Nobuaki Yoshikura

Haploinsufficiency of CSF-1R and clinicopathologic characterization in patients with HDLS

Objective: To clarify the genetic, clinicopathologic, and neuroimaging characteristics of patients with hereditary diffuse leukoencephalopathy with spheroids (HDLS) with the colony stimulating factor 1 receptor (CSF-1R) mutation. Methods: We performed molecular genetic analysis of CSF-1R in patients with HDLS. Detailed clinical and neuroimaging findings were retrospectively investigated. Five patients were examined neuropathologically. Results: We found 6 different CSF-1R mutations in 7 index patients from unrelated Japanese families. The CSF-1R mutations included 3 novel mutations and 1 known missense mutation at evolutionarily conserved amino acids, and 1 novel splice-site mutation. We identified a novel frameshift mutation. Reverse transcription PCR analysis revealed that the frameshift mutation causes nonsense-mediated mRNA decay by generating a premature stop codon, suggesting that haploinsufficiency of CSF-1R is sufficient to cause HDLS. Western blot analysis revealed that the expression level of CSF-1R in the brain from the patients was lower than from control subjects. The characteristic MRI findings were the involvement of the white matter and thinning of the corpus callosum with signal alteration, and sequential analysis revealed that the white matter lesions and cerebral atrophy relentlessly progressed with disease duration. Spotty calcifications in the white matter were frequently observed by CT. Neuropathologic analysis revealed that microglia in the brains of the patients demonstrated distinct morphology and distribution. Conclusions: These findings suggest that patients with HDLS, irrespective of mutation type in CSF-1R, show characteristic clinical and neuroimaging features, and that perturbation of CSF-1R signaling by haploinsufficiency may play a role in microglial dysfunction leading to the pathogenesis of HDLS.

Corticosteroid therapy in a patient with cerebral amyloid angiopathy-related inflammation

We studied longitudinal changes of the levels of anti-amyloid β (anti-Aβ) antibody, amyloid β (Aβ) protein, and interleukin 8 (IL-8) in cerebrospinal fluid (CSF) of a patient with cerebral amyloid angiopathy-related inflammation (CAA-ri) in whom steroid treatment resulted in clinical improvement. The diagnosis of CAA-ri was established with brain biopsy. Levels of anti-Aβ 42 antibody, Aβ 40, Aβ 42 and IL-8 in CSF were measured in the CAA-ri patient at 23 time points in the 8-month clinical course. These CSF samples were divided into 2 groups: those obtained before (n = 12) and those after (n = 11) oral corticosteroid therapy was started. We compared these levels between CSF samples obtained before and after therapy. The mean levels of anti-Aβ 42 antibody and IL-8 were significantly higher in CSF samples of the CAA-ri patient before oral corticosteroid therapy than those after therapy. A positive correlation was noted between levels of anti-Aβ 42 antibodies and IL-8 in CSF of this patient. There were no significant differences of mean levels of Aβ 40 and Aβ 42 between CSF samples obtained before and after oral corticosteroid therapy. It was possible that the autoinflammatory process with anti-Aβ 42 antibodies and IL-8 may have been involved in the pathogenesis of CAA-ri, and that corticosteroid therapy directly affected levels of anti-Aβ 42 antibody and IL-8. In summary, CAA-ri encephalopathy is a relapsing or progressive disorder and may be treatable by adequate immunosuppressive therapy. The anti-Aβ 42 antibody in CSF is a useful biological marker for therapeutic monitoring of CAA-ri.

Decreased regional cerebral blood flow in the bilateral thalami and medulla oblongata determined by an easy Z-score (eZIS) analysis of 99mTc-ECD-SPECT images in a case of MM2-thalamic-type sporadic Creutzfeldt–Jakob disease

We report a case of autopsy-verified MM2-thalamic-type sporadic Creutzfeldt-Jakob disease (sCJD) in a 46-year-old patient with a 16-month history of abnormal behavior, progressive dementia, insomnia, and speech disturbances without family history. Neurological examination revealed progressive dementia, frontal signs, insomnia, speech disturbance, gait disturbance and bilaterally exaggerated tendon reflexes. Both brain MRI and cerebrospinal fluid examinations, including 14-3-3 protein, yielded normal results. An easy Z-score (eZIS) analysis for (99m)Tc-ethyl cysteinate dimer-single photon emission computed tomography ((99m)Tc-ECD-SPECT) revealed decreased regional cerebral blood flow in the bilateral thalami and medulla oblongata. PRNP gene analysis revealed methionine homozygosity at codon 129 without mutation. Neuropathological examinations revealed severe neuronal loss, gliosis, and hypertrophic astrocytosis in the medial thalamus and inferior olivary nucleus. A slight depletion of Purkinje cells was observed. PrP immunostaining showed no obvious PrP deposits in the basal ganglia, thalamus, cerebellum, or brainstem; however, mild synaptic-type PrP deposits with some smaller plaque-like structures were only partially observed in the localized region of the frontal lobe with the spongiform change. Western blot analyses of protease-resistant PrP showed a type 2 pattern. In conclusion, eZIS analysis of (99m)Tc-ECD-SPECT images is useful for detecting both thalamic and medullary lesions. This is the first case of medullary lesions detected in a live patient with MM2-thalamic-type sCJD using SPECT.

Reduction in the numbers of drugs administered to elderly in-patients with polypharmacy by a multidisciplinary review of medication using electronic medical records.

Polypharmacy is a major problem for elderly patients in developed countries. We investigated whether a multidisciplinary medication review using electronic medical records could reduce the number of drugs administered to elderly patients receiving polypharmacy.

An autopsy-verified case of FTLD-TDP type A with upper motor neuron-predominant motor neuron disease mimicking MM2-thalamic-type sporadic Creutzfeldt-Jakob disease

ABSTRACT Here we report an autopsy-verified case of frontotemporal lobar degeneration (FTLD)-transactivation responsive region (TAR) DNA binding protein (TDP) type A with upper motor neuron-predominant motor neuron disease mimicking MM2-thalamic-type sporadic Creutzfeldt-Jakob disease (sCJD). A 69-year-old woman presented with an 11-month history of progressive dementia, irritability, insomnia, and gait disturbance without a family history of dementia or prion disease. Neurological examination revealed severe dementia, frontal signs, and exaggerated bilateral tendon reflexes. Periodic sharp-wave complexes were not observed on the electroencephalogram. Brain diffusion MRI did not reveal abnormal changes. An easy Z score (eZIS) analysis for 99mTc-ECD-single photon emission computed tomography (99mTc-ECD-SPECT) revealed a bilateral decrease in thalamic regional cerebral blood flow (rCBF). PRNP gene analysis demonstrated methionine homozygosity at codon 129 without mutation. Cerebrospinal fluid (CSF) analysis showed normal levels of both 14-3-3 and total tau proteins. Conversely, prion protein was slowly amplified in the CSF by a real-time quaking-induced conversion assay. Her symptoms deteriorated to a state of akinetic mutism, and she died of sudden cardiac arrest, one year after symptom onset.  Despite the SPECT results supporting a clinical diagnosis of MM2-thalamic-type sCJD, a postmortem assessment revealed that this was a case of FTLD-TDP type A, and excluded prion disease. Thus, this case indicates that whereas a bilateral decreasing thalamic rCBF detected by 99mTc-ECD-SPECT can be useful for diagnosing MM2-thalamic-type sCJD, it is not sufficiently specific. Postmortem diagnosis remains the gold standard for the diagnosis of this condition.

B-cell-activating factor belonging to the tumor necrosis factor family (BAFF) and a proliferation-inducing ligand (APRIL) levels in cerebrospinal fluid of patients with meningoencephalitis

The B-cell-activating factor belonging to the tumor necrosis factor family (BAFF) and a proliferation-inducing ligand (APRIL) are important factors for the survival of transitional and mature B cells. High levels of BAFF and APRIL are present in adults with several autoimmune diseases. However, there are few reports about BAFF and APRIL levels in the cerebrospinal fluid (CSF) of patients with meningoencephalitis. We evaluated BAFF and APRIL levels in CSF samples from patients with viral meningitis (VM) (28 patients), autoimmune encephalitis (AE) associated with antineuronal antibodies (15 patients), idiopathic normal pressure hydrocephalus (iNPH) (11 patients), herpes simplex encephalitis (HSE) (9 patients), bacterial meningitis (BM) (6 patients), and cryptococcal meningitis (CM) (4 patients). The CSF BAFF levels were significantly higher in patients with HSE, BM, or VM than AE or iNPH, and significantly higher in patients with CM than iNPH. The CSF APRIL levels were significantly higher in patients with HSE or BM than AE, VM, or iNPH. Although this is a preliminary report due to within-group variation and small sample size, the data suggest that CSF BAFF and APRIL levels are increased in HSE and BM, but not AE.

An autopsy-verified case of steroid-responsive encephalopathy with convulsion and a false-positive result from the real-time quaking-induced conversion assay

ABSTRACT We report an autopsy-verified case of steroid-responsive encephalopathy with convulsion and a false-positive result from the real-time quaking-induced conversion (RT-QUIC) assay. A 61-year-old Japanese man presented with acute onset of consciousness disturbance, and convulsions, but without a past medical or family history of progressive dementia, epilepsy, or prion disease. Brain diffusion and fluid-attenuated inverted recovery MR images revealed edematous cortical hyper-intensity, which diminished after the acute phase. Steroid pulse therapy was partially effective, although he continued to have dementia with myoclonus and psychiatric symptoms, despite resolution of the consciousness disturbance. Cerebrospinal fluid (CSF) analysis revealed a normal cell count, with significantly elevated levels of 14–3–3 protein and total tau protein. In addition, prion protein in the CSF was slowly amplified by the RT-QUIC assay. PRNP gene analysis revealed methionine homozygosity at codon 129 without mutation. The patient died of sudden cardiac arrest at 3 months after the onset of symptoms. The positive result from the RT-QUIC assay led us to suspect involvement of prion disease, although a postmortem assessment revealed that he had pathological changes after convulsion, and no prion disease. This case indicates that convulsion may cause false-positive RT-QUIC results, and that a postmortem evaluation remains the gold standard for diagnosing similar cases.

Association between naturally occurring anti-amyloid β autoantibodies and medial temporal lobe atrophy in Alzheimer's disease

Background Naturally occurring autoantibodies against amyloid β (Aβ) peptide exist in the serum and cerebrospinal fluid (CSF) of healthy individuals. Recently, it was reported that administration of intravenous immunoglobulin at the mild cognitive impairment (MCI) stage of Alzheimers disease (AD) reduces brain atrophy. Objective To examine the association between naturally occurring anti-Aβ autoantibodies and brain atrophy in patients with cognitive impairment. Methods Serum and CSF levels of anti-Aβ autoantibodies and CSF biomarkers were evaluated in 68 patients with cognitive impairment, comprising 44 patients with AD, 19 patients with amnestic MCI and five patients with non-Alzheimers dementia. The degree of brain atrophy was assessed using the voxel-based specific regional analysis system for AD, which targets the volume of interest (VOI) in medial temporal structures, including the whole hippocampus, entorhinal cortex and amygdala. Results CSF levels of anti-Aβ autoantibodies were inversely correlated with the extent and severity of VOI atrophy, and the ratio of VOI/grey matter atrophy in patients with AD, but not in MCI or non-AD patients. Serum levels of anti-Aβ autoantibodies were not associated with these parameters in any of the patient groups. Conclusions These results indicate that CSF levels of naturally occurring anti-Aβ autoantibodies are inversely associated with the degree of the VOI atrophy in patients with AD. Although the mechanism is unclear, CSF levels of naturally occurring anti-Aβ autoantibodies may be implicated in the progression of atrophy of the whole hippocampus, entorhinal cortex and amygdala, in AD.

Characteristic microglial features in patients with hereditary diffuse leukoencephalopathy with spheroids.

To clarify the histopathological alterations of microglia in the brains of patients with hereditary diffuse leukoencephalopathy with spheroids (HDLS) caused by mutations of the gene encoding the colony stimulating factor‐1 receptor (CSF‐1R).

Preserved regional cerebral blood flow in the occipital cortices, brainstem, and cerebellum of patients with V180I-129M genetic Creutzfeldt-Jakob disease in serial SPECT studies

Creutzfeldt-Jakob disease (CJD) with a causative point mutation of valine to isoleucine at codon 180 (V180I) is one of the major types of genetic CJD (gCJD) in Japan. V180I gCJD is rarely accompanied by a family history, and its clinical characteristics include late-onset, long disease duration, and edematous cortical hyperintensity in diffusion, fluid attenuate inversion and T2-weighted MRI. We performed serial imaging with single-photon emission computed tomography (SPECT) and MRI in three V180I gCJD cases over long-term observation. All cases were characterized by progressive dementia, parkinsonism, and the absence of cerebellar signs or cortical visual dysfunction in their clinical courses. Moreover, during the end-stage, SPECT findings showed preserved regional cerebral blood flow (rCBF) in the occipital cortices, brainstem, and cerebellum. Similarly, no apparent atrophy or increased signal intensities were observed in MRI images of the occipital and cerebellar regions. In conclusion, we report a decrease in rCBF predominantly in the frontal and temporal cortices during the early-stage, which became more widespread as the disease progressed. Importantly, rCBF was preserved in the occipital cortices, brainstem, and cerebellar regions until the end-stage, which may be distinct to V180I gCJD cases.