Differentiating psychosis versus fluent aphasia

Jargonaphasia in logopenic variant primary progressive aphasia

BACKGROUND

Logopenic variant primary progressive aphasia (lvPPA), which is most commonly an early onset variant of Alzheimer's disease (AD), is a progressive impairment in word retrieval and language expression. Clinicians often misdiagnose these patients when they present with severely unintelligible speech consistent with jargonaphasia.

METHODS

We reviewed all patients presenting to a behavioral neurology program over a 23-year period who met criteria for lvPPA after completion of an evaluation extending to positron emission tomography (PET) of the brain. Among these lvPPA patients, we additionally identified and characterized those whose presentation involved incomprehensible yet fluent verbal output.

RESULTS

Out of 95 patients with lvPPA, 9 (9.47%) had jargonaphasia on presentation. These patients differed from the remaining 86 patients in lacking awareness or concern for their impaired communication, having worse mental status scale scores, greater auditory comprehension difficulty, and more bilateral temporo-parietal hypometabolism. In addition, 44.4% of those with jargonaphasia, compared to 14% of those without, were bi/multilingual.

CONCLUSION

Nearly 1 in 10 patients with lvPPA present with severely unintelligible speech. These patients have disease extending to bilateral temporoparietal areas affecting language comprehension and disease awareness. Jargonaphasia can be a confusing presentation of AD and must be differentiated from other progressive aphasias, Wernicke's aphasia, and the word salad of "schizoaphasia".

Interdisciplinary considerations for diagnosing aphasia in the schizoaffective patient: A case report

BACKGROUND

Patients with schizophrenia present with both cognitive impairment as well as language difficulties. There are similarities in the language output of patients with schizophrenia and patients with aphasia, thus a differential diagnosis of patients who present with a question of dual diagnoses can be a clinical challenge. This case report highlights the importance of an interdisciplinary approach to a patient with schizophrenia who benefitted from intervention from both psychiatry and speech-language pathology services due to the patient's unique verbal output.

AIMS

The primary aim of this case report is to highlight the critical importance of interdisciplinary collaboration in this patient population. The secondary aim is to disseminate an interesting and unique clinical phenomenon whereby the patient demonstrated an awareness of two distinct speech patterns and the unique ability to 'code switch' between them, something not commonly appreciated in this clinical population.

METHODS & PROCEDURES

This case report describes a patient seen as part of routine clinical care. Information shared was solely observational and involved dissemination of information regarding case history, assessment and treatment plan. No interventions were implemented as a part of this study.

OUTCOMES & RESULTS

Interprofessional communication was critical in order to diagnose a patient with schizophrenia with an atypical speech pattern. The patient's language output did not manifest as a true aphasia but rather as two distinct language patterns that the patient could use at will. This ability to 'code switch' between languages is a unique clinical profile that is atypical of patients with schizophrenia.

WHAT THIS PAPER ADDS

What is already known on this subject Contemporary literature discusses the similarities between the language patterns of patients with aphasia and those with schizophrenia. There has been debate about how to classify and identify the mechanism of schizophrenic language. It is unclear whether the tangential press of speech in schizophrenia is a consequence of a formal thought disorder, or whether it constitutes an actual disorder or expressive language. Additionally, the mechanism for this speech pattern is not well defined in the literature as there is no consensus on whether it is a breakdown in linguistic processing or simply a patient's disordered thoughts being put into words. A less robust literature exists that suggests that there is a cognitive mechanism responsible for these speech patterns, as tangential speech has been linked to poor goal maintenance in other types of cognitive tasks. What this paper adds to existing knowledge This study adds an important discussion about the critical importance of interprofessional collaboration when differentially diagnosing this complex patient population. It highlights the importance of the clinical exchange of information between the two disciplines of psychiatry and speech-language pathology about a patient population where clinical information is intertwined in the way described above. Regardless of the cause of the disordered output, what is lacking in the literature is evidence of how to address the complexities of the output of these patients and how to best manage the care of the patient. This study adds a practical clinical approach to collaborating on the assessment and management of this complex patient population. Importantly, it adds a description of a clinical manifestation of the language output of a patient with schizophrenia that we do not believe to have been previously published in the literature. What are the potential or actual clinical implications of this work? Implications of this study include a much-needed shift in the field in two regards. First, to include this patient population in the groups of patients that can benefit from interprofessional collaboration for differential diagnosis and consideration for speech and language therapy. Second, it offers a practical clinical approach to inter-professional management in this patient population, something the literature is currently lacking. Additionally, publication of this unique clinical manifestation provides foundational knowledge for other clinicians appreciating similar clinical patterns of language output. To our knowledge, this is the first published case in which a patient could volitionally inhibit certain speech characteristics and thus this case study may assist in future differential diagnosis of patients with schizophrenia.

Parsing the phonological loop: activation timing in the dorsal speech stream determines accuracy in speech reproduction

Despite significant research and important clinical correlates, direct neural evidence for a phonological loop linking speech perception, short-term memory and production remains elusive. To investigate these processes, we acquired whole-head magnetoencephalographic (MEG) recordings from human subjects performing a variable-length syllable sequence reproduction task. The MEG sensor data were source localized using a time-frequency optimized spatially adaptive filter, and we examined the time courses of cortical oscillatory power and the correlations of oscillatory power with behavior between onset of the audio stimulus and the overt speech response. We found dissociations between time courses of behaviorally relevant activations in a network of regions falling primarily within the dorsal speech stream. In particular, verbal working memory load modulated high gamma power in both Sylvian-parietal-temporal and Broca's areas. The time courses of the correlations between high gamma power and subject performance clearly alternated between these two regions throughout the task. Our results provide the first evidence of a reverberating input-output buffer system in the dorsal stream underlying speech sensorimotor integration, consistent with recent phonological loop, competitive queuing, and speech-motor control models. These findings also shed new light on potential sources of speech dysfunction in aphasia and neuropsychiatric disorders, identifying anatomically and behaviorally dissociable activation time windows critical for successful speech reproduction.

Identifying and assessing psychosis in deaf psychiatric patients

This article reviews recent research in the area of psychotic disorders in deaf psychiatric patients. Comparisons of the rates of psychotic disorders in the deaf and hearing populations suggest that psychotic disorders occur equally as often or even somewhat less often in the deaf population as in the hearing population. Consideration is given to the limitations of this small body of research, and recommendations for future research are provided. The contradictory literature on hallucinations in the deaf is also reviewed, and current theory about the manner in which hallucinations are manifested and experienced based on audiological history is presented. The challenges encountered by clinicians in accurately assessing symptoms of thought disorganization in deaf people are reviewed. Specifically, the etiology of deafness, language dysfluency, and the skill and training of American Sign Language interpreters are considered as factors impacting accurate diagnosis. Recommendations from the current literature are also provided.