronal intranuclear inclusion disease (NIID), we performed a skin biopsy which demonstrated p62-positive intranuclear inclusions, and genetic testing identified the GGC repeat expansion in the NOTCH2NLC gene. The pathogenicity of the SH3TC2 variant identified in this patient remains uncertain, and her peripheral neuropathy was consistent with mild demyelination attributable to NIID. Therefore, we interpret the patient’s symptoms as primarily driven by NIID. This case highlights the importance of long-term follow-up and additional assessment when variants of uncertain significance are identified in genetic testing.

A 58-year-old male was transported by ambulance to our hospital due to shivering, headache, and abnormal behavior, with a high fever, impaired consciousness, and neck stiffness. The cerebrospinal fluid (CSF) tests revealed increase in mononuclear cell count. Cryptococcal antigen tests were positive in both the serum and CSF samples, especially with remarkably high titer in the latter. According to these findings, he was diagnosed with cryptococcal meningoencephalitis (CM). Antifungal therapy was partially effective for the initial neurological symptoms and in the abnormal CSF findings, but on the 17th day of hospitalization, severe neck pain and paralysis were developed. Spinal MRI showed abnormal signal areas in the spinal cord, extending longitudinally from the C2 to Th3 level. Steroid pulse therapy was administered, followed by post-therapy with oral prednisolone. Afterwards, the spinal lesions diminished, and the patient was able to walk independently upon discharge on the 91st day. While late deterioration in CM after antifungal treatment is known, effectiveness of steroid therapy for late-onset myelitis has not been reported so far. This case suggests usefulness of steroid therapy for longitudinal extensive transverse myelitis as late deterioration.

We report herein a 57-year-old man who presented with recurrent cerebral infarctions in one year. His father had multiple stroke episodes starting in his late 50s. Brain MRI FLAIR showed diffuse hyperintensities in the deep white matter, suggesting cerebral small vessel disease (CSVD). Notably, susceptibility-weighted imaging (SWI) revealed dot-like lesions along the surface of the midbrain (“Chocolate Chip Sign”). These findings suggested high temperature requirement A serine peptidase 1 (HTRA1)-related CSVD. The mutational analysis of the HTRA1 gene disclosed a heterozygous missense variant (NM_002775.4:c.754G>A, p.Ala252Thr). “Chocolate Chip Sign” on SWI could be useful in diagnosing heterozygous HTRA1-related CSVD.

We report a case of a 79-year-old woman who presented with transient left upper limb weakness following recent cardiac surgery. Brain MRI revealed an acute infarction in the right caudate nucleus and multiple old microbleeds. Magnetic resonance angiography and contrast-enhanced CT demonstrated extensive fusiform dilatation of the supraclinoid internal carotid arteries, middle cerebral arteries, and posterior circulation, consistent with dolichoectasia involving both anterior and posterior circulations. The episode was diagnosed as a transient ischemic attack (TIA), and antithrombotic therapy was withheld due to coexisting chronic subdural hematomas and cerebral microbleeds. While posterior circulation dolichoectasia is relatively well documented, anterior involvement and combined anterior–posterior cases are rare. This case underscores the importance of considering dolichoectasia in the differential diagnosis of TIA, especially when neuroimaging reveals atypical vascular morphology. Recognition of this entity and further accumulation of case data are crucial to elucidate its underlying mechanisms and optimize treatment strategies.

A 36-year-old woman with a history of neurofibromatosis type 1 (NF1) presented with acute onset of left-hand weakness, numbness, and pain. Neurological examination revealed Horner’s syndrome, distal weakness in the C8–T1 myotomes, and sensory disturbances in the corresponding dermatomes. The constellation of these signs was consistent with Pancoast syndrome, involving both the sympathetic trunk and the lower brachial plexus. Nerve conduction studies demonstrated reduced distal compound muscle action potentials and reduced or absent sensory nerve action potentials from multiple nerves in the C8–T1 territories, supporting involvement of the lower trunk. Chest X-ray revealed a large apical mass, and cervical MRI showed that the mass was compressing the brachial plexus at that level, accounting for her symptoms. Histopathological examination of a specimen obtained from the apical mass confirmed malignant peripheral nerve sheath tumor (MPNST). The patient underwent multimodal treatment including partial resection, embolization, radiotherapy, and chemotherapy, which controlled tumor growth and allowed her to maintain functional independence over a two-year follow-up. This case highlights the importance of early recognition of MPNST in NF1 patients presenting with new neurological symptoms. It also underscores the value of careful neurological examination and electrophysiological studies in accurately localizing the responsible lesion.

The patient, a 71-year-old woman, was admitted for a generalized tonic-clonic seizure. Initial investigations, including plasma ammonia, were normal, and she was treated for status epilepticus. Consciousness recovered to Japan Coma Scale (JCS) 0, but on day 4 her alertness declined; plasma ammonia exceeded 500 ‍μg/dl, and a dietary preference for beans became apparent. Plasma citrulline was markedly elevated, and genetic analysis confirmed adult-onset type II citrullinemia (CTLN2). A low-carbohydrate, high-fat diet enriched with medium-chain triglyceride oil was initiated, yet higher order cognitive deficits persisted. Because CTLN2 exhibits diurnal fluctuations in blood ammonia, in cases of unexplained impaired consciousness it is essential to ask about food preferences and to measure plasma ammonia repeatedly to enable timely diagnosis and treatment.