¹¹C-PiB PET imaging of encephalopathy associated with cerebral amyloid angiopathy.

We herein report that the clinical, laboratory, and radiographic features and positron emission tomography (PET) imaging may provide valuable clues to the pathogenesis of cerebral amyloid angiopathy (CAA)-associated encephalopathy, which currently remains unclear. We herein describe two cases of encephalopathy with CAA, with an emphasis on PET imaging with (11)C-Pittsburgh compound B ((11)C-PiB) and (18)F-fluorodeoxyglucose ((18)F-FDG). One case of Alzheimer's disease for which a brain biopsy was performed showed CAA-related inflammation. Another case that had developed sudden sensory aphasia presented with posterior reversible encephalopathy syndrome-like vasogenic edema in the left temporal region with (11)C-PiB uptake and microhemorrhages. (11)C-PiB and (18)F-FDG PET are useful for detecting CAA-associated encephalopathy, including atypical CAA cases.

[An advanced case of myopathy and dementia with a new mutation in the valosin-containing protein gene].

We report a 51-year-old man with myopathy and dementia probably caused by a novel mutation of the valosin-containing protein (VCP) gene, in the form of a p.Ala439Pro substitution. At 43 years old, he presented at least 2-year history of weakness of right ankle dorsiflexion. Findings from muscle biopsy suggested distal myopathy with rimmed vacuoles. However, no mutation in the GNE gene was identified. He complained of giving way of the knee, and muscle imaging study showed adipose tissue infiltration in the quadriceps. Ten years later, he was confined to a wheelchair and became reticent and antisocial with slightly impaired memory. A muscle CT revealed atrophy or replacement by adipose tissue in the muscles of neck, trunks and extremities muscles with laterality and variation of the degree. The magnetic resonance imaging of the brain showed bilateral frontal and temporal lobe atrophy with left dominance. Findings were compatible with inclusion body myopathy with Paget's disease of bone and frontotemporal dementia.

[A case of limbic encephalitis associated with leucine-rich glioma-inactivated 1 antibody].

We report a 55-year-old woman with limbic encephalitis associated with leucine-rich glioma-inactivated 1 (LGI1) antibody. She first developed a generalized seizure, following by consciousness loss. Although anticonvulant was initially effective, she began to present frequently with seizure and memory impairment. After eleven months from onset, she was admitted due to generalized seizure. Neurological examination after recovering from the treatment with anesthetic agent demonstrated disorientation and memory impairment. Cerebrospinal fluid analysis was unremarkable. MR brain FLAIR imaging demonstrated high intensity lesions in the medial parts of the both temporal lobes, suggesting limbic encephalitis. There were no signs of malignant tumor detected on systemic examination. LGI1 antibody was positive in the cerebrospinal fluid and we finally diagnosed this patient as having limbic encephalitis associated with LGI1 antibody. She demonstrated a good response to steroid therapy and was discharged after one month.

[Beneficial effects of rituximab in a case of anti-myelin antibody-associated neuropathy].

We report here in a 61-year-old woman in whom sensory disturbance predominantly affecting the distal portion of the limbs progressed over the course of 1 year. Blood tests showed IgM monoclonal gammopathy as well as the presence of anti-myelin-associated glycoprotein (MAG) antibody. Nerve conduction studies revealed significant prolongation of distal latency, and sural nerve biopsy showed IgM deposition on the myelin sheath. She was diagnosed as suffering anti-MAG neuropathy. High-dose intravenous immunoglobulin therapy proved to be ineffective and her symptoms progressed. Therefore, rituximab was administered and the sensory disturbance improved. Although no detailed studies on rituximab therapy for anti-MAG neuropathy have been reported in Japan, the present findings suggest that rituximab may be more effective than immunoglobulin therapy and other conventional therapies that have been used for autoimmune neuropathies.

Effects of 1-Hz repetitive transcranial magnetic stimulation on acute pain induced by capsaicin.

The aim of this study is to investigate the efficacy of 1-Hz repetitive transcranial magnetic stimulation (rTMS) over the primary motor cortex (M1) on acute pain induced by intradermal capsaicin injection and to elucidate its mechanisms by single-photon emission computed tomography (SPECT). We compared time courses of a subjective scale of pain induced by intradermal capsaicin injection in seven normal subjects under three different conditions: rTMS over M1, sham stimulation, and control condition (natural course of acute pain without any stimulation). In ten normal subjects, using SPECT, we also studied differences in regional cerebral blood flow (rCBF) after capsaicin injection between two conditions: rTMS over M1 and the control condition. rTMS over M1 induced earlier recovery from acute pain compared with the sham or control conditions. Under rTMS over the right M1 condition compared with the control condition, the SPECT study demonstrated a significant relative rCBF decrease in the right medial prefrontal cortex (MPFC) corresponding to Brodmann area (BA) 9, and a significant increase in the caudal part of the right anterior cingulate cortex (ACC) corresponding to BA24 and the left premotor area (BA6). A region-of-interest analysis showed significant correlation between pain reduction and rCBF changes in both BA9 and BA24. We conclude that rTMS over M1 should have beneficial effects on acute pain, and its effects must be caused by functional changes of MPFC and caudal ACC.