Clinical Aspects of Dyskinesia

Tardive dyskinesia (TD) is a syndrome manifesting in abnormal involuntary movements following prolonged exposure to neuroleptic treatment and the syndrome may be irreversible. This syndrome was initially described by Hall et al. (1956), Schonecker et al. (1957) and Sigwald et al. (1959). Clinically, this syndrome includes a variety of hyperkinetic involuntary movements primarily of the tongue, mouth and face even though other parts can be affected. These movements are chorieform, coordinated, involuntary, stereotyped and rhythmic. They continue as long as there are no internal or external events to disturb them. Generally, onset of these symptoms is gradual as in the unfolding of a flower and not dramatic as in dystonia. TD is greatly increased by anxiety or heightened vigilance and completely disappears during sleep. Any behavior that increases associated movements will enhance TD. Thus, an asymptomatic patient may manifest dyskinesia of his hands and fingers when his arms swing while walking. The abnormal movements disappear in areas directly involved in a voluntary activity as noticed by the cessation of buccal movements while talking and of the finger movements while writing. On the other hand, dyskinesia js enhanced in areas other than those of voluntary activity. Involuntary movements are more pronounced in a standing than in a sitting or supine position. Generally, it has been noted that patients are unaware of and not disturbed by these movements (Ayd, 1970) but this is far from universal (Uhrbrand and Faurbye, 1960). While this is true in older chronically institutionalized patients, younger patients do feel embarassed and uncomfortable. It is also stated that respiration, mastication or speech are not affected which is generally true. However, gruntling vocalizations, jerky respirations and oral ulcerations are noted in some. Alertness and intelligence are not affected. Oral facial dyskinesia is the characteristic feature of this syndrome. Initial symptoms include mild forward backward or lateral movements of the tongue (Ayd, 1967). Later, more obvious twisting and protruding movements of the tongue, pouting and sucking movements of the lips, and various chewing movements of the mouth develop. Even though the upper portion of the face is generally spared (Degkwitz, 1969), frequent blinking, blepharospasm and arching of the eyebrows may occur. While orofacial dyskinesia is common and is the first to appear in older patients, abnormal movements of the extremities and trunk are more common in young individuals (Ayd, 1970 ; Degkwitz, 1969). In addition, in advanced cases, chorieform movements and distal athetosis of limbs and tapping motions of the feet are noted. Postural and gait disturbances include exaggerated lordosis, rocking and swaying, shoulder shrugging and rotary pelvic movements. Lipper (1973) noted impaired or absent optokinetic nystagmus more frequently among the TD patients than among nondyskinetic control group. However, in parkinsonian patients as well, optokinetic nystagmus is decreased.