Deep brain stimulation for movement disorders: morbidity and mortality in 109 patients
Journal of Neurosurgery
Umemura A, Jaggi JL, Hurtig HI, Siderowf AD, Colcher A, Stern MB, Baltuch GH Deep brain stimulation for movement disorders: morbidity and mortality in 109 patients Journal of Neurosurgery, 2003 Apr;98(4):779-84
DBS-STN and DBS-GPi were approved by the FDA in 2002. Both surgeries replaced the previous ablative therapies (pallidotomy and thalamotomy) as both were nondestructive and reversible. However, as both DBS procedures are relatively in their infancy, there is little research that discusses the surgical techniques, selection criteria, morbidity (rate of adverse events), and mortality (rate of deaths). These authors wanted to publish their data of 109 patients (70 men, 39 women, age range 24-79, mean age 57.5) that underwent DBS in the STN, Vim (ventralis intermedius nucleus), GPi, and the anterior nucleus of the thalamus (ANT). Patients had various diagnoses including PD (78; 63 bilateral STN, 15 unilateral), PD tremor (3, unilateral Vim), essential tremor (24; 3 bilateral, 21 unilateral Vim), dystonia (1, bilateral GPi), or epilepsy (3, bilateral ANT). All patients underwent surgery at the same hospital in Pennsylvania. All patients underwent postoperative MRI to evaluate electrode placement and evaluate for adverse effects. Programming was completed within 2 weeks of surgery. The majority of patients had improvement in their motor symptoms (PD), tremors, seizures, and mobility (dystonia pt). Follow-up duration was approximately 20 months after surgery (range 3-51 months). Fourteen of the 109 patients (12.8%) had an adverse event. Thirteen of those 14 were older patients with PD and the occurrence rate for patients with PD was 16% (13 of 81). Two patients died postoperatively. One patient died from a pulmonary embolus (obstruction from a blood clot in the area of the pulmonary artery; 65 year old male) four days after surgery and another patient (54 year old male) passed away three months postsurgery but had mild to moderate preoperative dysphagia (difficulty swallowing) and suffered from repeated aspiration pneumonia postoperatively. The noted morbidities included pulmonary embolism not resulting in death (2), subcortical hemorrhage (2; bleeding in the brain), postoperative falls or seizures causing a fall and subsequent subdural hematoma (2; bruise in the brain), venous infarction (1; lack of blood supply to a certain area), seizure (1), infection (4), cerebrospinal fluid leak (1), skin erosion at the lead wire (1), and transient confusion (3; confusion lasting a few days). The authors noted that the morbidities occurred at various points in the each patient’s recovery. They also found lesser significant morbidities that were reversible such as dysarthria (difficulty talking), paresthesias, eyelid-opening apraxia (difficulty opening the eyelid), hemiballismus (throwing of the limbs to one side of the body), and dizziness in patients but they did not say how many patients experienced these reversible events. Overall, the mortality rate in their patient group was 1.8% and permanent adverse events was 4.6%. They found that mortality and morbidity was also more common in PD patients than essential tremor. They note that older age, immobility, and disease severity may contribute to higher rates of comorbidities for PD patients. They discuss that the morbidity rates for DBS as compared to thalamotomy and pallidotomy is lower, and lower than the mortality rate as compared to thalamotomy. They also go into significant detail in explaining each morbidity and mortality. They conclude that many factors may contribute to adverse events in DBS including, stimulator settings and adjustments, surgeon experience, surgical techniques, and patient selection.