Progression of logopenic variant primary progressive aphasia to apraxia and semantic memory deficits.

BACKGROUND: Due to the nature of neurodegenerative disorders, patients with primary progressive aphasia develop cognitive impairment other than aphasia as the disorder progresses. The progression of logopenic variant primary progressive aphasia (lvPPA), however, has not been well described. In particular, praxic disorders and semantic memory deficits have rarely been reported. CASE PRESENTATIONS: We report three patients in the initial stage of lvPPA who subsequently developed apraxia in the middle stage and developed clinically evident semantic memory deficits in the advanced stages. CONCLUSIONS: The present case series suggests that some patients with lvPPA develop an atypical type of dementia with apraxia and semantic memory deficits, suggesting that these cases should be classified as a type of early-onset Alzheimer's disease.

Prognostic value of brain perfusion single-photon emission computed tomography (SPECT) for language recovery in patients with aphasia.

AIM: To determine the prognostic value of brain perfusion single-photon emission computed tomography (SPECT) in patients with aphasia after a stroke. METHODS: Brain perfusion SPECT with 99mTc-ethyl cysteinate dimer (99mTc-ECD) was used in 16 right-handed patients with aphasia after a left-sided cerebrovascular accident (CVA) in the early chronic period after the onset of CVA. The region of interest (ROI) method was used to calculate the relative regional cerebral blood flow (rCBF) in each cerebral lobe, the thalamus, the putamen and the cerebellum as ratios to the count in the left cerebellar hemisphere. The Standard Language Test of Aphasia (SLTA) was performed twice, once at the same time as SPECT, a mean of 2.3 months after CVA onset (early SLTA), and again a mean of 17.0 months after CVA onset (late SLTA). In addition to the overall language function score, scores for taking dictation (Dictation), oral reading (Speaking) and comprehension (Comprehension) were calculated, and the correlations with each of the rCBF values were evaluated. RESULTS: Left temporal CBF correlated with the late Dictation score; bilateral frontal, bilateral temporal and right parietal CBF correlated with the late Speaking score; and right frontal, left temporal and left occipital CBF correlated with the late Comprehension score. CONCLUSION: Brain perfusion SPECT in the early chronic stage was shown to be useful for predicting recovery from aphasia, recovery of oral reading, ability to take dictation and comprehension.

Type-2 astrocyte-like cells are more resistant than oligodendrocyte-like cells against non-N-methyl-D-aspartate glutamate receptor-mediated excitotoxicity.

Glutamate causes excitotoxicity via non-N-methyl-D-aspartate (NMDA) glutamate receptors (GluR) in oligodendrocytes. Because both oligodendrocytes and type 2 astrocytes are differentiated from oligodendrocyte-type 2 astrocyte (O-2A) progenitor cells, we investigated whether astrocytes are also vulnerable to non-NMDA GluR-mediated excitotoxicity. For these studies, oligodendrocyte-like cells (OLC) and type 2 astrocyte-like cells (2ALC) were derived from CG-4 cells, an immortalized rat O-2A progenitor cell line. About 50% of 2ALC were positive for glial fibrillary acidic protein and 90% were positive for A2B5, verifying that these cells have an type 2 astrocytic phenotype. A 24-hr exposure of OLC to 2 mM kainate, an activator of non-NMDA GluR, caused cell damage as shown by the release of lactate dehydrogenase. The extent of kainate-induced OLC damage was increased by cyclothiazide. In contrast, exposure of 2ALC to 2 mM kainate alone did not induce injury, though mild 2ALC injury was elicited by exposure to 2 mM kainate plus 100 microM cyclothiazide. Furthermore, we found that the kainate induced Ca(2+) uptake by 2ALC was 27.5% of that induced by kainate in OLC. Finally, both OLC and 2ALC expressed non-NMDA GluR subunit mRNAs, including GluR2, GluR3, GluR4, GluR6, GluR7, KA1, and KA2, but quantitative Western blot analysis revealed higher immunodetectable GluR2 and lower immunodetectable GluR3 and GluR4 in 2ALC than in OLC. Together, these results suggest that astrocytes are relatively resistant to non-NMDA GluR-mediated excitotoxicity because they have a higher expression of GluR2 and lower expression of GluR3 and GluR4.

[A case of portal-systemic shunt encephalopathy due to congenital portal vein hypoplasia presenting with abnormal cerebral white matter lesions on the MRI].

A 49-year-old woman, without any past history of liver diseases and blood transfusion, was admitted to our service because of somnolence, and flapping tremor. Neurologically, she was drowsy and disoriented. She had bilateral pyramidal tract signs and flapping tremor. Although the laboratory examination showed marked hyperammonemia (217 micrograms/dl), neither abdominal CT nor liver biopsy showed any evidence of liver cirrhosis. An abdominal angiography showed portal vein hypoplasia associated with the portal-systemic shunt. A T2-weighted MRI showed the high intensity areas in the bilateral deep cerebral white matter, and the posterior limbs of the bilateral internal capsules. This is a rare case of portal-systemic shunt encephalopathy due to congenital portal vein hypoplasia presenting with abnormal cerebral white matter lesions on the MRI.

[A case of Gitelman's syndrome presenting with the hypokalemic periodic paralysis].

We report a rare case of Gitelman's syndrome (GS) presenting with the hypokalemic periodic paralysis. A 27-year-old man was admitted to our hospital because of transient weakness of the limbs. Past history was unremarkable, including the delivery and early developmental milestones, except for a transient limb weakness 7 times since the age of 15 years. The blood pressure was 140/90 mmHg. The physical examinations were unremarkable. Neurologically, the patient was fully oriented. The cranial-nerve functions were intact. Manual muscle tests revealed 1/5 weakness in his neck and extremities. Sensation was normal in all modalities. The deep tendon reflexes were present but decreased mildly. Laboratory tests showed hypokalemia (1.9 mEq/l), hypomagnesemia (1.8 mEq/l), and hypocalciuria (40.0 mg/dl). Plasma rennin activity and aldosterone concentration were elevated. The molar ratio of urinary calcium/creatinine was 0.11 (< 0.2). Arterial blood gas showed mild metabolic alkalosis with respiratory compensation. Because of these data, the diagnosis of GS was made. Gene mutations in the renal thiazide sensitive Na-Cl cotransporter (TSC) have already been shown to cause GS. Although we searched for gene mutation of TSC, none of 25 mutations in 18 out of 26 exons which had been previously reported were found. This is the first report of Gitelman's syndrome presenting with the hypokalemic periodic paralysis in Japan.