Shifting of global aphasia to Wernicke's aphasia in a patient with intact motor function: a case report.

BACKGROUND: Global aphasia without hemiparesis (GAWH) is a rare stroke syndrome characterized by the dissociation of motor and language functions. Here, we present a case of GAWH with the patient later regaining speech fluency. CASE PRESENTATION: A 73-year-old man was admitted to our emergency department immediately after an episode of syncope. On arrival, we noted his global aphasia but without any focal neurologic signs. Computed tomography (CT) perfusion scans showed a large hypodense region over his left perisylvian area. Under the impression of acute ischaemic stroke, he received recombinant tissue plasminogen activator (rtPA) injection and was treated as an inpatient. The patient was later discharged with GAWH status and received regular speech rehabilitation. After 14 months of rehabilitation, the patient gradually recovered his language expression ability. The degree of aphasia was evaluated with the Concise Chinese Aphasia Test (CCAT), and we obtained brain single photon emission computed tomography (SPECT) scans to assess cerebral blood flow. CONCLUSION: A patient with severe impairments of Broca's and Wernicke's areas was able to talk fluently despite being unintelligible. SPECT revealed relative high level of radioactivity uptake in the right frontal lobe, suggesting the deficits in speech fluency could have been compensated by the right hemisphere. Although this is a single case demonstration, the results may strengthen the role of the right hemisphere in GAWH patients and suggests additional study that examines the possible benefits of stimulating activity at right homologous regions for recovering language function after global aphasia.

Arabidopsis DND2, a second cyclic nucleotide-gated ion channel gene for which mutation causes the "defense, no death" phenotype.

A previous mutant screen identified Arabidopsis dnd1 and dnd2 "defense, no death" mutants, which exhibit loss of hypersensitive response (HR) cell death without loss of gene-for-gene resistance. The dnd1 phenotype is caused by mutation of the gene encoding cyclic nucleotide-gated (CNG) ion channel AtCNGC2. This study characterizes dnd2 plants. Even in the presence of high titers of Pseudomonas syringae expressing avrRpt2, most leaf mesophyll cells in the dnd2 mutant exhibited no HR. These plants retained strong RPS2-, RPM1-, or RPS4-mediated restriction of P. syringae pathogen growth. Mutant dnd2 plants also exhibited enhanced broad-spectrum resistance against virulent P. syringae and constitutively elevated levels of salicylic acid, and pathogenesis-related (PR) gene expression. Unlike the wild type, dnd2 plants responding to virulent and avirulent P. syringae exhibited elevated expression of both salicylate-dependent PR-1 and jasmonate and ethylene-dependent PDF1.2. Introduction of nahG+ (salicylate hydroxylase) into the dnd2 background, which removes salicylic acid and causes other defense alterations, eliminated constitutive disease resistance and PR gene expression but only weakly impacted the HR- phenotype. Map-based cloning revealed that dnd2 phenotypes are caused by mutation of a second CNG ion channel gene, AtCNGC4. Hence, loss of either of two functionally nonredundant CNG ion channels can cause dnd phenotypes. The dnd mutants provide a unique genetic background for dissection of defense signaling.