A scientific article from Pain journal called Compulsive thalamic self-stimulation a case with metabolic, electrophysiologic, and behavioral correlates chronicles the 1986 case of a woman addicted to stimulating herself with a brain implant The unnamed woman had been suffering from chronic pain (as a result of an injury) for over a decade and had tried a variety of medications to alleviate it. Despite being an alcoholic, doctors prescribed opium-based painkillers to her, and she was known to take more than her prescribed dose. With her history of drug addiction, it's easy to see why doctors thought a brain implant would be the best option for treating her chronic pain. They had no idea the woman would become addicted to it as well. Doctors implanted an electrode deep in her thalamus.
Case report
A 48-year-old, right-handed alcoholic woman developed a chronic pain syndrome following an L5-S1 herniated nucleus pulposus 10 years prior to presentation. Conservative treatments during the ensuing years included a variety of antide-pressant and analgesic drugs, acupuncture, transcutaneous nerve stimulation, and cognitive behavioral therapies; all consistently failed to provide lasting benefit despite numerous trials. Opioid drugs were prescribed throughout her course, despite occasional problems with unsanctioned dose escalation. Surgical therapies also provided only transient relief of pain. These included 4 laminectomies during the 2 years after pain onset: unilateral, then bilateral, facet denervations; 2 trials of spinal epidural stimulation; multi-level hemilaminectomy; and L5 and S1 dorsal rhizotomies. Five years prior to presentation, a right posterior medial thalamic electrode was inserted, with the tip lateral to the posterior aspect of the third ventricle. Stimulation elicited a flush and a warm sensation in the left hemibody which was associated with analgesia for less than 6 months. The ineffective electrode was left in situ and a low cervical percutaneous right anterolateral cordotomy was performed, which relieved pain for only 6 weeks. Approximately 4 years prior to presentation, a second electrode was implanted in the right nVPL. Stimulation here elicited tingling paresthesias in the left side of the body associated with several months of adequate analgesia. Pain then recurred, and though slight improvement with stimulation was thereafter reported by the patient, pain remained generally intractable from that time on.
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| FDG/PET images of regional cerebral metabolic rate for glucose (rCMRGlu) in the unstimulated (left tier) and stimulated (right tier) states. Images in the upper and lower rows correspond to PET brain slices at the level of the thalami and the semioval centers, respectively. The global increase in cerebral metabolic rate for glucose associated with right thalamic stimulation becomes apparent when the left tier images are compared with the co-planar images to the right. The right side of the scan is the patient’s right. |
Soon after insertion of the nVPL electrode, the patient noted that stimulation also produced erotic sensations. This pleasurable response was heightened by continuous stimulation at 75% maximal amplitude, frequently augmented by short bursts at maximal amplitude. Though sexual arousal was prominent, no orgasm occurred with these brief increases in stimulation intensity. Despite several episodes of paroxysmal atrial tachycardia and the development of adverse behavioral and neurological symptoms during maximal stimulation, compulsive use of the stimulator developed. At its most frequent, the patient self-stimulated throughout the day, neglecting personal hygiene and family commitments. A chronic ulceration developed at the tip of the finger used to adjust the amplitude dial and she frequently tampered with the device in an effort to increase the stimulation amplitude. At times, she implored her family to limit her access to the stimulator, each time demanding its return after a short hiatus. During the past 2 years, compulsive use has become associated with frequent attacks of anxiety, depersonalization, periods of psychogenic polydipsia, and virtually complete inactivity.
Hundreds of scientific papers on thalamic stimulators as a treatment for patients with Parkinson's disease and Tourette's syndrome have been published in medical journals. Our unnamed addict's experience (increased loss of motor control) is most likely related to these new therapies (which help minimize loss of motor control). These addicts were once dubbed "wireheads" by science fiction author Larry Niven, but science fiction has now become science fact. As thalamic stimulators and other brain implants become more common, our anonymous implant addict is unlikely to be an outlier. She is only the first known case of a new type of addiction.
