This type of systematic examination will enable one to decide whether a patient has a predominantly: (1) motor or Broca aphasia, sometimes called “expressive,” “anterior,” or “nonfluent” aphasia; (2) sensory or Wernicke aphasia, referred to also as “receptive,” “posterior,” or “fluent” aphasia; (3) a total or global aphasia, with loss of all or nearly all speech and language functions; (4) transcortical aphasia, meaning a motor or sensory aphasia with preserved repetition; or (5) one of the disconnection language syndromes, such as conduction aphasia, word deafness (auditory verbal agnosia), and word blindness (visual verbal agnosia or alexia). In addition, there is a condition of mutism, or a complete absence of verbal output, but this syndrome does not permit one to predict the exact locus of the lesion. Anomia (also called nominal or amnesic aphasia, meaning loss of naming ability) and the impaired ability to communicate by writing (agraphia) are found to some degree in practically all types of aphasia. As for agraphia, it rarely exists alone. Table 22-1 summarizes these main aphasic syndromes, which are described in the following text. Even though these descriptions are based largely on deficits from vascular occlusion, they serve well in most circumstances of focal brain disease that cause language disturbances.
Broca aphasia conforms to a primary deficit in language output and speech production with relative preservation of comprehension. There is a wide range of variation in the severity of the motor speech deficit, from the mildest poverty of speech and minimal dysarthria with entirely intact comprehension and ability to write (so-called Broca area aphasia; “mini-Broca”), to a complete loss of all means of lingual, phonetic, written, and gestural communication. Because the muscles that can no longer be used in speaking may still function in other acts, they are not paralyzed. The term apraxia has been imprecisely applied to this deficit in oro-buccal-lingual use (it does not represent the loss of a previously learned ability) but there are accompanying apractic deficits of the orofacial apparatus as noted in the following text.
In the most advanced form of the syndrome, patients lose all power of speaking. Not a word can be uttered in conversation, in attempting to read aloud, or in trying to repeat words that are heard. One might suspect that in this mutism the lingual and phonatory apparatus is paralyzed, until patients are observed to have no difficulty chewing, swallowing, clearing the throat, crying or shouting, and even vocalizing without words. Occasionally, the words yes and no can be uttered, usually in the correct context. Or patients may repeat a few stereotyped utterances over and over again, as if compelled to do so, a disorder referred to as monophasia (Critchley), recurring utterance (Hughlings Jackson), verbal stereotypy, or verbal automatism. If speech is possible at all, certain habitual expressions, such as “hi,” “fine, thank you,” or “good morning,” seem to be the easiest to elicit, and the words of well-known songs may be sung hesitantly, or counting by consecutive numbers may remain facile. When angered or excited, an expletive may be uttered, thus emphasizing the fundamental distinction between propositional and emotional speech. The patient recognizes his verbal ineptitude and mistakes. Repeated failures in speech cause demonstrations of exasperation.