高松 直子, Yusuke Osaki, Hiroki Yamazaki, Kazutaka Kuroda, Hirohisa Ogawa, Hisanori Uehara, Koichi Tsuneyama, Hiroyuki Nodera and Yuishin Izumi : A case of led to diagnosis of malignancy by brachial plexus ultrasonography, Neurosonology, Vol.33, No.2, 36-40, 2020.
(Summary)
A 72-year-old man admitted to our hospital due to severe pain and drop hand in the left arm. MRI and CT of the head and neck at an outside hospital showed no abnormality. Neurological findings revealed distal weakness in the left upper extremity, vague pain between the radial aspect of the left hand and the middle of the digits 1-3, as well as brisk reflexes in the left extremities. Small masses were palpable in the posterior neck, the lower jaw, and the left neck. Clinically, left radial neuropathy and cervical radiculopathy were suspected. We performed ultrasound of the nerve roots, brachial plexus, and the radial nerve. There was a mass compressing the left brachial plexus from the caudolateral direction. Additionally, nerve swelling in the left arm was identified. Skin biopsy over the mass suggested metastatic adenocarcinoma. Chest CT scan showed a mass in the upper right lobe suggestive of a lung cancer. We concluded that the pain was due to radial neuropathy and upper and middle trunk disturbance of the left brachial plexopathy, of which neuromuscular ultrasound was useful in diagnosis.
Toshitaka Kawarai, Hiroki Yamazaki, Ryosuke Miyamoto, Naoko Takamatsu, Atsuko Mori, Yusuke Osaki, Antonio Orlacchio, Hiroyuki Nodera, Akihiro Hashiguchi, Yujiro Higuchi, Akiko Yoshimura, Hiroshi Takashima and Ryuji Kaji : PMP22-related disease: A novel splice site acceptor variant and intrafamilial phenotype variability., Neuromuscular Disorders, Vol.26, No.6, 422-426, 2019.
(Summary)
PMP22 is the most frequent mutated gene in Charcot-Marie-Tooth disease (CMT) type 1A. Another phenotype, hereditary neuropathy with pressure palsies (HNPP), could be caused by PMP22 mutations. PMP22 encodes a peripheral myelin protein with molecular weight 22-kDa. Various pathomechanisms have been postulated in PMP22-related disease, including dysfunction due to missense mutations, and alteration of a gene dose due to duplication/deletion mutations. We identified a novel PMP22 splice site acceptor variant, c.179-1G>A, in a patient with adult-onset chronic generalized polyneuropathy and two asymptomatic family members. Pathophysiological features of the members mainly overlapped with those reported in HNPP, but broad intrafamilial clinical variations were observed. PMP22 transcripts lacking of exon 4 were produced by the variant, presumably leading to in-frame deletion of 47 amino acids. The variant was also shown to exert effect on dosage of PMP22 mRNA. The complex molecular pathology would lead to the unique clinical and pathophysiological conditions.
(Keyword)
Adult / family / female / Gene Dosage / Hereditary Sensory and Motor Neuropathy / Humans / male / Middle Aged / Mutation / Myelin Proteins / Pedigree / Phenotype / Polyneuropathies / RNA Splice Sites