The nosology of tardive syndromes

Since the original description of side effects of neuroleptics, different terminologies and definitions for tardive dyskinesia (TD) and tardive syndrome (TS) have been used by different authors, and often these two terms have been used interchangeably. This paper proposes a nosology designed to define and clarify various terms and phenomenologies within the TS spectrum. We propose to use the term tardive dyskinesia to refer to the original description of repetitive and complex oral-buccal-lingual (OBL) movements, as well as to the analogous repetitive movements that can appear in the limbs, trunk, or pelvis. The repetitive, relatively rhythmic nature of the movements is the common denominator of this phenomenologic category. The term tardive syndrome refers to the spectrum of all persistent hyperkinetic, hypokinetic and sensory phenomenologies resulting from chronic dopamine receptor blocking agents (DRBA) exposure. Thus, TS is an umbrella term. When dystonia is the main feature of TS it is considered to be tardive dystonia (TDyst). Retrocollis appears to be the predominant form of cervical dystonia in this condition. Cranial dystonias, particularly oromandibular dystonia, are also common forms of TDyst. Tardive akathisia refers to the inability to remain still with an urge to move, giving the appearance of restlessness. It is a sensory phenomenon and a common and disabling form of TS. Unlike acute akathisia, tardive akathisia tends to occur late and persists after the drug is withdrawn. In tardive tourettism, the patient exhibits the features of Tourette syndrome with complex motor and phonic tics associated with premonitory urge and relief of tension after performing the tic behavior. Tardive tremor differs from the resting tremor seen in drug-induced parkinsonism in that it is mainly a postural and kinetic greater than resting tremor. Tardive pain has been reported in association with chronic use of DRBA's. The pain involved the mouth, tongue and the genital region. The patients tended to obsess over the pain and usually had some other form of motor tardive syndrome, either tardive dyskinesia, tardive akathisia or tardive dystonia. The term tardive parkinsonism has been proposed for those drug induced parkinsonism patients who have persistent symptoms following discontinuation of the DRBA. However, there is a strong possibility that the DRBA may have simply unmasked subclinical parkinsonism or that there is coincident Parkinson disease developing during the period the patient is taking the DRBA.