Tardive and idiopathic oromandibular dystonia: a clinical comparison
- Parkinson's Disease Center and Movement Disorders Clinic, Department of Neurology, Baylor College of Medicine, Houston, Texas, USA
- Professor Joseph Jankovic, Parkinson's Disease Center and Movement Disorders Clinic, Baylor College of Medicine, Department of Neurology 6550 Fannin, Smith 1801, Houston, Texas 77030, USA email
- Received 17 May 1999
- Revised 6 September 1999
- Accepted 17 September 1999
OBJECTIVE Most patients with tardive dystonia have a focal onset involving the cranial-cervical region. Because of its resemblance to idiopathic cranial dystonia, a common form of dystonia, it often poses a diagnostic problem. To compare clinical features and response to botulinum toxin (BTX) injections between patients with tardive and idiopathic oromandibular dystonia (OMD).
METHODS Patients seen in a movement disorder clinic who satisfied the inclusion criteria for tardive or idiopathic OMD were studied. The clinical variables and responses to BTX between the two groups of patients were compared. In the tardive group, we also compared the clinical variables between those with oro-facial-lingual stereotypies, and those without.
RESULTS Twenty four patients with tardive OMD and 92 with idiopathic OMD were studied. There were no differences in the demographic characteristics. Most were women, with duration of symptoms longer than 8 years. The mean duration of neuroleptic exposure was 7.1 (SD 7.9) years. Jaw closure was the most frequent subtype of OMD (tardive=41.7%, idiopathic=51.1%). Idiopathic patients were more likely to have coexistent cervical dystonia (p<0.05), whereas isolated OMD was significantly higher in tardive patients (p<0.05). Limb stereotypies, akathisia, and respiratory dyskinesia were seen only in the tardive OMD. Frequency of oro-facial-lingual stereotypy was significantly higher in the tardive than the idiopathic group (75.0% v 31.5%, p<0.0001). The peak effect of BTX was similar in both groups.
CONCLUSIONS Oro-facial-lingual stereotypies were significantly more frequent in the tardive than the idiopathic group. Presence of stereotypic movements in the limbs, akathisia, and respiratory dyskinesias in patients with OMD strongly suggests prior neuroleptic exposure. Dystonia in tardive OMD is more likely to be restricted to the oromandibular region, whereas in patients with idiopathic OMD, there is often coexistent cervical dystonia. BTX is equally effective in both groups of patients.