The Journal of Neuroscience has a surprising case report of a patient who was treated with an implanted brain stimulator to treat severe movement side-effects from an extended period of taking antipsychotic drugs for behavioural problems.
This is the background to the case:
A 27-year-old woman with developmental delay and severe behavioural disturbance was treated with risperidone 6 mg/day from age 14. At age 20, she developed facial twitching, blinks, and truncal extension spasms, which persisted during both sitting and lying supine. By age 21, she was no longer able to walk due to the spasms. She became housebound and was forced to ambulate by crawling, to the extent that she developed post-traumatic cysts over both knees. She was unable to sit in a chair. She was forced to eat from a plate on the floor while kneeling because the extension spasms were too severe in other positions.
The movement problems were due to tardive dystonia – a problem where the brain’s automatic control of muscle tone stops working.
When you move, some muscles need to contract while others need to relax. This happens automatically but turns out to be a complex brain process that is mediated by important dopamine pathways in a deep brain area called the basal ganglia.
Antipsychotic medication was first widely used to treat the delusions and hallucinations of psychosis but is increasingly being used to treat ‘behavioural disturbance’ (normally meaning aggression) as it can be slightly sedating and reduces anxiety.
This medication works by blocking dopamine receptors but in high doses it can lead to temporary and, occasionally, permanent movement problems due to its effects on the dopamine-mediated movement pathways in the brain.
This most typically appears as tic-like movements called tardive dyskinesia, Parkinson’s-disease like stiffness, a form of restlessness called akithisia, or movement problems that affect muscle tone – which is what this patient had.
These severe symptoms were treated in similar way to one option for Parkinson’s disease – a deep brain stimulation device was inserted into the brain to send electrical pulses directly into the basal ganglia to help regulate the movement circuits.
It turns out that many studies have reported the results of putting brain implants in people to treat movement side effects from antipsychotic drugs.
It’s probably true to say that some people have been left with permanent movement problems from the days when large doses of antipsychotics were prescribed and the side-effects were poorly understood.
These days, one of a psychiatrist’s most important jobs is to avoid these unwanted effects.
From one perspective, no matter how the situation arose, patients deserve the best possible treatments, of which deep brain stimulation is certainly one.
But still, you can’t help thinking it’s kind of a bleak situation where brain implants are needed to treat medication side-effects.
When used appropriately, antipsychotics can be a genuinely useful form of treatment but cases like these serve to remind us how far we have to go in developing safer psychiatric medications.
Link to locked Journal of Neuroscience case report.
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