Carbamazepine-induced tics.

Although a variety of dyskinesias are known to develop during anticonvulsant therapy, carbamazepine-induced tics are rarely recognized. We report three patients with an underlying movement disorder (Huntington's disease, tardive dyskinesia, and Tourette's syndrome) who experienced the onset or exacerbation of tics after the introduction of carbamazepine. These cases confirm the phenomenon of carbamazepine-induced tics and suggest that basal ganglia neuropathology may be an important predisposing factor. The dopaminergic effects of carbamazepine may be responsible for the induction of tics.

Assessment of functional recovery after spinal cord injury in rats by reticulospinal-mediated motor evoked responses.

Auditory startle reflexes (ASR) and cortico-myoelectric evoked potentials (CMyEP) were investigated as possible tests of descending motor function in a rat spinal cord injury model. ASR, which consist of stereotyped myoelectric responses recorded in limb and axial muscles to brief loud tones, were found to provide a simple, objective, and reliable measure of motor recovery after spinal cord injury (SCI). While ASR are easily recorded in awake rats, they are blocked by anesthetics, and thus cannot be recorded during the acute injury period. ASR were compared with CMyEP, which can be recorded while the animal is anesthetized. CMyEP were found to produce large myoelectric responses in the vastus lateralis and tibialis anterior hindlimb muscles of the rat similar to ASR except that latencies were approximately 3 msec earlier. Both ASR and CMyEP tended to be bilaterally symmetric regardless of the stimulus configuration, and threshold for responses were the same for both muscles in both hindlimbs. The results suggest that CMyEP may be related to ASR and thus mediated partly by reticulospinal pathways. Evidence supporting this hypothesis is reviewed.

Preliminary examination of the comorbidity of anxiety and depression in Parkinson's disease.

Significant anxiety in combination with depression may represent a specific depressive subtype in Parkinson's disease (PD). To ascertain the prevalence of this symptom complex, we administered a self-report survey and standardized psychological tests that measure anxiety and depression to 164 PD patients and 150 age-matched healthy spouse control subjects. The reporting of depression in combination with panic/anxiety best differentiated the two populations (38% vs. 8%). Depression and anxiety were highly correlated in relationship to clinical features of PD. Our findings suggest that clinically significant levels of depression and anxiety may frequently coexist in PD. The specific neuropathology of PD may predispose to this pattern of behavioral disturbance.

Neurosurgical treatment of severe obsessive-compulsive disorder associated with Tourette's syndrome.

We describe two patients with Gilles de la Tourette's syndrome (TS) and disabling obsessive-compulsive and ritualistic behaviors who underwent bilateral radiofrequency anterior cingulotomy. Both achieved a limited but sustained improvement in behavioral symptoms and overall functional abilities. Our observations indicate involvement of limbic structures in this disorder. The procedure should be considered for patients with TS complicated by resistant obsessive-compulsive disorder.