A 33-year-old man admitted to our hospital for the evaluation of progressive muscular atrophy of his left lower leg. From his childhood, he had suffered from transient attacks of limb paralysis and myalgia lasting about 1 hour. At age 30, the muscle weakness and atrophy of his left lower leg emerged and progressed gradually. Muscle MR images showed atrophy and fat replacement in left lower leg, and muscle biopsy revealed tubular aggregates (TA). Genetic analysis showed heterozygous c.2111C>T/p.T704M missense mutation of SCN4A gene, which causes hyperkalemic periodic paralysis (HyperPP). Although HyperPP is rare, it is quite critical for clinicians to recognize that the patients of HyperPP often present progressive myopathy. We emphasize the importance of paying attention to progressive myopathy and discuss the pathological mechanism of myopathy through this case report.

A 56-year-old man noted sudden onset of headache, fever, right pupil-spared oculomotor nerve palsy and consciousness disturbance. Swelling of pituitary with T₁ high intensity on brain MRI suggested the diagnosis of pituitary apoplexy. Considering significant decrease of pituitary anterior lobe hormone and central diabetes insipidus, high dose of hydrocortisone was administered. Eight days after onset, consciousness level and headache improved. On day 30, brain MRI revealed the reduction of mass size, and on day 46, photophobia and double vision disappeared. Following the rapid response to steroid and disappearance of pituitary lesion, pituitary apoplexy was probably caused by panhypophisitis. Thin-slice brain MRI confirmed the compression of oculomotor nerve at inlet zone of cavernous sinus, suggesting the mechanism of oculomotor palsy was perfusion impairment of feeding artery.

We report the case of a 43-year-old female patient who presented with symptoms of abnormal behavior, hearing loss, ataxic gait, central hyperventilation which had appeared over the course of one month. Brain MRI showed no abnormal findings in DWI and EEG did not indicate periodic synchronous discharge (PSD). Over the course of the same month, she also presented with central apnea that intermittently showed spontaneous improvement and reappearance. Cerebrospinal fluid 14-3-3 protein tested negative and there was no family history, but an abnormal prion protein was detected in the cerebrospinal fluid by the RT-QUIC assay. We diagnosed her with familial Creutzfeldt-Jakob disease (CJD) with an E200K mutation after genetic examination. Both high cortical signals on MRI and PSD on EEG were not recognized even in the advanced stage. Central apnea was presumed to be caused by disorders of the respiratory center of the brainstem. Hearing loss was also considered to be an obstacle at the brainstem level from the latency delay after the III wave in auditory brainstem response (ABR). The possibility of brain stem symptoms occurring in the early stages of CJD should be considered.

The case is a 75-year-old female. She had dysesthesia in the distal extremities and truncal ataxia, and they had progressed in two months. Neurological examination revealed the findings of segmental dysesthesia in the distal extremities, impaired deep sensations in the trunk and four limbs, and painful legs and moving toes (PLMT). After workup, she was diagnosed with small cell lung cancer and her blood sample was positive for anti-Hu antibody. We concluded that her neurological symptoms were attributable to sensory neuronopathy associated with paraneoplastic syndrome. No cases with PLMT caused by paraneoplastic syndrome have been reported so far. She had chemotherapy to lung cancer and Duloxetine without improvement of PLMT. On the other hand, intravenous immunoglobulin treatment improved lightening pain in the toes without improvement of moving toes.

A 57-year-old man developed rapidly progressive dementia and a gait disturbance over 4 months. The patient had a slowly progressive executive dysfunction and speech problems for 4 years and was previously monitored in our outpatient clinic following a diagnosis of frontotemporal dementia. Diffusion-weighted MRI revealed high signal intensities in the right caudate nucleus and the bilateral cortices. Cerebrospinal fluid analysis showed increased levels of the 14-3-3 and total tau proteins. Periodic synchronous discharge was not evident on an electroencephalogram. Prion protein gene analysis identified a glutamate-to-lysine substitution at codon 219 (E219K) in the presence of the E200K mutation, leading to a genetic diagnosis of genetic Creutzfeldt-Jakob disease (CJD). The E219K polymorphism found on the allele of the E200K mutation may have influenced the characteristic clinical course of our patient that differed from that of typical E200K genetic CJD.

A 35-year-old male was admitted to our hospital because of suspected myelitis. T₂-weighted spinal MRI revealed a high intensity area at Th7–9. On admission, he showed mild weakness of the lower extremities and hyperreflexia of all extremities. Therefore, he was diagnosed with having spastic paraplegia. He presented no trismus or opisthotonos. There was pleocytosis in the cerebral spinal fluid. Dysuria, constipation and spasticity of the bilateral legs worsened, even though we administered methylprednisolone pulse therapy. Nonetheless, the symptoms had progressed on the 11th hospital day, opisthotonus and optic hyperesthesia were presented. On the 13th hospital day, we suspected local tetanus and administered tetanus toxoid. After one month, his symptoms had gradually improved. In the case of spastic paraplegia showing a subacute progression course and a faint abnormality on spinal MRI, the possibility of local tetanus should be considered.

A 33-year-old woman developed progressive weakness in the proximal limbs with myalgia and morning stiffness. Physical examination revealed low-grade fever, heliotrope eyelids and mechanic’s hand. On neurological examination, she showed Medical Research Council grade 4 weakness in the shoulder girdle, proximal limb muscles, and grade 4 weakness in the abdominis muscle according to Daniels’s scale. Laboratory tests revealed elevated serum creatine kinase (6,824 IU/l) and positive anti-PL-7 antibody. A needle electromyography study detected short motor unit potentials of myogenic pattern with abundant fibrillations and positive sharp waves. Whole-body MRI detected high intensity signals in the muscles of the shoulder girdle, proximal limbs, and thoracoabdominal trunk on short-tau inversion recovery sequence images. We diagnosed her as anti-PL-7 myopathy. After treatments with steroid, immunosuppressant, and immunoglobulin, her symptoms improved and abnormal MRI signals were normalized. Although MRI is known to be useful for detection of asymptomatic muscular inflammation in myositis, thoracoabdominal muscles are generally not covered in routine evaluation. To our knowledge, ours is the first case to detect acute inflammation of the thoracoabdominal muscles in antisynthetase syndrome. The present study suggests that whole-body MRI is useful for comprehensive evaluation of muscular involvement and longitudinal assessment for treatment outcomes.

A 71-year-old male with no previous medical history was admitted to our hospital for paralysis of the right upper extremity. Although DWI of the brain revealed high-intensity signals in the bilateral frontal and left parietal lobes, CT revealed a hyperdense spot in the anterior superior sagittal sinus (SSS). Because CT venography revealed SSS occlusion, he was diagnosed with cerebral venous thrombosis (CVT). In addition, laboratory findings, including free triiodothyronine, 8.85 pg/ml; thyroxine, 3.39 pg/dl, thyroid-stimulating hormone (TSH), < 0.02 μU/ml; and anti-TSH receptor antibody, 5.7 IU/l, led to the diagnosis of hyperthyroidism for the first time. Moreover, factor VIII procoagulant protein levels exhibited a marked increase (187.5%). Based on these findings, the patient was diagnosed with CVT due to Graves’ disease.