How to identify non-neurogenic language disorders
Clinicians and researchers insufficiently emphasize the presence of non-neurogenic language disorders (NNLDs), their characteristics and their identification.
Yet, these disorders may be the first or predominant manifestation of a psychologically-mediated illness, says Mario Mendez, MD, PhD, director of neurobehavior, UCLA and VA Greater Los Angeles, in a literature review for the January/February issue of Psychosomatics.
The two steps to recognition, he says, are:
NNLDs are defined as alterations in language owing to psychosomatic preoccupations, conversion disorder, psychiatric disorders or other psychological reasons.
“NNLDs are varied and distinct psychogenic disorders that are probably much more common than realized,” says Dr. Mendez. Yet there are few studies on these conditions—which include psychogenic aphasia with dysgrammatism, the “lalias,” word usage abnormalities, psychotic language, and some patients categorized as having foreign accent syndrome (FAS).
Distinguishing characteristics of NNLDs include the fact that they do not fit the typical neurogenic pattern, have marked variability, lack commensurate concern or distress, and often readily respond to interventions or therapy.
NNLDs are not psychogenic speech disorders. “Speech is limited to the vocal expression of language,” says Dr. Mendez, “whereas language involves using symbols for communication and may involve other modalities, such as auditory comprehension and writing.”
Speech disorders may manifest as psychogenic dysphonia (non-neurogenic loss or alteration in voice—pitch, loudness, and quality); or neurogenic causes, such as dysarthria (deficits in speech articulation), acquired stuttering, and apraxia of speech (affecting the motor planning of speech with decreased initiation and distorted articulation). The neurogenic form of FAS is often manifest as alterations in prosody, or the intonation and rhythm of speech. However, some patients with FAS, especially if psychogenic, have alterations in grammar (hence FAS can be an NNLD).
Recognizing NNLDs requires carefully listening to the patient’s speech followed by a systematized examination of language fluency and overall intelligibility, comprehension, naming, and alterations in word usage.
Normal fluency includes normal quantity (words per minute, phrase length), flow (no word-finding hesitance or effort) and grammar (syntax and presence of grammatical words or parts of words).
After listening for fluency and altered word usage, the examiner tests comprehension with simple and complex commands, confrontational naming of presented items, and the repetition of complex sentences. In addition, normal reading and writing can be supportive of the presence of an NNLD.
The examiner may suspect an NNLD when this language examination, and the rest of the neurological evaluation, does not fit the typical pattern of a neurogenic aphasia or language disturbance.
Dr. Mendez provides four tables to guide the practitioner:
“This article presents a preliminary classification and is, undoubtedly, only a beginning,” says Dr. Mendez, who hopes the discussion may stimulate further research and consideration of language in its own right as a psychosomatic symptom.