Akiko Matsunaga

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.

Consensus Paper: Neuroimmune mechanisms of cerebellar ataxias

In the last few years, a lot of publications suggested that disabling cerebellar ataxias may develop through immune-mediated mechanisms. In this consensus paper, we discuss the clinical features of the main described immune-mediated cerebellar ataxias and address their presumed pathogenesis. Immune-mediated cerebellar ataxias include cerebellar ataxia associated with anti-GAD antibodies, the cerebellar type of Hashimoto’s encephalopathy, primary autoimmune cerebellar ataxia, gluten ataxia, Miller Fisher syndrome, ataxia associated with systemic lupus erythematosus, and paraneoplastic cerebellar degeneration. Humoral mechanisms, cell-mediated immunity, inflammation, and vascular injuries contribute to the cerebellar deficits in immune-mediated cerebellar ataxias.

Increased oxidative stress is related to disease severity in the ALS motor cortex: A PET study

Objective: To investigate cerebral oxidative stress based on an over-reductive state caused by mitochondrial dysfunction and its relationship to disease severity in patients with amyotrophic lateral sclerosis (ALS) using PET with [62Cu]diacetyl-bis(N4-methylthiosemicarbazone) (62Cu-ATSM). Methods: Twelve patients with ALS and 9 age-matched healthy controls underwent a 20-minute dynamic brain PET scan after 62Cu-ATSM injection. The standardized uptake value (SUV) images obtained from the last 10 minutes of frames were normalized by the global mean (nSUV). Regional 62Cu-ATSM retention in the nSUV images was compared between groups using statistical parametric mapping (SPM) and region of interest (ROI) analysis. Secondary analyses evaluated the correlations between regional nSUVs and the clinical characteristics of the participants. Results: In SPM mapping, patients with ALS showed a significantly greater accumulation of 62Cu-ATSM compared to controls in the bilateral cortices around the central sulcus, including the motor cortex, and the right superior parietal lobule. ROI analysis also revealed significantly greater nSUVs in patients than controls in these regions. Increases in nSUV for these regions were associated with decreases in the revised ALS Functional Rating Scale score, suggesting a good correlation with the severity of ALS. In controls, age was correlated with nSUV for the bilateral cortices around the central sulcus, although this correlation was not observed in patients with ALS. Conclusions: 62Cu-ATSM PET imaging demonstrated increased oxidative stress based on an over-reductive state, primarily in the motor cortex, in patients with ALS. The magnitude of oxidative stress correlated well with clinical severity, indicating that it may be associated with neurodegenerative changes in ALS.

Hashimoto’s Encephalopathy as a Treatable Adult-Onset Cerebellar Ataxia Mimicking Spinocerebellar Degeneration

Background: Hashimoto’s encephalopathy (HE) presents with a variety of neurologic and neuropsychiatric features. In this study, we investigated the clinical and immunological profiles of the cerebellar ataxic form of HE. Methods: The clinical features, treatments, laboratory features, brain imaging, and serum anti-NH2-terminal of α-enolase autoantibodies (anti-NAE Abs), a useful diagnostic marker for HE, were investigated in 13 patients who presented with sporadic adult-onset cerebellar ataxia and fulfilled the HE diagnostic criteria (antithyroid Abs and responsiveness to immunotherapy). Results: All of the patients presented with truncal ataxia, but nystagmus was uncommon (17%). Eight patients had an insidious onset that mimicked spinocerebellar degeneration (SCD), but brain imaging showed little or no cerebellar atrophy in all of the patients. Those patients with serum anti-NAE Abs (n = 8) did not have nystagmus and tended to respond better to immunotherapy than the anti-NAE Ab-negative patients. Conclusion: The present study suggests that insidious adult-onset and truncal ataxia are common in the cerebellar ataxic form of HE, which mimics SCD, but that nystagmus and severe cerebellar atrophy are uncommon. Antithyroid and anti-NAE Abs may be useful for diagnosing cerebellar ataxic HE.

Detection of preclinically latent hyperperfusion due to stroke-like episodes by arterial spin-labeling perfusion MRI in MELAS patients.

In stroke-like episodes (SEs) of patients with mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS), the detection of preclinically latent lesions is a challenge. We report regional cerebral hyperperfusion observed on arterial spin labeling (ASL) perfusion magnetic resonance imaging (MRI) in the preclinical phase more than 3 months before the clinical onset of SEs in 3 MELAS patients. These hyperperfused areas were not detected by conventional MRI in the preclinical phase and developed into acute lesions at the clinical onset of SEs, suggesting that ASL imaging has the potential for predicting the emergence of SEs.

Pathophysiological decrease in the regional cerebral blood flow in Hashimoto's encephalopathy : a multiple-case SPECT study

Background: The aim of this study was to evaluate the changes in regional cerebral blood flow (rCBF) in multiple cases of Hashimotos encephalopathy (HE). Methods: Seven untreated patients with HE and 10 age-matched healthy controls underwent brain single photon emission computed tomography (SPECT) with N-isopropyl-p-[123I]iodoamphetamine. All patients had anti-NH2-terminal of α-enolase autoantibodies (Abs), which served as a useful diagnostic marker for HE, in addition to anti-thyroid Abs in their sera and responded to corticosteroid therapy. The obtained SPECT images were compared between the patients and the controls using 3D-SSP analysis. Results: The rCBF of all patients with HE was significantly decreased in the bilateral anterior cingulate areas and left prefrontal cortex compared with the controls (p < 0.05). Focusing on the HE patients with acute neuropsychiatric symptoms (n = 5) such as consciousness disturbance and/or psychosis, the decreased rCBF in these areas was more significant, and the rCBF in the right frontal cortex was also decreased. Conclusion: Statistical analysis of these multiple-case SPECT images revealed the regions of decreased CBF associated with clinical symptoms, especially acute neuropsychiatric symptoms, in HE patients. This study shed light on the pathophysiological decrease in rCBF observed in HE.

Transient elevation of international normalized ratio during cisplatin-based chemotherapy in patients who are taking warfarin.

Objective: To report 2 cases of a probable interaction between cisplatin and warfarin. Case Summary: Two cases of transient elevation of international normalized ratio (INR) during Irinotecan (60 mg/m2 on days 1, 8, and 15) plus cisplatin (60 mg/m2 on day 1) chemotherapy with concomitant warfarin are presented. In both cases, warfarin dosages were stable at the therapeutic target range prior to initiation of chemotherapy. Granisetron hydrochloride (3 mg on days 1, 6, and 15) and dexamethasone (13.2 mg on day 1 and 6.6 mg on days 2, 3, 8, and 15) were used prior to irinotecan administration in both patients. In addition, aprepitant was administered to both patients for 3–5 days with cisplatin. One of these patients also received aprepitant with irinotecan on days 8 and 15. During chemotherapy, INR was transiently elevated almost 1.5-fold over baseline level on day 3. This variation did not occur in subsequent irinotecan cycles on days 8 and 15. The timing of these increases was similar in each of the cycles. Discussion: Cisplatin was the common drug in the cases presented and therefore could be related to the INR elevations. To our knowledge, these are the first reports of an Interaction between warfarin and irinotecan-cisplatin chemotherapy, but reports of a similar interaction with chemotherapy including platinum derivatives exist. Use of the Horn Drug Interaction Probability Scale indicated a probable interaction between warfarin and cisplatin. Conclusions: Cisplatin might affect the anticoagulation function of warfarin. Careful INR monitoring is necessary during antineoplastic chemotherapy with cisplatin in patients taking warfarin.

Presynaptic dysfunction caused by cerebrospinal fluid from a patient with the ataxic form of Hashimoto's encephalopathy

Hashimotos encephalopathy is an autoimmune disease associated with Hashimotos thyroiditis. The mechanism underlying the development of ataxia is unclear.

Limbic encephalitis associated with anti-NH2-terminal of α-enolase antibodies: A clinical subtype of Hashimoto encephalopathy.

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Muscle MRI of the Upper Extremity in the Myotonic Dystrophy Type 1.

Background: The purpose of this study was to explore the relation between muscle MRI findings and weakness of the upper extremity muscles in patients with myotonic dystrophy type 1 (DM1). Methods: Nineteen DM1 patients from 15 families were enrolled in this study. Muscle weakness was evaluated using the modified Medical Research Council scale. Subjects also underwent a genetic study and muscle MRI of the upper extremities. Results: In patients with DM1, the flexor digitorum profundus (FDP), flexor pollicis longus, flexor digitorum superficialis (FDS), extensor pollicis, abductor pollicis longus (APL), lateral head of triceps brachii and infraspinatus (INF) muscles were frequently and severely affected. Muscle strength was significantly correlated with the severity of muscle MRI findings in the FDP, short head of biceps brachii (SBB), and medial head of triceps brachii muscles. Disease duration was correlated significantly with MRI findings in the FDP, FDS, long head of biceps brachii, INF, APL, and SBB muscles. Unexpectedly, the degree of trinucleotide expansion of myotonin protein kinase was not correlated with muscle MRI findings. Conclusion: Muscle MRI of the upper extremity is useful to detect affected muscles in DM1 patients.