Alexia in recent and late Broca''s aphasia

The hypothesis was tested that alexia associated with Broca's aphasia may often be a residual receptive disorder of a broader picture of global aphasia. It was found that alexia does tend to be associated, as expected, to the long-standing Broca's aphasias more often than to the recent ones. However, the CT scan failed to disclose larger and more posterior lesions in Broca's alexic than in Broca's non-alexic patients.     

Alexia and agraphia in Wernicke''s aphasia.

Three patients with otherwise typical Wernicke's aphasia showed consistently greater impairment of reading than auditory comprehension. While this syndrome resembles alexia with agraphia, the paraphasia of speech, repetition, and naming underline the aphasic nature of the disorder. Together with previous reports of isolated word deafness in Wernicke's aphasia, these cases suggest a relative independence of auditory and visual language processing.     

Progressive aphasia with Lewy bodies

Dementia with Lewy bodies (DLB) may include both Alzheimer and Lewy body pathology, but has never been reported to cause primary progressive aphasia. We report a 69-year-old woman who died 11 years after presenting with the syndrome of progressive aphasia. Six years after aphasia onset she developed visual hallucinations, and subsequently parkinsonism. Autopsy examination revealed Alzheimer's disease (AD), cortical Lewy bodies, and depigmentation and Lewy bodies in the substantia nigra and locus ceruleus. The aphasia most likely reflected the initial onset of AD, and the psychosis and parkinsonism most likely reflected the subsequent onset of Lewy body pathology. This first reported case of progressive aphasia occurring within the context of AD and Lewy body pathology uniquely illustrates the clinical and pathological nosological relationships between these two disease processes, and demonstrates a limitation of the general term, 'DLB'.     

Alexia with agraphia of kanji (Japanese morphograms).

The case of the right-handed young Japanese woman with alexia with agraphia of kanji (the Japanese morphograms) due to a small circumscribed haematoma in the left posterior inferior temporal gyrus is described. Her chief complaint was the inability to read and write kanji. Detailed examination showed that her alexia with agraphia was much more predominant for kanji than kana (the Japanese syllabograms). These facts suggest that the processing of kanji and kana involves different intrahemispheric mechanisms.     

Progressive aphasia presenting with deep dyslexia and dysgraphia

Primary progressive aphasia is clinically heterogeneous. We report a patient, alias Don, with a novel form of progressive aphasia, characterised by deep dyslexia and dysgraphia and dissociated access to phonological and orthographic word forms. The hallmarks of deep dyslexia and dysgraphia were present early in the course and persisted over time. Writing was initially poorer than reading, but this reversed over time. There was a lack of concordance between reading and writing errors. Don benefited from a semantic mediation strategy to learn letter sounds, involving associating letters with a country name (e.g., A = Afghanistan). Remarkably, he continued to be able to generate those phonologically complex country names when no longer able to name or sound letters. Don’s performance is compatible with a traditional dual-route account of deep dyslexia and dysgraphia. The findings have potential practical implications for speech and language therapy in progressive aphasia. Moreover, they illustrate both the remarkable specificity yet clinical diversity in presentation of progressive aphasia.     

Progressive aphasia without dementia: further documentation

Two patients with progressive aphasia without dementia had magnetic resonance imaging findings of focal left temporal lobe abnormality. Unlike most of the other documented cases of progressive aphasia, onset was not presenile, occurring at ages 68 and 69.     

Japanese crossed Wernicke's aphasia.

A right-handed Japanese man with no personal or family history of left-handedness developed severe Wernicke's aphasia, a mild constructional disorder, and slight left hemiparesis. MRI revealed infarction in the territory of the righ middle cerebral artery, including areas homologous to Broca's and Wernicke's areas. The cerebral blood flow in these areas remained diminished even after language activation. The most likely explanation is that language production occurred in the left Broca's area, while language comprehension occurred in the right Wernicke's area (a dissociated aphasia).     

Progressive nonfluent aphasia and its characteristic motor speech deficits

Progressive nonfluent aphasia (PNFA) is a clinical syndrome characterized by motor speech impairment and agrammatism, with relative sparing of single word comprehension and semantic memory. PNFA has been associated with the characteristic pattern of left anterior insular and posterior frontal atrophy, including the motor and premotor regions and Broca's area. Postmortem histopathologic evidence has shown that PNFA is usually associated with tau pathology, although focal Alzheimer disease pathology and tau-negative, ubiquitin-TDP-43 inclusions also have been reported in association with this clinical syndrome. We performed a detailed analysis of motor speech errors in 18 patients with PNFA and investigated their neural correlates using voxel-based morphometry on magnetic resonance imaging scans. Seven patients demonstrated only apraxia of speech (AOS) errors, whereas 11 showed AOS along with dysarthria. Slow rate of speech, effortful articulation with groping, and consonant distortions were the most common AOS errors. Hypernasality was the most represented dysarthric feature and dysarthria was most often classified as spastic, hypokinetic, or mixed spastic-hypokinetic. Neuroimaging results demonstrated that patients with AOS-only and AOS plus dysarthria showed atrophy in the left posterior frontal, anterior insular, and basal ganglia regions when compared with controls. Patients with AOS plus dysarthria showed greater damage than patients with AOS-only in the left face portion of primary motor cortex and left caudate. PNFA is a distinct frontotemporal lobar degeneration clinical syndrome associated with characteristic clinical, neuroimaging, and pathologic features. The clinical features are driven by the severity of left frontal and caudate damage.     

Progressive nonfluent aphasia with dementia: a case report.

We report a patient with progressive nonfluent aphasia and mild dementia. On 9-month follow-up evaluation, there was significant deterioration in both language and cognition. Unlike in Alzheimer's disease, the aphasia was of the Broca's type. In contrast with primary progressive aphasia, a dementia was present and the cognitive and language decline showed a rather rapid course.     

Alexia and related reading disorders

Peripheral dyslexias are the result of impairment to processes that convert letters on the page into an abstract orthographic representation. Many aspects of these disorders are difficult to understand in depth. Invariably, there is evidence that some type of word-level perception occurs rapidly in many patients with LBL reading or neglect dyslexia, yet apparently contradictory evidence indicates that part of the word has been misperceived or that the letters must be analyzed laboriously for conscious identification to occur. Current theories attempt to synthesize these different aspects of the patients' performance, but their development is at an early stage. Questions remain also about the domain specificity of the perceptual impairment in LBL reading and about the nature of spatial attention and spatial frames in neglect dyslexia and other forms of attentional disorder. Current understanding of central dyslexias has perhaps advanced further. Well-developed computational models exist of these dyslexias, as do plausible experimental techniques for revealing the activity of semantic and non-semantic routes in normal readers. Nevertheless, the difficult issue of domain specificity arises again with respect to some of the mechanisms invoked, and in this regard, central and peripheral dyslexias continue to pose the same challenge.     

Progressive aphasia without dementia: two cases with focal spongiform degeneration

Two patients with the syndrome of progressive aphasia without evidence of generalized dementia underwent postmortem neuropathological examinations. In both patients, characteristic changes of Alzheimer's disease, Pick's disease, or Creutzfeldt-Jakob disease were absent. Both patients showed a focal spongiform change involving primarily layer 2 of the left inferior frontal gyrus (and temporal cortex in Patient 1) and a mild astrocytosis in layer 2 and deeper cortical layers. This focal, spongiform cortical degeneration in patients with progressive aphasia does not appear to duplicate any known central nervous system degenerative disease.     

Progressive nonfluent aphasia associated with a new mutation V363I in tau gene

Reported here is a new missense mutation V363I in exon 12 of the microtubule-associated protein tau (MAPT) gene associated with progressive nonfluent aphasia, with onset at the age of 69 years in a woman. Although near mute, she maintained complex activities and had no discernible deficits outside of language until the age of 75 years, when progressive gait and swallowing disturbances appeared. There was a history of late-onset aphasia and apraxia in her father. All of her children were asymptomatic adults, but psycholinguistic abnormalities were detected in those bearing the mutation, consisting of difficulties in comprehension, both reading (symbol discrimination and comprehension of oral spelling) and oral (matching sentences to pictures and comprehension of locative relationships). A mutation-bearing sibling showed no abnormalities at 70 years old, consistent with the limited penetrance expected in late-onset disease. The mutation, corresponding to a highly conserved residue in the fourth tubulin-binding repeat, was not present in 194 normal individuals with the same genetic background.     

Alexia and left homonymous hemianopia in a non-right-hander

A non-right-handed patient developed alexia without agraphia from a right occipital lobe infarction. An intracarotid amobarbital test showed left hemispheric dominance for speech. The cause of alexia in this patient could not be explained simply by the accepted disconnection hypothesis, which proposes that speech, handedness, and reading functions reside in the same hemisphere. The findings in this patient suggest that his speech function is located on the left, whereas his functions for reading and writing are located in the right hemisphere.