A 70-year-old female presented with bilateral numbness in her upper limbs. She was diagnosed with cervical spondylotic myelopathy and underwent cervical laminoplasty. However, there was no significant improvement in sensory disturbance, and at 6 months after surgery, she developed subacute motor and gait disturbance in four extremities. Spinal MRI revealed a long lesion of the spinal cord with edema, and a part of the lesion showed gadolinium contrast enhancement. Bronchoscopy revealed an elevated CD4/8 ratio, and gallium scintigraphy demonstrated an accumulation in the hilar lymph nodes, leading to a diagnosis of neurosarcoidosis. In case of rapid deterioration during the course of cervical spondylotic myelopathy, neurosarcoidosis should be considered as a differential diagnosis, which can be assessed by contrast-enhanced MRI.

A 61-year-old man with right hearing loss and staggering for seven months was diagnosed with sudden deafness although previous evaluation with MRI indicated minor abnormal findings. During follow-up, he developed hypogeusia, right facial nerve palsy, pain in right mandible, right-sided temporal pain, and cerebellar ataxia. Cerebrospinal fluid examination at admission revealed reduced glucose concentration and elevated soluble interleukin-2 receptor (sIL-2R) level, whereas serum sIL-2R level was within the normal range. Brain MRI showed a swollen contrast-enhanced lesion extending from the right internal auditory canal to the middle cerebellar peduncle. Gallium-67 (⁶⁷Ga) single-photon emission-computed tomography-computed tomography (SPECT-CT) revealed abnormal accumulation at the lesion site. Pathologic analysis of the tumor after resection led to the diagnosis of primary central nervous system lymphoma. In the present case, the MRI and ⁶⁷Ga SPECT-CT characteristics were distinct from those of vestibular schwannoma. In addition, elevation of sIL-2R in the cerebrospinal fluid but not in serum was useful for differential diagnosis.

The patient is a 41-year-old woman. She presented with vomiting and lightheadedness, and blood tests showed a generalized decrease in pituitary hormones and hyperprolactinemia. A head MRI showed increased signal intensity lesions on FLAIR image in the pituitary stalk, corpus callosum, periventricular area of the fourth ventricle, and superior cerebellar peduncle. The lesions were homogeneously enhanced, and a brain biopsy confirmed the diagnosis of primary diffuse large B-cell lymphoma of the central nervous system, and chemotherapy was started. Although the suprasellar region is a rare site for primary central nervous system lymphoma (PCNSL), it should be diagnosed early by biopsy.

A 46-year-old man with neck pain and impaired physical mobility called for emergency medical services. The patient was able to communicate with the emergency medical team upon their arrival. However, he went into cardiopulmonary arrest 5 minutes later. Cardiopulmonary resuscitation was immediately performed, and the patient was admitted to our hospital with a Glasgow Coma Scale score of E1V1M1. His respiratory rate was 5 breaths/minute and his partial pressure of carbon dioxide in arterial blood (PaCO₂) was 127 ‍mmHg, necessitating intubation and ventilation. His consciousness improved as the PaCO₂ level decreased. However, he was unable to be weaned off the ventilator and breathe independently. Neurological examination revealed flaccid quadriplegia, pain sensation up to the C5 level, absence of deep tendon reflexes, indifferent plantar responses, and absence of the rectoanal inhibitory reflex. Magnetic resonance imaging showed a hyperintense lesion with slight enlargement of the anterior two-thirds of the spinal cord at the C2–C4 level on both T₂-weighted and diffusion-weighted images, consistent with a diagnosis of spinal cord infarction. Although the quadriplegia and sensory loss partially improved, the patient was unable to be weaned from the ventilator. Cervical cord infarction of the anterior spinal artery can cause rapid respiratory failure leading to cardiopulmonary arrest. Therefore, cervical cord infarction should be included as a differential diagnosis when examining patients after cardiopulmonary resuscitation.

[Objective] To investigate association between Wernicke encephalopathy (WE) and brain MRI. [Subjects] 26 patients (7 females, mean age 63.9 ± 12.7 years) with WE admitted to our department between May 2008 and September 2022. [Methods] Wernicke’s encephalopathy in patients with MRI lesions was defined as “MRI-positive group” (MPG), and those without MRI lesions as “MRI-negative group” (MNG). The following parameters were assessed between the two groups: age, sex, alcoholism, neurological symptoms, vitamin B₁, lymphocyte, total cholesterol, albumin, and outcome at discharge. [Results] There were 17 patients in MPG. Compared to MNG, MPG had lower rates of alcohol abuse (10.0% vs 77.8%, P = 0.025), lower vitamin B₁ (median 10.0 ‍ng/ml vs 29.0 ‍ng/ml, P < 0.001), and more vitamin B₁ treatment dose (median 1900 ‍mg vs 600 ‍mg, P = 0.016). [Conclusion] Alcoholic WE may be overlooked if the focus is solely on brain MRI findings.

Leber’s hereditary optic atrophy (LHON) is a genetic optic neuropathy that is more prevalent in young males but can occur from childhood to old age. The primary cause is mitochondrial genetic mutations, which are associated with dysfunction of mitochondrial electron transport chain complex I. It manifests as acute to subacute visual impairment, often starting unilaterally but progressing to involve both eyes within weeks to months. Visual loss is severe, with many patients having corrected visual acuity below 0.1. The differential diagnosis of optic neuritis is essential, and assessments such as pupillary light reflex, fluorescein fundus angiography, and magnetic resonance imaging can be useful for differentiation. LHON should be considered as one of the differential diagnoses for optic neuritis, and collaboration between neurologists and ophthalmologists is crucial for accurate diagnosis and appropriate treatment.

A Japanese woman experienced slowness of movement in her early teens and difficulty in opening her hands during pregnancy. On admission to our hospital at 42 years of age, she showed grip myotonia with warm-up phenomenon. However, she had neither muscle weakness, muscle atrophy, cold-induced symptomatic worsening nor episodes of transient weakness of the extremities. Needle electromyography of the first dorsal interosseous and anterior tibial muscles demonstrated myotonic discharges. Whole exome sequencing of the patient revealed a heterozygous single-base substitution in the CLCN1 gene (c.1028T>G, p.F343C). The same substitution was identified in affected members of her family (mother and brother) by Sanger sequencing, but not in healthy family members (father and a different brother). We diagnosed myotonia congenita (Thomsen disease) with a novel CLCN1 mutation in this pedigree. This mutation causes a single amino acid substitution in the I–J extracellular loop region of CLCN1. Amino acid changes in the I–J loop region are rare in an autosomal-dominantly inherited form of myotonia congenita. We think that this pedigree is precious to understand the pathogenesis of myotonia congenita.

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a most common chronic immune-mediated demyelinating neuropathy, and includes a number of clinical subtypes. The major phenotype is “typical CIDP”, which is characterized by symmetric polyneuropathy and “proximal and distal” muscle weakness. During the historical changes in the concept of CIDP, multifocal motor neuropathy, anti-myelin-associated glycoprotein (MAG) neuropathy, and autoimmune nodopathy have been excluded. Currently CIDP is considered as a syndrome including typical CIDP and CIDP variant such as distal CIDP and multifocal CIDP. In 2021, the international guideline of diagnosis and treatment for CIDP, European Academy of Neurology (EAN)/Peripheral Nerve Society (PNS) Guideline, was published. This review article introduces the putline of the guideline with medical-social situation in Japan. The diagnosis of CIDP is based on (1) phenotype of typical CIDP or variant, (2) electrophysiologic evidence of peripheral nerve demyelination, and (3) exclusion criteria. The first-line treatments are corticosteroids or immunoglobulin therapy, and plasma exchange should be considered if the 2 treatments were not effective sufficiently. This guideline recommends intravenous or subcutaneous immunoglobulin as a maintenance therapy, and suggests other immune-suppressive agents. In the near future, new treatment with biologics, such as monoclonal antibodies against neonatal Fc receptors, complements, and CD19/20 will be approved.