Publications by authors named "Nana Izawa"

Article Synopsis
  • Task-specific dystonia (TSD) was observed in a 53-year-old man, where symptoms only occurred in the lower extremities while walking, despite normal neurological function in other activities.
  • The patient had been on several neuropsychiatric medications, particularly aripiprazole (ARP), for depression, and his abnormal gait worsened two years after starting ARP, even after the removal of a brain tumor (meningioma).
  • After stopping ARP and undergoing treatment with trihexyphenidyl hydrochloride and rehabilitation, the patient's symptoms improved, although some gait abnormalities persisted, highlighting the complexity of diagnosing and treating TSD.
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Background: The effects of subthalamic nuclear deep brain stimulation therapy (STN-DBS) and combined postoperative rehabilitation for patients with Parkinson's disease with postural instability have yet to be well reported. This study investigated the effects of short-term postoperative rehabilitation with STN-DBS on physical function in patients with Parkinson's disease.

Methods: Patients diagnosed with Parkinson's disease who were admitted to our hospital for STN-DBS surgery were included in this study.

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Article Synopsis
  • A study was conducted on 2,527 Parkinson's disease (PD) patients to explore the effects of parkin RBR E3 ubiquitin protein ligase (PRKN) variants, enrolling 2,322 patients, including those with familial and sporadic PD.
  • Out of 242 patients with identified PRKN variants, 13 were newly discovered, and patients were categorized based on whether they had one or two mutated alleles.
  • Those with two mutated alleles experienced earlier onset of PD symptoms and exhibited more severe disease progression over 15 years compared to those with only one mutated allele, indicating a correlation between the number of mutations and symptom severity.
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Mutations in CHCHD2 are linked to a familial, autosomal dominant form of Parkinson's disease (PD). The gene product may regulate mitochondrial respiratory function. However, whether mitochondrial dysfunction induced by CHCHD2 mutations further yields α-synuclein pathology is unclear.

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Background: Deep brain stimulation of the subthalamic nucleus (STN-DBS) is a surgical treatment to reduce the "off" state motor symptoms of Parkinson's disease (PD). Postural instability is one of the major impairments, which induces disabilities of activities of daily living (ADLs). The effectiveness of STN-DBS for postural instability is unclear, and the effect of rehabilitation following STN-DBS has remained uncertain.

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The ubiquitin (Ub) kinase PINK1 and the E3 Ub ligase Parkin, two gene products associated with young-onset Parkinson's disease (PD), participate in mitochondrial quality control. The phosphorylation of mitochondrial polyUb by PINK1, which is activated in a mitochondrial membrane potential (ΔΨm)-dependent manner, facilitates the mitochondrial translocation and concomitant enzymatic activation of Parkin, leading to the clearance of phospho-polyUb-tagged mitochondria via mitophagy. Thus, Ub phosphorylation is a key event in PINK1-Parkin-mediated mitophagy.

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We report a case of fulminant brachial plexopathy with radicular involvement. A 25-year-old man developed acute total monoplegia in the left upper limb. Needle electromyography showed extensive acute denervation in the C5-T1 spinal segments, and peripheral sensory nerve conduction was normal, mimicking a pre-ganglionic lesion.

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Neck dystonia is the most common cause of dropped head sign in parkinsonism. Isolated neck extensor myopathy, which is a rare condition, can also cause dropped head sign in parkinsonism, but no improvement has been achieved with immunosuppressive therapy. We report three cases of treatable neck extensor myopathy causing dropped head sign in patients with Parkinson's disease.

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We report a long-term outcome on a large cohort of Japanese patients with Parkinson's disease (PD). A total of 1,768 (793 men, 975 women) consecutive patients visited our clinic from 1 January 1989 to 31 December 2002. Among them, 1,183 patients (531 men, 652 women) came to our clinic within 5 years from the onset of disease and at the Hoehn & Yahr Stage III or less at the first visit.

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We report a family with autosomal dominant (AD) motor neuron disease. A 41-year-old man developed muscle weakness and fasciculation of the lower extremities. The weakness progressed to the upper extremities and bulbar muscles.

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