Anti-Ku antibody-positive myositis presenting as a wide range of axial myopathies and myocarditis: A case report and review of the literature.

Idiopathic inflammatory myopathies (IIMs) are autoimmune diseases predominantly affecting proximal muscles; paraspinal muscle involvement is relatively rare. Because paraspinal myopathies do not always cause clinically evident symptoms, the diagnosis of IIMs with axial myopathies can be challenging. Anti-Ku autoantibodies, initially reported in polymyositis/systemic sclerosis overlap syndrome, are myositis-associated antibodies observed in patients with a wide variety of connective tissue diseases. Few reports have been published demonstrating predominant axial myopathy in IIM patients with anti-Ku antibodies. Herein, we investigated a previously healthy Japanese woman in her early 70s who presented with Raynaud's phenomenon, back pain, and exertional dyspnoea. The creatine kinase was elevated and antinuclear antibody staining was positive, but myositis-specific antibodies were negative. Magnetic resonance imaging revealed myocarditis and a wide range of axial muscle inflammation, including bilateral thoracolumbar paraspinal, infraspinatus, and trapezius muscles. The muscle biopsy was consistent with IIM. In addition, anti-Ku antibody was positive. The administration of prednisolone and tacrolimus quickly alleviated the symptoms, and the creatine kinase level returned to normal. The diagnosis of IIM was arduous in this case because she did not present with camptocormia, muscle weakness involving the proximal limbs was not apparent, and myositis-specific antibodies were negative. Whether axial myopathy and myocarditis are more prevalent in IIM patients with than without anti-Ku antibodies is uncertain. Clinicians should suspect axial myopathy and myositis-associated antibodies, such as anti-Ku antibodies, especially in patients in whom muscle weakness of the proximal limbs is not noticeable.

Cranial Nerve Involvement and Dysautonomia in Post-COVID-19 Guillain-Barré Syndrome.

The clinical characteristics of Guillain-Barré syndrome (GBS) after coronavirus disease 2019 (COVID-19) remain unclear due to the small number of cases. We herein report a case of a Japanese patient with post-COVID-19 GBS who presented with facial and limb muscle weakness, sensory deficits, and autonomic dysfunction. Nerve conduction studies revealed demyelination. Head magnetic resonance imaging showed contrast enhancement in the bilateral facial nerves. Systemic management, including intubation, intravenous immunoglobulin therapy, and rehabilitation, improved the patient's condition. This was the first Japanese case of acute inflammatory demyelinating polyneuropathy after COVID-19 and was characterized by autonomic dysfunction and facial nerve enhancement.

Cancer association as a risk factor for anti-HMGCR antibody-positive myopathy.

OBJECTIVE: To show cancer association is a risk factor other than statin exposure for anti-3-hydroxy-3-methylglutaryl coenzyme A reductase autoantibody-positive (anti-HMGCR Ab+) myopathy. METHODS: We analyzed the clinical features and courses of 33 patients (23 female and 10 male) with anti-HMGCR Ab+ myopathy among 621 consecutive patients with idiopathic inflammatory myopathies. RESULTS: Among the 33 patients, 7 (21%) were statin-exposed and 26 were statin-naive. In relation with cancer, there were 12 patients (statin-exposed, n = 4) with cancers detected within 3 years of myopathy diagnosis (cancer association), 3 patients (all statin-naive) with cancers detected more than 3 years before myopathy diagnosis (cancer history), 10 cancer-free patients followed up for more than 3 years (all statin-naive), and 8 patients without cancer detection but followed up for less than 3 years (statin-exposed, n = 3). Therefore, 12 patients with cancer association (36%) formed a larger group than that of 7 statin-exposed patients (21%). Among 12 patients with cancer association, 92% had cancer detection within 1 year of myopathy diagnosis (after 1.3 years in the remaining patient), 83% had advanced cancers, and 75% died of cancers within 2.7 years. Of interest, 1 patient with cancer history had sustained increase in creatine kinase level over 12 years from cancer removal to the development of weakness. CONCLUSIONS: Patients with cancer association formed a large group with poor prognosis in our series of patients with anti-HMGCR Ab+ myopathy. The close synchronous occurrence of cancers and myopathies suggested that cancer association is one of the risk factors for developing anti-HMGCR Ab+ myopathy.

[Subacute encephalopathy after high-dose methotrexate as prophylaxis for central nervous system relapse in a patient with intravascular large B-cell lymphoma].

A 52-year-old female presented with stroke-like symptoms after high-dose methotrexate (HDMTX) therapy and MTX intrathecal injection (IT-MTX) as central nervous system (CNS) prophylaxis for intravascular large B-cell lymphoma (IVLBCL). She had been diagnosed as having IVLBCL without CNS involvement 5 months earlier and had received 6 courses of R-CHOP and 2 courses of HDMTX combined with IT-MTX. She experienced acute-onset right hemiparesis involving the face and arm, along with dysarthria, 7 days after the second HDMTX infusion. Brain magnetic resonance imaging (MRI) and cerebrospinal fluid results were normal and suggested neither stroke nor CNS infiltration. Her symptoms gradually resolved within 4 days and follow-up neurologic examination showed no abnormalities. MRI on day 2 (after the onset) showed an area of hyper-intensity on diffusion weighted imaging (DWI). Follow-up MRI performed on day 38 showed resolution of the DWI intensity, while the T2 and FLAIR signals became more evident. Based on her clinical course and these MRI findings, she was diagnosed as having MTX-induced subacute encephalopathy. This syndrome has been reported mainly in children with ALL after HDMTX or IT-MTX, but there have been few reports of adult patients. MTX-induced subacute encephalopathy should be taken into account as a possible cause of neurologic manifestations because early differentiation from stroke and CNS infiltration is essential to successful management.

[Vertebral artery dissection due to the C6 transverse process and laryngeal cartilage associated with vertebral artery anomaly].

A 52-year-old woman complained of the sudden onset of a left temporal headache, left neck stiffness and dizziness. Brain magnetic resonance imaging showed a high-intensity lesion in the right medial medulla. Dynamic cerebral angiography revealed vertebral artery dissection and compression at the C6 level due to a transverse process at the C6 level associated with rightward head rotation. Removal of bone and decompression of the vertebral artery were performed from the C5 to C6 levels. Intraoperasively, obstruction of blood flow due to a laryngeal cartilage that rotated with the passive rotation of the patient's head to the right was found. To the best of our knowledge this is the first reported case of vertebral artery occlusion due to a laryngeal cartilage associated with head rotation.