Introduction: Twiddler syndrome (TS) is described as a spontaneous rotation or intentional external manipulation of implanted cardiac or occasionally deep brain stimulation (DBS) devices (1,2). The predisposing factors for development of TS include advanced age with more loose subcutaneous tissue, adipose patients with thick tissue layer precluding proper immobilization of internal pulse generator (IPG), creation of excessively large pocket or obsessive-compulsive behavior (3,4). Additional factor related to the construction of the implanted hardware itself may be the number of anchoring holes in the IPG.
Methods: A prospectively collected database of all hardware related complications for patients operated on at the Neurosurgical Department of Postgraduate Medical Center of Warsaw was performed. In a total number of 347 leads implanted in 211 patients since 1999 we have identified 3 patients diagnosed with TS. All 3 patients with TS in our series were implanted with the IPG harboring one anchoring hole. This complication did not occurred in patients with the IPG harboring two anchoring holes.
Results: All 3 patients underwent revision surgery. During reoperations all IPGs were replaced and sutured with one additional silk suture through the plastic housing of the IPG to immobilize it properly in subcutaneous pocket. There were no recurrences of TS in our patients. All patients gained the previously derived benefit from STN DBS.
Conclusions: Our case series suggests that a predisposing factor of TS may also be the construction of IPG itself (one anchoring hole intended for fixation) which naturally represents less fixation of the IPG to the fascia or muscle in the subcutaneous pocket. This preliminary report may favor the IPG with two anchoring holes which is less prone for development of TS. Placing additional silk suture that pass through a plastic housing of the IPG may help better immobilize the IPG and reduce the occurrence of TS.
Patient Care: This report stresses that internal pulse generators with two anchoring holes may have lower incidence of Twidller syndrome than internal pulse generators with one anchoring hole. Placing additional silk suture that pass through a plastic housing of the IPG may help better immobilize the IPG and reduce the occurrence of TS.
Learning Objectives: The main learning objectives of this report are as follows:
1) To recognize Twidller syndrome.
2) To know the predisposing factors related to Twidller syndrome.
3) To stress the importance of proper fixation of the internal pulse generator in the subcutaneous poket.
4) To manage surgically this uncommon hardware-related complication.
References:  Bayliss CE, Beanlands DS, Baird RJ: The pacemaker-twiddler's syndrome: a new complication of implantable transvenous pacemakers. Can Med Assoc J 1968; 371-373.
 Geissinger G, Neal JH: Spontaneous twiddler's syndrome in a patient with a deep brain stimulator. Surg Neurol 2007;68:454-456.
 Burdick AP, Okun MS, Haq IU, Ward HE, Bova F, Jacobson CE, Bowers D, Zeilman P, Foote KD: Prevalence of Twiddler's syndrome as a cause of deep brain stimulation hardware failure. Stereotact Funct Neurosurg 2010;88:353-359.
 Machado AG, Hiremath GK, Salazar F, Rezai AR: Fracture of subthalamic nucleus deep brain stimulation hardware as a result of compulsive manipulation: case report. 2005;57:E1318.